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Biomedical subjects

Z S Rosenberg

Publications and source records attributed to Z S Rosenberg.

At least 19 recordsLinked to original sources

The C sign: more specific for flatfoot deformity than subtalar coalition.

OBJECTIVE: To assess the sensitivity and specificity of the C sign, a C-shaped line created by the outline of the talar dome and the inferior margin of the sustentaculum tali on lateral ankle radiographs, for patients with both flatfoot deformity and specifically talocalcaneal (TC) coalition. DESIGN AND PATIENTS: All patients in this retrospective study were under 35 years of age and had a lateral ankle radiograph and follow-up CT scan for a non-traumatic indication. Forty-eight cases over the past 5 years fulfilled these criteria. Two masked musculoskeletal radiologists determined the presence or absence of the C sign for each lateral radiograph by consensus. Each CT study was then assessed by a third musculoskeletal radiologist for the presence of tarsal coalition. Observations were correlated with clinical history regarding presence or absence of flatfoot deformity. RESULTS: Ten cases of TC coalition were diagnosed, four of which demonstrated a C sign (40%). Eight cases with a C sign were encountered, four of which had TC coalition (50%) and four did not. All patients with a positive C sign had a flatfoot clinically (100%), while only eight of 24 flatfooted patients had a C sign (33%). CONCLUSION: The C sign is specific, but not sensitive, for flatfoot deformity, and is neither sensitive nor specific for subtalar coalition.

Adolescent↗

Partial tears of the distal biceps tendon: MR appearance and associated clinical findings.

PURPOSE: To describe the magnetic resonance (MR) appearance and associated clinical findings of partial distal biceps tendon tears. DESIGN: Twenty elbow MR images at 1.5 T, performed over a 7 year period, were reviewed for an appearance of partial tears in the distal biceps. These images were assessed by two musculoskeletal radiologists for the extent of: (a) abnormal signal intensity within the tendon, and the presence of (b) bicipitoradial bursitis, and (c) bony microavulsive injury of the radial tuberosity. Medical records for nine of the 20 cases were reviewed for the clinical findings of ecchymosis, trauma, sensation of a "pop", loss of function, and acuity of onset. RESULTS: Twenty partial distal biceps tendon tears were seen. All displayed an abnormally increased signal in the distal biceps tendon. Three of 20 (15%) showed a 25% to 50% tear, ten of 20 (50%) showed a 50% tear, and seven of 20 (35%) showed a 75% to 90% tear. Bicipitoradial bursitis was seen in 11 of 20 (55%) cases. Bony microavulsive injury of the radial tuberosity was observed in 10 of 20 (50%). Of the nine cases reviewed for associated clinical findings, surprisingly, only three (33%) experienced an acute traumatic episode with an abrupt onset of pain. An insidious onset was reported in four of nine (44%). Sensation of a "pop" was recorded in only two of nine (22%) cases. Ecchymosis and loss of function were not seen in any of the cases. Finally, surgical conformation was obtained for three cases. CONCLUSION: Partial distal biceps tendon tears have a characteristic MR appearance, demonstrate little functional deficit, and may be attritional in their etiology due to the observation of a low number of patients reporting trauma or an acute onset.

Adult↗

Normal variants and pitfalls in MR imaging of the ankle and foot.

Normal anatomic variants may erroneously be interpreted as pathologic conditions on MR imaging of the ankle and foot. Therefore, sufficient knowledge of the normal anatomy and its variations is crucial for accurate diagnostic analysis of such images. This article will focus on outlining variants and MR imaging interpretation pitfalls of the tendons, ligaments, muscles, bones, and other miscellaneous structures of the foot and ankle.

Ankle Joint↗

MR imaging of the accessory muscles around the ankle.

Familiarity with the accessory muscles around the ankle is crucial in preventing misinterpretation and unnecessary treatment. A review of the MR imaging appearances, prevalence, and clinical features of the more common accessory muscles around the ankle is presented. Emphasis is placed on their distinguishing MR imaging features.

Ankle Joint↗

MR imaging features of diseases of the peroneal tendons.

Injuries of the peroneal tendons including peritendinosis/tenosynovitis, tendinosis, rupture, dislocation are being detected with greater frequency since the advent of MR imaging. This article focuses on the normal as well as pathologic MR features of the peroneal tendons.

Ankle Injuries↗

MR imaging of ligamentous abnormalities of the ankle and foot.

Ankle sprains are among the most common musculoskeletal injuries. MR imaging is useful in establishing an accurate diagnosis and, before initiation of treatment, excluding other causes of persistent ankle pain. This article reviews the common features of acute and chronic ligamentous injuries on MR imaging and site-specific pathologic lesions related to the injured ligaments.

Ankle Injuries↗

MR imaging of exercise-induced lower leg pain.

MR imaging of the lower leg is frequently performed to evaluate the active patient who presents with an exercise-induced injury. This article discusses both common and obscure osseous and soft tissue conditions that are seen in the athletic population with leg pain.

Athletic Injuries↗

MR imaging and CT in the assessment of osseous abnormalities of the ankle and foot.

This article focuses on the contributions of MR imaging and CT toward the evaluation of painful osseous abnormalities of the foot and ankle. Inconclusive findings on conventional radiographs often mandate further work up with the more advanced cross-sectional imaging techniques. Often, however, the radiologist remains unsure, which modality, CT or MR imaging, should be used. Based on our experience, CT and MR imaging play a complementary role in the assessment of these disorders.

Foot Bones↗

MR imaging features of tumors of the ankle and foot.

MR imaging is a useful technique in the work-up of neoplasms of the foot and ankle. Certain MR imaging traits may confer a specific diagnosis. For instance, the presence of fat in a homogeneous lesion would indicate a lipoma, while an intraarticular, poorly defined mass with low signal intensity on all pulse sequences is suspicious for pigmented villonodular synovitis. Most neoplasms, however, have no specific trademark MR features. In these cases, MR imaging is useful in imparting information that can assist in treatment and prognosis once a histologic diagnosis is made. For instance, MR imaging may help ascertain the presence and degree of bone marrow involvement, invasion of adjacent anatomical structures, and size of the lesion. MR imaging is an essential and effective modality for the preoperative staging of neoplasms of the foot and ankle.

Ankle↗

Traumatic musculotendinous injuries of the knee: diagnosis with MR imaging.

Magnetic resonance (MR) imaging is the imaging modality of choice for evaluation of acute traumatic musculotendinous injuries of the knee. Three discrete categories of acute injuries to the musculotendinous unit can be defined: muscle contusion, myotendinous strain, and tendon avulsion. Among the quadriceps muscles, the rectus femoris is the most susceptible to injury at the myotendinous junction due to its superficial location, predominance of type II fibers, eccentric muscle action, and extension across two joints. Among the muscles of the pes anserinus, the sartorius is the most susceptible to strain injury due to its superficial location and biarticular course. The classic fusiform configuration of the semimembranosus along with a propensity for eccentric actions also make it prone to strain injury. MR imaging findings associated with rupture of the iliotibial tract include discontinuity and edema, which are best noted on coronal images. The same mechanism of injury that tears the arcuate ligament from its fibular insertion can also result in avulsion injury of the biceps femoris. The gastrocnemius muscle is prone to strain injury due to its action across two joints and its superficial location. Injuries of the muscle belly and myotendinous junction of the popliteus are far more common than tendinous injuries.

Contusions↗

From the RSNA Refresher Courses. Radiological Society of North America. MR imaging of the ankle and foot.

Magnetic resonance (MR) imaging has opened new horizons in the diagnosis and treatment of many musculoskeletal diseases of the ankle and foot. It demonstrates abnormalities in the bones and soft tissues before they become evident at other imaging modalities. The exquisite soft-tissue contrast resolution, noninvasive nature, and multiplanar capabilities of MR imaging make it especially valuable for the detection and assessment of a variety of soft-tissue disorders of the ligaments (eg, sprain), tendons (tendinosis, peritendinosis, tenosynovitis, entrapment, rupture, dislocation), and other soft-tissue structures (eg, anterolateral impingement syndrome, sinus tarsi syndrome, compressive neuropathies [eg, tarsal tunnel syndrome, Morton neuroma], synovial disorders). MR imaging has also been shown to be highly sensitive in the detection and staging of a number of musculoskeletal infections including cellulitis, soft-tissue abscesses, and osteomyelitis. In addition, MR imaging is excellent for the early detection and assessment of a number of osseous abnormalities such as bone contusions, stress and insufficiency fractures, osteochondral fractures, osteonecrosis, and transient bone marrow edema. MR imaging is increasingly being recognized as the modality of choice for assessment of pathologic conditions of the ankle and foot.

Ankle Injuries↗

Superior labrum anterior-posterior lesions: diagnosis with MR arthrography of the shoulder.

PURPOSE: To determine the accuracy of magnetic resonance (MR) arthrography in the diagnosis of superior labrum anterior-posterior (SLAP) lesions of the shoulder. MATERIALS AND METHODS: From January 1995 to June 1998, MR arthrography of the shoulder was performed in 159 patients with a history of chronic shoulder pain or instability. Fifty-two patients underwent arthroscopy or open surgery 12 days to 5 months after MR arthrography. Diagnostic criteria for SLAP lesion included marked fraying of the articular aspect of the labrum, biceps anchor avulsion, inferiorly displaced bucket handle fragment, and extension of the tear into the biceps tendon fibers. Surgical findings were correlated with those from MR arthrography. RESULTS: SLAP injuries were diagnosed at surgery in 19 of the 52 patients (37%). Six of the 19 lesions (32%) were classified as type I, nine (47%) as type II, one (5%) as type III, and three (16%) as type IV. MR arthrography had a sensitivity of 89% (17 of 19 patients), a specificity of 91% (30 of 33 patients), and an accuracy of 90% (47 of 52 patients). The MR arthrographic classification showed correlation with the arthroscopic or surgical classification in 13 of 17 patients (76%) in whom SLAP lesions were diagnosed at MR arthrography. CONCLUSION: MR arthrography is a useful and accurate technique in the diagnosis of SLAP lesions of the shoulder. MR arthrography provides pertinent preoperative information with regard to the exact location of tears and grade of involvement of the biceps tendon.

Adult↗

Tear of the peroneus longus tendon: MR imaging features in nine patients.

PURPOSE: To determine the magnetic resonance (MR) imaging features that characterize tear of the peroneus longus tendon at the midfoot. MATERIALS AND METHODS: Medical records and MR images in nine patients with a tear of the middle segment of the peroneus longus tendon were retrospectively reviewed. All nine patients had undergone routine ankle MR imaging; three had undergone additional oblique coronal MR imaging. Surgical proof of a tear was available for three patients. RESULTS: Partial tear was present in four patients, and complete tear was present in five. Partial tears were characterized by heterogeneous signal intensity and thickening of the tendon. Complete tears were characterized by discontinuity of the tendon. Additional findings included fluid in the tendon sheath (n = 6), marrow edema of the lateral calcaneal wall (n = 3), enlarged peroneal tubercle (n = 3), and tear of the peroneus brevis tendon (n = 2). The extent of the tear was better assessed with oblique coronal MR images. CONCLUSION: The characteristic MR imaging appearance of complete or partial tear of the middle portion of the peroneus longus tendon includes foci of increased signal intensity in the distal tendon, morphologic alterations, and/or discontinuity of tendon. Bone marrow edema along the lateral calcaneal wall may be suggestive of the diagnosis. Additional oblique coronal midfoot MR images may help in assessment of the extent of the tear.

Adult↗

Morton's neuroma: is it always symptomatic?

OBJECTIVE: We determined the prevalence of clinically silent Morton's neuroma and searched for distinguishing MR imaging features of Morton's neuroma in patients with clinical complaints related to this entity and in patients with clinically silent lesions. MATERIALS AND METHODS: One radiologist who was unaware of clinical findings retrospectively reviewed 85 consecutive foot MR examinations. MR imaging criteria for Morton's neuroma included a low- to intermediate-signal-intensity soft-tissue mass in the intermetatarsal space. The size, location, and signal intensity of each neuroma and the presence of intermetatarsal bursae were recorded. The patients were subdivided into symptomatic or asymptomatic groups on the basis of the patients' answers on a questionnaire documenting the locations and characteristics of symptoms and discussions with each referring physician about clinical findings. Surgical confirmation was available in eight of 25 symptomatic patients. RESULTS: The prevalence of Morton's neuroma in patients with no clinical evidence of this condition was 33% (19/57). Twenty-five patients had symptomatic Morton's neuroma, 19 had Morton's neuroma based on MR imaging findings with no clinical manifestations, and 41 did not have Morton's neuroma. Slightly larger lesions were observed in the symptomatic group, although significant overlap was noted between the two groups. The mean transverse diameter of symptomatic neuromas was 5.3 mm (standard deviation, 2.14) compared with 4.1 mm (standard deviation, 1.75) for asymptomatic neuromas; this difference was marginally significant (p = 0.05). CONCLUSION: The MR imaging diagnosis of Morton's neuroma does not imply symptomatology. Careful correlation between clinical and MR imaging findings is mandatory before Morton's neuroma is considered clinically relevant.

Adolescent↗

MR imaging of flexor digitorum accessorius longus.

OBJECTIVE: The flexor digitorum accessorius longus muscle (FDAL), an anomalous muscle about the ankle, has recently been implicated in tarsal tunnel syndrome. The purpose of this study is to document the prevalence of the FDAL, its MR appearance and its relation to the neurovascular bundle in the tarsal tunnel. DESIGN AND PATIENTS: The prevalence of the FDAL was determined from 100 ankle MR examinations in asymptomatic individuals. The appearance of the FDAL was summarized from 20 examples of FDAL: six gathered from the asymptomatic group and 14 acquired from a group of randomly collected cases of patients with ankle complaints. RESULTS: The prevalence of the FDAL was 6%, calculated from the group of 100 asymptomatic individuals. Possessing a dominant fleshy component in the tarsal tunnel, the FDAL accompanies the posterior neurovascular bundle as it descends the ankle. CONCLUSION: The FDAL is encountered in 6% of asymptomatic individuals. Its prominent fleshy component in the tarsal tunnel and its close proximity to the posterior tibial neurovascular bundle readily differentiate the FDAL from other medial anomalous muscles on MR imaging.

Adolescent↗

MR imaging in sports injuries of the foot and ankle.

MR imaging has become the diagnostic modality of choice for the evaluation of traumatic ligamentous and tendinous injures of the foot and ankle, occult bony trauma, and osteochondral lesions of the talus. This article reviews the current applications of MR imaging for the evaluation of sports-related injuries of the foot and ankle, including fractures, sprains, tendon injuries, and heel pain.

Ankle Injuries↗

Low incorporation of soleus tendon: a potential diagnostic pitfall on MR imaging.

We describe a case of thickening and longitudinal increased signal within the Achilles tendon in a patient denying any recent or previous history of Achilles tendon injury. The MR appearance, while simulating tendinosis or rupture, was compatible with incomplete incorporation of the soleus tendon into the gastrocnemius tendon. This constitutes a normal anatomical variant, not previously described in the radiologic literature, and should not be confused with increased signal and thickening due to disease of the Achilles tendon.

Achilles Tendon↗