Harold A. Goldstein

Detection of unsuspected malignant pleural effusion by bone scan.

Technetium-99m phosphate compounds may occasionally accumulate in malignant pleural effusions. A case of metastatic pleural effusion first diagnosed by bone scan, prior to its clinical or roentgenographic detection, is reported.

Incidence of rapid resolution of defects on stress thallium scans

A prospective study was performed to determine the frequency with which defects on stress thallium images undergo rapid resolution. Analysis of paired views showed that 15% of the defects present in anterior views resolve in less than 30 minutes. This study documents the loss of sensitivity that can occur if imaging does not begin promptly after injection.

Variation of the spleen-liver activity ratio due to a change in position

The ratio of splenic to hepatic activity in the posterior view of a Tc-99m SC liver-spleen scan has been used as an indicator of parenchymal disease. Analysis of liver-spleen scans from a series of patients acquired in both the supine and erect positions revealed that the spleen-liver ratio varied considerably with a change in the patient position. Qualitatively there was a shift of colloid from the liver to the spleen in five of 18 supine views and ten of 18 erect views. Quantitative analysis of 37 cases showed that the median erect spleen-liver ratio was 20% greater than the spleen-liver ratio observed in supine patients. Criteria for an abnormal spleen-liver ratio need to be established in each position.

Automated calculation of gallbladder ejection fraction

We have developed a computer method which by automatically locating the border of the gallbladder in each image and subtracting a varying location-dependent background corresponding to the gallbladder border overcomes the difficulties associated with quantitating gallbladder contraction. These difficulties are attributable to significant and changing background activity, imprecise manual delineation of the gallbladder, and the changing position and shape of the gallbladder. Validation studies using a gallbladder phantom showed the method to be very accurate. No significant difference (P>0.05) was observed between the expected and calculated ejection fractions. Ten patient studies were analyzed, with a resulting range of gallbladder ejection fractions of 22–79%. Excellent reproducibility was obtained with an average intraobserver coefficient of variation of 3.5%, and no statistically significant difference in interobserver measurements (P>0.05). The regression line for interobserver measurements had a slope of 0.96±0.08, an intercept of 1.6±4.0%, and a correlation coefficient of 0.99. From these preliminary results we conclude that this method offers a reliable means of quantitating gallbladder contraction.

Unusual appearance of a highly vascular lesion on Tc-99m DISIDA hepatobiliary scintigraphy

A lesion was identified on the late images of a hepatobiliary scintigraphic study, but was not detected on the very early images, due to its enlarged blood pool. This combination of scan findings has not been previously described. The implication of the observation is that one must examine all the images of the hepatobiliary study in an effort to detect spaceoccupying lesions of the liver.