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Biomedical subjects

M H Kathol

Publications and source records attributed to M H Kathol.

At least 19 recordsLinked to original sources

Hamstring injuries: radiographic, conventional tomographic, CT, and MR imaging characteristics.

PURPOSE: To review experience with the imaging features of hamstring injuries. MATERIALS AND METHODS: Imaging findings in 18 male and four female patients with clinically proved hamstring injuries were reviewed. The patients' ages ranged from 13 to 61 years (mean, 26 years). Radiography, conventional tomography, computed tomography (CT), and magnetic resonance (MR) imaging were performed. RESULTS: Plain radiographs obtained less than 1 week after injury were normal or showed avulsion of an ischial apophysis. Plain radiographs and conventional tomograms obtained more than 1 week but less than 3 months after injury were confusing, because callus and osteolysis were present. CT helped identify a healing avulsion of an ischial apophysis. MR imaging was helpful no matter how long after the injury it was performed. It provided a means to evaluate muscle, tendon, and bone. CONCLUSION: Familiarity with the variable appearance of hamstring injuries over time and with different modalities facilitates accurate characterization.

Adolescent

Imaging of acute injuries of the cervical spine: value of plain radiography, CT, and MR imaging.

Imaging of injuries of the cervical spine has undergone substantial changes in the past 10 years. The use of CT and MR imaging has been emphasized by many authors. Other studies have stressed the proper use and interpretation of plain radiographs in the emergency setting. There is confusion about whether plain films, CT, or MR imaging is best used to evaluate specific injuries. This review explores the usefulness of CT and MR imaging in the diagnosis and management of acute injuries of the cervical spine and emphasizes the continued importance of conventional radiography. Specific examples that illustrate the relative merits of plain radiography, CT, and MR imaging are shown.

Acute Disease

Unusual radiological features in Paget's disease of bone.

The radiological diagnosis of Paget's disease of bone is usually straightforward because most cases conform to well-established classic descriptions. Diagnosis becomes more difficult, however, when radiological appearances are not typical or other disease processes mask or alter the behavior of Paget's disease. Examples are presented to illustrate four categories of unusual radiological presentation of Paget's disease: (1) unusual disease progression, (2) massive post-immobilization lysis, (3) metastatic spread to pagetic bone, and (4) vertebral end-plate destruction that mimics infection.

Bone Diseases

Elastofibroma dorsi: a radiological diagnosis.

Elastofibroma dorsi is a rarely made radiological diagnosis. The rarity of the condition, lack of a suitable imaging modality, and an inconsistent clinical approach in evaluating indeterminate soft tissue tumors has contributed to this failure. With magnetic resonance imaging now being recognized as the examination of choice for all indeterminate soft tissue tumors, a prebiopsy diagnosis can frequently be made by radiologists familiar with the characteristic periscapular location, predilection for elderly females, and short T2 on magnetic resonance imaging.

Female

Comparison of a videodisc system with a conventional film file for medical student teaching.

PURPOSE: The authors assessed the effectiveness of a videodisc film file compared with a conventional film file for teaching radiology to medical students. METHODS: Fourth-year medical students (N = 134) studied 116 cases selected from the American College of Radiology Learning File. Half the students studied 58 skeletal cases using conventional films and half studied the same cases on a videodisc system. Student groups were then switched and those who studied skeletal cases on films studied 58 chest cases on videodisc and vice versa. Students received the same skeletal and chest tests and completed a questionnaire. RESULTS: For both skeletal and chest radiology, students studying films scored minimally higher than students using the videodisc. Students rated films superior to the videodisc for amount learned, convenience of use, and ability to detect lesions. CONCLUSIONS: Conventional film and videodisc methods resulted in similar levels of learning; however, students perceived conventional films to be a superior learning experience.

Education, Medical, Undergraduate

Gadolinium-enhanced MRI of soft tissue masses.

The efficacy of gadopentetate dimeglumine (Gd-DTPA) enhanced magnetic resonance (MR) imaging in the diagnosis and differentiation of soft-tissue, neoplastic and non-neoplastic lesion has not been well established. Thirty patients with soft tissue masses (18 neoplastic and 12 non-neoplastic) were studied, using MR imaging with and without administration of Gd-DTPA. Gd-DTPA proved helpful in characterisation of several entities, including differentiation of solid mass from proteinaceous cyst, demonstration of tumour nodules within haemorrhagic or necrotic masses, and delineation of tumour adjacent to oedema. The use of Gd-DTPA may provide additional information for tissue specificity and, in complicated cases, Gd-DTPA may also provide essential information that cannot be obtained using other methods. We recommend the use of contrast enhanced MR as an adjunct to conventional MR imaging in the initial assessment of musculoskeletal soft tissue masses. However, T2-weighted images show better tissue contrast of the lesions, and are equal to contrast enhanced images in delineation of tumour margins. Non-contrast enhanced images are, therefore, probably adequate for the delineation of lesions for surgical planning when a diagnosis has already been made.

Connective Tissue Diseases

The use of intravenous gadopentetate dimeglumine in magnetic resonance imaging of synovial lesions.

Spin echo T1- and T2-weighted images and intravenously administered gadopentetate dimeglumine-enhanced T1-weighted images were obtained in 4 normal volunteers and 11 patients (11 joints) with painful, intermittent, or persistent joint swelling of unknown etiology. These studies were retrospectively reviewed to assess the benefits of contrast-enhanced magnetic resonance imaging (MRI) in evaluating the synovium. Normal synovium and joint fluid showed no visually apparent enhancement on images obtained immediately after intravenous injection of gadopentetate dimeglumine. Abnormal synovium enhanced significantly, allowing the precise identification of equivocal or unsuspected synovial disease processes. These results suggest that, in selected cases, enhanced MRI can be a useful adjunct in the evaluation of suspected synovial disease processes.

Adult

Curriculum for musculoskeletal radiology.

Although general suggestions have been made regarding a radiology residency curriculum, no specific list of entities has been offered. Over the past ten years, we have developed a resident-run morning conference in musculoskeletal radiology that is supervised by faculty and covers a specific curriculum. We offer our curriculum as an example that may assist other departments in developing their own curricula.

Curriculum

Intraspinal synovial cysts. Magnetic resonance evaluation.

Five intraspinal synovial cysts in four patients were evaluated with noncontrast magnetic resonance imaging and magnetic resonance imaging with the contrast agent gadolinium diethylenetriaminepentaacetic acid. Useful findings included demonstration of both solid and cystic components, early enhancement of the solid component and cyst periphery, delayed enhancement of the cyst, persistent enhancement of the solid component and cyst capsule, enhancement of the apophyseal joint, and recognition of a possible connection between the cyst and apophyseal joint. Although computed tomographic findings of synovial cysts are quite characteristic for the diagnosis in most cases, contrast magnetic resonance imaging may provide additional information for a more definitive diagnosis.

Adult

Calcaneal insufficiency avulsion fractures in patients with diabetes mellitus.

Radiographs and clinical records of 61 patients with calcaneal fractures were studied. Twenty-one patients had diabetes mellitus, and 40 were nondiabetic. All diabetic patients were insulin dependent for more than 5 years and had clinically evident peripheral neuropathy. Eighteen of the diabetic patients had no history of significant trauma. Fourteen had calcaneal insufficiency avulsion (CIA) fractures limited to the posterior third of the calcaneus. The fracture pattern in this group occurred in the same plane as a fatigue-type calcaneal fracture. Fragments of the posterior tuberosity were usually displaced 10-30 mm and were frequently rotated. The mean time from diagnosis of diabetes mellitus to CIA fracture was 20 years. Fractures in the nondiabetic group and in the three diabetic patients with a history of trauma did not resemble the CIA pattern. In the nondiabetic group, there were no insufficiency fractures; 39 fractures occurred with significant force (eg, motor vehicle accident or fall from height), and 33 had extension to subtalar or calcaneocuboid joints.

Adult

Sarcoma in Paget disease of bone: clinical, radiologic, and pathologic features in 22 cases.

The clinical, radiologic, and histologic features of 22 cases of Paget sarcoma were reviewed to determine in which patients with Paget disease these tumors are most likely to develop and what radiologic findings suggest the diagnosis. Clinical findings at presentation included pain and/or a mass (11 patients), pathologic fracture (seven), and neurologic symptoms (four). Survival time in 20 patients ranged from 5 days to 2.5 years. Two patients were lost to follow-up: one at 2 years and one at 8 years. There were 16 high-grade osteosarcomas, three chondrosarcomas, two fibrosarcomas, and one malignant fibrous histiocytoma. The most common site was the femur. Tumors also were observed in unusual sites. In one case of multifocal osteosarcoma, the tumor involved only pagetic bone. In 15 patients, Paget disease was polyostotic, clinically significant, and had been documented previously. In four patients, a sarcoma developed near the site of a fracture that had occurred between 2 months and 15 years previously. All cases showed radiologic evidence of a destructive lesion; other findings included a mass and evidence of tumor mineralization. Periosteal reaction was not observed. All but one tumor developed in a site of osteoblastic or mixed osteoblastic and lytic Paget disease. Our results suggest that sarcomas can develop in any part of any bone affected by Paget disease but are more likely to occur with advanced disease and to present with a destructive lesion without periosteal reaction.

Aged

Abnormalities of the foot in patients with diabetes mellitus: findings on MR imaging.

The MR appearances of foot problems in patients with diabetes mellitus are illustrated. MR has been found to be effective in the diagnosis of osteomyelitis, the most common indication for imaging the feet of diabetic patients. MR has the ability to image numerous pathologic processes, especially subtle soft-tissue changes, that are not detectable with other imaging methods.

Diabetes Complications

Satisfaction of search in diagnostic radiology.

A subset of underreading errors (false-negative responses) in radiology has been attributed to "satisfaction of search," which occurs when lesions remain undetected after detection of an initial lesion. This phenomenon has not been studied in the experimental laboratory. A primary goal of this study was to develop a procedure or paradigm to study satisfaction of search. The authors measured detection accuracy for native lesions in images before and after the addition of a simulated nodular lesion. Simulated and native lesions were not spatially superimposed and the native abnormalities were physically identical with and without the nodules. Only responses related to the native lesion were analyzed. Accuracy parameters of receiver operating characteristic (ROC) curves were estimated by the method of maximum likelihood and jackknife. The average perceptual accuracy of the individual ROC curves as measured by Az and de' was significantly reduced with addition of the nodules (t = 2.364, p = 0.025, t = 2.648, p = 0.017, respectively). Az and de' parameters of the pooled ROC curve showed a similar effect (t = 1.573, p = 0.080; t = 1.934, p = 0.047, respectively). The results indicated a substantial satisfaction-of-search effect, with diminished accuracy in perception of native lesions.

Adolescent

Osteomyelitis of the foot in diabetic patients: evaluation with plain film, 99mTc-MDP bone scintigraphy, and MR imaging.

Diagnosis of osteomyelitis of the foot in diabetic patients may be difficult because of the coexistence of chronic cellulitis, vascular insufficiency, and peripheral neuropathy. This study compared the diagnostic accuracies of plain films, bone scans, and MR imaging studies in diabetic patients with suspicion of osteomyelitis of the foot. Twenty-nine plain radiographs, 20 bone scans, and 30 MR studies were obtained in 24 patients. Twenty-nine bones from 14 patients were pathologically proved either positive (25 bones) or negative (four bones) for osteomyelitis. Another 15 bones (10 patients) studied with MR had no pathologic proof, but the bones healed with only local wound care and/or a short course of oral antibiotics. These patients had trauma, cellulitis, or unhealed ulcers. The sensitivity and specificity of plain films were both 75%. Bone scans had a very low specificity (100% false-positive rate). A negative bone scan should strongly exclude the probability of osteomyelitis. Unlike the findings in previous reports, MR had much higher sensitivity and specificity than bone scans in detecting osteomyelitis in diabetic patients. When the 10 patients without pathologic proof (those who presumably had neuroarthropathy, vascular insufficiency, and/or cellulitis) were included, the sensitivity and specificity of all three techniques decreased. Our experience with this small group of patients suggests that MR is a useful imaging technique for diagnosing osteomyelitis of the foot in diabetic patients.

Adult

Patellofemoral joint motion: evaluation by ultrafast computed tomography.

Patellofemoral maltracking is a recognized cause of peripatellar pain. Measurements of the patellofemoral relationships during active motion are not available, and clinicians currently rely on observation, palpation, and static radiographic images to evaluate the symptomatic patient. Ultrafast computed tomography (ultrafast CT) offers objective observations of the dynamic influences of muscle contraction on the patellofemoral joint as the knee is actively moved through a range of motion from 90 degrees flexion to full extension. This study reports our initial observations and establishes a range of normal values so that patients with a clinical suspicion of patellar maltracking may be evaluated.

Adult

Seronegative and seropositive rheumatoid arthritis: radiographic differences.

Patients with seronegative and patients with seropositive rheumatoid arthritis (RA) have clinical, genetic, and immunologic differences. This study was undertaken to determine whether the two populations differ radiologically. Seventeen patients with seronegative RA were closely matched with seropositive control subjects. Radiographs of the hands and wrists were studied blindly, and disease severity was quantified with use of a modification of the Beaver Creek grading sheet. The following distinguishing features were also evaluated: osteosclerosis, new bone formation, carpal predominance, ankylosis (fusion), symmetry, and classical erosions. Seropositive patients had more severe disease, with larger and more numerous erosions, while the seronegative group had more osteosclerosis, carpal predominance, fusion, and new bone formation. Symmetry was equal in both groups. Although there were definite quantitative and qualitative differences between the two populations, radiologists should be cautious in using these criteria because of the great deal of overlap between the two groups.

Arthritis, Rheumatoid