Detection of hemorrhagic hypointense foci in the brain on susceptibility-weighted imaging clinical and phantom studies.

Rationale And Objectives: To determine the sensitivity of susceptibility-weighted imaging (SWI) for depicting hemorrhagic hypointense foci of the brain in comparison with gradient-recalled echo (GRE)- and GRE-type single-shot echo-planar imaging (GREI, GRE-EPI), and to assess the basic characteristics of the susceptibility effect by using a phantom.

Materials And Methods: We prospectively examined 16 patients (9 males, 7 females, aged 10-74 years, mean 43 years) with hypointense foci using SWI, GREI, and GRE-EPI at a 1.5-T magnetic resonance (MR) unit.

Determination of overall perturbation factors for plane-parallel ionization chambers in electron beams.

Most dosimetry protocols recommend the use of plane-parallel chambers for dose determination in electron beams with energies below 10 MeV. The new IAEA TRS 381 (1997) protocol includes the overall perturbation factor p(Q) that consists of the in-scattering correction factor p(cav) (or P(repl)) and the wall correction factor p(wall) (or P(wall)). In this work, p(Q) for the commonly applied NACP, PTW/Roos and PTW/Markus plane-parallel chambers was determined experimentally.

Abnormal perfusion of the pituitary gland secondary to dural arteriovenous fistulas in the cavernous sinus: dynamic MR findings.

Background And Purpose: If venous congestion is the primary cause of pituitary gland enlargement in cases of dural arteriovenous fistulas (AVFs), other abnormal pituitary findings may be detectable on MR images. We sought to investigate the perfusion abnormality of the pituitary gland secondary to dural AVFs in the cavernous sinus and to clarify its clinical importance.

Methods: Nine consecutive patients (all female; age range, 50-77 years) with dural AVFs in the cavernous sinus underwent prospective MR examinations, including dynamic studies, before and after therapy.

Normal structures in the intracranial dural sinuses: delineation with 3D contrast-enhanced magnetization prepared rapid acquisition gradient-echo imaging sequence.

Background And Purpose: The potential pitfalls in the diagnosis of dural sinus thrombosis include the presence of arachnoid granulations, intrasinus fibrotic bands (so-called septa), and hypoplasia or aplasia of the dural sinuses. The purpose of this study was to assess the appearance, distribution, and prevalence of arachnoid granulations and septa in the dural sinuses by using a high resolution 3D contrast-enhanced magnetization prepared rapid acquisition gradient-echo (MPRAGE) imaging sequence.

Methods: Conventional MR images and contrast-enhanced MPRAGE images of 100 consecutive patients who had no abnormalities of the dural sinuses were retrospectively reviewed.

Comparison of 2D and 3D digital subtraction angiography in evaluation of intracranial aneurysms.

Background And Purpose: Although digital subtraction angiography (DSA) is considered the criterion standard for depiction of intracranial aneurysms, it is often difficult to determine the relationship of overlapping vessels to aneurysms when using 2D DSA. We compared 2D and 3D DSA in evaluation of intracranial aneurysms.

Methods: Thirty-six consecutive patients with cerebral aneurysms underwent 2D and 3D DSA.

Acute interstitial pneumonia: comparison of high-resolution computed tomography findings between survivors and nonsurvivors.

This study compared high-resolution computed tomography (CT) findings between 10 survivors and 21 nonsurvivors of acute interstitial pneumonia and evaluated whether the CT findings were predictive of patients' response to treatment. The survivor and nonsurvivor groups with pathologically or clinically diagnosed acute interstitial pneumonia were similar in age, sex, disease duration, and lung injury score. Retrospective, subjective evaluations of the CT scans were conducted by two independent observers without knowledge of patient outcomes.

Basilar artery aneurysm treated with coil embolization via persistent primitive trigeminal artery.

A saccular aneurysm of the right basilar-superior cerebellar artery associated with a persistent primitive trigeminal artery (PPTA) was successfully treated by endovascular occlusion with Guglielmi detachable coils. Since both vertebral arteries and the basilar artery proximal to the junction with the PPTA were hypoplastic, a microcatheter was advanced via the PPTA. To our knowledge, this is the first case report describing the treatment of the aneurysm through the PPTA.

Prospective evaluation of suspected stenoocclusive disease of the intracranial artery: combined MR angiography and CT angiography compared with digital subtraction angiography.

Background And Purpose: MR angiography is primarily and increasingly used to assess intracranial arterial stenoocclusion. However, MR angiography can cause overestimation of stenosis. Although CT angiography is accurate, it has limitations.