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Biomedical subjects

M H Kathol

Publications and source records attributed to M H Kathol.

At least 37 records · Page 2Linked to original sources
PubMed1991

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↗
PubMed1991

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↗
PubMed1991

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↗
PubMed1991

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↗
PubMed1990

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↗
PubMed1989

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↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1987

Right vs. left hemispheric blood-brain barrier permeability in schizophrenia: a dynamic computed tomographic study.

Dynamic computerized tomographic brain scanning was used to make determinations of mean cerebral tissue nonenhanced density and contrast-enhanced density in 10 bilateral brain regions in 10 psychotic subjects. Asymmetry of both nonenhanced and contrast-enhanced density was observed; left regional nonenhanced values were higher than right, whereas contrast-enhanced density values were higher on the right than on the left. No significant differences were observed in arterial mean transit time (AMTT) between right and left middle cerebral artery branches or in capillary or tissue mean transit time (CMTT) in the middle temporal cortex. However, corrected CMTT (CCMTT), i.e., CMTT minus AMTT, may have been prolonged in five subjects either on the left or right, or in both homologous regions. Only 2 of 10 subjects exhibited anterior-posterior (AP) gradients that resembled to some extent the hyperfrontal pattern reported in normal subjects by other investigators with different techniques.

Adult↗
PubMed1987

Hemangiomas of skeletal muscle: MR findings in five patients.

Skeletal muscle hemangiomas are uncommon tumors of young adults. More than 90% are misdiagnosed preoperatively. Plain-film examinations, bone scans, CT studies, and angiography may not always be specific for this tumor. Seven MR examinations were performed in five young adult patients with pathologically proved skeletal muscle hemangiomas. All five hemangiomas showed high signal intensity on both T1- and T2-weighted images. The signal intensity in these tumors was less than that of subcutaneous fat on relatively T1-weighted images and greater than that of fat on relatively T2-weighted images. Four tumors had a serpiginous pattern. Four patients had focal muscle atrophy. Three patients had all three findings (high signal intensity on both T1- and T2-weighted images, serpiginous pattern, and associated focal muscle atrophy) while the other two patients had at least two of the three findings. These three patients did not undergo angiography or needle biopsies before surgery because the MR findings were highly suggestive of hemangioma. Our experience with this small series of patients suggests that skeletal muscle hemangiomas have a consistent appearance on MR. MR may be able to contribute significantly to the preoperative diagnosis of this tumor and may also supply valuable information about the extent of the lesion.

Adolescent↗
PubMed1986

Posterior atlantooccipital subluxation in Down syndrome.

Three Down syndrome patients with posterior atlantooccipital (AO) subluxation are described. All are asymptomatic. The subluxation becomes manifest during active extension of the neck and reduces in flexion. Methods of assessing posterior AO subluxation are discussed. The abnormality is attributed to ligamentous laxity in patients with Down syndrome.

Adolescent↗
PubMed1986

Shoulder instability: impact of glenohumeral arthrotomography on treatment.

We used arthrotomography to study the glenoid labrum in 114 patients. Sixty-nine of the patients had anatomic instability of the shoulder (including recurrent dislocation and subluxation of the shoulder), and 45 patients had functional instability of the shoulder (denoted by chronic pain, clicking of the joint, and the sensation that an unstable condition exists without the objective signs of it). Labral tears were revealed arthrotomographically in 86% of the patients with anatomic instability, while only 40% of the patients with functional instability had labral abnormalities, and these were primarily of minor severity. Fifty-six patients (44 of whom had anatomic instability; 12, functional instability) required surgery. The surgical findings were correlated with the arthrotomographic findings, and no false-positive results were revealed. However, arthrotomography demonstrated only part of the pathologic condition of two patients. These results confirm that there is a strong correlation between labral pathologic conditions and anatomic instability of the shoulder. Arthrotomographic studies have a great impact on the selection of therapy in cases of both anatomic and functional instability of the shoulder.

Adolescent↗
PubMed1980

Neuropathic fractures in patients with diabetes mellitus.

Six patients with diabetes mellitus sustained neuropathic fractures. All had depressed or absent pain sensation in their legs. Four patients had unusual avulsion fractures in the posterior tubercle of the calcaneus. One had sustained six fractures within a period of six months. In 4 patients the fractures were followed by or associated with neuroarthropathy. The incidence and etiology of such fractures are discussed.

Adult↗
PubMedDate not supplied

Imaging features of avulsion injuries.

Avulsion injuries are common among participants in organized sports, especially among adolescent participants. Imaging features of both acute and chronic avulsion injuries of the pelvis, knee, ankle and foot, shoulder, and elbow were evaluated to help distinguish these injuries from more serious disease processes such as neoplasm and infection. At radiography, acute injuries (ie, those resulting from extreme, unbalanced, often eccentric muscular contractions) may be associated with avulsed bone fragments, whereas subacute injuries have an aggressive appearance that may include areas of mixed lysis and sclerosis. Chronic injuries (ie, those resulting from repetitive microtrauma or overuse) or old inactive injuries may be associated with a protuberant mass of bone and may bear a striking resemblance to a neoplastic or infectious process. Although not usually required, computed tomography is helpful in the diagnosis if radiographic findings are equivocal or if the injury is not in the acute phase. MR imaging is best suited for the evaluation of injuries to muscles, tendons, and ligaments. Recognition of characteristic imaging features and familiarity with musculotendinous anatomy will aid in accurate diagnosis of avulsion injuries.

Acute Disease↗