An important step in PET brain kinetic analysis is the registration of functional data to an anatomical MR image. Typically, PET-MR registrations in nonhuman primate neuroreceptor studies used PET images acquired early post-injection, (e.g., 0-10 min) to closely resemble the subject's MR image. However, a substantial fraction of these registrations (~25%) fail due to the differences in kinetics...

BACKGROUND AND PURPOSE To our knowledge, a detailed analysis of MR findings in spinal hemangioblastoma has not been conducted to date. Our purpose was to elucidate the MR features of this disease with special attention to tumor size, correlation with MR findings and clinical symptoms, and any differences between patients with and without von Hippel-Lindau disease (VHLD). METHODS MR images in ...

BACKGROUND AND PURPOSE Spinal epidural abscesses are major complications of epidural anesthesia, and their MR features have been reported. In patients receiving continuous infusion via an epidural catheter, MR findings may mimic those of spinal epidural abscess in the absence of infection. The purpose of this study was to assess the spinal MR findings associated with continuous epidural anesthe...

CONTEXT In the United States an estimated 6 million persons are affected by scoliosis, which is characterized by a 3-dimensional deformity of the spine that involves a curvature in the sagittal, frontal, and transverse planes. OBJECTIVE To determine the rates of scoliosis in patients with spine-related pain unassociated with cancer, as demonstrated by magnetic resonance (MR) images obtained w...

The MR finding of an acute spinal epidural hematoma (SEH) can mimic epidural neoplastic or inflammatory lesions, because acute SEH appears hypointense on T1-weighted images and hyperintense on T2-weighted images. We report on two cases of acute SEH with unusual contrast enhancement patterns on MR images. Contrast enhancement can be an MR finding of acute SEH, especially in bleeding diathesis, w...

In this paper we present a Bayesian method to enhance functional 3D PET images using apriori knowledge about the brain anatomy obtained from 3D MR images. We use a Markov Random Field as a prior model, which have the possibility of incorporating this information. We show both a small test example as well as a true PET-MR result, and further more show how to obtain the desired information from t...

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. METHODS Ten subjects were studied with both PET and functional MR. Clinical diagnoses included probable Alzheimer disease (n = 5), possible Alzhe...

Introduction: Adenomyomatosis of the gallbladder (AGB) is a relatively common disease. AGB is defined as epithelial proliferation and hypertrophy of the muscularis of the gallbladder with outpouching of the mucosa into the thickened muscular layer ( RAS; Rokitansky-Aschoff sinus). It is known that AGB is classified into three different morphological types including diffuse , segmental, and fund...

PURPOSE To evaluate the utility of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) in characterizing atypically enhanced cirrhotic nodules detected on conventional Gd-DTPA-enhanced MR images. MATERIALS AND METHODS We enrolled 61 consecutive patients with 88 atypical nodules seen on conventional Gd-DTPA-enhanced MR images who underwent Gd-EOB-DTPA-enhanced MRI within a 3-month period. Us...

Medical image segmentation is an essential and challenging aspect in computer-aided diagnosis and also in pattern recognition research. This paper proposes a hybrid method for magnetic resonance (MR) image segmentation. We first remove impulsive noise inherent in MR images by utilizing a vector median filter. Subsequently, Otsu thresholding is used as an initial coarse segmentation method that ...