Melorheostosis with an ossified soft tissue mass: MR features.
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Femur↗
Biomedical subjects
D Resnick
Publications and source records attributed to D Resnick.
Desmoplastic fibroma of the calcaneus.
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Adult↗
Glenoid labrum: MR imaging with histologic correlation.
PURPOSE: To document the histopathologic basis of altered intralabral and sublabral signal intensity on magnetic resonance (MR) images. MATERIALS AND METHODS: Ten fresh cadaveric shoulder specimens underwent transaxial MR imaging with T1-weighted, proton-density-weighted, and T2-weighted spin-echo; multiplanar gradient-recalled echo (MPGR); three-dimensional Fourier transform gradient-recalled echo (GRE); spoiled gradient-recalled echo (SPGR); and T1-weighted, fat-suppressed sequences before and after intraarticular injection of gadolinium. Shoulders were then frozen and transversely sectioned, and histologic analysis of the labrum was performed. RESULTS: Altered intralabral signal intensity correlated with fibrovascular tissue, mucoid or eosinophilic degeneration, calcification, ossification, synovial tissue, or combinations of these findings. A sublabral transitional band of intermediate signal intensity correlated with a transitional zone of fibrocartilage. CONCLUSION: There are several causes of altered intralabral signal intensity. A transitional fibrocartilaginous zone correlates with sublabral increased signal intensity. Intraarticular administration of gadolinium improves evaluation of the glenoid labrum.
Aged↗
Distribution of calcification in the triangular fibrocartilage region in 181 patients with calcium pyrophosphate dihydrate crystal deposition disease.
PURPOSE: To investigate the occurrence of calcification around the triangular fibrocartilage complex in calcium pyrophosphate dihydrate (CPPD) crystal deposition disease. MATERIALS AND METHODS: The radiographs of 316 wrists in 181 patients with a definite or probable diagnosis of CPPD disease were reviewed to determine the occurrence of calcification in the inferior radioulnar joint cartilage, triangular fibrocartilage, lunotriquetral ligament, lunotriquetral cartilage, and triquetral cartilage. RESULTS: The distribution of calcification in the 316 wrists was as follows: inferior radioulnar joint cartilage, 87 wrists (28%), triangular fibrocartilage, 233 (74%); lunotriquetral ligament, 244 (77%); lunotriquetral cartilage, 167 (53%); and triquetral cartilage, 66 (21%). Forty-nine wrists had calcification in the lunotriquetral ligament or cartilage but not in the triangular fibrocartilage; 30 wrists had calcification in the triangular fibrocartilage but not in the lunotriquetral ligament or cartilage. This difference in prevalence was statistically significant (P = .0429). CONCLUSION: Radiologic diagnosis of CPPD crystal deposition disease in the wrist necessitates careful evaluation of the lunotriquetral ligament as well as the triangular fibrocartilage.
Aged↗
Complete dislocation of the knee: spectrum of associated soft-tissue injuries depicted by MR imaging.
OBJECTIVE: Complete knee dislocation is a rare injury. The purpose of this study was to evaluate the spectrum of injuries that are depicted by MR imaging in patients with a dislocation of the knee and to determine if there is any predictive factor that might indicate those patients who may be at risk for popliteal nerve injury. MATERIALS AND METHODS: A retrospective search for patients sustaining traumatic knee dislocations who had radiographs and an MR imaging examination of the knee as part of their initial evaluation was done at three level I trauma centers for the period between 1989 and 1993. Each MR examination was independently reviewed by three osteoradiologists for ligamentous, tendinous, meniscal, and osseous injuries. Equivocal diagnoses were decided by consensus. Only patients who underwent surgery were selected. MR imaging findings were confirmed at the time of surgery. Seventeen patients (15 men, two women; age range, 14-62 years; mean age, 29 years) were studied. Motor vehicle accident, fall from a height, a vehicle striking a pedestrian, and football injury were common mechanisms of injury. Posterior dislocation (seven patients) and anterior dislocation (five patients) were the most common injuries. RESULTS: At the time of surgery, all patients had complete tears of the anterior cruciate ligament, 15 had complete tears of the posterior cruciate ligament, nine had complete tears of the medial collateral ligament, and 12 had tears of the fibular collateral ligament (nine tore both the fibular collateral ligament and the biceps femoris tendon). Popliteal tendon tears occurred in eight patients (six complete, two partial). Of the six patients with complete tears of the popliteal tendon, five occurred at the musculotendinous junction; all were the result of either posterior or posterolateral dislocations. Four patients had injuries to the peroneal nerve; three of the four also had tears of the popliteal tendon. On MR imaging, the integrity of the anterior cruciate and lateral collateral ligaments was correctly depicted in all 17 patients; evaluation of the posterior cruciate ligament resulted in one false-positive and one false-negative diagnosis of a tear; evaluation of the medial collateral ligament resulted in one false-positive diagnosis of a tear; and one false-positive diagnosis of a tear occurred with evaluation of the popliteal tendon. CONCLUSION: Knee dislocations cause extensive disruption of the ligaments that stabilize the knee and the surrounding soft-tissue structures, including the popliteal artery. Nearly all will result in disruption of the cruciate ligments and, often, injury of the collateral ligaments. An injury to the popliteal tendon denotes a more severe injury. The mechanism of injury that results in a popliteal tendon tear may also increase the possibility of a peroneal nerve injury. Recognition of this pattern of injuries on MR imaging enables precautionary observation for ischemic changes of the foot to be instituted in patients that otherwise may not be considered at risk for acute vascular compromise.
Adolescent↗
Localization of specific joint causing hindfoot pain: value of injecting local anesthetics into individual joints during arthrography.
OBJECTIVE: The purpose of this study was to evaluate the utility of selective injection of local anesthetic into hindfoot articulations for localizing the source of posttraumatic pain and to compare clinical response with the severity of degenerative change in the various articulations evident on plain radiographs or CT scans. SUBJECTS AND METHODS: Anesthetic arthrography was performed in 18 patients with posttraumatic hindfoot pain. In all, 32 joints were assessed: 15 talocalcaneonavicular, 11 subtalar, five ankle, and one calcaneocuboid. Following intraarticular injection of a mixture of equal amounts of meglumine diatrizoate 60%, lidocaine 1%, and bupivacaine 0.25%, patients were asked to grade the degree of pain relief they experienced on a scale from 0% to 100%. The degree of degenerative changes seen on preliminary radiographs and CT scans was graded blindly and retrospectively by an experienced musculoskeletal radiologist using a 3-point scale (grade 0 indicated a normal joint, grade 1 indicated mild to moderate degenerative change, and grade 2 indicated severe degenerative change). The value of findings on both routine radiographs and CT scans as predictors of the degree of symptomatic relief obtained from specific joint injections was determined. Arthrodesis was performed in nine patients on the basis of the results of anesthetic injections. RESULTS: The degree of pain relief experienced after intraarticular injection of anesthetic correlated with the severity of degenerative change as assessed by routine radiography in 15 of 32 joints and as assessed by CT in eight of 18 joints. In 14 of 32 joints assessed by routine radiography and in seven of 18 joints assessed by CT, the amount of pain relief achieved by anesthetic arthrography was less than that predicted by imaging evidence of degenerative disease. In five of 32 joints judged normal on plain film radiographs, significant pain relief was experienced following anesthetic injection, resulting in a change in the proposed surgical procedure. Long-term follow-up indicated satisfactory results in eight of the nine patients in whom arthrodesis was performed. CONCLUSION: Selective intraarticular anesthetic injections afford a direct method of confirming the site of hindfoot pain and may aid in surgical planning, because plain film radiography or CT may underestimate or poorly indicate the most symptomatic articulations.
Adult↗
Assessment of articular cartilage thickness of the humeral head: MR-anatomic correlation in cadavers.
OBJECTIVE: The purpose of our study was to evaluate several commonly used MR sequences to determine how accurately each demonstrates the thickness of the articular cartilage of the humeral head. MATERIALS AND METHODS: Ten cadaveric shoulders (age at death, 58-92 years; mean, 79 years) were imaged with fat-suppressed transaxial T1-weighted spin-echo three-dimensional gradient-recalled sequences, both before and after injection of 12 ml of diluted gadopentetate dimeglumine. Articular cartilage was measured to the nearest 10th of a millimeter on the MR images and corresponding anatomic sections. RESULTS: Cartilage could not be differentiated from surrounding structures in 14 of 112 locations (13%) on the spin-echo images obtained without contrast material, in 4 of 112 locations (4%) on the spin-echo images obtained with contrast material, in 4 of 112 locations (4%) on the gradient-echo images obtained without contrast material, and in 6 of 112 locations (5%) on the gradient-echo images obtained with contrast material. Mean true cartilage thickness was 1.23 mm (SD, 0.52 mm). The mean MR-anatomic differences (absolute values) were 0.38 mm for the spin-echo images obtained without contrast material, 0.42 mm for the spin-echo images obtained with contrast material, 0.49 mm for the gradient-echo images obtained without contrast material, and 0.37 mm for the gradient-echo images obtained with contrast material. There was a tendency to overestimate thin cartilage and to underestimate thick cartilage. CONCLUSION: Several of the routinely used MR sequences, with and without intraarticular contrast medium, may cause errors in the assessment of the articular cartilage of the humeral head. Some of these errors result from either insufficient contrast between cartilage and surrounding structures or inadequately concentrated contrast medium.
Aged↗
MR arthrography of the hip: improved imaging of the acetabular labrum with histologic correlation in cadavers.
OBJECTIVE: The objective of this study was to correlate findings on conventional MR imaging and MR arthrography of the hip with pathologic findings in cadavers with abnormal labra to determine (1) the efficacy of MR imaging in assessing labral degeneration, (2) whether delineation of the labrum from the joint capsule is possible, and (3) if the conspicuity of surface abnormalities of the labrum is improved by administering intraarticular contrast material. MATERIALS AND METHODS: Twelve cadaveric hip joints were obtained from elderly cadavers. Each hip was examined using fat-suppressed three-dimensional spoiled GRASS (gradient-recalled acquisition in the steady state) (SPGR) imaging and T1-weighted spin-echo imaging before and after intraarticular injection of contrast material. Thirty-six labral sections (three from each hip joint) were evaluated histologically to determine the labral-capsular relationship, the presence of degeneration, and the configuration of the labral base. These findings were correlated with the results of a blinded MR evaluation of these sections. RESULTS: Delineation of the labrum from the adjacent joint capsule was possible on SPGR and T1-weighted MR arthrographic images (34 of 36 and 33 of 36 specimens, respectively), but was not consistently possible on standard SPGR and T1-weighted MR images (7 of 36 and 4 of 36 specimens, respectively). The sensitivities and specificities of the various MR sequences in evaluating labral degeneration varied from 50% to 67%, and from 25% to 94%. Increased signal at the base was common in both the normal (n = 12) and the abnormal (n = 24) labrum. CONCLUSION: Conspicuity of the acetabular labral complex is enhanced with the intraarticular administration of contrast material. Although MR arthrography did not improve our specificity for diagnosing labral degeneration, the detection of surface abnormalities, particularly those near the base, was significantly improved.
Acetabulum↗
[Systemic diseases and blastomas of the foot].
Analysis of roentgenograms by location, pattern of destruction, classification of tumor matrix and periosteal new bone formation, together with clinical data, preserves valuable information for discrimination of neoplasms in the foot. Furthermore, specific information on tumor histology and tumor extension in the bone marrow and soft tissues can be obtained by CT and MRI. Preoperative staging, guided biopsy of tumor tissue, monitoring of chemotherapeutic response and postoperative observation are further indications for MRT and other modern imaging modalities.
Bone Marrow↗
Magnetic resonance imaging of articular cartilage: the state of the art.
Recent advances in the treatment of articular cartilage abnormalities have created a need for an accurate noninvasive imaging method for the evaluation of articular cartilage. Although its role remains undefined in this regard, magnetic resonance imaging (MRI) appears to be the most promising method. We review the current status and possible future directions of MRI of articular cartilage.
Cartilage, Articular↗
Imaging findings in spinal neuroarthropathy.
STUDY DESIGN: The literature is reviewed and five case reports are presented. OBJECTIVE: The objective was to review and emphasize the characteristic magnetic resonance imaging and radiologic findings. SUMMARY OF BACKGROUND DATA: Spinal neuroarthropathy is a destructive process involving the disc space, the adjoining vertebral bodies, and the facet joints that can be induced by traumatic paralysis as well as tabes dorsalis, syringomyelia, and diabetes mellitus. METHODS: Five cases of neuropathic spine in two patients with quadriplegia and three patients with paraplegia from the authors' spinal cord unit were reviewed. RESULTS: On plain radiographs and computed tomography scans, the findings of neuropathic spine were similar to those of disc space infection, severe degenerative disease, and skeletal metastasis. Magnetic resonance imaging, however, showed characteristic hypointensity of signal on T1- and T2-weighted images, which makes it possible to differentiate neuropathic spine and infection. CONCLUSIONS: In neuropathic spine, neuropathic destructive changes in the vertebral bodies lead to fracture, followed by additional changes, including bone sclerosis, large osteophytes, and loss of disc space. A large paraspinal mass develops because of improper fracture healing. At the end stage of this process, a pseudarthrosis may form, as was evident in three of the five patients reviewed.
Adult↗
The type I macrophage scavenger receptor binds to gram-positive bacteria and recognizes lipoteichoic acid.
Macrophage scavenger receptors exhibit unusually broad binding specificity for polyanionic ligands and have been implicated in atherosclerosis and various host defense functions. Using a radiolabeled, secreted form of the type I bovine macrophage scavenger receptor in an in vitro binding assay, we have found that this receptor binds to intact Gram-positive bacteria, including Streptococcus pyogenes, Streptococcus agalactiae, Staphylococcus aureus, Enterococcus hirae, and Listeria monocytogenes. Competition binding studies using purified lipoteichoic acid, an anionic polymer expressed on the surface of most Gram-positive bacteria, show that lipoteichoic acids are scavenger receptor ligands and probably mediate binding of the receptor to Gram-positive bacteria. Lipoteichoic acids, for which no host cell receptors have previously been identified, are implicated in the pathogenesis of septic shock due to Gram-positive bacteria. Scavenger receptors may participate in host defense by clearing lipoteichoic acid and/or intact bacteria from tissues and the circulation during Gram-positive sepsis. Since scavenger receptors have been previously shown to bind to and facilitate bloodstream clearance of Gram-negative bacterial endotoxin (lipopolysaccharide), these receptors may provide a general mechanism for macrophage recognition and internalization of pathogens and their cell surface components.
Animals↗
MR imaging of the accessory soleus muscle appearance in six patients and a review of the literature.
We examined seven ankles with an accessory soleus muscle to determine if the magnetic resonance (MR) imaging features were sufficient to allow accurate diagnosis of this anomalous muscle. We believe that the diagnosis of an accessory soleus muscle is unequivocal with MR imaging on the basis of morphology and signal intensity. Therefore, we suggest that this imaging method should be utilized in patients suspected of having a mass or with persistent swelling in the region of the ankle with or without pain, for the noninvasive diagnosis of this muscle and to better define the regional anatomy presperatively if surgery is being considered for relief of symptoms.
Adolescent↗
The healed Segond fracture: a characteristic residual bone excrescence.
This report describes the natural history of the Segond fracture and documents the radiographic appearance of the healed Segond fracture. The clinical and radiographic records of 129 patients with acute anterior cruciate ligament (ACL) injuries were reviewed. Four (3.1%) of these patients had Segond fractures. On follow-up radiographic examination, seven patients demonstrated a characteristic bone excrescence arising 3-6 mm inferior to the lateral tibial plateau. In four of the five patients for whom acute injury films were available this excrescence arose at the site of the earlier Segond fracture. Healing of such fractures is associated with a characteristic bone excrescence distinct from an osteophyte. This excrescence implies significant internal derangement of the knee.
Adolescent↗
Isolated or dominant lesions of the patella in gout: a report of seven patients.
Isolated or dominant osteolytic lesions of the patella are an unusual manifestation of gout. We present seven patients who had such patellar lesions unilaterally (six patients) or bilaterally (one patient) and analyze the radiologic characteristics to determine whether they can be differentiated from those of other osteolytic lesions of the patella. The lesions were uniformly characterized by a geographic pattern of bone destruction in the superolateral aspect of the patella. Five lesions were each accompanied by a peripatellar soft tissue mass, four of which contained calcification. It therefore appears that an osteolytic lesion of the superolateral portion of the patella, especially when associated with a peripatellar calcified soft tissue mass, should alert one to the possible diagnosis of gout. Awareness of this possibility may obviate the need for invasive diagnostic procedures.
Adult↗
Ossification of the Achilles tendon: imaging abnormalities in 12 patients.
Ossification of the Achilles tendon is a rare clinical entity that is characterized by the presence of an ossific mass contained within the fibrocartilaginous substance of the tendon. Because the radiographic features of this condition have not been documented entirely and the magnetic resonance (MR) imaging findings have not been determined, a review of 16 affected tendons in 12 patients was performed in an attempt to characterize the imaging abnormalities associated with this process. MR imaging was performed in three Achilles tendons which demonstrated thickening of the tendons at the level of the ossifications and a lack of intratendinous signal abnormalities compatible with acute tendinitis. Signal intensity similar to that of bone marrow was present in the ossifications.
Achilles Tendon↗
The MR appearance of cruciate ganglion cysts: a report of 16 cases.
Intra-articular ganglion cysts arising from the cruciate ligaments are unusual lesions, there being only nine previously reported cases. We report 16 cases and describe their MR appearance. Nine ganglia originated from the posterior cruciate ligament, most often appearing as well-defined multilocular lesions. The seven ganglia arising from the anterior cruciate ligament most often appeared as fusiform cystic lesions extending along and interspersed within the fibers of the ligament. Although uncommon, intra-articular ganglion cysts arising from the knee appear to have a distinctive MR appearance which should allow their correct diagnosis.
Adult↗
Meniscal ossicle: MR imaging appearance in three patients.
Meniscal ossicles are rare. Radiographically, these ossicles often are mistaken for intra-articular bodies. We evaluated the application of magnetic resonance imaging to determine whether this technique is efficacious in differentiating meniscal ossicles from intra-articular bodies.
Humans↗