Accurate localization and surgical management of active lower gastrointestinal hemorrhage with technetium-labeled erythrocyte scintigraphy.

Objective: There is disagreement over the reliability of technetium Tc 99m (99mTc)-labeled erythrocyte scintigraphy in the localization of active lower gastrointestinal hemorrhage. A previous study at The New York Hospital-Cornell Medical Center that showed a superior sensitivity for localization of scintigraphy versus angiography in surgical patients led the authors to emphasize scintigraphy as the diagnostic test of first choice in the clinical diagnostic algorithm. The authors hypothesized that tagged erythrocyte scintigraphy can be used accurately as the primary diagnostic modality in localizing acute bleeding and guiding surgical intervention.

Quantitative MRI studies for assessment of multiple sclerosis.

Although magnetic resonance imaging (MRI) is a valuable aid in the initial diagnosis of multiple sclerosis (MS), quantitatively MRI has been disappointing in staging and evaluating therapy protocols by means of serial examinations. In this study, image processing algorithms were developed for the global analysis of MR images of the cerebrum. Limited three-dimensional segmentation was achieved through histogram analysis by these algorithms, which are essentially operator independent.

Magnetic resonance imaging evaluation of spontaneous portosystemic collaterals.

Three patients, two of whom had histories of episodic hepatic encephalopathy, were shown by magnetic resonance imaging (MRI) to have occult spontaneous portosystemic shunts. The multiplanar imaging capabilities of MRI provided an optimal, noninvasive method of visualization of collateral anatomy in each case.

MRI of primary amyloidosis.

In a patient with primary amyloidosis, we compared T2 values and relative signal intensity ratios of involved organs to those of normal patients. T2 was significantly decreased in the spleen and adrenals, while significantly increased in the pancreas. T2 values were insignificantly changed in the liver, subcutaneous fat, bone marrow, or kidney.