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Biomedical subjects

D Resnick

Publications and source records attributed to D Resnick.

At least 73 records · Page 4Linked to original sources

Contracture of the deltoid muscle: imaging findings in 17 patients.

OBJECTIVE: A retrospective review of the MR images and radiographs of 26 shoulders in 17 patients suffering from contracture of the deltoid muscle was used to establish the characteristic imaging findings. MATERIALS AND METHODS: Deltoid muscle contractures in 26 shoulders in 17 patients encountered over a 4-year period are reported. The history of intramuscular injection and clinical symptoms and signs are detailed. Imaging studies including routine radiographs (24 shoulders), MR images (25 shoulders), and computed arthrotomograms (two shoulders) were reviewed. On MR images, the winging angle of the scapula (angle between the axis of the scapular body and the coronal plane of the chest) and the diameter of the lesion were measured and compared with data derived from 24 age-matched control subjects. RESULTS: Diagnostic MR features of deltoid muscle contracture include fibrotic cord in the deltoid muscle, especially its middle portion, extending from the superior acromial surface to the deltoid tuberosity, and winging of the scapula (increased winging angle of the scapula). Characteristic radiographic features include abduction contracture, winging of the scapula, lateral down-sloping of the acromial process, and a superior acromial enthesophyte. CONCLUSION: MR images are sensitive and accurate in the diagnosis of contracture of the deltoid muscles. Characteristic features also allow accurate routine diagnosis on radiographs.

Arm↗

Evidence of the subperiosteal origin of osteoid osteomas in tubular bones: analysis by CT and MR imaging.

OBJECTIVE: A large series of patients with pathologically proven osteoid osteoma of tubular bones was reviewed to determine the frequency of a subperiosteal site of origin. MATERIALS AND METHODS: Thirty-eight cases that were included met two criteria: the tumor was located in a tubular bone, and the lesion had been evaluated by CT scanning or MR imaging, or both. The location of the osteoid osteoma was categorized as intracortical, sub-periosteal, endosteal, or medullary. RESULTS: Among the 38 cases, 19 were imaged with CT scanning, 14 with MR imaging, and five with both techniques. The most common affected sites were the femur (n = 13), tibia (n = 15), and humerus (n = 4). Among these 38 cases, 18 were intracortical, two were intramedullary, and 18 were subperiosteal. CONCLUSION: Osteoid osteomas occurring in a subperiosteal or surface location are not rare. Indeed, many osteoid osteomas arising in a tubular bone possibly originate in a subperiosteal site and later appear as an intracortical lesion. This site of origin appears to relate principally to continual remodeling of bone with subperiosteal deposition and endosteal erosion.

Adult↗

Detection of ankle effusions: comparison study in cadavers using radiography, sonography, and MR imaging.

OBJECTIVE: The purpose of this study was to compare radiography, sonography, and MR imaging in revealing ankle effusions in cadaveric specimens. MATERIALS AND METHODS: Known quantities of saline solution were instilled in increments into the ankle joints of three cadaveric specimens. Imaging was completed after each injection with the ankle in dorsiflexion, plantar flexion, and a neutral position. Imaging included radiography, sonography, and MR imaging. Three observers who were aware of possible joint fluid evaluated the images by consensus and determined the presence or absence of joint effusion. RESULTS: MR imaging revealed 1 ml of fluid within the anterior recess of the ankle in a neutral position and in plantar flexion and within the posterior recess in dorsiflexion. Sonography revealed 2 ml of fluid within the anterior recess in a neutral position and in plantar flexion. Radiography revealed 5 ml of fluid within the anterior recess in a neutral position. CONCLUSION: MR imaging, sonography, and lateral radiography, in order of decreasing sensitivity, revealed ankle effusion. The power to reveal with each technique is influenced by the precise position of the ankle.

Adipose Tissue↗

MR imaging of tears of discoid lateral menisci.

OBJECTIVE: The purpose of this study was to determine the positive predictive value (PPV) for diagnosis of discoid lateral meniscal tear using MR imaging and to describe various patterns of such tears in the knee. SUBJECTS AND METHODS: MR reports of 77 patients (10-67 years old) who underwent prospective MR imaging that led to a diagnosis of discoid lateral meniscal tear were correlated with arthroscopic results. MR images obtained in 71 patients confirmed to have discoid lateral meniscial tear were retrospectively reviewed for the presence, site, and pattern of discoid lateral meniscal tear, including type of displacement of the torn segment. MR abnormalities were correlated with arthroscopic findings. RESULTS: For the prospective MR interpretations, the PPV for discoid meniscus was 92%. PPV for discoid meniscal tear was 57%. PPVs for individual types of discoid meniscal tears were 46% (peripheral tear, 19/41), 76% (peripheral tear with horizontal tears, 16/21), 56% (horizontal tear, 5/9), 50% (transverse tear, 1/2), 67% (horizontal tear combined with transverse tear, 2/3), and 100% (longitudinal tear, 1/1). Peripheral tear alone and peripheral tear with horizontal tear were the most common types of tears (n = 20, 28%). Multiple tears (n = 34, 48%) were common. Displacement of the torn segments was seen in 51 patients (72%). CONCLUSION: MR imaging has a low PPV for diagnosing discoid lateral meniscal tear. Peripheral tear alone and peripheral tear with horizontal tear were the most common types of tears, and displacement of the torn segment was frequent.

Adult↗

Normal and abnormal medial meniscocapsular structures: MR imaging and sonography in cadavers.

OBJECTIVE: The purpose of this study was to develop imaging criteria for the diagnosis of meniscocapsular separation by correlating findings on MR imaging, MR arthrography, and sonography of normal and abnormal medial meniscocapsular structures with corresponding anatomic sections in cadavers. MATERIALS AND METHODS: Eight cadaveric knee specimens were examined with MR imaging, MR arthrography, and sonography before arthroscopy. In six specimens the following lesions were arthroscopically created: meniscocapsular separation (n = 3), medial collateral ligament (MCL) tear (n = 3), tear of the meniscofemoral extension of the deep MCL (n = 2), and coronary ligament tear (n = 2). After arthroscopy, all imaging studies were repeated. The specimens were sectioned for correlation with imaging studies. RESULTS: MR findings that correlated with meniscocapsular separation were interposition of fluid between the meniscus and the MCL, irregular meniscal outline, and increased distance between the meniscus and the MCL. On MR arthrography meniscocapsular separation correlated with interposition of contrast medium between the meniscus and the MCL. Tears of the meniscofemoral extension of the deep MCL were best shown on MR arthrography. Sonography showed deep and superficial MCL lesions but did not show meniscocapsular separations. CONCLUSION: In arthroscopically created meniscocapsular separation, the lesion is suggested on MR images when fluid is interposed between the meniscus and the MCL, when the meniscal outline is irregular, or when the distance between the meniscus and the MCL is increased. On MR arthrograms, a meniscocapsular separation is suggested when contrast medium is interposed between the meniscus and the MCL. Sonography does not allow accurate diagnosis of meniscocapsular separation.

Cadaver↗

Anterior labroligamentous structures of the glenohumeral joint: correlation of MR arthrography and anatomic dissection in cadavers.

OBJECTIVE: The purpose of this study was to establish the accuracy of MR arthrography in depicting the morphology of the glenohumeral ligaments and the superior portion of the glenoid labrum. MATERIALS AND METHODS: Findings on MR arthrography and those derived from careful dissection of gross specimens were compared in 15 cadaver shoulders, focusing on the morphology and size of the superior and middle glenohumeral ligaments and the morphology of the inferior glenohumeral ligament. The frequencies of sublabral recess and sublabral foramen seen on MR arthrography and at anatomic dissection were also compared. RESULTS: For the superior and middle glenohumeral ligaments, moderate correlation of size was found between measurements made on MR arthrograms and at anatomic dissection, with the Spearman's rank correlation coefficient calculated as .69990 and .71133, respectively. Morphologic descriptions of the inferior glenohumeral ligament based on MR arthrography and on anatomic dissection also showed good association (Cohen's kappa = .8936). Dissection revealed that the sublabral recess was present in 11 specimens. Of these, 10 recesses were identified on MR arthrograms. MR arthrography also revealed a sublabral recess that was not found at dissection. Four sublabral foramina were identified by both MR arthrography and dissection, and two were revealed only by MR arthrography. CONCLUSION: MR arthrography is useful in the evaluation of the glenohumeral ligaments and the superior portion of the labrum. Anatomic variations of these anterior intraarticular structures can be accurately shown by MR arthrography. In addition, estimation of the size of glenohumeral ligaments can be achieved with acceptable accuracy on MR arthrograms.

Aged↗

Classification system based on kinematic MR imaging in cervical spondylitic myelopathy.

BACKGROUND AND PURPOSE: Functional myelographic studies are often used to evaluate the dynamic changes of the cervical spinal canal during flexion and extension. The purposes of this study were to use kinematic MR imaging to assess the dynamic changes of the cervical spine in patients at different stages of degenerative disease and to describe a classification system based on static and dynamic factors in the pathogenesis of cervical spondylitic myelopathy. METHODS: Eighty-one patients with different stages (I-IV) of degenerative disease of the cervical spine were examined with MR imaging. In the neutral position (0 degrees) and at maximum flexion and extension, spinal stenosis was classified for each segment according to the following grading system: 0 = normal, 1 = partial obliteration of the anterior or posterior subarachnoid space, 2 = complete obliteration of the anterior or posterior subarachnoid space, and 3 = cervical cord compression or displacement. RESULTS: At flexion and extension, the prevalence of spinal stenosis and cervical cord impingement increased as the stage of degenerative disease progressed. With regard to a pincer effect (anterior and posterior cord impingement) and cord encroachment at multiple segments, statistically significant differences were observed at stages III and IV as compared with stages I and II. Significant increase in cord impingement was seen in 22 (27%) of 81 patients at extension, as compared with four (5%) of 81 patients at flexion. CONCLUSION: Regardless of the stage of degenerative disease and grade of spinal stenosis at the neutral position (0 degrees), cervical spinal motion may contribute to the development of cervical spondylitic myelopathy.

Adult↗

Magnetic resonance imaging of articular cartilage: an overview.

MR imaging is the best noninvasive method for the evaluation of articular cartilage. Recent studies have clarified the MR appearance of normal articular cartilage and proven that MR imaging can detect chondral lesions with high accuracy. Quantitative imaging holds promise for the accurate determination of cartilage volumes and thickness measurements, as well as the ability to detect early chondral degeneration and biochemical changes before gross morphologic changes occur.

Cartilage, Articular↗

Magnetic resonance imaging of knee cartilage repair.

Cartilage injury resulting in osteoarthritis is a frequent cause of disability in young people. Osteoarthritis, based on either cartilage injury or degeneration, is a leading cause of disability in the United States. Over the last several decades, much progress has been made in understanding cartilage injury and repair. Magnetic resonance (MR) imaging, with its unique ability to noninvasively image and characterize soft tissue, has shown promise in assessment of cartilage integrity. In addition to standard MR imaging methods, MR imaging contrast mechanisms under development may reveal detailed information regarding the physiology and morphology of cartilage. MR imaging will play a crucial role in assessing the success or failure of therapies for cartilage injury and degeneration.

Cartilage, Articular↗

Paraplegia due to ossification of ligamenta flava in X-linked hypophosphatemia. A case report.

STUDY DESIGN: Spinal canal decompression at the most prominent of multiple posterior calcified thoracic lesions in a case of X-linked hypophosphatemia was undertaken for treatment and diagnosis purposes, as well as to assess possible nature of the pathophysiology underlying the presenting deficits. OBJECTIVES: To discuss the clinical assessment diagnostic and treatment aspects of this rare coincidence of ossification of ligamenta flava in the patient with the skeletal deformities of X-linked hypophosphatemia. SUMMARY OF BACKGROUND DATA: The patient with the stigmata and chemical findings of an X-linked hypophosphatemia presented with paraplegia and multiple calcified posterior spinal thoracic lesions. This was studied with magnetic resonance imaging and electrophysiologic studies of the spinal sensory pathways of the legs. These data constituted the preoperative information required to assess later results of surgical intervention. METHODS: Presurgical clinical, imaging and electrophysiologic studies and laboratory and pathologic investigations of the surgical specimens. RESULTS: Resolution of the paraplegia with walking and return to work in a physically demanding job for the last 4 or 5 years of postoperative follow-up after surgical decompression of the spinal cord only at the worst and highest of the effected spinal levels. CONCLUSION: The coincidence of X-linked hypophosphatemia and ossification of ligamenta flava has been reported only in two or three cases in the literature. Removal of the offending ossifying lesion is known to result in resolution of the clinical deficits but similar lesions at other spinal levels are suspected of producing recurrences. The return of function and of the corresponding electrophysiologic correlates indicate a neurono-apractic nature of the neurologic symptoms.

Bone and Bones↗

Gorham syndrome of the thorax and cervical spine: CT and MRI findings.

Gorham syndrome is a rare disorder that is characterized by local osseous invasion and surrounding soft tissues by an angiomatous mass, eventually causing lysis of the affected bone. To date, only four cases have reported the MR imaging appearance of this disease and the findings have been variable. We present a case involving the cervical and thoracic spine and part of the osseous hemithorax with attention to the MR findings.

Angiomatosis↗

Ischemic necrosis of the entire femoral head and rapidly destructive hip disease: potential causative relationship.

OBJECTIVE: Rapidly destructive hip disease (RDHD) is an uncommon disorder of the hip that has been considered a disease of unknown cause and distinct from ischemic necrosis of the femoral head. The objective of this study was to investigate ischemic necrosis of the femoral head as one potential cause of RDHD. DESIGN AND PATIENTS: In 600 patients who underwent MR imaging of the hip, 20 cases of ischemic necrosis involving the entire femoral head in 18 patients (3%) were retrospectively studied with routine radiography and MR imaging. All patients had surgically confirmed ischemic necrosis of the femoral head. RESULTS AND CONCLUSIONS: All patients showed rapid destruction of the femoral head on routine radiography and MR imaging as compared with the gradual onset of clinical symptoms. Plain radiographs showed several bone fragments at the inferomedial aspect of the femoral head (75%), acetabular erosions (55%), eccentric depression at the lateral articular surface of the femoral head conforming to the adjacent acetabulum (35%), and mild osteoarthritis (15%). Bone sclerosis was often present at sites of impaction between the femoral head and the acetabulum. MR imaging showed marked distention of the joint capsule in all cases. In 14 of 20 cases, the contents of the joint space showed predominantly low or intermediate signal intensity on T1- and T2-weighted images. Ischemic necrosis involving the entire femoral head may represent one of the causes of RDHD.

Adult↗

Fibrolipomatous hamartoma: MR imaging findings.

OBJECTIVE: To analyze the MR imaging features of fibrolipomatous hamartoma (FLH) of nerves. DESIGN AND PATIENTS: MR imaging studies from six patients (three men and three women) were retrospectively reviewed by three musculoskeletal radiologists. In four patients, a biopsy of the nerve lesion was performed. In two patients, biopsy data were unavailable and the diagnosis was based on the clinical history combined with the MR imaging findings. RESULTS AND CONCLUSION: MR imaging demonstrated fusiform nerve enlargement that was caused by fatty proliferation and thickening of nerve bundles. Nerve bundles appeared as serpentine tubular structures, hypointense on both T1- and T2-weighted images. The degree of fatty proliferation varied among patients. In addition, significant variation in the distribution of fat along the course of the nerves was noted. In three patients, FLH followed the branching pattern of the nerves, a characteristic pathologic finding. In two patients, intramuscular fat deposition (biceps and tibialis posterior muscles) was present. MR imaging findings of FLH are typical, allowing a confident diagnosis. The variation of fatty proliferation among patients and involved nerves as well as the tendency of the abnormalities to follow the branching pattern of the nerves is well demonstrated with MR imaging. FLH may present as an isolated nerve lesion, may be associated with intramuscular fat deposition, or may occur as a feature of macrodystrophia lipomatosa (MDL).

Adult↗

Hemophilic pseudotumor: spectrum of MR findings.

OBJECTIVE: To determine the MR imaging appearance of hemophilic pseudotumor (HP) and its clinical implications. DESIGN AND PATIENTS: Five hemophilic patients (aged 35-77 years) with 12 HPs in various anatomic locations were included in this study. The MR images were retrospectively evaluated for the appearance of the lesions and accompanying abnormalities, as well as their clinical implications. RESULTS AND CONCLUSION: MR images of all five patients (12 lesions) showed well-defined masses containing blood clots in various stages of organization surrounded by a fibrous capsule in subcutaneous fat or in intramuscular, interfascial, subperiosteal, and intraosseous locations. Intramuscular HP frequently had mural nodules. This is an almost unique appearance that is somewhat unexpected. MR imaging allowed determination of number, size, and extent of the lesions, evidence of neurovascular involvement, and accompanying musculoskeletal alterations. It is concluded that MR imaging not only is a sensitive and accurate method for detecting and diagnosing HP and providing useful information for therapeutic decision making, but can also be used to assess results of treatment by allowing evaluation of the evolution of blood products, the size of lesions in regions difficult to access by physical examination, and recurrent bleeding within a chronic lesion.

Adult↗