Ischemic stroke and atrial fibrillation. A clinical study.

In view of the higher prevalence of severe ischemic stroke among patients with atrial fibrillation (AF) and of the recently reported higher frequency of stroke with AF in females, 516 consecutive patients with ischemic stroke, of whom 93 had AF, were retrospectively evaluated. The main anamnestic, clinical and laboratory features of the AF and non-AF groups were statistically compared and the features of the AF group were statistically evaluated according to gender and age. Our results confirm the greater severity of stroke in AF patients than in non-AF patients and the higher frequency of stroke with AF in female patients.

Hemodynamic assessment of vascular malformations by angio CT with generation of functional transit time images.

We performed a CT dynamic study during the first pass of an intravenously injected bolus of a iodinated contrast medium, followed by generation of the regional arm-brain circulation time (rABCT) image, in 11 patients with vascular malformations. All lesions could be detected as changes of rABCT, and the comparison with values of normal arteries and veins allowed the deduction of the hemodynamic conditions of the lesions. Seven cases showed evidence of altered distribution of rABCT in the corresponding brain hemisphere, suggesting a perfusion reserve impairment.

Functional circulation time images in the diagnosis of cerebral lesions by angio CT.

An application of angio CT as an adjunct to contrast enhancement evaluation of cerebral lesions is presented. We performed rapid sequential scanning following intravenous bolus injection of an iodinated contrast medium, analyzed the time contrast curves and generated a functional circulation time image. This was accomplished by calculating on a pixel-by-pixel basis the first mathematical moment of the monitored time-density curves about injection time which corresponds to regional arm brain circulation time (rABCT).

Assessment of 99mTc-HM-PAO parameters with SPECT for improved evaluation of blood flow in cerebral lesions.

A method for investigating the linearity between blood flow and distribution of 99mTc-HM-PAO uptake in patients undergoing single photon emission computed tomography (SPECT) is presented. This method, based on particular elaboration techniques of sequential multiple acquisitions, provides a local index: cumulative transit time (CTT) related to all factors, other than blood flow, affecting 99mTc-HM-PAO uptake. Because a correct qualitative blood flow estimation is based on the uniformity of the above factors, the occurrence of a change of this index indicates a nonlinear relation between blood flow and 99mTc-HM-PAO uptake distributions.