Francis J. Y. Hahn

The Normal Range and Position of the Pineal Gland on Computed Tomography

Precise measurements with the Vanguard Motion Analyzer were made to determine the position of the pineal gland as shown on the Polaroid displays of 145 normal scans. The relatively midline positions of the gland are expressed in terms of percentage shift of the gland in these 145 normal cases is defined by a mean value of 0.8% with a standard deviation of 0.6%. More than 99% of normal CT scans can be expected to show a percentage shift of 2.6% or less.

Thromboembolic complications of angiography for peripheral arterial disease: prospective assessment by Doppler ultrasound.

The incidence of thromboembolic arterial complications related to percutaneous angiography done for patients with arterial disease was assessed in 101 cases (105 procedures). There were 2 instances of anterior tibial artery obstruction and 3 of a decline in ankle pressure greater than 20 mmHg in patients with preexisting leg arterial disease. No patient evidenced symptoms of the complications. This incidence of thromboembolic accident, detected by Doppler ultrasound, is significantly less than those incidence rates noted previously, although the reasons for this difference have not yet been established.

Retroperitoneal fibroxanthosarcoma: report of a case.

Abstract The clinical and roentgenographic manifestations of a rare retroperitoneal fibroxanthosarcoma are presented and briefly discussed.

A quantitative analysis of ventricular size on computed tomographic scans

Abstract In the daily practice of radiology the occasional problem of defining the range of normal ventricular size arises. In a previous communication the investigators reported originally on frontal ventricular dimensions as seen on computed tomographic (CT) scans of 200 patients considered to be neurologically normal (1). Recently, similar studies have also been reported by other investigators, one dealing with 35 patients (2), one with 44 normal adults (3), and another one with 62 patients (4). In order to establish a broader statistical base for the quantitative criteria, an additional 188 normal CT scans were reviewed and combined with the previous 200 scans for a total population of 388 cases. Results were correlated with sex and distributed in three broad age groups. In addition, a quantitative criterion for the normal bithalamic index is based on the analysis of 100 normal CT scans.

Renal Lymphoma Simulating Adult Polycystic Disease

Multiple cyst-like involvement of the kidney in a patient with lymphocytic lymphoma is presented. Both kidneys demonstrated the swiss-cheese appearance on nephrograms, simulating a typical adult type of polycystic disease. No tumor vessels or strains were noted.

The overshoot artifact as an aid in differentiating low densities on the computed tomographic scan

This brief report describes an artifact that is seen as a thin, white rim outlining an air collection on the EMI 80 X 80 and 160 X 160 matrix CT scanners. This artifact is not associated with fat density and, therefore, its recognition allows presumptive differentiation between air and fat densities. The attenuation numbers of the lesion should then be obtained for confirmation.

Scintigraphic Findings in Hyperostosis Frontalis Interna

Transient diminution of activity was seen on early radionuclide images of the brain in 5 patients with hyperostosis frontalis interna and filled in on subsequent studies. Radiographs confirmed the diagnosis. In 3 patients the changes corresponded extremely well with both modalities. This entity should be considered when diminished activity is seen in the frontal area.

Brain image manifestation in the patient with cavernous sinus occlusion

Radionuclide findings in a case of cavernous sinus occlusion by an intracavernous aneurysm are described. A brain image obtained 10 minutes after injection of 99Tc pertechnetate shows diminished activity in the area of the right cavernous sinus and increased activity in the area of the right sylvian veins; these are attributed to abnormal venous blood flow and may serve as a sign of cavernous sinus occlusion.