MRI Glossary: 161 Report Terms Explained in Plain Language [2026]

Hyperintensity

This refers to areas that appear brighter or whiter on MRI scans compared to surrounding tissues. Different tissues naturally have varying brightness levels on MRI images, and hyperintensity can indicate normal tissue variations or sometimes areas of swelling, fluid, or other changes that need further evaluation.

Learn more: Bone Edema ›

Hypointensity

This describes areas that appear darker or blacker on MRI scans compared to surrounding tissues. Like hyperintensity, this represents how different tissues naturally appear on MRI, and can indicate normal variations in tissue composition, calcifications, or areas with less water content.

T1 Sequence

This is a specific type of MRI scanning technique that provides excellent detail of anatomy and structure. On T1 images, fat appears bright while water appears dark, making it particularly useful for showing the overall shape and borders of organs and tissues clearly.

T2 Sequence

This is another MRI scanning technique where water and fluid appear bright while fat appears darker. T2 sequences are especially good at detecting swelling, inflammation, or fluid collections, as these conditions contain more water and therefore show up as bright areas.

STIR Sequence

STIR stands for Short Tau Inversion Recovery, which is an MRI technique that suppresses the bright signal from fat tissue. This makes it easier to see swelling, inflammation, or other abnormalities that might otherwise be hidden by bright fat signals, particularly useful in bone and muscle imaging.

Learn more: Stress Bone Edema ›

Heterogeneous Signal

This means that an area shows mixed or varied brightness patterns on the MRI scan, rather than appearing uniformly bright or dark. Heterogeneous signals can indicate complex tissue composition, areas of healing, or regions where different types of tissue changes are occurring together.

Normal Signal

This indicates that tissues appear with their expected brightness patterns on MRI scans. Normal signal means the tissue is showing the typical appearance for that particular body part and MRI sequence, suggesting no significant abnormalities are detected in that area.

Post-contrast Enhancement

This refers to areas that become brighter on MRI scans after injection of contrast material (gadolinium). Enhancement occurs when tissues have increased blood flow or disrupted barriers, which can be normal in some tissues or may indicate inflammation, healing, or other active processes.

FLAIR Sequence

FLAIR stands for Fluid Attenuated Inversion Recovery, which is an MRI technique that suppresses signals from normal fluid like cerebrospinal fluid. This makes it easier to detect abnormalities near fluid-filled spaces, particularly useful for brain imaging to identify lesions that might otherwise be obscured.

Gradient Echo Sequence

This is a fast MRI scanning technique that is particularly sensitive to blood products and certain types of tissue changes. Gradient echo sequences are often used to detect bleeding, blood vessel abnormalities, or areas with iron deposits, as these appear very dark on these images.

Motion Artifact

These are image distortions that occur when patients move during the MRI scan. Motion artifacts appear as blurring, streaking, or ghosting on images and can sometimes obscure important details, which is why remaining still during scanning is important for clear image quality.

Contrast Agent (Gadolinium)

This is a safe metal-based substance injected through an IV during some MRI scans to improve image quality. Gadolinium helps highlight blood vessels, areas of inflammation, or regions with abnormal blood flow by making them appear brighter on certain MRI sequences.

Proton Density

This refers to an MRI sequence that shows the natural water content of tissues without emphasizing other tissue properties. Proton density images provide good contrast between different soft tissues and are useful for evaluating cartilage, tendons, and other structures with intermediate signal characteristics.

Fat Saturation

This is an MRI technique that suppresses or darkens the normally bright signal from fat tissue. Fat saturation makes it easier to see other abnormalities like swelling or enhancement that might be masked by bright fat signals, particularly useful in joint and soft tissue imaging.

DWI (Diffusion Weighted Imaging)

This specialized MRI technique measures how water molecules move within tissues. DWI is particularly sensitive to cellular changes and can detect areas where normal water movement is restricted, making it valuable for identifying certain types of tissue damage or abnormalities.

Bone Marrow Edema

Bone marrow edema refers to swelling and fluid accumulation within the spongy interior of bones. This appears on MRI scans as bright areas and typically indicates recent injury, inflammation, or stress to the bone. It commonly occurs after trauma, overuse injuries, or in conditions affecting bone metabolism.

Learn more: Bone Edema ›

Bone Bruise

A bone bruise is swelling and minor damage within the bone tissue that doesn’t involve a complete fracture. It occurs when the bone experiences trauma that damages the internal structure while leaving the outer bone surface intact. This condition typically causes pain and may take several weeks to months to heal completely.

Subchondral Sclerosis

Subchondral sclerosis is the hardening and thickening of bone tissue directly beneath joint cartilage. This process occurs as the body’s response to increased stress or wear on joints, commonly seen in arthritis. The bone becomes denser and appears whiter on X-rays as it adapts to protect the joint from further damage.

Learn more: Subchondral Bone Edema ›

Osteophyte / Osteophytosis

Osteophytes are small bone spurs that develop along the edges of joints, while osteophytosis refers to the presence of multiple bone spurs. These bony growths form as the body attempts to stabilize joints affected by arthritis or wear and tear. They may cause stiffness or pain if they interfere with joint movement or press on surrounding tissues.

Geode / Subchondral Cyst

A geode or subchondral cyst is a fluid-filled cavity that develops within the bone beneath joint cartilage. These cysts form when joint fluid is forced into the bone through damaged cartilage, typically in arthritic joints. They appear as dark spots on X-rays and may contribute to joint pain and stiffness.

Stress Fracture

A stress fracture is a small crack in bone that develops gradually from repetitive stress or overuse rather than a single traumatic event. These fractures commonly occur in weight-bearing bones of athletes or individuals who suddenly increase their activity level. They typically cause localized pain that worsens with activity and improves with rest.

Learn more: Stress Bone Edema ›

Osteonecrosis

Osteonecrosis is the death of bone tissue due to inadequate blood supply to that area. This condition can result from trauma, certain medications, alcohol use, or various medical conditions that affect blood circulation. The affected bone may collapse if the condition progresses, leading to joint dysfunction and pain.

Transient Osteoporosis

Transient osteoporosis is a temporary condition causing bone loss and pain, most commonly affecting the hip. The exact cause is unknown, but it typically resolves on its own within 6-12 months without permanent damage. This condition is different from regular osteoporosis because the bone density returns to normal after the episode.

Bone Callus

Bone callus is new bone tissue that forms during the healing process of a fracture. This tissue initially appears as a soft, cartilage-like material that gradually hardens and remodels into mature bone. The callus serves as natural scaffolding to bridge the gap between broken bone fragments during recovery.

Bone Island

A bone island is a small, dense area of compact bone tissue within the normal spongy bone structure. This benign finding appears as a bright white spot on X-rays and represents normal bone tissue that has developed differently. Bone islands are typically harmless incidental findings that require no treatment.

Bone Infractions

Bone infractions are microscopic cracks or incomplete fractures within bone tissue that don’t extend completely through the bone. These tiny fractures may occur from repetitive stress or minor trauma and can be precursors to stress fractures. They often cause localized pain and may progress to complete fractures if the underlying cause isn’t addressed.

Bone Remodeling

Bone remodeling is the continuous process by which old bone tissue is broken down and replaced with new bone tissue. This natural process helps maintain bone strength, repair microscopic damage, and adapt bone structure to mechanical stress. Changes in remodeling patterns may be visible on imaging and can indicate various bone conditions or healing processes.

Demineralization

Demineralization refers to the loss of minerals, particularly calcium, from bone tissue, making bones less dense and more fragile. This process can occur locally around an injury site due to reduced activity or systemically throughout the skeleton in conditions like osteoporosis. On X-rays, demineralized bones appear less white or more transparent than healthy bones.

Chondropathy / Chondromalacia

This refers to damage or softening of the cartilage, which is the smooth tissue that covers the ends of bones in joints. Chondropathy is a general term for any cartilage problem, while chondromalacia specifically describes cartilage that has become soft and may be breaking down. This condition commonly affects the knee, particularly under the kneecap, and can cause pain and stiffness during movement.

Chondral Surface Irregularity

This describes cartilage that has lost its normally smooth surface and has become rough or uneven. Healthy cartilage should be smooth like glass to allow joints to move freely, but when it becomes irregular, it can cause friction and discomfort. This roughness may be an early sign of wear and tear or injury to the joint surface.

Cartilage Thinning

This means the protective cartilage layer has become thinner than normal due to wear, aging, or injury. Cartilage naturally provides cushioning between bones, so when it thins, there is less protection and shock absorption in the joint. This can lead to increased friction between bones and may cause pain, especially during weight-bearing activities.

Full-thickness Chondral Lesion

This is a deep defect that goes completely through the entire thickness of the cartilage layer, potentially exposing the underlying bone. It represents significant cartilage damage that extends from the surface all the way down to the bone beneath. This type of lesion is more serious than surface damage and may require specific treatment approaches.

Chondral Flap

This describes a piece of damaged cartilage that has partially torn away but remains attached, creating a loose flap of tissue. The flap can move around within the joint and may catch or pinch during movement, causing sudden sharp pain or a catching sensation. This mechanical problem often requires treatment to prevent further joint irritation.

Cartilage Fissures

These are cracks or splits in the cartilage surface, similar to cracks that might appear in dried mud. Fissures can be shallow surface cracks or deeper splits that extend further into the cartilage layer. They often develop as part of the natural aging process or following injury, and may progress over time if not managed properly.

Loose Body

This refers to a free-floating fragment of bone, cartilage, or other tissue that has broken off and moves freely within the joint space. These fragments can get caught between joint surfaces during movement, causing sudden locking, catching, or sharp pain. Loose bodies can interfere with normal joint function and may require removal depending on their size and symptoms they cause.

Subchondral Edema

This indicates swelling and inflammation in the bone tissue that lies directly beneath the cartilage layer. The swelling occurs when excess fluid accumulates in the bone, often as a response to increased stress, injury, or cartilage problems above it. This condition typically shows up on MRI scans as bright areas and may cause deep, aching pain that can be worse with weight-bearing activities.

Learn more: Subchondral Bone Edema ›

Meniscal Tear

A meniscal tear is a rip or damage to the C-shaped cartilage cushions (menisci) that sit between the thigh bone and shin bone in the knee. These tears can occur from sports injuries, sudden twisting motions, or gradual wear and tear with age. The severity and location of the tear determines symptoms and treatment options.

Stoller Grades (I, II, III)

Stoller grades classify the severity of meniscal damage seen on MRI scans. Grade I shows minor internal signal changes without surface damage, Grade II shows more extensive internal changes that may extend to the surface, and Grade III indicates a definite tear that reaches the meniscal surface. Higher grades typically correlate with more significant symptoms and may require different treatment approaches.

Intrameniscal Signal Change

Intrameniscal signal change refers to abnormal brightness or patterns seen within the meniscus on MRI scans. These changes often represent early degeneration, small internal tears, or wear-and-tear that hasn’t yet reached the surface. This finding may indicate the beginning stages of meniscal breakdown before a full tear develops.

Meniscal Extrusion

Meniscal extrusion occurs when part of the meniscus is pushed or squeezed out from its normal position between the knee bones. This displacement reduces the meniscus’s ability to cushion and protect the knee joint effectively. Extrusion often indicates significant meniscal damage or loss of tissue integrity.

Meniscosis

Meniscosis refers to degenerative changes or wear-and-tear of the meniscus without a distinct tear. This condition typically develops gradually over time and represents aging or breakdown of the meniscal tissue. The changes may cause knee stiffness, mild pain, or catching sensations during movement.

Bucket-handle Tear

A bucket-handle tear is a specific type of meniscal tear where a large portion of the meniscus splits and flips over, resembling the handle of a bucket. This type of tear often causes the knee to lock or catch during movement because the torn piece can block normal joint motion. Bucket-handle tears typically require prompt surgical attention.

Radial Tear

A radial tear is a meniscal tear that runs perpendicular to the normal curved edge of the meniscus, like a spoke on a wheel. These tears disrupt the meniscus’s ability to distribute weight evenly across the knee joint. Radial tears are often difficult to repair surgically and may require removal of the damaged tissue.

Parameniscal Cyst

A parameniscal cyst is a fluid-filled sac that forms near the meniscus, usually as a result of meniscal tears. These cysts develop when joint fluid leaks through meniscal tears and collects in nearby tissues. They may cause localized swelling or a noticeable bump around the knee joint line.

Discoid Meniscus

A discoid meniscus is a developmental variation where the meniscus is thicker and more disc-shaped than the normal C-shaped crescent. This condition is present from birth and is more common in the lateral (outer) meniscus. Discoid menisci are more prone to tearing and may cause symptoms even without injury.

Root Tear

A root tear occurs at the attachment point where the meniscus connects to the bone, similar to how a tree root anchors to the ground. These tears are particularly problematic because they disrupt the meniscus’s ability to stay in proper position and function effectively. Root tears often lead to rapid joint degeneration if left untreated.

ACL Tear

The ACL (anterior cruciate ligament) is a strong band of tissue that helps stabilize the knee joint by preventing the shin bone from sliding forward. A tear means this ligament has been damaged or completely ruptured, often during sports activities involving sudden stops, pivoting, or direct impact. This injury can cause knee instability, swelling, and difficulty bearing weight on the affected leg.

PCL Tear

The PCL (posterior cruciate ligament) is located at the back of the knee and prevents the shin bone from sliding backward relative to the thigh bone. A PCL tear typically occurs from direct impact to the front of the knee, such as in car accidents or falls onto a bent knee. While less common than ACL tears, PCL injuries can cause knee instability and pain, especially when walking downstairs or on slopes.

Ligament Sprain

A ligament sprain occurs when the tough bands of tissue connecting bones are stretched beyond their normal range or partially torn. Sprains are graded from mild (Grade 1) to severe (Grade 3) based on the extent of damage. Common symptoms include pain, swelling, bruising, and reduced joint mobility, with healing time varying depending on the severity.

Ligament Thickening

Ligament thickening refers to an increase in the normal width or size of a ligament, often visible on imaging scans. This can occur as a healing response after injury, chronic inflammation, or repeated stress to the ligament. While thickened ligaments may still provide stability, they can sometimes cause stiffness or altered joint mechanics.

Ligament Laxity

Ligament laxity means the ligament has become loose or stretched, resulting in reduced ability to properly stabilize a joint. This can occur after injury, with aging, or due to genetic factors that affect tissue elasticity. Lax ligaments may allow excessive joint movement, potentially leading to instability and increased risk of further injury.

Partial Tear

A partial tear means that some, but not all, of the ligament fibers have been damaged or torn. Unlike a complete tear where the ligament is fully ruptured, partial tears maintain some structural integrity and function. The severity can vary significantly, and healing potential is generally better than with complete tears, though proper rehabilitation is still essential.

Osseous Pivot Shift

Osseous pivot shift refers to abnormal bone movement patterns in the knee when the ACL is damaged or absent. During certain movements, the shin bone slides forward and rotates abnormally relative to the thigh bone, creating a characteristic shifting sensation. This finding on examination confirms significant knee instability and helps clinicians assess the functional impact of ligament injuries.

Tendinopathy / Tendinosis

This describes a condition where the tendon tissue has become damaged or worn down over time. The tendon may appear thickened, discolored, or show changes in its normal fiber structure on imaging scans. This commonly occurs from repetitive use, aging, or gradual wear and tear rather than a sudden injury.

Learn more: Posterior Tibial Tendinitis ›

Partial Tendon Tear

This means that some of the tendon fibers are torn while others remain intact. The tendon is damaged but still maintains some of its connection and structural integrity. This type of injury often results from sudden stress or chronic overuse and appears on scans as a disruption in part of the tendon’s normal appearance.

Full-thickness Tendon Tear

This indicates a complete rupture where the tendon is torn all the way through its width. The tendon connection is completely severed, often creating a visible gap on imaging scans. This type of injury typically occurs from sudden, forceful movements or trauma and represents the most severe form of tendon damage.

Tendon Calcification

This refers to calcium deposits that have formed within the tendon tissue, appearing as bright white spots on X-rays or scans. These calcium buildups can develop due to chronic irritation, previous injuries, or metabolic factors. The deposits may cause stiffness and can sometimes be felt as hard lumps under the skin.

Tenosynovitis

This describes inflammation of the protective sheath that surrounds certain tendons. The normally smooth lining becomes swollen and irritated, which can cause pain and restrict smooth tendon movement. This condition often results from repetitive motions or bacterial infections and may cause visible swelling along the tendon path.

Enthesopathy

This term describes problems at the enthesis, which is the specific spot where a tendon or ligament attaches to bone. The attachment site becomes inflamed, damaged, or shows abnormal changes on imaging. This commonly occurs from repetitive stress or inflammatory conditions affecting these crucial connection points.

Peritendinitis

This refers to inflammation of the tissue that surrounds the tendon, rather than the tendon itself. The outer covering and surrounding tissues become swollen and irritated, often causing pain with movement. This condition typically develops from overuse activities or friction between the tendon and nearby structures.

Tendon Retraction

This describes how the torn ends of a tendon pull away from each other, creating a gap at the injury site. When a tendon tears completely, the muscle attached to it contracts and pulls the tendon ends apart. The amount of retraction visible on scans helps determine the severity of the injury and treatment approach needed.

Tendon Thickening

This indicates that the tendon has become larger than its normal size, appearing swollen or enlarged on imaging scans. Thickening usually develops as a response to chronic irritation, repeated small injuries, or inflammatory processes. The enlarged tendon may cause symptoms by pressing against nearby structures or affecting normal movement patterns.

Mucoid Degeneration

This describes a process where normal tendon tissue is replaced by a jelly-like substance, making the tendon weaker and less functional. The healthy collagen fibers break down and are replaced with mucus-like material that appears different on scans. This degenerative change typically occurs gradually over time due to aging, chronic stress, or poor blood supply to the tendon.

Joint Effusion

Joint effusion refers to excess fluid accumulation within a joint space, commonly called ‘water on the knee’ when it affects the knee joint. This fluid buildup occurs when the joint produces more fluid than it can absorb, often in response to injury, inflammation, or underlying conditions. The excess fluid can cause swelling, stiffness, and reduced range of motion in the affected joint.

Bursitis

Bursitis is inflammation of a bursa, which is a small fluid-filled sac that acts as a cushion between bones, tendons, and muscles around joints. When a bursa becomes inflamed, it can cause pain, swelling, and tenderness in the affected area. This condition commonly occurs in shoulders, elbows, hips, and knees, often due to repetitive motions or prolonged pressure on the joint.

Baker’s Cyst

A Baker’s cyst is a fluid-filled swelling that develops behind the knee joint. It forms when excess joint fluid from conditions like arthritis or meniscus tears gets pushed into the back of the knee, creating a visible bulge. While often painless, Baker’s cysts can cause stiffness and discomfort, particularly when bending the knee or during physical activity.

Synovitis

Synovitis is inflammation of the synovial membrane, the thin layer of tissue that lines the inside of joint capsules and produces joint fluid. When this membrane becomes inflamed, it can produce excess fluid and cause joint swelling, pain, and stiffness. Synovitis can occur due to injury, overuse, infection, or autoimmune conditions affecting the joints.

Hydrarthrosis

Hydrarthrosis is a medical term for the accumulation of clear, watery fluid within a joint space. This condition is essentially another name for joint effusion when the fluid is non-inflammatory and appears clear rather than cloudy or bloody. It commonly occurs in response to joint irritation, minor injuries, or degenerative changes in the joint.

Hemarthrosis

Hemarthrosis refers to bleeding into a joint space, causing blood to mix with the normal joint fluid. This condition typically occurs after significant trauma, such as a torn ligament or fracture involving the joint. The presence of blood in the joint can cause severe swelling, pain, and limited movement, and often requires prompt medical attention to prevent complications.

Ganglion / Synovial Cyst

A ganglion or synovial cyst is a fluid-filled lump that develops near joints or tendons, most commonly on the wrists and hands. These cysts contain a thick, jelly-like fluid similar to joint fluid and can vary in size, sometimes appearing and disappearing spontaneously. While typically harmless, they may cause discomfort or interfere with joint movement depending on their location and size.

Synovial Hypertrophy

Synovial hypertrophy refers to the thickening and overgrowth of the synovial membrane that lines joint capsules. This thickening occurs when the synovial tissue becomes chronically inflamed and responds by growing larger and more vascular. The condition can contribute to joint stiffness, pain, and reduced range of motion, and is commonly seen in inflammatory arthritis conditions.

Synovial Plica

Synovial plica are normal folds or bands of synovial tissue within certain joints, most commonly the knee. These tissue folds are remnants from fetal development and are present in most people without causing problems. However, when a plica becomes thickened, inflamed, or irritated due to injury or overuse, it can cause pain, clicking sensations, or catching feelings during joint movement.

Degenerative Disc Disease

This describes the natural wear and tear of the spinal discs that occurs with aging. The discs between vertebrae gradually lose water content and flexibility, becoming thinner and less effective as shock absorbers. Despite the name, it’s not actually a disease but a normal aging process that can sometimes cause pain or stiffness.

Learn more: L5-S1 Spondylolisthesis ›

Disc Protrusion

This occurs when a spinal disc extends beyond its normal boundary but the outer wall remains intact. The disc pushes out asymmetrically, similar to a tire with a bulge on one side. This can sometimes press on nearby nerves, potentially causing pain or other symptoms.

Disc Herniation

This happens when the soft inner material of a spinal disc breaks through the tough outer wall. The leaked disc material can press on nearby nerves, potentially causing pain, numbness, or weakness. It’s often called a ‘slipped disc,’ though the disc doesn’t actually slip out of place.

Sequestered Disc Herniation

This is a severe type of disc herniation where a piece of disc material completely separates and moves away from the main disc. The separated fragment can travel within the spinal canal and may press on nerves at a distance from the original disc location. This type typically requires more intensive treatment approaches.

Spinal Canal Stenosis

This refers to a narrowing of the main channel through the spine where the spinal cord passes. The narrowing can result from bone spurs, thickened ligaments, or bulging discs pressing into the canal space. When severe, it can compress the spinal cord and cause pain, numbness, or walking difficulties.

Spondylolisthesis

This condition occurs when one vertebra slides forward over the vertebra below it. It can result from stress fractures, degenerative changes, or developmental abnormalities. The forward slippage can narrow the spaces where nerves exit the spine, potentially causing pain or neurological symptoms.

Learn more: Spondylolisthesis exercises ›

Modic Changes (type I, II, III)

These are bone marrow changes visible on MRI scans adjacent to damaged discs. Type I represents active inflammation and appears as increased water content in the bone. Type II shows fatty replacement of normal bone marrow, indicating chronic changes. Type III represents bone hardening and is less commonly seen.

Disc Bulge

This describes a disc that extends evenly beyond its normal boundaries, like a tire that’s slightly under-inflated. Unlike a herniation, the outer wall of the disc remains intact and the bulging is typically symmetrical. Many disc bulges cause no symptoms and are found incidentally on imaging studies.

Foraminal Stenosis

This refers to narrowing of the openings where nerve roots exit the spine on their way to other parts of the body. These openings, called foramina, can become smaller due to bone spurs, disc bulges, or thickened ligaments. The narrowing can compress nerve roots, potentially causing pain that radiates into the arms or legs.

Disc Dehydration

This describes the loss of water content in spinal discs, which is a normal part of aging. Healthy discs are about 80% water, but this decreases over time, making discs less flexible and effective as shock absorbers. On MRI scans, dehydrated discs appear darker than normal, healthy discs.

Spondylolysis

This is a stress fracture or defect in a specific part of the vertebra called the pars interarticularis. It commonly occurs in the lower back and can result from repetitive stress or overuse. While some people have no symptoms, others may experience lower back pain, especially with extension movements.

Dural Sac

This is the protective covering that surrounds the spinal cord and nerve roots, containing cerebrospinal fluid. It’s mentioned in reports when describing how other structures like herniated discs or bone spurs might be pressing against it. Compression of the dural sac can affect nerve function and cause various symptoms.

Facet Joint Arthrosis

This refers to arthritis in the small joints at the back of the spine that help guide spinal movement. These joints can develop bone spurs and cartilage loss over time, similar to arthritis in other joints. The condition can cause stiffness, pain, and reduced range of motion in the spine.

Schmorl’s Node

This occurs when disc material pushes through the end plate of a vertebra into the bone itself, creating a small indentation. These are usually discovered incidentally on imaging and rarely cause symptoms. They represent a type of disc herniation that goes vertically into the bone rather than horizontally toward nerves.

Radiculopathy

This describes symptoms caused by compression or irritation of a nerve root as it exits the spine. Common symptoms include pain, numbness, tingling, or weakness that follows the path of the affected nerve into the arm or leg. The location and pattern of symptoms help identify which specific nerve root is involved.

Rotator Cuff Tear

This refers to damage or tearing of the muscles and tendons that surround the shoulder joint and help lift and rotate the arm. Tears can be partial (affecting only part of the tendon) or full-thickness (going completely through the tendon). These injuries commonly occur from repetitive overhead activities, aging, or sudden trauma, and typically cause pain and weakness when lifting the arm.

Subacromial Impingement

This condition occurs when the tendons of the rotator cuff muscles become pinched or compressed in the narrow space beneath the shoulder blade (acromion). The pinching typically happens when raising the arm overhead, causing inflammation and pain. This is one of the most common causes of shoulder pain, especially in people who perform repetitive overhead activities.

SLAP Tear

SLAP stands for Superior Labrum Anterior to Posterior, referring to a tear in the cartilage rim (labrum) that surrounds the shoulder socket. This specific type of tear occurs at the top of the shoulder socket where the biceps tendon attaches. SLAP tears often result from repetitive overhead motions or traumatic injuries and can cause deep shoulder pain and clicking sensations.

Adhesive Capsulitis

Also known as frozen shoulder, this condition involves inflammation and thickening of the shoulder joint capsule, leading to severe stiffness and pain. The shoulder becomes increasingly difficult to move in all directions, as if it’s ‘frozen’ in place. This condition typically develops gradually and can last for months or years, often affecting people between ages 40-60.

Bankart Lesion

This is a specific type of injury where the cartilage rim (labrum) tears away from the front edge of the shoulder socket, often taking a small piece of bone with it. Bankart lesions typically occur during shoulder dislocations when the arm is forced backward and outward. This injury can lead to shoulder instability and recurrent dislocations if left untreated.

Hill-Sachs Lesion

This refers to a dent or compression fracture on the back of the upper arm bone (humerus) that occurs during a shoulder dislocation. When the shoulder dislocates forward, the arm bone gets pressed against the edge of the shoulder socket, creating this characteristic indentation. Hill-Sachs lesions often accompany Bankart lesions and can contribute to ongoing shoulder instability.

Subacromial Bursitis

This condition involves inflammation of the bursa, a small fluid-filled sac that acts as a cushion between the rotator cuff tendons and the shoulder blade above. When inflamed, the bursa becomes swollen and painful, often causing discomfort when lifting the arm or lying on the affected side. This inflammation commonly results from repetitive overhead activities or direct trauma to the shoulder.

Supraspinatus Tendinopathy

This refers to damage, inflammation, or degeneration of the supraspinatus tendon, which is part of the rotator cuff and helps lift the arm away from the body. Tendinopathy can range from mild inflammation to partial tearing of the tendon fibers. This condition commonly causes pain on the outer side of the shoulder and weakness when initiating arm elevation.

Long Head of Biceps Tendinopathy

This involves inflammation, irritation, or degeneration of the long biceps tendon as it passes through the shoulder joint and travels down the arm. The tendon can become inflamed from repetitive overhead activities or may develop wear and tear over time. Patients typically experience pain in the front of the shoulder that may radiate down the arm, especially with overhead reaching or lifting activities.

Femoroacetabular Impingement (FAI)

This condition occurs when the ball and socket of the hip joint don’t fit together properly, causing the bones to rub against each other during movement. The abnormal contact typically happens because either the ball (femoral head) has an irregular shape or the socket (acetabulum) covers too much of the ball. This rubbing can cause pain, stiffness, and may lead to damage of the cartilage and labrum over time.

Acetabular Labrum Tear

The labrum is a ring of cartilage that surrounds the hip socket, helping to deepen it and provide stability to the joint. A labral tear means this cartilage has been damaged or torn, often due to repetitive movements, trauma, or structural problems like FAI. This injury commonly causes deep hip or groin pain, clicking sensations, and may lead to feelings of hip instability or catching during movement.

Hip Osteoarthritis

This is a degenerative joint disease where the smooth cartilage covering the hip bones gradually wears away over time. As the cartilage deteriorates, the bones may begin to rub directly against each other, causing pain, stiffness, and reduced range of motion. This condition typically develops with age, previous injuries, or due to abnormal hip mechanics, and symptoms often worsen with activity and improve with rest.

Avascular Necrosis of Femoral Head

This condition occurs when the blood supply to the ball portion of the hip joint (femoral head) is disrupted, causing the bone tissue to die. Without adequate blood flow, the bone begins to collapse and break down, leading to severe hip pain and eventual joint destruction. This can result from trauma, certain medications, alcohol use, or other medical conditions that affect blood circulation.

Greater Trochanteric Bursitis

This involves inflammation of the fluid-filled sacs (bursae) located on the outer side of the hip, near a bony prominence called the greater trochanter. These bursae normally help reduce friction between muscles, tendons, and bones during movement. When inflamed, patients typically experience pain on the outer hip that may radiate down the thigh, often worsening when lying on the affected side or climbing stairs.

Piriformis Syndrome

This condition occurs when the piriformis muscle, located deep in the buttock, becomes tight or spasms and irritates the nearby sciatic nerve. The piriformis muscle helps rotate the hip and stabilize the pelvis during walking and running. When this muscle becomes problematic, it can cause pain in the buttock area and may lead to sciatica-like symptoms, including pain, tingling, or numbness that radiates down the leg.

Gluteal Tendinopathy

This refers to damage or degeneration of the tendons that attach the gluteal muscles (buttock muscles) to the outer hip bone. These tendons can become irritated, thickened, or partially torn due to overuse, repetitive activities, or age-related changes. The condition typically causes pain on the outer hip and buttock area, particularly noticeable when walking, climbing stairs, or lying on the affected side.

Groin Pain / Osteitis Pubis

Osteitis pubis is inflammation of the pubic symphysis, which is the joint where the two pubic bones meet at the front of the pelvis. This condition often affects athletes involved in running, kicking, or pivoting sports due to repetitive stress on the pelvic area. The inflammation causes pain in the groin region that may radiate to the inner thigh or lower abdomen, typically worsening with activity and improving with rest.

Plantar Fasciitis

This is inflammation or irritation of the thick band of tissue that runs along the bottom of the foot from the heel to the toes. The plantar fascia acts like a bowstring to support the arch of the foot. When this tissue becomes strained, it causes heel and arch pain that is typically worst with the first steps in the morning or after periods of rest.

Heel Spur

This is a bony growth that develops on the underside of the heel bone where muscles and ligaments attach. Heel spurs form when calcium deposits build up over time, often in response to repeated stress or inflammation. While the spur itself may not cause pain, it often occurs alongside plantar fasciitis and indicates chronic strain on the foot structures.

Ankle Ligament Injury

This refers to damage to the strong bands of tissue that connect the bones around the ankle joint and provide stability. Ligament injuries typically occur from twisting or rolling the ankle beyond its normal range of motion. The severity can range from mild stretching to partial or complete tearing of the ligament fibers, affecting ankle stability and function.

Posterior Tibial Tendinopathy

This condition involves damage or degeneration of the tendon that runs behind the inner ankle bone and helps support the arch of the foot. The posterior tibial tendon is crucial for maintaining the foot’s arch and allowing normal walking mechanics. When this tendon becomes inflamed or torn, it can lead to arch collapse and flat foot deformity if left untreated.

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Achilles Tendinopathy

This is a condition affecting the large tendon that connects the calf muscles to the heel bone at the back of the ankle. The term describes degeneration, inflammation, or microscopic tears within the tendon tissue rather than acute injury. This condition commonly develops from overuse or repetitive stress and causes pain and stiffness in the back of the heel and lower calf.

Morton’s Neuroma

This is a thickening of tissue around one of the nerves leading to the toes, most commonly between the third and fourth toes. The condition develops when the nerve becomes compressed or irritated, often from tight shoes or repetitive stress. Patients typically experience burning pain, numbness, or the sensation of having a pebble in the shoe in the ball of the foot.

Osteochondral Lesion of the Talus

This refers to damage to both the cartilage surface and underlying bone of the talus, which is the ankle bone that sits between the leg bones and heel bone. These lesions can result from acute injury or develop gradually over time. The damage affects the smooth joint surface, potentially causing ankle pain, stiffness, and catching sensations during movement.

Hallux Rigidus

This is arthritis of the joint at the base of the big toe, causing stiffness and limited motion in the toe. The condition involves wearing away of the cartilage that covers the joint surfaces, leading to bone-on-bone contact. As the name suggests, the primary symptom is rigidity or reduced ability to bend the big toe upward, which can significantly affect walking and push-off during movement.

Calcaneal Bone Edema

This refers to swelling or fluid accumulation within the heel bone tissue, which appears as increased signal on MRI scans. Bone edema typically indicates stress, inflammation, or microscopic injury to the bone structure. This finding often accompanies conditions like plantar fasciitis or stress injuries and represents the bone’s response to increased mechanical stress or inflammation.

Tarsal Tunnel Syndrome

This condition occurs when the tibial nerve becomes compressed as it passes through a narrow space called the tarsal tunnel on the inside of the ankle. Similar to carpal tunnel syndrome in the wrist, this compression causes numbness, tingling, burning, or shooting pain along the inside of the ankle and into the foot. The symptoms often worsen with prolonged standing or walking and may improve with rest.

Lateral Epicondylitis

Lateral epicondylitis, commonly known as tennis elbow, is inflammation or irritation of the tendons on the outside of the elbow. This condition occurs when the tendons that attach to the bony bump on the outer side of the elbow become overused or strained. It typically causes pain and tenderness on the outside of the elbow that may worsen with gripping activities or lifting objects.

Medial Epicondylitis

Medial epicondylitis, often called golfer’s elbow, involves inflammation of the tendons on the inside of the elbow. This condition affects the tendons that attach to the bony prominence on the inner side of the elbow joint. Patients typically experience pain and tenderness on the inside of the elbow, which may radiate down the forearm and worsen with wrist flexion or gripping activities.

Carpal Tunnel Syndrome

Carpal tunnel syndrome occurs when the median nerve becomes compressed as it passes through a narrow passageway in the wrist called the carpal tunnel. This compression happens when the tissues around the tendons in the carpal tunnel become swollen or inflamed. The condition typically causes numbness, tingling, and pain in the thumb, index, middle, and part of the ring finger, often worsening at night.

De Quervain’s Tenosynovitis

De Quervain’s tenosynovitis is inflammation of the tendons and their surrounding sheaths on the thumb side of the wrist. This condition affects the tendons that control thumb movement, particularly when moving the thumb away from the palm. Patients typically experience pain and swelling near the base of the thumb that worsens with thumb and wrist movements, especially when making a fist or grasping objects.

Trigger Finger

Trigger finger is a condition where one of the fingers gets stuck in a bent position and may snap straight like pulling and releasing a trigger. This occurs when inflammation narrows the space within the sheath that surrounds the tendon in the affected finger. The finger may feel stiff and patients may notice a painful clicking or popping sensation when trying to straighten or bend the finger.

Ganglion Cyst

A ganglion cyst is a fluid-filled lump that commonly develops along tendons or joints in the wrist and hand. These benign cysts contain a jelly-like fluid similar to that found in joints and are the most common type of soft tissue mass in the hand and wrist. While often painless, ganglion cysts may cause discomfort if they press on nearby nerves or interfere with joint movement.

TFCC Tear

A TFCC tear refers to an injury to the triangular fibrocartilage complex, a structure on the pinky side of the wrist that acts like a shock absorber and stabilizer. This complex consists of cartilage, ligaments, and tendons that help support the small bones in the wrist during rotation and loading activities. TFCC tears typically cause pain on the pinky side of the wrist that worsens with twisting motions or weight-bearing on the hands.

Scaphoid Fracture

A scaphoid fracture is a break in the scaphoid bone, which is one of the small bones located in the wrist near the base of the thumb. This boat-shaped bone is particularly vulnerable to injury during falls when people instinctively put out their hand to break the fall. Scaphoid fractures can be challenging to diagnose initially and may cause persistent pain and tenderness in the wrist, particularly in the area between the thumb and wrist joint.

Thumb Base Osteoarthritis

Thumb base osteoarthritis, also known as basal joint arthritis, affects the joint where the thumb meets the wrist at the base of the thumb. This condition involves the breakdown of cartilage in the carpometacarpal joint, which is heavily used in gripping and pinching activities. Patients typically experience pain, stiffness, and weakness at the base of the thumb, particularly when performing tasks that require pinching or grasping objects.

Dupuytren’s Disease

Dupuytren’s disease is a condition that causes the tissue beneath the skin of the palm to thicken and contract over time. This thickening forms cords of tissue that can pull one or more fingers into a bent position toward the palm. The condition typically progresses slowly and most commonly affects the ring and pinky fingers, potentially making it difficult to straighten these fingers completely.

Muscle Tear Grades I-III

Muscle tears are classified into three grades based on severity. Grade I is a mild strain with minimal fiber damage, Grade II involves partial tearing of muscle fibers with moderate pain and swelling, and Grade III represents a complete rupture of the muscle. The grading system helps determine treatment approach and expected recovery time.

Muscle Edema

Muscle edema refers to fluid accumulation within muscle tissue, causing swelling. This commonly occurs after injury, overuse, or inflammation as the body’s natural response to tissue damage. The excess fluid appears as increased brightness on MRI scans and typically resolves as healing progresses.

Muscle Hematoma

A muscle hematoma is a collection of blood within or around muscle tissue, typically resulting from torn blood vessels during injury. This appears as a localized area of bleeding that may cause pain, swelling, and bruising. Most hematomas gradually absorb naturally, though larger ones may require monitoring.

Muscle Fibrosis

Muscle fibrosis occurs when normal muscle tissue is replaced by scar tissue composed of fibrous connective tissue. This typically develops after injury, chronic inflammation, or repeated trauma. Fibrotic tissue is less flexible and functional than normal muscle, potentially affecting strength and range of motion.

Muscle Atrophy

Muscle atrophy refers to the shrinkage or wasting away of muscle tissue, resulting in decreased muscle mass and strength. This can occur due to disuse, nerve damage, aging, or various medical conditions. The affected muscles appear smaller on imaging studies and may show reduced function clinically.

Goutallier Fatty Infiltration grades I-IV

This grading system measures the amount of fat that has replaced normal muscle tissue, commonly seen in rotator cuff muscles. Grade I shows minimal fat streaks, Grade II has more fat than muscle, Grade III shows equal amounts of fat and muscle, and Grade IV indicates more fat than muscle tissue. Higher grades generally indicate more severe muscle degeneration and poorer surgical outcomes.

Muscle Contracture

A muscle contracture is the permanent shortening and tightening of muscle fibers, leading to restricted joint movement. This typically develops after prolonged immobilization, scarring, or neurological conditions. The affected muscle cannot lengthen normally, resulting in limited range of motion and functional impairment.

Myositis

Myositis is inflammation of muscle tissue that can cause pain, weakness, and swelling. This condition may result from infection, autoimmune disorders, or injury to the muscle. The inflamed muscle appears abnormal on imaging studies and may feel tender or weak during clinical examination.

Fasciitis

Fasciitis is inflammation of the fascia, the thin connective tissue that surrounds and separates muscles. This condition causes pain, stiffness, and sometimes swelling in the affected area. The inflamed fascia may appear thickened or show increased signal on imaging studies.

Muscle Hernia

A muscle hernia occurs when muscle tissue protrudes through a defect or weakness in the surrounding fascia or connective tissue covering. This creates a visible or palpable bulge that may become more prominent during muscle contraction. Most muscle hernias are relatively harmless but can occasionally cause discomfort or functional limitations.

Medial/Lateral Femoral Condyle

These are the two rounded knobs at the bottom of the thigh bone (femur) that form part of the knee joint. The medial condyle is on the inner side of the knee, while the lateral condyle is on the outer side. These structures are commonly mentioned in reports because they can develop wear and tear, stress fractures, or cartilage damage that affects knee function.

Tibial Plateau

This is the flat, weight-bearing surface at the top of the shin bone (tibia) where it meets the thigh bone to form the knee joint. The tibial plateau is divided into medial (inner) and lateral (outer) sections that support the body’s weight during walking and movement. It appears in reports because fractures, bone bruising, or cartilage damage in this area can significantly impact knee stability and function.

Patella

The patella is the medical name for the kneecap, a small triangular bone that sits in front of the knee joint. It acts like a pulley system, helping the thigh muscles straighten the leg more efficiently and protecting the underlying knee joint. Reports often mention the patella when assessing fractures, dislocations, or tracking problems that can cause knee pain.

Suprapatellar Recess

This is a small pouch-like space located above the kneecap where the joint capsule extends upward. It normally contains a small amount of joint fluid that helps lubricate the knee. This area is frequently mentioned in reports because excess fluid collection here (effusion) or inflammation can indicate various knee conditions or injuries.

Patellar Tendon

This is the strong, rope-like tissue that connects the kneecap to the shin bone, continuing from the quadriceps tendon above the kneecap. It plays a crucial role in straightening the leg and is essential for activities like walking, jumping, and climbing stairs. The patellar tendon commonly appears in reports when assessing conditions like tendinitis, tears, or inflammation that can cause pain below the kneecap.

Hoffa’s Fat Pad

This is a cushion of fatty tissue located behind the patellar tendon and below the kneecap within the knee joint. It acts as a shock absorber and helps with knee movement by filling spaces as the joint bends and straightens. Reports may mention Hoffa’s fat pad when it becomes inflamed, impinged, or swollen, which can cause pain and limit knee movement.

Iliotibial Band

This is a thick band of fibrous tissue that runs along the outside of the thigh from the hip to just below the knee. It helps stabilize the knee and hip during movement and plays an important role in walking and running. The iliotibial band appears in reports when it becomes tight, inflamed, or irritated, often causing pain on the outer side of the knee or hip.

MRI with Contrast

This type of MRI scan uses a special dye called gadolinium that is injected into a vein before the scan. The contrast material helps highlight certain tissues, blood vessels, and areas of inflammation or injury more clearly on the images. It’s particularly useful for detecting soft tissue problems, infections, or areas where there might be increased blood flow or inflammation.

MRI without Contrast

This is a standard MRI scan performed without any injection of contrast dye. It provides excellent detail of bones, muscles, tendons, ligaments, and other soft tissues using only the natural magnetic properties of the body. Most musculoskeletal problems can be diagnosed effectively with this type of scan, making it the most commonly ordered MRI for joint and spine issues.

1.5T vs 3T MRI

These numbers refer to the magnetic field strength of the MRI machine, measured in Tesla units. A 3T MRI has twice the magnetic strength of a 1.5T machine, which generally produces sharper, more detailed images and faster scan times. However, 1.5T machines are perfectly adequate for most musculoskeletal conditions and may actually be better for certain types of scans or patients with metal implants.

MR Arthrography

This is a specialized MRI technique where contrast material is injected directly into a joint space before the scan. The contrast outlines the internal structures of the joint, making it easier to see small tears in cartilage, ligaments, or joint capsules that might not show up on a regular MRI. It’s commonly used for shoulder, hip, and wrist problems where detailed joint anatomy needs to be evaluated.

Scan Planes

These refer to the different angles or directions from which the MRI takes images of the body. The three main planes are sagittal (side view), coronal (front/back view), and axial (cross-sectional view from above). Multiple planes provide a complete three-dimensional picture of the anatomy, allowing healthcare providers to see structures from different angles and better understand the location and extent of any problems.

MRI Contraindications

These are medical conditions or circumstances that make an MRI scan unsafe or inappropriate for certain patients. Common contraindications include certain types of metal implants, pacemakers, cochlear implants, or metal fragments in the eyes. Some patients may also be unable to have an MRI due to severe claustrophobia, inability to lie still, or kidney problems that prevent the use of contrast material when needed.

Within Normal Limits

This means the examined area appears healthy and normal for someone of the patient’s age and condition. It indicates that no abnormalities or concerning changes were detected during the examination or imaging study.

Consistent With

This phrase indicates that the findings match or support a particular diagnosis or condition. The radiologist or examiner has observed features that typically occur with a specific problem, though additional testing may be needed for confirmation.

Cannot be Excluded

This means that while a particular condition wasn’t clearly seen, it’s still possible that it exists. The imaging or examination may not be sensitive enough to completely rule out the condition, or the findings are unclear.

Degenerative in Nature

This refers to changes that occur naturally over time due to wear and tear on the body’s tissues. These changes are typically related to aging and normal use of joints, bones, or other structures rather than injury or disease.

Sequelae of

This describes changes or conditions that have developed as a result of a previous injury, illness, or medical event. These are the long-term effects or consequences that remain after the original problem has healed or been treated.

Incidental Finding

This is something unexpected that was discovered during an examination or scan performed for a different reason. While not related to the original concern, incidental findings may or may not require further attention depending on their nature.

Clinical Correlation Advised

This means the imaging or test results should be compared with the patient’s symptoms and physical examination findings. The radiologist is recommending that the treating physician consider all available information together to make the best treatment decisions.

Age-appropriate Findings

This indicates that the observed changes are normal and expected for someone of the patient’s age. These findings represent typical wear and tear or natural aging processes rather than disease or injury.

No Significant Change

This means that when compared to previous imaging or examinations, the findings appear essentially the same. Any minor differences observed are not considered medically important or concerning.

Requires Clinical Evaluation

This indicates that the findings need to be assessed by a healthcare provider in person. The radiologist has identified something that requires physical examination, symptom review, or additional testing to determine its significance.

Well-defined / Ill-defined Margins

Well-defined margins mean the edges of a finding are clear and sharp, often suggesting a benign or less aggressive condition. Ill-defined margins indicate blurry or unclear edges, which may suggest inflammation, infection, or other processes that require evaluation.

Discontinuity / Disruption

This describes a break or interruption in the normal structure of tissues like bones, muscles, or ligaments. It typically indicates an injury such as a fracture, tear, or rupture that has caused the normal anatomy to be altered.

Finding Requiring Follow-up

This indicates that something was observed that needs to be monitored over time or investigated further. While not necessarily serious, the finding requires additional attention to determine if it changes or needs treatment.

In Situ

This means something is located in its original or natural position. In medical contexts, it often refers to abnormal cells or growths that remain confined to their original location and haven’t spread to surrounding tissues.