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R Wee

Publications and source records attributed to R Wee.

10 recordsLinked to original sources

Reversible cerebral, hepatic and renal lesions in severe pre-eclampsia.

Several authors have reported the appearance of reversible hypoattenuated cerebral lesions, representing ischemia, in computed tomography scans of patients with severe pre-eclampsia. Hepatic hemorrhage and sometimes rupture have also been reported in this setting, but these problems have apparently never occurred in a patient with reversible ischemia. The authors describe a 34-year-old patient with severe pre-eclampsia in whom reversible cerebral ischemia developed in combination with hepatic and renal hematomas, which subsequently partially resolved.

Adult

The diagnostic accuracy of preoperative CT scanning in the evaluation of pituitary ACTH-secreting adenomas.

Between 1980 and 1985, 35 patients (26 women and nine men) who had coronal CT scans of the sella turcica for suspected ACTH-secreting pituitary adenoma underwent transsphenoidal exploration. The CT examinations were performed with a fourth-generation EMI scanner (CT 7070). The reports of the preoperative CT examinations were compared with the findings at transsphenoidal exploration; in cases with negative CT scans, the decision to operate was based on biochemical evidence of Cushing's disease. In 27 patients, distinct adenomas were found at surgery; in the eight others, total hypophysectomy (four cases) or resection of the central core of the pituitary gland (four cases) was performed. Three patients had macroadenomas, all of which had been identified correctly on preoperative CT scan. Among the 24 microadenomas (less than 10 mm diameter), 14 had been correctly identified on preoperative CT scan while 10 were found in patients with negative scans. The CT examinations in these 35 patients showed probable adenomas in 20 cases, of which 17 (85%) were confirmed at surgery. In the other three cases (15%), adenomas were not found. Among the 15 patients with negative CT scans, 10 (66.6%) had distinct adenomas found at surgery. Coronal CT scans for ACTH-secreting adenomas had a sensitivity of 63%, a specificity of 62.5%, and an overall accuracy rate of 62.8%. Thus, in our experience, CT scanning with current state-of-the-art equipment has poor diagnostic accuracy in Cushing's disease. The possible reasons for this are that most of the adenomas in this series were microadenomas less than 6 mm in diameter, and that ACTH microadenomas probably show almost the same degree of enhancement with contrast medium as the surrounding normal pituitary tissue.

Adenoma

Progressive multifocal leukoencephalopathy.

The radionuclide, radiographic and pathologic findings in a patient with progressive multifocal leukoencephalopathy were correlated. Radionuclide imaging demonstrated the largest two of the many lesions observed at pathology. On repeated studies, one of the lesions developed a "doughnut" sign due to central necrosis. Cerebral angiography disclosed only one lesion which was initially suggestive of tumor encasement, but four weeks later, this deteriorated into an avascular zone. There were no characteristic features of the lesions demonstrated by radionuclide imaging and cerebral angiography that could be specifically attributed to progressive multifocal leukoencephalopathy.

Carotid Arteries

Diagnostic accuracy of preoperative CT scanning of pituitary prolactinomas.

Between 1980 and 1985, 102 patients (84 women and 18 men) who had coronal CT scans of the sella turcica for suspected prolactin adenoma underwent transsphenoidal exploration. The CT examinations were performed with a fourth-generation EMI scanner (CT 7070), and reports of the preoperative CT examinations were compared with the findings at transsphenoidal exploration. The same neurosurgeon performed all the operations. In 97 patients distinct adenomas were found at surgery, among which were 36 macroadenomas (diameter larger than 10 mm) and 62 microadenomas (one patient had two coexisting microadenomas). All macroadenomas were identified correctly on the preoperative CT scans. Preoperative CT scans correctly localized 58 microadenomas in 57 of 62 patients, for a sensitivity rate of 91.9%; this included correct localization in four patients with recurrent microprolactinomas and in the one patient with two coexisting adenomas. Three patients in whom the adenomas were found in a location other than that reported on the preoperative CT scan were considered to have false-negative scans for the purpose of statistical calculations; two other false negatives occurred in patients whose scans had been interpreted as entirely normal and who were subsequently found to have adenomas at operation. Four patients had negative surgical explorations and the preoperative CT scan was correct in one, for a specificity of 25%. The overall accuracy rate was 92.1% for the entire group of patients and 87.7% for the subgroup of microadenomas. In our experience, coronal CT scanning has high diagnostic accuracy in patients with pituitary prolactinomas.

Adenoma

Diagnostic accuracy of preoperative CT scanning of pituitary somatotroph adenomas.

Between 1980 and 1986, 58 patients (23 women and 35 men) had coronal CT scans of the sella turcica for suspected growth hormone-secreting adenoma and underwent transsphenoidal exploration. The CT examinations were performed with a fourth-generation EMI scanner (CT 7070), and reports of the preoperative CT were compared with the findings at transsphenoidal exploration. The same neurosurgeon performed all the operations. In three patients arthritic changes in the neck caused difficulties in positioning, which made it impossible to obtain adequate coronal CT scans. These nondiagnostic examinations are excluded from the statistical calculations. In all 55 patients with scans that were able to be evaluated, distinct adenomas were found at surgery. Among these were 39 macroadenomas (diameter larger than 10 mm) and 16 microadenomas. Three macroadenomas and two microadenomas caused combined hypersecretion of growth hormone and prolactin. All macroadenomas were localized correctly on the preoperative CT scans (sensitivity 100%), but in two cases there was a discrepancy in size of more than 5 mm compared with the operative findings. Preoperative CT scans correctly localized 13 of 16 microadenomas, for a sensitivity rate of 81.2%. Two patients with negative scans and one patient in whom the adenoma was found in a location other than that reported on the preoperative CT scan were considered to have negative scans for the purpose of statistical calculations. If both correct localization and size estimation within 2 mm of that found at surgery are considered, the accuracy rate was 90.9% for the entire group of patients, 94.9% for those with macroadenomas, and 81.2% for microadenomas.

Adenoma