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Biomedical subjects

M K Dalinka

Publications and source records attributed to M K Dalinka.

At least 19 recordsLinked to original sources
PubMed1995

Merrill C. Sosman Lecture. MR imaging of the wrist.

Imaging of the wrist should always begin with a plain film examination. Sonography and tenography are sometimes used to evaluate tendon abnormalities. Sonography is operator dependent; tenography, because of its invasive nature, is rarely used today. Arthrography, with single or triple injection techniques, with [1] or without [2] digital subtraction, has been the procedure of choice for detecting abnormalities of the interosseous ligaments and the triangular fibrocartilage (TFC). MR imaging is the only imaging technique that can directly depict the interosseous ligaments and the TFC. It is the imaging technique of choice for the early diagnosis of aseptic necrosis, for tumor staging, and for evaluating soft-tissue masses. MR imaging enables noninvasive global examination of the wrist that is extremely sensitive in detecting osseous and soft-tissue disease. Because technical advances will allow more rapid data acquisition, thinner slices, and higher resolution, I predict MR imaging will replace arthrography in the near future.

Humans↗
PubMed1995

Update in shoulder magnetic resonance imaging.

The shoulder is capable of the largest range motion of any articulation in the human body. Because it is inherently unstable, the glenohumeral joint is dependent on the support given by surrounding muscular, ligamentous, and tendonous structures. A variety of disorders may involve these structural supports and lead to shoulder pain and dysfunction. Refinements in magnetic resonance (MR) imaging techniques have allowed improved characterization of these abnormalities and may permit earlier and more specific diagnoses in patients with shoulder pain. Theories as to the pathogenesis of rotator cuff disease include intrinsic and extrinsic impingement as well as overload tendinosis. MR is useful in the evaluation of rotator cuff impingement and tears. The classification and MR assessment of glenohumeral instability has recently received increased attention yet remains an area of difficulty. MR arthrography has been used with some success in the evaluation of instability demonstrating improved diagnostic sensitivities and specificities when compared with conventional MR. Relatively little attention has been paid to MR evaluation of the shoulder after surgery. Micrometallic artifact, distortion of soft-tissue planes, and persistent signal abnormalities within rotator cuff and capsulolabral structures may hinder assessment of recurrent tear or instability in the postoperative patient.

Humans↗
PubMed1994

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↗
PubMed1994

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↗
PubMed1994

Osteoporosis and bone morbidity in cardiac transplant recipients.

PURPOSE: To evaluate the incidence and etiology of osteopenia and pathologic fractures in cardiac transplant recipients. PATIENTS: Thirty-one adult male cardiac transplant recipients and 14 adult men with congestive heart failure (CHF) awaiting cardiac transplantation. METHODS: Assessment of indices of bone and mineral metabolism and of bone mineral density (BMD) by dual-energy x-ray absorptiometry. RESULTS: BMD in the proximal femur was below normal in both groups compared to that in age-matched control subjects, whereas BMD in the lumbar spine was normal. There was no significant difference in BMD at any site between the two groups. No clinical parameter predicted BMD. In all patients, laboratory indices of bone mineral metabolism, except parathyroid hormone (PTH) levels, were normal and not statistically different between the two groups. CHF patients had a trend toward elevations of PTH, 1,25-dihydroxyvitamin D, and urinary calcium excretion compared to transplant patients. Eight of 31 transplant patients and 2 of 14 CHF patients had vertebral compression fractures (c2 = 11.8, p < 0.0006). Transplant recipients with fractures had twice as many rejection episodes as did transplant patients without fractures, but did not differ in cumulative dose of steroids. Two patients developed avascular necrosis of the femoral head following transplantation. CONCLUSIONS: Cardiac transplant recipients and patients with CHF awaiting transplantation had decreased hip BMD, but normal spine BMD. Although immunosuppressive therapy did not appear to influence bone mass, loop diuretics prior to transplantation may have stimulated a mild secondary increase in PTH that could have differentially caused loss of bone density at the hip in both groups. Pulse corticosteroids used in treating rejection may have contributed to the increased incidence of vertebral fractures in transplant patients. These data suggest that severe CHF with its associated diuretic use and decreased activity are primary contributors to osteopenia in these patients.

Absorptiometry, Photon↗
PubMed1994

Magnetic resonance imaging for the diagnosis of osteomyelitis in the diabetic patient with a foot ulcer.

Twenty-seven diabetic patients (12 males and 15 females) with clinically suspected osteomyelitis complicating soft tissue infection of the foot underwent 29 magnetic resonance imaging studies of the suspected lesion. Of these patients, 26 had plain film radiographs, 11 had technetium bone scanning, and 12 had indium-labeled leukocyte scintigraphy performed within 2 weeks of the magnetic resonance imaging. Definitive diagnosis of the presence or absence of osteomyelitis was obtained on the basis of surgical findings, histological evidence, or resolution with nonoperative therapy. Magnetic resonance imaging was 90% accurate (sensitivity 77%, specificity 100%) in the diagnosis of osteomyelitis in this patient population. Technetium bone scan was 45% accurate (sensitivity 100%, specificity 25%); indium-labeled leukocyte scintigraphy was 50% accurate (80% sensitivity, 29% specificity); and plain film roentgenography was 73% accurate (60% sensitivity, 81% specificity). Magnetic resonance imaging is a powerful, noninvasive tool for determining the presence or absence of osteomyelitis in the patient with a diabetic foot ulcer.

Adult↗
PubMed1994

MR diagnosis of meniscal tears of the knee: value of fast spin-echo vs conventional spin-echo pulse sequences.

OBJECTIVE: Contrast can be similar on fast spin-echo and conventional spin-echo MR images, but data acquisition is faster with fast spin-echo sequences. This study was designed to evaluate the performance of fast spin-echo sequences in the detection of meniscal tears in the knee, with the established conventional spin-echo technique used as a reference standard. SUBJECTS AND METHODS: We imaged 66 consecutive patients (129 menisci) who were referred for MR examination with suspected meniscal tears. We used our routine two-dimensional, multisection, long repetition time/double-echo spin-echo sequence and one of two fast spin-echo sequences. The fast spin-echo parameters were chosen to minimize the loss of high-resolution detail while otherwise maintaining the sequence as close as possible to the spin-echo sequence. We then did a retrospective evaluation of the fast spin-echo images, using the spin-echo images as the gold standard. RESULTS: Fast spin-echo images showed only 30 (65%) of the 46 meniscal tears seen on the conventional spin-echo images. In addition, four of the 30 tears seen with both sequences were diagnosed with greater confidence on the conventional spin-echo images. In the cases in which both sequences allowed a diagnosis of definite meniscal tear, the abnormalities tended to be more conspicuous on the spin-echo images. CONCLUSION: Our results suggest that the fast spin-echo sequence should not be used for the diagnosis of meniscal tears.

Adult↗
PubMed1994

Categorization of acromial shape: interobserver variability with MR imaging and conventional radiography.

OBJECTIVE: Our purpose was to determine interobserver variability in the interpretation of the shape of the acromion on sagittal oblique MR images and conventional radiographs. The shape of the acromion was defined according to a previously described classification scheme. MATERIALS AND METHODS: We reviewed 26 sets of sagittal oblique MR images and corresponding conventional Y- or outlet-view radiographs of the shoulder. The shape of the acromion was graded for each study independently by four reviewers. Interobserver agreement was measured by using the kappa statistic. Analysis of variance and the chi 2-test were used for univariate analysis. RESULTS: The acromion was interpreted most often as being curved. The observers scored 9% of MR images and 28% of conventional radiographs as nondiagnostic (p < .001) (41% of transscapular Y views and 3% of supraspinatus outlet views were also considered nondiagnostic [p < .0001]). Kappa values were .23 for MR images and .43 for conventional radiographs. Variability in interpretation between techniques when controlled for observer was not statistically significant. CONCLUSION: Although sagittal oblique MR images were significantly more likely than conventional radiographs to be considered diagnostic by observers, interobserver agreement for MR examinations was poor. There was moderate agreement with conventional radiographs. This calls into question the usefulness of the previous system of interpretation and suggests that it might be more applicable with conventional radiographs than with MR images.

Acromion↗