Stereotactic localization of breast lesions: how it works and methods to improve accuracy.

A computer simulation of stereotactic breast biopsy was developed that paralleled the geometric configuration of a currently available breast biopsy system. This model was developed to define and improve the targeting of breast lesions with stereotactic biopsy techniques. Lesions must be clearly identified and accurately targeted on both views for successful localization. Nonvisualization of a lesion may result from overlying tissue or from the geometric configuration of the imaging system. Familiarity with the geometric configuration of the biopsy unit, especially the location of the reference point and center of rotation, facilitates understanding of apparent changes in lesion position (parallax shift). Inaccuracy in lesion targeting on one or both views will manifest predominantly as an error in the calculated z value (depth). The magnitude and direction of this error are largely determined by the direction of the targeting error. Compensatory strategies include use of a long-throw core biopsy gun or directional vacuum-assisted biopsy device and additional sampling along the z axis and should be accompanied by critical evaluation of both pre- and postfire images. Understanding geometric considerations as well as how targeting accuracy affects accuracy in lesion localization should lead to greater success in sampling even challenging breast lesions at stereotactic biopsy.

Distinction of consolidative bronchioloalveolar carcinoma from pneumonia: do CT criteria work?

OBJECTIVE: The purpose of this study was to compare the CT findings of consolidative bronchioloalveolar carcinoma (BAC) with consolidative infectious pneumonia and determine if any pattern revealed by CT is more specific for one disease than the other and may therefore expedite a diagnosis of consolidative BAC using CT. MATERIALS AND METHODS: The CT findings in 20 patients with consolidative BAC and 20 patients with consolidative infectious pneumonia were reviewed. Radiologic features included the presence and distribution of consolidation, nodules, and ground-glass opacities; the presence of air bronchogram, mucous bronchogram, contrast enhancement, cysts, or cavities within the consolidation; and pulmonary fibrosis or significant parenchyma scarring. RESULTS: Statistically significant (p < .003) findings that were more often seen on CT scans of patients with consolidative BAC than on those of patients with consolidative pneumonia included coexisting nodules (p < .001) and a peripheral distribution of consolidation (p < .001). CONCLUSION: When nonresolving peripheral consolidative pneumonia, especially with associated nodules, is shown on CT, radiologists should suspect BAC when the patient is an adult with normal immunity.

Plasma lipid concentrations in children with cystic fibrosis: the value of a high-fat diet and pancreatic supplementation.

Impaired digestion of dietary fat is an almost universal feature of cystic fibrosis (CF) which results in low concentrations of essential fatty acids in plasma lipids. We have evaluated the effect of a high-lipid diet and pancreatic enzyme supplementation, using enteric-coated microsphere preparations, on plasma lipid concentrations in paediatric CF patients. Absorption of dietary lipid was comparable between control and CF subjects. This resulted in plasma cholesterol, triacylglycerol, total phosphatidylcholine and individual phosphatidylcholine molecular species concentrations in CF patients which were in the same range as those in controls. Normal values for these variables were also found in patients with clinically detectable liver disease. These results show that present dietary management of CF patients supports normal plasma lipid concentrations.