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Biomedical subjects

F Feldman

Publications and source records attributed to F Feldman.

At least 37 records · Page 2Linked to original sources

Patellar height on sagittal MR imaging of the knee.

OBJECTIVE: The aim of this study was to determine if the radiographic assessment of patella alta using the patellar tendon:patella ratio can be applied to sagittal MR images of the knee. MATERIALS AND METHODS: Sagittal T1-weighted MR images of 46 knees were reviewed with corresponding radiographs. After lengths of the patella and patellar tendon were measured on the lateral radiographs and on the sagittal mid patellar images, the tendon:patella ratios were calculated. RESULTS: We found the mean tendon:patella ratio on radiographs to be 1.0 +/- 0.2 (SD) and on MR imaging, 1.1 +/- 0.1. These two values were not significantly different (p = .01) and had good-to-excellent correlation (r = .7). We found no statistical difference between the sexes on either radiographs or MR imaging, nor did we find statistical differences on MR imaging between the tendon:patella ratios of straight and wavy patellar tendons. CONCLUSION: As on radiographs, patellar height can be reliably assessed on sagittal MR imaging using the patellar tendon:patella ratio. On sagittal MR imaging, patella alta is suggested at values greater than 1.3 (1.1 + 2 SD).

Adult↗

The symptomatic accessory tarsal navicular bone: assessment with MR imaging.

PURPOSE: To determine if a symptomatic accessory navicular bone, a normal variant, displays a pattern of altered signal intensity on magnetic resonance (MR) images indicative of an abnormality that could account for the patient's foot pain. MATERIALS AND METHODS: Both feet were imaged in seven patients with an accessory navicular bone on radiographs and unilateral foot pain. Five patients had focal medial foot pain, and two had vague, diffuse pain. T1-weighted spin-echo and T2-weighted fat-suppressed sequences were used. RESULTS: A bone marrow edema pattern (BMEP) was noted in the accessory navicular bones of the five patients with focal pain and in the adjacent navicular tuberosities of three of them. The two patients with vague pain showed no osseous or soft-tissue abnormalities. Two patients with positive MR images underwent surgical excision of the accessory navicular bone, and histologic examination revealed osteonecrosis in one patient. CONCLUSION: The BMEP in a symptomatic accessory navicular bone is indicative of chronic stress and/or osteonecrosis. This information can furnish an objective basis for surgical or conservative management.

Adult↗

Improved safety from plasma derivatives: purification and viral elimination characteristics of mononine.

The occurrence of viral transmission with coagulation factor concentrates treated with a single virus elimination step has resulted in a consensus that multiple virus elimination steps must be incorporated in the processing of these proteins. As an example of this methodology, the steps included in the purification of the factor VIII concentrate Monoclate-P are reviewed and those used to purify the factor IX concentrate Mononine--monoclonal antibody chromatography, sodium thiocyanate incubation, and a novel ultrafiltration system--are described. Rigorous quality control/quality assurance during processing is essential. The ultimate safety of the product used clinically further requires monitoring of long-term stability and verification of the absence of neoantigens that could stimulate unusual levels of antibody formation. Standardization of regulatory compliance will further strengthen the safety of all products. The zeal to add further barriers to viral contamination should not compromise the timely assessment of these additional protections.

Antibodies, Monoclonal↗

Value of the coronal plane in MRI of internal derangement of the knee.

Sagittal images usually receive the most scrutiny in the magnetic resonance evaluation of meniscal and anterior cruciate ligament tears. We assessed the relative contribution of the coronal view. All knee magnetic resonance examinations performed over a 2-year period that had surgical confirmation were reviewed with respect to the presence of meniscal and anterior cruciate ligament tears. The appearance of an attenuated but uninterrupted anterior cruciate ligament was also evaluated. The coronal and sagittal plane images were evaluated separately. The study included 68 medial menisci, 67 lateral menisci, and 71 anterior cruciate ligaments. The coronal view is especially useful in the evaluation of the lateral meniscus. An anterior cruciate ligament that appears attennated but uninterrupted should be considered intact. The anterior cruciate ligament may be evaluated on the coronal view. The coronal view should be regarded as similar to the lateral chest radiograph, which supplements, but does not replace, the frontal chest radiograph.

Anterior Cruciate Ligament↗

Magnetic resonance imaging of occult fractures of the proximal femur.

The evaluation of the painful hip in the elderly osteoporotic patient with normal plain radiographs can be difficult. We studied 15 osteopenic patients with normal plain radiographs and suspected hip fractures with magnetic resonance (MR) imaging and found MR to be an excellent aid in detecting occult fractures. A clear fracture was seen in 10 of the 15 patients, who then underwent surgical repair based on the MR study. The remaining patients had no MR-demonstrable fracture and were successfully treated nonoperatively. Some believe that a negative bone scan in this population of patients should be repeated within 3 days prior to a definitive "no fracture" decision being made. Unfortunately, bone scanning lacks spatial resolution, and increased osteoblastic activity may be caused by other pathologic processes besides fracture. Two of the 15 patients had MR-demonstrated bone infarcts near the fracture. One patient also had femoral head osteonecrosis on the side of the fracture. One patient with metastatic prostatic carcinoma had a hip fracture and one patient with metastatic breast carcinoma had no fracture. No only is MR imaging an excellent technique for delineating occult fractures, but due to its spatial resolution, associated bone disorders adjacent to fractures can be detected in most instances. From a cost perspective, rapid diagnosis and early treatment of an occult femoral fracture is advisable. A reduced hospital stay pending diagnosis and the early institution of definitive therapy also decrease the chance that a simple non-displaced fracture will displace and require more complex management with resultant increased morbidity and cost.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

MR imaging: its role in detecting occult fractures.

Magnetic resonance (MR) studies were performed on 30 consecutive patients who continued to be symptomatic despite negative or inconclusive findings on radiographs and other imaging studies including radionuclide bone scans, computed tomography, and/or polytomography. There were 9 men and 21 women, 20-92 years old (mean age 63 years) whose MR studies were done 3-72 h after frank trauma in 22 cases and in another 8 after 1-4 weeks of increasing pain subsequently attributed to trauma or unaccustomed effort. MR studies were performed using 0.5-T (Phillips) or 1.5-T (Phillips, GE) superconductive magnets. Results indicated that: (1) MR images allowed identification of acute fractures in an emergency room setting, as well as subtle subacute or chronic fractures in the context of strong clinical suspicions despite negative or inconclusive radiographs and other subsequently indecisive imaging studies. (2) MR imaging is the most sensitive way of documenting the earliest changes in traumatized osseous and soft tissue structures simultaneously.

Adult↗

Coraco-clavicular joint: normal variant in humans. A radiographic demonstration in the human and non-human primate.

The coraco-clavicular joint is a true synovial joint that may become painful in some patients after trauma. Among the descriptions of this entity is the assertion that the coraco-clavicular joint is routinely seen in gorillas and gibbons. We undertook to assess the incidence of this variant among gorillas, gibbons, and other non-human primates. All available radiographs of large primates performed at the International Wildlife Conservation Park/Bronx Zoo (IWCP) over the past 10 years were reviewed by a musculoskeletal radiologist (human radiology). All radiographs were taken during the normal clinical care of the non-human primate population of the IWCP and are a part of each animal's clinical record. Eighty-one non-human primate radiographs were suitable for study as they contained the region of interest. The 81 radiographic examinations included 14 different species of non-human primates. The coraco-clavicular joint was seen in 4 out of 9 silver-leaf langur, 2 out of 8 lowland gorilla, and in 1 out of 6 white-handed gibbon. In all non-human primate cases where the coraco-clavicular joint occurred, it was bilateral. In 1 out of 8 mandrill, there were very wide distal clavicular ends that articulated both with the coracoid and with the acromion. The coraco-clavicular joint differs from an ossified coraco-clavicular ligament. The radiographic appearance is characteristic and is found in both humans and some non-human primate species. It may rarely become painful following trauma. When symptomatic in humans, resection of this anomalous articulation is curative.

Acromioclavicular Joint↗

Abnormal geometry of the distal radioulnar joint: MR findings.

Previously developed criteria of normal distal radioulnar joint (DRUJ) axial geometry were applied to routine magnetic resonance (MR) images of 50 wrists. All wrists lacked clinically evident DRUJ instability. An attempt to apply the three geometric criteria to seven of the cases was not possible, since the prescribed landmarks were not visible. The remaining 43 cases were retrospectively divided into a symptomatic group (25 wrists), with clinical abnormalities referable to the ulnar side of the wrist, and an asymptomatic group (18 wrists), with no such abnormalities. Abnormal DRUJ geometry was found in 12 symptomatic and 2 asymptomatic wrists. This difference between the groups is significant (p = 0.02), suggesting that many symptomatic wrists exhibit different DRUJ geometry than is found in most asymptomatic wrists.

Adolescent↗

O'Donoghue's triad: magnetic resonance imaging evidence.

OBJECTIVE: The objective was to search for magnetic resonance imaging evidence of medial collateral ligament (MCL) injury in knees with proven tears of the anterior cruciate ligament (ACL) and medial meniscus; the three abnormalities that make up O'Donoghue's triad. Although the MCL injury can be unapparent clinically, knee joint stability may be compromised. DESIGN: The superficial portion of the MCL was evaluated on 19 MR studies of 16 knees with arthroscopically proven ACL and medial meniscal tears. MCL thicknesses were compared to those on MR images of 19 normal knees. PATIENTS: The injured knees were of 13 men and 3 women, ranging in age from 19 to 56 years; the normal knees were of 10 men and 9 women, ranging in age from 19 to 55 years. RESULTS AND CONCLUSIONS: The medial collateral ligaments of all injured knees were abnormal, and, as a group, they had greater thicknesses and more intraligamentous thickness variability than normal knees. The MR appearance of both ACL and medial meniscal tears served as indirect evidence of MCL injury, with irregular MCL thickening indicative of prior injury.

Adult↗

Case report 875: Multifocal osteomyelitis--a manifestation of chronic brucellosis.

A 62-year-old man who had had chronic brucellosis for at least 14 years, presumably caused by ingestion of unpasteurized milk, presented with recurrent, multifocal osteomyelitis involving both tibias and a humerus, which had a pathologic fracture. Radiographs showed a large destructive lesion in the humeral diaphysis with a pathologic fracture and multiloculated radiolucencies, together with sclerotic zones in multiple long bones. Histologically, necrotizing, granulomatous inflammatory changes were compatible with a diagnosis of osteomyelitis. Bone biopsy cultures and agglutination titers were positive for Brucella abortus. The case represents an uncommon manifestation of Brucella infection which is particularly rare in the United States. A proper clinical examination should lead to consideration of the diagnosis.

Bone and Bones↗

Ocular toxicity of mitomycin C and 5-fluorouracil in the rabbit.

We studied the histotoxic effects of mitomycin C and 5-fluorouracil (5-FU) in the eyes of New Zealand white rabbits using light microscopy. Twenty-four eyes of 24 rabbits received subconjunctival injections of mitomycin C (0.025, 0.05, 0.10, 0.20, 0.40 or 0.80 mg/mL) or 5-FU (10.0 mg/mL), either alone (0.25 mL) or in combination with anterior chamber injections (0.05 mL), once daily for 4 consecutive days. Two eyes of two rabbits received subconjunctival and anterior chamber injections of unpreserved sterile saline. The eyes were examined regularly for external signs of toxicity and were enucleated 4 weeks after the last injection. Mitomycin C produced considerable tissue damage in the anterior segment, the severity being related to both the concentration and the route of administration. Eyes that received both subconjunctival and anterior chamber injections showed more damage than those that received subconjunctival injections alone. At the highest concentration of mitomycin C the cornea was inflamed, with stromal necrosis and marked endothelial loss. Hemorrhagic iris necrosis was also seen. In contrast, the 5-FU-treated eyes showed no microscopic evidence of toxicity. We conclude that there is greater risk of toxic anterior segment effects when mitomycin C is used as adjunctive therapy following filtration or pterygium surgery.

Animals↗

Ultrasound biomicroscopic features of pigmentary glaucoma.

We have developed a device capable of producing subsurface images in eyes at microscopic resolution. We call this method "ultrasound biomicroscopy." We examined 19 patients with pigmentary glaucoma or pigmentary dispersion syndrome using ultrasound biomicroscopy. Ten patients were found to have concave irides with small distances between the back of the iris and the zonule. In these patients iris-lens contact was greater than in patients without iris concavity and healthy patients. Nine patients did not show iris concavity or increased iris-lens contact. The finding of iris concavity and increased iris-lens contact is compatible with a theory of reverse pupil block producing intermittent iris-zonule touch, with a valve effect preventing posterior flow of aqueous. This theory was supported by the loss of concavity following iridotomy in three patients. The force that produces a reversal of the normal pressure gradient remains unclear, but recent evidence suggests that accommodation plays a major role. The patients who did not show iris concavity and increased iris-lens contact may have been examined at a time when these forces were not acting or had ceased to act.

Adult↗

The flipped meniscus sign.

Meniscal fragments may be difficult to detect on magnetic resonance (MR) imaging and yet are clinically significant. This paper describes and illustrates the MR appearance of an easily overlooked meniscal fragment. Ten knees, each appearing to show an abnormally large anterior meniscal horn (8 mm or more in height) were prospectively identified on MR images. In each case demonstrable large tears of the ipsilateral posterior horns were present (same meniscus as had large anterior horns). The lateral meniscus was involved in nine cases and the medial in one. Two of the ten patients imaged had surgically proven bucket-handle meniscal tears as well as meniscal fragments overlying the ipsilateral anterior horn. In one case previous MR imaging at our institution had demonstrated the affected anterior horn to be of normal caliber. The striking MR appearance of an abnormally enlarged anterior meniscal horn in association with a tear of the ipsilateral posterior horn suggests the presence of a meniscal fragment or of a posteriorly detached bucket-handle tear of the posterior horn of the meniscus.

Female↗

MRI of soft tissue abnormalities: a primary cause of sickle cell crisis.

The early manifestations of sickle cell crisis in soft tissues are important to recognize, though rarely manifest on radiographs and difficult to evaluate on computed tomography and bone scans. Documentation is critical, however, if appropriate judgments as to emergency treatment versus conservative measures are to be made. Seventeen adults seen in the emergency room or hospitalized in presumed sickle cells crisis underwent magnetic resonance imaging within 24-72 h of presentation. Results indicate that magnetic resonance imaging is a sensitive modality for documenting early soft tissue pathology which may be the predominant or sole cause of sickle cell crisis.

Adult↗

Heterogeneous in vivo MR images of soft tissue tumors: guide to gross specimen sampling.

Twelve soft tissue tumors preoperatively studied with magnetic resonance (MR) imaging contained areas of inhomogeneous intralesional signal intensity. The pathologist's selection of biopsy sites from gross specimens was based on specific MR images selected by a radiologist and depended on close cooperation between the radiologist and pathologist. The histopathology so sampled, further depended on the lesion's size, careful gross specimen orientation, discrete sampling, and a specially developed Grid Analysis technique. Our initial experience indicates that (1) histology may vary within different and often neighboring sites of a single soft tissue lesion; (2) that such variability is common in soft tissue tumors; (3) that histological variability within different sites of a single lesion influences signal heterogeneity; and (4) that although differing MR signal intensities per se are not tissue specific, MR may enhance the histopathological accuracy of pathologists who can be directed to particular gross specimen sites by magnetic resonance images. To our knowledge such a specific, detailed effort has not been made.

Adult↗