Search results for " MR imaging"
showing 10 items of 16 documents
Peritumoral perfusion and proton spectroscopic MR imaging in the differentiation of gliomas and solitary metastases
2015
Purpose: To asses the value of peritumoural perfusion-weighted and proton spectroscopic MR imaging in preoperative grading of gliomas and in differentiating between primary gliomas and solitary metastases. Methods and Materials: Ten low-grade gliomas, eight high-grade gliomas, and ten metastases were prospectively evaluated with MR imaging, dynamic susceptibility contrast-enhanced perfusion imaging, and single-voxel proton MR spectroscopy before surgical resection or stereotactic biopsy. Maximal rCBV values and maximal Cho/Cr ratios were calculated from peritumoural region surrounding the tumour. Tumour grade presumed with these values was compared to histopathologic grading. Differences in…
Temperature Measurement by Diffusion-Weighted Imaging
2021
Diffusion-weighted imaging (DWI) thermometry is a magnetic resonance-based imaging tool that allows the noninvasive measurement of brain core temperature. Although only applicable to cerebrospinal fluid, it is thought to be potentially useful in assessing the thermal pathophysiology of the brain in both patients and healthy subjects. The objective of this article is to provide a concise but thorough review of the basic physical principles and the principal applications of DWI thermometry as a potential method to elucidate the pathophysiology of several brain diseases and neurologic syndromes.
Neuronavigated-biopsy in the diagniosis of demyelinating pseudotumoral brain lesions. Case report.
2013
Introduction: Pseudotumoral-demyelinating lesions are typically characterized by severe difficulties in differential diagnosis from gliomas, metastatic tumors and abscesses. Marburg’s disease (MD) is an extremely rare and aggressive form of Mutiple Sclerosis (MS) with acute onset, rapid neurological deterioration, and poor prognosis. MRI images often show pseudotumoral lesions characterized by mild and focal or, sometimes, ring enhancement. Perhaps, radiological aspect can vary, making necessary hystopathological confirmation. Objectives: There is increasing interest in the role of surgical biopsy for a correct and early diagnosis of pseudotumoral demyelinating lesions. We report an histopa…
INTRACRANICAL HEMANGIOPERICYTOMA: CASE REPORT AND REVIEW OF LITERATURE
2013
PURPOSE: We present a case of intracranical hemangiopericytoma (HPC) in a patient with migraine (male, 49 years old), who also presented mental confusion and partial left sensorimotor syndrome. We will also provide some elements regarding the international classification of this rare and highly vascularized mesenchymal tumor, and will consider possible differential diagnosis with other more common extra-axial masses. METHODS: After a preliminary examination in ER, patient underwent to head CT examination and was then transferred to the neurosurgical unit. The day after a brain MR examination was performed using advanced techniques too (PWI, and MRS); before surgery also functional MR imagin…
Neuro-radiosurgery treatments: MRI brain tumor seeded image segmentation based on a cellular automata model
2016
Gross Tumor Volume (GTV) segmentation on medical images is an open issue in neuro-radiosurgery. Magnetic Resonance Imaging (MRI) is the most promi-nent modality in radiation therapy for soft-tissue anatomical districts. Gamma Knife stereotactic neuro-radiosurgery is a mini-invasive technique used to deal with inaccessible or insufficiently treated tumors. During the planning phase, the GTV is usually contoured by radiation oncologists using a manual segmentation procedure on MR images. This methodology is certainly time-consuming and op-erator-dependent. Delineation result repeatability, in terms of both intra- and inter-operator reliability, is only obtained by using computer-assisted appr…
Pigmented villonodular bursitis (PVNB) in the medial gastrocnemius bursa:report of an unusual case.
2009
INTRODUCTION: Pigmented villonodular synovitis (PVNS) represents an uncommon benign proliferative disorder that may involve the synovium of the joint diffusely or focally, or that may occur extraarticularly in a bursa (pigmented villonodular bursitis [PVNB]) or tendon sheath (pigmented villonodular tenosynovitis [PVNTS]). The knee, followed by the hip, is the most common location for PVNS or PVNB, whereas PVNTS occurs most often in the hand and foot. It primarily involves young adults, the peak age being between the second and fourth decade of life and appears with non-specific symptoms which mimic other pathologies, including traumatic knee injuries, thus often delaying the correct diagnos…
Using anatomic and metabolic imaging in stereotactic radio neuro-surgery treatments
2016
High-b-Value Diffusion-weighted MR Imaging of Benign Hepatocellular Lesions: Quantitative and Qualitative Analysis
2012
PURPOSE:To analyze the signal intensity (SI) of benign hepatocellular lesions in high-b-value diffusion-weighted (DW) magnetic resonance (MR) images and to compare the apparent diffusion coefficient (ADC) values of focal nodular hyperplasias (FNHs) with those of hepatocellular adenomas (HCAs). MATERIALS AND METHODS: This retrospective study was approved by institutional review board, with waiver of informed consent. Inclusion criteria were consecutive patients with diagnosed FNH or HCA who underwent MR imaging with a DW sequence of the liver at three b values, 0, 150, and 600 sec/mm2. The final study population included 67 patients (seven men, 60 women) with 90 hepatocellular lesions (54 FN…
Automated prostate gland segmentation based on an unsupervised fuzzy C-means clustering technique using multispectral T1w and T2w MR imaging
2017
Prostate imaging analysis is difficult in diagnosis, therapy, and staging of prostate cancer. In clinical practice, Magnetic Resonance Imaging (MRI) is increasingly used thanks to its morphologic and functional capabilities. However, manual detection and delineation of prostate gland on multispectral MRI data is currently a time-expensive and operator-dependent procedure. Efficient computer-assisted segmentation approaches are not yet able to address these issues, but rather have the potential to do so. In this paper, a novel automatic prostate MR image segmentation method based on the Fuzzy C-Means (FCM) clustering algorithm, which enables multispectral T1-weighted (T1w) and T2-weighted (T…