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Biomedical subjects

D Resnick

Publications and source records attributed to D Resnick.

At least 199 records · Page 11Linked to original sources

Gamekeeper thumb: differentiation of nondisplaced and displaced tears of the ulnar collateral ligament with MR imaging. Work in progress.

Ulnar collateral ligament (UCL) injury of the first metacarpophalangeal joint (gamekeeper thumb) is common. If the UCL becomes displaced superficially to the adductor pollicis aponeurosis, surgical treatment has been advocated. Radiography cannot help differentiate between displaced and nondisplaced tears. The authors investigated the use of magnetic resonance (MR) imaging in the evaluation of UCL injury. Ten displaced and six nondisplaced UCL tears were surgically created in 16 nonembalmed cadaveric specimens. Twelve unaltered specimens served as controls. Coronal MR images were obtained and interpreted by two observers. The MR images were compared with corresponding anatomic slices. MR imaging depicted UCL displacement in all 10 specimens with displaced tears. A displaced tear was interpreted in one control specimen. Non-displaced tears were diagnosed in four control specimens. Although MR imaging was only 67% specific for all tears, it was 100% sensitive and 94% specific for depicting UCL displacement and, therefore, may be useful for evaluating gamekeeper thumb.

Adult↗

Patterns of vertebral ossification and pelvic abnormalities in paralysis: a study of 200 patients.

To clarify the characteristics, extent, and frequency of spinal ossification and abnormalities of the sacroiliac joint, symphysis pubis, and hip in paralysis, routine radiographs of the lumbar spine, pelvis, and abdomen were retrospectively evaluated in 95 quadriplegic, 105 paraplegic, and 100 age-matched control patients, with attention to age and race and to spinal level and duration of paralysis. The spinal radiographs were evaluated for presence of osteophytes, syndesmophytes, paravertebral ossification, and flowing hyperostosis characteristic of diffuse idiopathic skeletal hyperostosis (DISH); the pelvic radiographs were used to measure the widths of the sacroiliac joint, hip, and symphysis pubis articulations and evaluate for presence of enthesopathy. Bone formation around vertebral bodies was often seen in quadriplegic (n = 41 [43%]) and paraplegic (n = 46 [44%]) patients. In quadriplegic patients, four distinct vertebral ossification patterns were evident: osteophytosis, paraspinal ossification resembling that found in psoriasis, syndesmophytosis, and flowing ossification similar to that in DISH. In paraplegic patients, osteophytosis was most frequent. Vertebral ossification in quadriplegic patients was significantly associated with age (P < .01) and increased in frequency and severity with increasing age.

Adult↗

Diagnosis of osteomyelitis: utility of fat-suppressed contrast-enhanced MR imaging.

PURPOSE: To assess the value of fat-suppressed contrast material-enhanced magnetic resonance (MR) imaging in the diagnosis of osteomyelitis. MATERIALS AND METHODS: T1- and T2-weighted MR imaging was performed in 51 cases of suspected osteomyelitis. Nonenhanced and contrast-enhanced T1-weighted fat-suppressed MR images were also obtained. Three-phase bone scan results were available for 30 cases. Complicating clinical factors, including chronic osteomyelitis (n = 26), postoperative state (n = 17), and neuropathic disease of the foot (n = 5), were identified in 73% of cases. RESULTS: In the diagnosis of osteomyelitis, scintigraphy demonstrated a sensitivity of 61% and specificity of 33%. For nonenhanced MR imaging, sensitivity was 79% and specificity was 53%. For fat-suppressed contrast-enhanced imaging, sensitivity was 88% and specificity was 93%. CONCLUSION: In diagnosing osteomyelitis in patients with complicating clinical factors, fat-suppressed contrast-enhanced MR imaging was significantly more sensitive than scintigraphy (P = .04) and significantly more specific than nonenhanced MR imaging (P = .02) or scintigraphy (P = .008).

Adipose Tissue↗

MR imaging of the knee: can changes in the intracapsular fat pads be used as a sign of synovial proliferation in the presence of an effusion?

OBJECTIVE: Synovial proliferation is difficult to detect on MR images when joint effusions are present. The objective of this study was to assess the efficacy of MR changes in intracapsular fat pads (prefemoral, quadriceps, Hoffa's) as a sign of synovial proliferation in patients with knee effusions. MATERIALS AND METHODS: MR images were obtained in 70 patients with knee effusions. An effusion was considered present if the suprapatellar bursa was distended 1 cm in anterior to posterior diameter on T2-weighted sagittal images. The experimental group consisted of 32 patients with proliferative effusions (effusions associated with synovial proliferation) diagnosed on the basis of histologic or microbiologic data or strict rheumatologic criteria. This group comprised 11 patients with pigmented villonodular synovitis, six with rheumatoid arthritis, one with psoriatic arthritis, three with hemosideric arthritis, and 11 with septic arthritis. The control group comprised 38 subjects with knee effusions who had no arthroscopic evidence of synovial proliferation. After determining the MR criteria of proliferative effusion, two observers who had no knowledge of these cases evaluated abnormalities of the intracapsular fat pads seen on sagittal intermediate-weighted midline MR images. RESULTS: Characteristic changes in the fat pads were noted on MR images in patients with proliferative synovial effusions. Scalloping or truncation of the prefemoral fat pad was 77% sensitive and 95% specific as a predictor of proliferative effusion. Defects and displacement of Hoffa's fat pad had a sensitivity of 57% and a specificity of 99%, and nonvisualization or irregular margins of the quadriceps fat pad had a sensitivity of 61% and a specificity of 100%. CONCLUSION: Characteristic changes in intracapsular fat pads seen on MR images of patients with proliferative effusions can help distinguish these patients from those with effusions without synovial proliferation.

Adipose Tissue↗

Normal regional anatomy of the shoulder.

The shoulder joint is a remarkable structure enjoying a greater range of motion than any other articulation in the human body. The shoulder is not a single joint but actually four separate articulations that act synergistically. The authors review the complex anatomy of the shoulder.

Humans↗

Hyperostosis of ribs: association with vertebral ossification.

OBJECTIVE: Costal hyperostosis occurring with vertebral disorders, although not well known, has been described in patients with diffuse idiopathic skeletal hyperostosis (DISH). Our purpose was to examine the possible association of similar hyperostosis in other spinal conditions. METHODS: We investigated the frequency of hyperostotic rib changes on routine radiographs in 191 patients with various spinal disorders, including DISH (51 cases), ankylosing spondylitis (AS) (58 cases), psoriasis (21 cases) and quadriplegia (61 cases), and in a healthy control group (191 cases). RESULTS: Results showed that the frequency of rib hyperostosis was significantly higher in DISH (21.6%), AS (10.3%) and quadriplegia (6.6%) than in the healthy control group (0.5%). There was no significant difference in the frequency of right and left-sided involvement. The main radiographic features were a short segment of cortical thickening and sclerosis, which predominated in the medial aspect of the posterior portion of the rib. Some patients had a long segment of bone enlargement and extensive sclerosis. The resulting radiographic features simulated the appearance of Paget's disease. Osseous excrescences of adjacent costovertebral articulations were significantly related to the rib hyperostosis, seen in 73% of instances of rib involvement. CONCLUSION: Our observations suggest that diseases that lead to bone formation and resultant hypomobility of costovertebral articulations are associated with rib hyperostosis.

Adult↗

Calcium pyrophosphate dihydrate crystal deposition disease and pseudogout of the acromioclavicular joint: radiographic and pathologic features.

OBJECTIVE: To correlate the radiographic and pathologic findings in calcium pyrophosphate dihydrate (CPPD) crystal deposition disease and the pseudogout syndrome in the acromioclavicular (AC) joint, a relatively infrequent, but clinically important site. METHODS: We describe a case with a definite diagnosis of CPPD crystal deposition leading to pseudogout of the AC joint. We also identified 17 other patients with CPPD crystal deposition disease who showed intraarticular or periarticular calcification in this joint and investigated the radiographic findings in 26 AC joints in these 17 patients. We then correlated the results with the pathologic findings in 2 cadavers with AC joint manifestations of the disease. RESULTS: Intradiscal calcification, mainly linear or punctate in configuration, was found between adjacent bony margins in 9 of 26 AC joints (35%) or between the bony margins and extending above the upper articular bony margin in 14 AC joints (54%). Two joints (8%) showed diffuse calcification within the discs between, above, and below the articular bony margins. The remaining joint (3%) had intradiscal calcification only above the upper bony margins of the AC joint. All the joints with calcifications above the articular margins had associated globular or tumor-like soft tissue masses. A pseudogout attack at the AC joint may have nonspecific shoulder pain as its presenting symptom. CONCLUSION: CPPD crystal deposition disease leading to pseudogout syndrome of the AC joint is a clinically significant condition. We emphasize that careful assessment of the AC joint and adjacent soft tissue using intensive bright light on routine shoulder radiographs may increase the sensitivity of detecting discal and capsular calcifications in patients with pseudogout of the shoulder.

Acromioclavicular Joint↗

Imaging methods for assessment of pedal soft-tissue neoplasms.

The advent of cross-sectional, tissue-specific, noninvasive multiplanar imaging methods has enabled the radiologist to probe the etiopathogenesis of soft-tissue lesions of the foot to greater advantage than in the past. High-resolution, high-contrast images are now available so that a wide variety of conditions may be explored, resulting in accurate compartmental localization and assessment of both adjacent tissue as well as vascular invasion and distant metastasis.

Diagnostic Imaging↗

Advanced diagnostic imaging techniques for pedal osseous neoplasms.

It is a widely held view that the initial evaluation of foot and ankle osseous tumors and tumor-like lesions begins with the conventional radiograph. It is equally recognized that musculoskeletal radiology has undergone a veritable revolution in the last few decades, as it continues to experience refinements that allow increased sensitivity of anatomic localization, specificity of pathologic tissue characterization, and hence greater insight into the subsequent therapeutic maneuvers that may significantly affect case management and survival outcomes of more aggressive disease processes. This article discusses the basics of various imaging modalities and applies these principles to a number of examples of osseous tumors with the hope that podiatrists, orthopedists, radiologists, and others might develop an approach to selecting the most appropriate diagnostic study, as well as an increased awareness of the appearance of some of the entities that these specialists might encounter in routine practice.

Bone Neoplasms↗

Degenerative changes of the menisci of the knee. Value of different MR pulse sequences.

Increased meniscal MR signal attributable to meniscal degeneration is a common finding. The role of different MR sequences in the analysis of the extent and distribution of meniscal degeneration in middle-aged and elderly patients has not been thoroughly evaluated. We retrospectively studied the role of different MR sequences in 175 anatomic meniscal sections originating from 20 freshly frozen knees from 10 cadavers using MR-anatomic correlation. T1-weighted and proton-density spin-echo images as well as postprocessed meniscal windows based on T1-weighted spin-echo images proved to be the most reliable in this diagnosis (53.7%, 54.9%, and 53.1% correctly diagnosed meniscal sections, respectively). T2-weighted spin-echo images and gradient-echo images proved to be less reliable (37.1% and 40.0% correctly diagnosed meniscal sections). While the T2-weighted spin-echo images commonly underestimated the extent of meniscal degeneration, gradient-echo images commonly overestimated the extent of such changes. These last two types of sequences should not be used alone in the description of meniscal degeneration.

Aged↗

Fracture-dislocation of the elbow with inferior radioulnar dislocation: a variant of the Essex-Lopresti injury.

We describe two patients with an Essex-Lopresti fracture dislocation in association with a dislocation of the elbow. This combination of injuries has not been previously reported. The Essex-Lopresti fracture is a rare injury, and the associated distal radioulnar dislocation is often missed. Meticulous radiographic evaluation of the wrist, including dynamic stress radiographs of the forearm, can lead to an earlier diagnosis and improved care of these patients.

Adult↗

Bone excrescence at the medial base of the distal phalanx of the first toe: normal variant, reactive change, or neoplasia?

In a review of 157 anteroposterior (AP) foot radiographs in 117 adult and pediatric patients, we observed a medial excrescence on the plantar aspect of the terminal phalanx of the hallux in 88.5% of the feet. Histologic analysis documented the presence of reactive bone. The bony outgrowth appears after closure of the adjacent physeal plate and is rarely symptomatic. Its high prevalence indirectly implies that it is not specific to any particular type of foot. Although certain types of foot may contribute to its development, we believe that repetitive forces occurring during ambulation induce this reactive bone formation.

Adipose Tissue↗

Osteoma of soft parts.

Osteomas of soft tissue are rare tumors. All previously reported cases occurred in the head, usually in the posterior tongue. We present two patients with soft-tissue osteomas in the thigh. Both masses were densely ossified and consisted of mature trabecular bone on computed tomography and magnetic resonance examination. Increased uptake of bone-seeking radiopharmaceutical was found on scintigraphy. Histologically, mature lamellar bone was seen with small amounts of cartilage seen in the periphery. Symptoms of mass effect which resolved following surgery were noted. We believe that this previously unrecognized soft-tissue appendicular neoplasm lies at the end of a spectrum of post-traumatic ossifying lesions which includes soft-tissue chondromas and osteochondromas, as well as myositis ossificans.

Aged↗

Case report 713. Chondromyxoid fibroma of the third metatarsal.

In the case presented, the imaging features are those of an aggressive benign or less aggressive malignant lesion. The differential diagnosis radiographically included aneurysmal bone cyst with or without an accompanying lesion, giant cell tumor synovial sarcoma, and other mesenchymal sarcomas. Indeed, at times it is difficult to be certain whether the process originated in the bone or soft tissue. Pathological examination of the resected specimen showed the typical features of chondromyxoid fibroma. Grossly, the tumor was well demarcated and firm and composed of tan, translucent tissue that destroyed cortex but was confirmed by periosteum. Histologically, the tumor consisted of myxoid, chondroid, and fibrous elements. The tumor lobules were composed of predominately myxoid matrix containing stellate cells. Variable chondroid elements were present with immature appearing chondrocytes, containing eosinophilic cytoplasm and irregularly shaped nuclei.

Adult↗

Magnetic resonance imaging in assessing cartilage changes in experimental osteoarthrosis of the knee.

Cartilage degeneration in osteoarthrosis (OA) of the knee generally is believed to precede osseous abnormalities. Because cartilage abnormalities are not readily detected by routine radiography, we investigated the role of magnetic resonance imaging (MRI) in assessing cartilage damage in a goat model for OA. Four goats had the anterior cruciate ligament of one knee severed surgically to create instability and accelerate OA. Two goats each were killed at 4 and 6 weeks, respectively, after walking on the unstable knees. MRI of the knees was performed with Hybrid fat suppression sequences. The images were correlated with gross anatomic sections and histologic analysis of the knees. On gross examination, the unstable knees showed rapid development of thinning, surface irregularity, and focal defects of the cartilage. These findings correlated well with abnormalities detected on the MRIs. In addition, areas of decreased signal intensity in cartilage correlated with histologic evidence of degenerative changes in the cartilage substance, including fragmentation, fibrillary and eosinophilic changes, and chondrocyte proliferation, indicating attempted cartilage repair. Precise correlation of pathologic and MRI data, however, was lacking, related in part to inability to match perfectly the level and orientation of the gross section with that on the MRI examination.

Animals↗