Diffusion-weighted imaging (DWI) is a powerful imaging technique in neuroimaging; its value in abdominal and pelvic imaging has only recently been appreciated as a result of improvements in magnetic resonance imaging technology. There is growing interest in the use of DWI for evaluating pathology in the pelvis. Its ability to noninvasively characterize tissues and to depict changes at a cellular level allows DWI to be an effective complement to conventional sequences of pelvic imaging, especially in oncologic patients.
Diffusion-weighted (DW) imaging is playing an increasingly important role in disease detection, prognostication, and monitoring of treatment response. Particularly in the realm of oncology, the potential applications for DW imaging continue to expand. In this article, the authors detail the role of DW imaging for pathologic processes involving the male pelvis. The authors describe the current data, new insights, and ongoing controversies regarding DW imaging of the male pelvis with a particular emphasis on oncologic applications.
The CNS is frequently involved in human immunodeficiency virus (HIV) infection. In recent studies using proton magnetic resonance spectroscopy, investigators found a significant reduction in N-acetyl aspartate, a metabolic marker of neurons, in late stages of dementia. To further understand the relationship between proton magnetic resonance spectroscopy changes and clinical disease and dementia, we compared 20 HIV-infected patients presenting at varying stages of acquired immunodeficiency syndrome (AIDS) dementia complex and infection to 10 age-matched controls.
The aim of this research was to determine whether in vivo nuclear magnetic resonance spectroscopic measurement of N-acetyl aspartate, a neuron specific brain marker, provides a quantitative index of neuronal loss. Five rats were injected unilaterally in the corpus striatum with kainic acid, an analogue of glutamate that causes excitotoxic degeneration of intrinsic neurons, and were subjected to nuclear magnetic resonance imaging and spectroscopic imaging.
The purpose of this study was to determine whether, in Alzheimer disease (AD) patients, abnormalities in energy charge or phospholipid metabolism could be detected during life with quantitative phosphorus magnetic resonance spectroscopy (31P MRS). We performed in vivo 31P MRS in 16 patients with a clinical diagnosis of probable AD with mild to moderate dementia severity (mean Blessed Dementia Score = 17.5, range = 7-37) and in 8 healthy, nondemented, age-matched, control subjects. MR studies were performed on a commercial 1.5 T MR imager using a volume head coil.
OBJECTIVE: To study changes in cerebral hemodynamics related to HIV infection.
BACKGROUND: Cerebral injury is a well-known manifestation of HIV infection. Physiologic changes in the HIV brain may precede structural changes and may be detected by functional MRI (fMRI).
METHODS: Dynamic contrast fMRI was used to measure the cerebral blood volume (CBV) in 13 patients infected with HIV and in 7 healthy control subjects.
RESULTS: Significant increases in dynamic CBV were found in the deep (p
PURPOSE: To determine whether magnetic susceptibility functional MR imaging of cerebral blood volumes provides information similar to fludeoxyglucose F 18 positron emission tomography (PET) brain images in patients undergoing evaluation for dementia.
Overall body fat and its distribution in different regions are important predispositions to known aberrations in lipid and glucose metabolism. The accuracy of MR imaging in estimating overall body fatness and regional fat distribution at individual landmarks was determined by comparing it with well-accepted measures by deuterium-oxide (D2O) dilution and bioimpedance analysis. Fourteen normal young women (athletes and control subjects) were studied. A total of 308 axial, T1-weighted, spin-echo MR images over a specific region in the trunk (21-24 scans per subject) were obtained.
