Biomedical subjects
Publications and source records attributed to P L Munk.
A wide variety of common focal monoarticular synovial lesions may be encountered on imaging studies. A multi-modality approach to these lesions, with appreciation of the differing appearances, can often yield the correct diagnosis. This pictorial essay demonstrates and describes the imaging with illustration of pathologic findings in a spectrum of conditions.
Liver biopsy is still most commonly done via the percutaneous route; however, increasingly, transvascular venous liver biopsy has been used in patients with bleeding disorders. Although the jugular route is now generally favoured, a transfemoral route can be a useful alternative technique when the jugular route is not available. We describe the transfemoral technique and outline a number of commonly encountered problems and complications and suggested methods of addressing them.
Over the past decade, increasing use of chemo-embolization with chemotherapeutic agents emulsified in oil has been made in the treatment of both primary and metastatic liver tumours. These lesions are often not amenable to surgical resection and are not responsive to systemic chemotherapy. Chemo-embolization provides an additional therapeutic option which, in some instances, can provide significant benefit. This pictorial review discusses the technique of chemo-embolization, as well as aspects of patient selection, complications, and tumour response.
Muscle and nerve injuries in the hand may be difficult to detect and diagnose clinically. Two cases are reported in which magnetic resonance imaging showed ulnar nerve injury and intrinsic hand muscle denervation. The clinical, anatomical and radiological features of injury to the deep motor branch of the ulnar nerve and associated muscle denervation are discussed and illustrated.
Hemangiopericytoma of soft tissue is a controversial pathologic entity. The relative nonspecificity of the characteristic branching capillary pattern and cytologic features of the constituent cells, in addition to the lack of a distinct immunohistochemical staining profile, has resulted in uncertainty and a lack of consensus regarding this subgroup of tumors. Notwithstanding the doubt surrounding this entity, a morphologically unique variant, designated lipomatous hemangiopericytoma, was reported in 1995. To our knowledge, there have been no further reports of these tumors since the original description. We describe a lipomatous hemangiopericytoma that arose within the thigh of a 41-year-old woman. The tumor presented as a slowly enlarging, minimally tender, pulsatile mass. The tumor was completely excised and was found to be composed of an admixture of typical hemangiopericytoma and predominantly mature adipose tissue. Unlike previous descriptions of this entity, the current example exhibited a full range of adipocyte differentiation, including many multivacuolated adipocytes of variable size with characteristic nuclear scalloping (lipoblast-like cells). The mitotic count was less than 2 per 10 high-power fields examined. The clinical course has been benign during the short follow-up period. We discuss the pathologic features, including the immunohistochemical staining profile and ultrastructural appearance of this distinctive tumor, and briefly discuss the relationship between hemangiopericytoma and solitary fibrous tumor of soft tissue, a neoplasm with many clinical and pathologic similarities.
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We report an unusual case of a recurrent giant cell tumor of the patella which presented with metastatic disease to the posterior mediastinal lymph nodes with no evidence of pulmonary metastases. The patient underwent chemotherapy with subsequent successful removal of the mediastinal mass. A review of the reported cases of mediastinal giant cell tumor metastases is provided.
OBJECTIVE: To assess a three-dimensional computed tomography (3DCT) technique for measurement of acetabular coverage in adults. DESIGN: We used 3DCT to define the geometric centre of the femoral head and to measure centre-edge angles (CEAs) at 10 degrees rotational increments around the acetabular rim. The means, ranges, standard deviations and 95% confidence intervals for the CEAs at the various rotational increments were determined. Inter- and intra-observer variability was measured. The normal values are compared with two example cases of acetabular dysplasia. PATIENTS: The normal hips of 15 subjects aged 1949 years (mean 34.2 years) were measured. RESULTS: The 3DCT measurements are reproducible (mean difference interobserver, 1.7 degrees - 7.9 degrees; mean difference intra-observer, 0.6 degrees-6.9 degrees). Mean normal CEA at the lateral rim was 33 degrees with a 95% confidence interval of 23 degrees - 43 degrees. Mean normal CEAs at 10 rotational increments from anterior to posterior rim were determined, and graphed as a 'normal curve'. CONCLUSION: This new 3DCT method of assessing acetabular dysplasia is simple, reproducible, and applicable to diagnosis, quantification and surgical planning for adult acetabular dysplasia patients.
Giant cell tumour of bone is a relatively common neoplasm with limited potential for metastatic spread. These tumours usually occur at the ends of bones with their epicentre in the epiphysis. This essay will review the various common and some of the less frequently encountered manifestations of giant cell tumours at multiple different sites, as well as postoperative recurrence. Different imaging modalities including plain film, tomography, computed tomography and magnetic resonance imaging are shown.
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The aim of the present report was to evaluate the vascularity of fracture fragments of the fractured carpal scaphoid in the acute (< 4 weeks) and chronic (> 3 months) phases using a gadolinium-enhanced dynamic MRI sequence. Eight patients with acute scaphoid fractures, six patients with chronic scaphoid fractures, and three control patients without fractures were evaluated using a T1-weighted fast spoiled gradient recalled acquisition (fSPGR) sequence with gadolinium-DTPA enhancement (0.1 mmol/kg bodyweight). Signal intensity over time plots were obtained using region of interest measurements from both fracture fragments. Enhancement factors (EF) were then calculated from the plots. No enhancement of the scaphoid was seen in control subjects (EF: distal scaphoid pole 1.04 +/- 0.01, proximal pole 1.07 +/- 0.08). In acute fracture patients, enhancement of the distal pole was greater than that of the proximal in all cases but one in which the two poles enhanced in a similar fashion (EF: distal 1.99 +/- 0.77, proximal 1.43 +/- 0.99). In chronic fracture patients the enhancement pattern was reversed, as the proximal pole enhanced to a greater degree than the distal with the exception of one case where both poles enhanced equally (EF: distal 1.74 +/- 0.52, proximal 2.64 +/- 0.50). Using a two-tailed non-parametric Mann-Whitney U-test, the difference in enhancement of the proximal poles between the acute and chronic groups was found to be highly significant (P < 0.003). Dynamic contrast-enhanced (fSPGR) MRI demonstrates significant differences in the enhancement patterns of the scaphoid when chronic and acute fractures are compared.
Although it is established that small and medium sized arteries undergo extensive radiation damage, the effect on large vessels such as the carotid arteries is less well understood. We sought to determine if an increased severity of carotid artery stenosis is present in patients who have undergone radiotherapy for head and neck tumours. 45 patients aged 43-90 years (average 67) with head and neck malignancies treated with radiotherapy underwent colour Doppler ultrasonographic scanning of the carotid arteries. These patients were compared with a population of asymptomatic historical controls. 60% of patients demonstrated stenosis ranging from 21 to 86%. 38% of patients demonstrated a stenosis greater than or equal to 50%. Carotid artery stenosis appears to be increased in patients who have previously undergone treatment with radiotherapy to the head and neck regions compared with controls (p < 0.001). These findings suggest that radiation has an adverse effect on large vessels. Colour Doppler follow-up may be indicated for patients receiving head and neck radiation therapy.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.