Musculoskeletal Radiology — MCQs

Musculoskeletal Radiology Indian Medical PG Practice Questions and MCQs

Question 331: All the following are seen in Hyperparathyroidism except:

A. Pepper - pot skull
B. Loss of lamina dura
C. Calvarial thickening (Correct Answer)
D. Subperiosteal erosion of bone

Explanation: ***Calvarial thickening*** - **Calvarial thickening** is typically associated with conditions like **Paget's disease** of bone or certain anemias, which increase bone deposition, whereas hyperparathyroidism leads to bone resorption. - In hyperparathyroidism, the primary skeletal manifestation is **osteoclastic bone resorption**, leading to thinning of cortical bone and loss of bone density, not thickening. *Pepper-pot skull* - This describes the radiographic appearance of the skull due to **resorption of trabecular bone** and formation of numerous small lucencies, giving it a "pepper-pot" or "salt-and-pepper" appearance. - It's a classic sign of **hyperparathyroidism**, indicating diffuse bone demineralization in the skull. *Loss of lamina dura* - The **lamina dura** is the dense bone lining the tooth socket, which appears as a radiopaque line around the tooth root on radiographs. - Its **loss or absence** is a characteristic sign of hyperparathyroidism due to generalized bone demineralization, as it is one of the first cortical bone structures to undergo resorption. *Subperiosteal erosion of bone* - This is considered the **pathognomonic radiographic sign** of hyperparathyroidism, particularly seen in the phalanges of the hand. - It results from excessive **osteoclastic activity** leading to resorption of bone directly beneath the periosteum.

Question 332: Spine MRI shows 'pencil-sharpened' vertebral bodies and 'H-shaped' vertebrae on T1-weighted images. Most likely diagnosis?

A. Sickle cell disease (Correct Answer)
B. Paget's disease
C. Thalassemia
D. Osteopetrosis

Explanation: ***Sickle cell disease*** - **'Pencil-sharpened' vertebral bodies** and **'H-shaped' vertebrae** are characteristic findings in sickle cell disease due to chronic **ischemic necrosis** of the vertebral endplates. - This vertebral deformity arises from the collapse of the central portion of the vertebral body, often associated with episodes of **vaso-occlusion**. *Paget's disease* - Characterized by abnormal bone remodeling, leading to **bone enlargement** and thickening, not vertebral notching or collapse. - Common radiological findings include **cotton wool appearance** of the skull and **sclerosis** of the vertebrae, distinct from the described MRI findings. *Thalassemia* - Causes significant **bone marrow expansion** due to ineffective erythropoiesis, leading to cortical thinning and widened medullary spaces. - While it can affect bone morphology, it typically does not produce the specific 'H-shaped' or 'pencil-sharpened' vertebral body deformities. *Osteopetrosis* - Known as **'marble bone disease'**, characterized by abnormally dense bones due to defective osteoclast function. - Radiologically, it presents with **generalized increased bone density** and obliterated marrow spaces, which is opposite to the changes seen in sickle cell disease.

Question 333: STIR sequence in MRI is most useful for

A. Bone marrow lesions (Correct Answer)
B. Liver masses
C. Brain tumors
D. Kidney stones

Explanation: ***Bone marrow lesions*** - **STIR (Short Tau Inversion Recovery)** sequences are excellent for suppressing fat signals, making them highly sensitive for detecting **edema** and **fluid-rich lesions** within the **bone marrow**. - This characteristic makes it ideal for identifying conditions like **bone bruises**, **stress fractures**, **osteomyelitis**, and **marrow infiltration** by tumors. *Liver masses* - While STIR can show some features of liver lesions, other sequences like **T1-weighted fat-saturated** and **dynamic contrast-enhanced imaging** are typically more specific for characterizing liver masses. - The primary strength of STIR is fat suppression, which is less critical for distinguishing most liver mass types from the surrounding parenchyma. *Brain tumors* - **Fluid-attenuated inversion recovery (FLAIR)** sequences are generally preferred for evaluating brain tumors, as they suppress CSF signal effectively, making peritumoral edema and lesions visible. - While STIR can be used, its strong fat suppression isn't as critical in the brain as it is for musculoskeletal imaging, and FLAIR offers better grey/white matter contrast. *Kidney stones* - **CT scans**, especially **non-contrast helical CT**, are the gold standard for detecting and characterizing kidney stones due to their high spatial resolution and sensitivity to calcifications. - MRI, including STIR, has limited utility for identifying kidney stones as most stones are too small to be clearly visualized and do not typically exhibit features enhanced by fat suppression.

Question 334: Most sensitive imaging modality for detecting early osteomyelitis

A. Nuclear bone scan
B. CT scan
C. MRI (Correct Answer)
D. Plain radiograph

Explanation: **MRI** - **MRI** is the most sensitive imaging modality for detecting **early osteomyelitis** due to its superior ability to visualize **bone marrow edema** and soft tissue changes, which are the earliest signs of infection. - It can differentiate between **bone infection** and other processes like inflammation or tumor, even before cortical bone changes are evident. *Nuclear bone scan* - **Nuclear bone scans** (e.g., technetium-99m) are highly sensitive for detecting **increased bone turnover** but lack specificity for infection. - They can identify areas of **inflammation** or injury but cannot reliably distinguish between osteomyelitis and other conditions like **fractures** or **tumors**. *CT scan* - **CT scans** are excellent for visualizing **cortical bone destruction**, **sequestra**, and **involucrum** in later stages of osteomyelitis. - However, **CT scans** are not as sensitive as MRI for detecting early bone marrow changes and soft tissue involvement, making them less ideal for **early diagnosis**. *Plain radiograph* - **Plain radiographs** are often the first imaging study for suspected osteomyelitis but have **low sensitivity** in the early stages, with changes typically not visible until 10-14 days after infection onset. - Early findings may include **periosteal elevation** or soft tissue swelling, but **bone destruction** or new bone formation is usually required for a definitive diagnosis.

Question 335: In acute quadriceps tendon rupture, which radiographic finding is most specific?

A. Joint Space Narrowing
B. Osteophytes
C. Patella Baja
D. Patella Alta (Correct Answer)

Explanation: ***Patella Alta*** - **Patella alta**, or a high-riding patella, is a classic radiographic sign of acute quadriceps tendon rupture because the **patella** is no longer tethered inferiorly by the intact quadriceps tendon. - The unopposed pull of the patellar tendon elevates the patella, making this a highly **specific finding**. *Joint Space Narrowing* - **Joint space narrowing** is indicative of cartilage loss and is commonly seen in degenerative conditions like **osteoarthritis**. - It does not directly reflect soft tissue injury such as a quadriceps tendon rupture. *Osteophytes* - **Osteophytes**, or bone spurs, are a sign of **degenerative joint disease** and chronic stress on joints, often seen in osteoarthritis. - They are not specific to acute traumatic injuries like tendon ruptures. *Patella Baja* - **Patella baja**, or a low-riding patella, is typically associated with **patellar tendon rupture**, not quadriceps tendon rupture. - In a patellar tendon rupture, the patella *drops* due to the loss of its inferior anchor, which is the opposite of a quadriceps rupture.

Question 336: What is the most reliable radiological sign of early osteonecrosis of femoral head?

A. Double Line Sign on MRI (Correct Answer)
B. Osteopenia
C. Crescent Sign
D. Joint Space Narrowing

Explanation: ***Double Line Sign on MRI*** - The **double line sign on MRI** is considered the most reliable and earliest radiological sign of **osteonecrosis of the femoral head**. - It represents the reactive interface between the necrotic and viable bone, characterized by a **low-signal intensity rim** (fibrosis/sclerosis) and an **inner high-signal intensity line** (granulation tissue). *Osteopenia* - **Osteopenia** is a general sign of bone demineralization and can be seen in many conditions, not specific to early osteonecrosis. - It is a less sensitive and specific indicator for initial changes related to compromised blood supply in the femoral head. *Crescent Sign* - The **crescent sign** is indicative of a **subchondral collapse** and is a later finding in osteonecrosis, suggesting disease progression rather than early onset. - It appears on plain radiographs as a thin, radiolucent line parallel to the articular surface. *Joint Space Narrowing* - **Joint space narrowing** is a feature of **osteoarthritis** and other forms of degenerative joint disease, indicating cartilage loss. - It is not typically an early or specific sign of osteonecrosis, which primarily affects the bone itself.

Question 337: Which MRI finding is suggestive of a torn meniscus in the knee?

A. Loss of cartilage
B. Increased signal intensity in the meniscus (Correct Answer)
C. Effusion
D. Bone marrow edema

Explanation: ***Increased signal intensity in the meniscus*** A torn meniscus on MRI typically shows **increased signal intensity** within the meniscal substance that **extends to at least one articular surface**, which is the key diagnostic criterion. This high signal indicates **fluid within the tear** or degenerative changes. The signal must reach the surface to differentiate a true tear from intrasubstance degeneration, which shows signal that does not reach the surface. *Loss of cartilage* **Cartilage loss** is characteristic of **osteoarthritis** or chronic degenerative joint disease, not specifically an acute meniscal tear. While it can coexist with meniscal tears as part of degenerative joint disease, it is not a direct indicator of a tear within the meniscus itself. *Effusion* A **knee effusion** (fluid within the joint) is a general sign of joint irritation or injury and can be present with various conditions, including meniscal tears, ligament injuries, and arthritis. However, it is a **non-specific finding** and does not directly confirm a meniscal tear. *Bone marrow edema* **Bone marrow edema** is often seen with **bone bruises**, stress fractures, or osteonecrosis. It indicates stress or injury to the bone rather than soft tissue injury, and is not directly indicative of a meniscal tear.

Question 338: Which condition is associated with a 'sunburst' pattern on X-ray?

A. Ewing's sarcoma
B. Giant cell tumor
C. Chondrosarcoma
D. Osteosarcoma (Correct Answer)

Explanation: ***Osteosarcoma*** - This highly aggressive primary bone tumor is characterized by **malignant osteoid formation** and often presents with a **'sunburst' or 'spiculated' periosteal reaction** on X-ray. - The sunburst pattern represents **new bone formation perpendicular to the cortical surface**, indicating rapid tumor growth. *Ewing's sarcoma* - Ewing's sarcoma commonly presents with an **'onion skin' appearance** (lamellated periosteal reaction) on X-ray due to layers of reactive bone. - It is typically a **small round blue cell tumor** found in the diaphysis of long bones. *Giant cell tumor* - This tumor is characterized by a **soap bubble appearance** or **lytic, expansile lesions** on X-ray, typically located in the epiphysis of long bones. - It does not usually exhibit a periosteal reaction like a 'sunburst' pattern. *Chondrosarcoma* - Chondrosarcoma is characterized by a **calcified matrix** with a **'rings and arcs' or 'popcorn' calcification pattern** on X-ray. - While it is a primary bone tumor, its radiographic features differ significantly from the 'sunburst' pattern.

Question 339: In ankylosing spondylitis, which of the following is commonly seen on MRI?

A. Schmorl's nodes
B. Intervertebral disc prolapse
C. Sacroiliitis (Correct Answer)
D. Bamboo spine

Explanation: ***Sacroiliitis*** - **Sacroiliitis**, inflammation of the **sacroiliac joints**, is the hallmark and earliest radiological finding in **ankylosing spondylitis** and is readily visualized on MRI. - MRI is highly sensitive for detecting both **bone marrow edema** (indicating active inflammation) and **erosions** in the sacroiliac joints, even before changes are visible on conventional X-rays. *Schmorl's nodes* - **Schmorl's nodes** are **vertebral endplate infarctions** where the intervertebral disc herniates into the vertebral body, typically due to degeneration or trauma. - While they can be seen in various spinal conditions, they are **not specifically diagnostic** or characteristic of **ankylosing spondylitis**. *Intervertebral disc prolapse* - An **intervertebral disc prolapse**, commonly known as a **slipped disc**, involves the bulging or rupture of a disc, often causing nerve root compression. - This is a common cause of back pain in the general population but is **not a primary feature** or direct consequence of the inflammatory process in **ankylosing spondylitis**. *Bamboo spine* - **Bamboo spine** refers to the **fusion of vertebral bodies** due to syndesmophyte formation, leading to a rigid spine. - This is a **late-stage radiological change** seen on plain X-rays, representing chronic, irreversible damage, whereas MRI is used for early detection of active inflammation like sacroiliitis.

Question 340: Which radiological feature is a hallmark of adolescent idiopathic scoliosis?

A. Rotational deformity of the vertebrae (Correct Answer)
B. Lytic lesions
C. Vertebral collapse
D. Sclerotic lesions

Explanation: ***Rotational deformity of the vertebrae*** - **Adolescent idiopathic scoliosis** is characterized by a 3D spinal deformity, and an axial **rotational deformity of the vertebrae** is a hallmark finding on imaging. - This rotation contributes to the rib hump seen on physical examination and is crucial for measuring the severity of the scoliosis curve using methods like the **Cobb angle**. *Lytic lesions* - **Lytic lesions** indicate areas of bone destruction, often associated with tumors, infections like osteomyelitis, or metabolic bone diseases. - They are not characteristic findings in **idiopathic scoliosis**, which is a structural deformity rather than a destructive process. *Vertebral collapse* - **Vertebral collapse** (or compression fractures) is typically caused by trauma, osteoporosis, or metastatic disease, leading to a reduction in vertebral body height. - This is not a feature of **adolescent idiopathic scoliosis**, where the vertebral bodies generally maintain their structural integrity, albeit with rotation. *Sclerotic lesions* - **Sclerotic lesions** refer to areas of increased bone density, which can be seen in conditions like osteoblastic metastases, Paget's disease, or chronic stress responses. - They are not a characteristic radiological finding in **adolescent idiopathic scoliosis**, where the primary issue is spinal curvature and vertebral rotation.

Practice by Chapter

Radiographic Anatomy of Bones and Joints

Practice Questions

Imaging of Fractures and Dislocations

Practice Questions

Arthritides: Inflammatory and Degenerative

Practice Questions

Metabolic Bone Diseases

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Bone and Soft Tissue Tumors

Practice Questions

Congenital Skeletal Anomalies

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Spine Imaging

Practice Questions

Skeletal Infections

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Sports Medicine Imaging

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Imaging of Prostheses and Implants

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Musculoskeletal Ultrasound

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MSK Interventional Procedures

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