ACR Inservice Recall

1. 28th Annual
In-Training Examination
for Diagnostic
Radiology Residents
Rationales
Sponsored by:
Commission on Education
Committee on Residency Training in Diagnostic Radiology
February 3, 2005
The American College of Radiology www.acr.org

2. Section VIII – Musculoskeletal
Figure 1A Figure 1B
200. You are shown axial T1- and T2-weighted MR images (Figures 1A and 1B) of a 23-year-old woman
with foot pain. Which one of the following is the MOST likely diagnosis?
A. Posterior tibial tendon tear
B. Subtalar coalition
C. Dysplasia epiphysealis hemimelica
D. Tarsal tunnel syndrome
American College of Radiology

3. Section VIII – Musculoskeletal
Question #200
Findings:
Narrowing with closely opposed irregular articular interface at the medial subtalar joint with maldevelopment
of the sustentaculum tali, which slopes downward.
Rationales:
A. Incorrect. Posterior tibial tendon tears may be incomplete with thickening of the tendon, type I, incomplete
with tendon attenuation, type II and complete, type III. Associated fluid at the tendon sheath is typical.
Prominence of the medial soft tissues may be present. The posterior tibial tendon in the test case is normal.
B. Correct. The medial facet of the subtalar joint is one of the most common sites of developmental coalition
of the foot. Such unions may be fibrous, cartilaginous or bony. In either case, there is close approximation
of the 2 bones, often with down-sloping of the sustentaculum tali as seen in the test case.
C. Incorrect. Dysplasia epiphysealis hemimelica—also known as Trevor’s disease, tarsal aclasis, tarsoepiphyseal
aclasis—is a development anomaly (dysplasia) in which a bony outgrowth, exostosis like in appearance,
develops at an epiphysis or epiphysioid bone (epiphysealis) usually involving one side of the joint and one
side of the body (hemimelica). The most common sites are the ankle and knee. The abnormal appearance
of the medial subtalar joint in the test case represents coalition, not a bony outgrowth.
D. Incorrect. Tarsal tunnel syndrome is a compressive neuropathy involving the posterior tibial nerve resulting
from any space-occupying lesion, behind and below the medial malleolus, beneath the flexor retinaculum.
The tarsal tunnel in the test case is normal.
Citations:
Stoller, Tirman, Bredella. Diagnostic Imaging Orthopaedics. Amirsys Inc. Salt Lake City, UT.
Resnick, Niwayama. Diagnosis of Bone and Joint Disorders. W.B. Saunders. Philadelphia, PA. Fourth Ed.
Diagnostic In-Training Exam 2004

4. Section VIII – Musculoskeletal
Figure 2
201. You are shown an AP view (Figure 2) of the pelvis and hips of a 44-year-old woman. What is the
MOST likely diagnosis?
A. Osteopetrosis
B. Tuberous sclerosis
C. Renal osteodystrophy
D. Sickle cell disease
American College of Radiology

5. Section VIII – Musculoskeletal
Question #201
Findings:
Diffuse uniform sclerosis of the pelvis and hips with failure of differentiation between cortex and medullary
cavity, status post hip fixation.
Rationales:
A. Correct. Osteopetrosis is a sclerosing dysplasia involving a defect in osteoclastic resorption of the primary
spongiosa related to endochondral bone formation. Sclerosis is usually diffuse and uniform. Loss of the
cortical medullary junction is typical. Alternating bands of sclerosis may also be present reflecting the
periodicity of the disease. In the adult form or delayed type, autosomal dominant variety, originally
described by Albert-Schoenberg, the patient’s life expectancy may be normal but the skeleton is brittle and
prone to fracture.
B. Incorrect. Although the pelvis is a common site for osteoblastic deposits in patients with tuberous sclerosis,
they are usually multiple and discrete rather than diffuse and uniform as in the test case.
C. Incorrect. Renal osteodystrophy does not produce such uniform widespread sclerosis with loss of the
cortical medullary junction as in the test case. When there is extensive involvement, sclerosis tends to be
more patchy and ill-defined related to secondary hyperparathyroidism.
D. Incorrect. The sclerosis of sickle cell disease is secondary to infarction and osteonecrosis which overtime is
replaced by fibrosis and new bone formation. The diffuse, uniform sclerosis at the pelvis and hips with
diffuse loss of the cortical-medullary junction would be unusual.
Citations:
Greenspan. Orthopaedic Radiology. Lipincott Williams Wilkins. Philadelphia, PA. Third Ed.
Resnick, Niwayama. Diagnosis of Bone and Joint Disorders. W.B. Saunders. Philadelphia, PA. Fourth Ed
Diagnostic In-Training Exam 2004

6. Section VIII – Musculoskeletal
Figure 3A Figure 3B
202. You are shown a lateral radiograph (Figure 3A) and a non-contrast CT (Figure 3B) of a 9-year-old
boy with anterior leg bowing. What is the MOST likely diagnosis?
A. Intracortical osteosarcoma
B. Non-ossifying fibroma
C. Osteofibrous dysplasia
D. Aneurysmal bone cyst
American College of Radiology

7. Section VIII – Musculoskeletal
Question #202
Findings:
There is a cortically based, expansile lesion involving the anterior tibia shaft.
The tibia is mildly bowed anteriorly.
The majority of the lesion is lucent, with a lobulated contour and sclerotic margins.
Rationales
A. Incorrect. Intracortical osteosarcoma is the most uncommon form of osteosarcoma. They are diaphyseal,
usually arising in the femur or tibia. Intracortical osteosarcoma generally presents as lucency within the
cortex that measures less than 4 cm, with surrounding sclerosis. If small, they may be mistaken for an
osteoid osteoma or fibrous cortical defect.
B. Incorrect. Nonossifying fibromas may be mildly expansile, but they are not associated with bowing of the
bone.
C. Correct. Osteofibrous dysplasia is a benign fibro-osseous lesion that is almost exclusively found in the
tibia or fibula. It is a disorder of childhood, usually seen within the first 2 decades of life and often under
10 years of age. The lesion is centered in the anterior cortex, and may be associated with anterior bowing.
A lobulated lucency is seen, often with surrounding sclerosis. The appearance may mimic a nonossifying
fibroma, but the location and bow are key. Adamantinoma may be present in association with osteofibrous
dysplasia. The two disorders cannot be differentiated one from the other by imaging.
D. Incorrect. Aneurysmal bone cysts are eccentric, lytic lesions that are usually found in the medullary cavity.
They are most often metaphyseal, but may be present anywhere along a bone. Cortical and periosteal
locations have been reported, but are unusual. The cortex overlying the lesion is expanded and if growth is
rapid, it may be destroyed.
Citations:
Huvos AG. Bone Tumors: Diagnosis, Treatment, and Prognosis, 2nd Ed. WB Saunders Company, Philadelphia, PA,
1991.
Unni KK, Ed. Dahlin’s Bone Tumors: General Aspects and Data on 11, 087 cases, 5th ed. Lippincott-Raven
Publishers, Philadelphia, PA, 1996
Diagnostic In-Training Exam 2004

8. Section VIII – Musculoskeletal
Figure 4B
Figure 4A
203. You are shown frontal and lateral radiographs (Figures 4A and 4B) of a12-year-old boy who fell
from his skateboard. What is the fracture type?
A. Tillaux
B. Triplane
C. Pilon
D. Maisonneuve
American College of Radiology

9. Section VIII – Musculoskeletal
Question #203
Findings:
A Salter IV fracture with a sagittal epiphyseal, transverse physeal and coronal metaphyseal orientation.
Rationales:
A. Incorrect. A Tillaux fracture is a Salter type III avulsion of the anterolateral aspect of the distal tibial
epiphysis.
B. Correct. The radiograph shows a coronally oriented fracture of the distal metaphysis of the tibia, a
horizontally oriented fracture of the lateral aspect of the physis, and a sagittally oriented fracture of the
distal epiphysis, all of which comprise a triplane fracture. The injury results in part due to the partially
fused tibial physis, closure progressing medial to lateral.
C. Incorrect. A pilon fracture is a comminuted fracture of the distal tibia and tibial plafond due to impaction
of the talus into the tibia.
D. Incorrect. A Maisonneuve fracture involves the proximal fibula shaft and is associated with rupture of the
distal syndesmotic ligaments and widening of the tibia-fibular syndesmosis.
Citations:
Greenspan. Orthopedic Radiology. A Practical Approach. 2nd ed. Gower Medical Publishing, NY, NY 1992.
Diagnostic In-Training Exam 2004

10. Section VIII – Musculoskeletal
Figure 5
204. You are shown an oblique coronal T1-weighted MR image (Figure 5) of a 45-year-old woman with
chronic mild shoulder pain. What is the MOST likely diagnosis?
A. Parsonage-Turner syndrome
B. Chronic rotator cuff tear
C. Quadrilateral space syndrome
D. Suprascapular nerve entrapment
American College of Radiology

11. Section VIII – Musculoskeletal
Question #204
Findings:
Atrophy teres minor and deltoid musculature
Rationales:
A. Incorrect. Parsonage-Turner syndrome (also known as acute brachial neuritis) is an idiopathic denervation
of the shoulder muscles resulting in pain and weakness. The muscles demonstrate high SI on T2-weighted
imaging due to acute denervation edema and ultimately atrophy and fatty replacement. The suprascapular
nerve and, therefore, the supraspinatus and infraspinatus musculature are typically involved. Axillary nerve
involvement may occur but is less frequent.
B. Incorrect. While chronic tears of the rotator cuff tendons may be associated with muscle atrophy and fatty
replacement, no tears are demonstrated in the test case.
C. Correct. Quadrilateral space syndrome is caused by compression of the axillary nerve in the quadrilateral
space, usually by small fibrous bands or ganglion cysts and clinically manifests as mild shoulder pain.
Axillary nerve dysfunction may eventually lead to atrophy of the teres minor and deltoid musculature.
D. Incorrect. The teres minor and deltoid muscles are supplied by the axillary nerve, not the suprascapular
nerve. The suprascapular nerve innervates the supraspinatus and infraspinatus muscles, which appear
normal.
Citation:
Kaplan, Helms, Dussault, Anderson, Major. Musculoskeletal MRI. WB Saunders Co., Philadelphia, PA. 2001
Diagnostic In-Training Exam 2004

12. Section VIII – Musculoskeletal
205. The radiographic appearance of SI joint widening is associated with ALL of the following EXCEPT:
A. Infection
B. Hyperthyroidism
C. Trauma
D. Renal osteodystrophy
Question #205
Rationales:
A. Incorrect. Septic sacroiliitis may significantly erode the articular surfaces of the sacrum and ilium,
producing enough bone loss to create an appearance of joint widening.
B. Correct. Osteoporosis is the most characteristic feature of hyperthyroidism in the adult skeleton. In the
immature skeleton, there may be acceleration of skeletal maturity. Thyroid acropachy is an unusual
manifestation of thyroid disease usually observed after the treatment of hyperthyroidism at which time the
patient may be hypothyroid, euthyroid or even hyperthyroid. Periosteal new bone formation at the small
bones of the hands and feet is the characteristic radiographic finding. S-I joint involvement is not seen.
C. Incorrect. Trauma to the pelvis may result in diastasis at one or both SI joints producing a radiographic
appearance of SI joint widening.
D. Incorrect. Secondary hyperparathyroidism is characteristic of renal osteodystrophy and may result in
subchondral bone resorption at the SI joints.
Citations:
Resnick, Niwayama. Diagnosis of Bone and Joint Disorders. W B Saunders, Philadelphia, PA Fourth Ed.
American College of Radiology

13. Section VIII – Musculoskeletal
206. ALL of the following are associated with bone marrow edema on MRI EXCEPT:
A. Langerhans cell granuloma
B. Chondroblastoma
C. Giant cell tumor of bone
D. Osteoid osteoma
Question #206
Rationales:
A. Incorrect. Langerhans cell granuloma (formally known as eosinophilic granuloma) is a benign disorder that
represents a focal tumor-like proliferation of Langerhans-type histiocytes. The lesions are usually
intramedullary, but may arise in the cortex. They are lytic, most often with an oval shape. In the long
bones, the lesion is usually diaphyseal. On MRI, intense edema is usually seen in the marrow and
surrounding soft tissues.
B. Incorrect. Like giant cell tumor of bone, chondroblastoma is an epiphyseal lesion. While the location is
similar, other features may be used to distinguish the two. Chondroblastoma is usually seen in patients
under the age of 20 years. On plain film and CT, a well-defined sclerotic rim will be seen, often with
matrix mineralization. Chondroblastoma characteristically shows edema in the surrounding marrow on
MR imaging. This is especially prominent with the “inflammatory” subtype.
C. Correct. Giant cell tumor of bone is usually an epiphyseal lesion, eccentrically located within the bone.
Eighty percent of patients are between the ages of 20 and 50 years. The tumor generally lacks a defined
sclerotic rim, and contains no matrix mineralization. In the absence of a pathologic fracture, bone marrow
edema is not present.
D. Incorrect. Osteoid osteoma is a benign lesion that is characterized by a well-demarcated lucent nidus and
marked surrounding sclerosis when extraarticular. The nidus may be intramedullary, intracortical, or
subperiosteal. Because the nidus is usually quite small, it is often better depicted on CT than MR. The
MR will, however, show intense edema directing a search for the nidus that may otherwise be overlooked.
Citation:
Kaplan PA, Helms CA, Dussault R, Anderson MW, Major NM. Musculoskeletal MRI. WB Saunders
Company, Philadelphia, PA, 2001
Diagnostic In-Training Exam 2004

14. Section VIII – Musculoskeletal
207. Concerning MRI of the knee, what does the “double PCL” sign indicate?
A. Bucket-handle tear of the medial meniscus
B. Anterior subluxation of the tibia
C. Anterior cruciate ligament rupture
D. Posterior cruciate ligament rupture
Question #207
Rationales:
A. Correct. A bucket-handle tear is a longitudinal tear of the body of the meniscus with displacement of the
inner rim of that tear into the intercondylar notch of the knee. When such a tear involves the medial
meniscus, the flipped fragment characteristically lies underneath the curve of the posterior cruciate
ligament, usually mimicking it in contour and low signal intensity, thus giving rise to the “double PCL”
sign.
B. Incorrect. Anterior subluxation of the tibia causes buckling of the PCL, not a “double PCL”.
C. Incorrect. Rupture of the anterior cruciate ligament leads to anterior subluxation of the tibia, thus causing
buckling of the PCL. When the edema and hemorrhage of an acute, complete ACL tear is resolved, the
remaining ligament may be seen dropped within the notch, its slope almost parallel to the intercondylar
eminence, beneath the PCL, similar to but not characteristic of the “double PCL” sign.
D. Incorrect. Rupture of the PCL appears as swelling or discontinuity of the ligament.
Citation:
Ref: Kaplan, Helms, Dussault, Anderson, Major. Musculoskeletal MRI. WB Saunders Co., Philadelphia, PA.
2001
Resnick, Kang: Internal derangements of joints: Emphasis on MR imaging. WB Saunders Co., Philadelphia,
PA, 1997
American College of Radiology

15. Section VIII – Musculoskeletal
208. Concerning the various arthropathies, which one of the following is TRUE?
A. Osteoarthritis of the hand and wrist has a predilection for the radioscaphoid joint compartment.
B. The inflammatory arthritides spare the bare areas of the joint.
C. Joint space narrowing is a late manifestation of gout.
D. New bone formation is characteristic of adult onset rheumatoid arthritis.
Question #208
Rationales:
A. Incorrect. Osteoarthritis has a predilection for the radial aspect of the wrist, including the scaphoid
trapezium trapezoid complex and the trapezium first metacarpal joint compartment. The radioscaphoid
joint compartment, however, is typically spared unless there has been prior trauma. The PIP and DIP
joints are also preferentially involved.
B. Incorrect. The bare area of the joint refers to the intracapsular portion of bone not covered with articular
cartilage. These areas therefore are more susceptible to the inflammatory process, often an early site of
erosion before the articular cartilage is destroyed and the joint narrowed.
C. Correct. Although the hyaline articular cartilage is a common site for urate disposition and subsequent
tophi, intervening areas of noninvolved cartilage maintain the joint space until late in the course of the
disease, when all of the cartilage may be destroyed. This differs dramatically from the inflammatory
arthritides where cartilage destruction is a more uniform and more rapid process.
D. Incorrect. The carpal bones and tarsal bones may fuse during the progression of adult onset rheumatoid
arthritis as the joints of the wrist and foot are uniformly destroyed.
Otherwise, new bone formation is characteristically absent and is, rather, more typical of the sero-negative
arthropathies. Bony ankylosis, periostitis, appositional new bone formation at the end of the bone
(cupping), and ossification at the origin and insertion of ligaments and tendons (enthesopathy) are
manifestations of this productive tendency.
Citations:
Resnick, Niwayama. Diagnosis of Bone and Joint Disorders. W B Saunders, Philadelphia, PA. Fourth Ed.
Diagnostic In-Training Exam 2004

16. Section VIII – Musculoskeletal
209. The “rotator cuff interval” is defined as the anatomic space between which tendons?
A. Supraspinatus and infraspinatus
B. Infraspinatus and teres minor
C. Long head of biceps and subscapularis
D. Supraspinatus and subscapularis
Question #209
Rationales:
A. Incorrect. The scapula spine separates the supraspinatus and infraspinatus musculature. The tendons are
adjacent to one another.
B. Incorrect. There is no separation or interval between the adjacent infraspinatus and teres minor tendons.
C. Incorrect. The long head of the biceps tendon courses through the rotator cuff interval but does not define
its border.
D. Correct. The rotator cuff interval is a “space” between the supraspinatus and subscapularis tendons
through which the long biceps tendon travels from its origin on the supraglenoid tubercle to the bicipital
groove.
Citations:
Bigoni BJ, Chung CB. MR imaging of the rotator cuff interval. Magn Reson Imaging Clin N Am 2004; 12:61-
73.
Chung CB, Dwek JR, Cho Gj, et al. Rotator cuff interval: evaluation with MR imaging and MR arthrography
of the shoulder in 32 cadavers. J Comput Assist Tomogr 2000; 24(5):738-43.
American College of Radiology