James M. Mountz

SPECT imaging of Moyamoya disease using 99mTc-HM-PAO comparison with computed tomography findings

99mTc-HM-PAO was used to evaluate regional cerebral blood flow in a 26-year-old woman with Moyamoya disease. This patient had an 18-month history of recurrent neurologic deficits and had angiographic evidence of Moyamoya disease. She had used oral contraceptives and cigarettes, but had no other risk factors for stroke. Single photon emission computed tomographic images showed bilateral and asymmetric reductions in blood flow to anterior and lateral brain regions. These findings correlated better with clinical symptomatology and suggested more extensive brain involvement than did computed tomography.

Sequential Trials of Fluoxetine, Phenelzine, and Tranylcypromine in the Treatment of Obsessive-Compulsive Disorder

The effects of fluoxetine, phenelzine, and tranylcypromine in obses- sive-compulsive disorder (OCD) were compared in an open-label pilot study in- volving sequential treatment with these agents in six patients. Despite full (or maximally tolerated) trials on these medications, there was no improvement in OC symptoms referable to the pharmacotherapy. Three patients, however, subse- quently showed major improvement in symptoms following application of behav- ioral therapy techniques. Despite the small sample size, this study suggests that there may be many patients with OCD for whom these medications might be poorly tolerated or inef- fective, and emphasizes that behavioral-therapeutic techniques can be effective in patients for whom medications prove ineffective or intolerable. Of note, one pa- tient displayed simultaneous manic and OC symptoms, thus undermining pre- vious suggestions that the coexistence of these symptoms may not be possible. Several studies have found the serotonin reuptake inhibitor fluoxetine to be effective in the treatment of patients with obsessive-compulsive disorder (OCD) (Fontaine & Chouinard, 1986; Sommi, Crimson, & Bowden, 1987; Turner, Jacob, Beidel, & Himmelhoch, 1983, and several case reports suggest that the monoamine oxidase inhibitors (MAOIs) phenelzine and tranylcypromine may also be helpful in some patients

Brain structure localization in positron emission tomography: comparison of magnetic resonance imaging and a stereotactic method.

A method commonly used for localization of brain regions on positron emission tomographic (PET) images is direct visualization and designation of structure on the image itself. This technique, however, is limited to portions of the brain having sufficient differential radionuclide uptake to permit the recognition of structure by observers familiar with brain anatomy. Two other methods commonly used instead of direct visualization are magnetic resonance imaging (MRI) and stereotactic methods of localization. This report compares the accuracy of a MRI method versus a stereotactic method of brain structure localization of PET. The three localization methods were analyzed for sixteen different brain regions in 5 different subjects by two independent observers. The results were converted to PET pixel size (1 pixel = .127 cm) for comparison. MRI localization differed from direct visualization by a mean and standard deviation of approximately 2 +/- 1 pixels in both the X and Y dimensions. Stereotactic localization differed from direct visualization by approximately 2 +/- 1 pixels in the X dimension and by approximately 6 +/- 2 pixels in the Y dimension. This larger variation seen with the stereotactic method may be attributed to the questionable assumption of linearity of structure location with respect to size of the inner table of the calvarium.

Clinical SPRINT imaging. Preliminary results compared to conventional SPECT brain scanning using Tc-99m HMPAO.

We have performed initial clinical studies using the high resolution single photon ring tomograph (SPRINT) and Tc-99m HMPAO. To determine what additional anatomic detail can be depicted using this high resolution, dedicated head, multidetector SPECT device compared to conventional SPECT, six patients with stroke and one normal volunteer were imaged after the injection of 20 mCi Tc-99m HMPAO on a conventional rotating Anger gamma camera (GE-400AC), followed immediately by imaging on SPRINT. Imaging acquisition on the GE-400AC gamma camera was performed using 360 rotation, 64 stops, at 30 seclstop, yielding an average of 985,714 counts for a 10.0 mm thick slice. GE-400AC images were of good quality, having in-plane full width half maximum (FWHM) resolution of approximately 15mm. SPRINT acquisition of image data was performed using both the high resolution and high sensitivity apertures, with data collection over 15 or 20 minutes of imaging time accumulating approximately 500,000 counts and 1,000,000 counts, respectively, from patients in a 10.0 mm thick slice, achieving an in-plane FWHM resolution of approximately 8 mm and 10 mm for the two apertures, respectively. Both image resolution and contrast for visualization of gray, white, and cerebral spinal fluid filled brain structures were improved using SPRINT compared with theGE-4OOAC. We conclude that SPRINT is well suited for brain imaging with Tc-99m HMPAO and is of particular value for applications demanding high resolution.

Echocardiographic Confirmation of Mitral Valve Prolapse: A New Finding on Radionuclide Ventriculography- A Case Report

A prominent filling defect was depicted on a radionuclide ventriculogram in a patient with mitral regurgitation. This defect was later shown, by cardiac ultrasound, to be due to mitral valve prolapse into the left ventricle during diastole. This case illustrates that mitral valve prolapse should be added to the list of clinical entities that can result in an intraventricular defect on a radionu clide ventriculogram.