Search PubMed⌕ Search

Biomedical subjects

A C Friedman

Publications and source records attributed to A C Friedman.

112 records · Page 7Linked to original sources

Differential density of normal renal parenchyma on nonenhanced CT: a new observation.

PURPOSE: Nonenhanced CT scans through the kidneys commonly show a difference in radiopacity between the inner peripelvic portion of the renal parenchyma and the more peripheral regions of the renal parenchyma. This normal observation has not been described. METHOD: We reviewed 50 nonenhanced CT scans. Renal parenchyma was evaluated by both visual inspection and density measurements of inner and outer aspects of the kidneys in 38 and visual inspection only in 12. A narrower window was used to better show density differences (100 W, 35 L). We recorded the indication for the CT, history, and recent blood chemistries. RESULTS: The inner parenchyma was of greater radiopacity than the outer parenchyma in 35 of 50 cases by visual inspection and in all densitometry cases (38 of 38). There was no correlation with clinical history or blood chemistry. CONCLUSION: A difference in density between the inner and outer portions of the renal parenchyma is very common and will often be seen if one looks for it. We have not shown an etiology for this difference, and indeed, it may be physiological. One must be aware of this finding to avoid mistaking it for pathology.

Aged↗

Interpretation of chest radiographs in AIDS patients: usefulness of CD4 lymphocyte counts.

Specific infections and neoplasms that are complications of acquired immunodeficiency syndrome (AIDS) occur within various CD4 lymphocyte count ranges. Knowledge of how these counts correlate with radiographic appearances of these entities can limit the differential diagnosis because certain conditions are uncommon above a specific count. In patients with CD4 lymphocyte counts above 200 cells/mm3 and radiographic findings of cavitary and noncavitary consolidation, bacterial pneumonia and Mycobacterium tuberculosis are the major diagnostic considerations. As the CD4 lymphocyte count falls, these infections are still common; however, cavitation is seen less frequently with Mycobacterium tuberculosis, and unusual bacterial infections, including those caused by Rhodococcus equi and Nocardia asteroides, should be considered. In patients with counts below 200 cells/mm3, Pneumocystis carinii pneumonia is the most common infection, usually manifesting radiographically as a reticular interstitial pattern. At CD4 lymphocyte counts of 50-200 cells/mm3, disseminated fungal infection and Kaposi sarcoma become prevalent. In patients with advanced AIDS and counts below 50 cells/mm3, radiographic nodular or reticular patterns may indicate AIDS-related lymphoma and cytomegalovirus and Mycobacterium avium-intracellulare infections. When CD4 lymphocyte counts are applied to interpretation of chest radiographs in AIDS patients, the working differential diagnosis of a radiographic pattern can be tailored to the clinical situation of a given patient.

AIDS-Related Opportunistic Infections↗

Evaluation of unaccountable phlebitis with the long arm silastic catheter.

This study was initiated to identify the causal factor responsible for the development of "unaccountable phlebitis" when using the long arm silastic catheter. Use of computerized axial tomography has provided a means of analyzing veins containing indwelling silastic catheters of the upper arm. Physical data of diameters of the veins are limited to inaccuracies of the machine and must only be regarded as relative. We have been able to detect a great variability of cross-sectional vein diameter and area within any one patient. This narrowing tends to occur in the mid-upper arm region and may explain the occurrence of "unaccountable" phlebitis in this area. It appears that laminar blood flow and flotation of the catheter in the vein is inhibited in these areas of narrowing.

Arm↗