Search results for " Medical imaging"
showing 10 items of 1067 documents
Magnetic resonance myelography evaluation of the lumbar spine end plates and intervertebral disks.
2005
Purpose: To evaluate the value of magnetic resonance (MR) myelography in the evaluation of intervertebral disk and end‐plate degenerative changes in the lumbar spine.Material and Methods: Conventional MR and MR myelography examinations were performed in 150 consecutive patients (69 F and 81 M, mean age 45±15 years, range 18–89). Sagittal T1 and T2‐weighted TSE images were compared to MR myelography obtained with a multishot‐TSE‐T2‐weighted sequence (4000/250/fat suppression). Coronal, sagittal, and both oblique MR myelography projections were obtained. Image analysis was carried out independently by two radiologists who categorized lumbar disks into normal, degenerated, or edematous; and ve…
T2-mapping of the sacroiliac joints at 1.5 Tesla: a feasibility and reproducibility study
2018
Objective: To evaluate the reproducibility of T2 relaxation time measurements of the sacroiliac joints at 1.5 T. Materials and methods: Healthy volunteers underwent an oblique axial multislice multiecho spin-echo sequence of the sacroiliac joints at 1.5 T. Regions of interest were manually drawn using a dedicated software by two musculoskeletal radiologists to include the cartilaginous part of the sacroiliac joints. A senior radiologist performed the measurement twice, while a resident measured once. Intra- and inter-observer reproducibility was tested using the Bland-Altman method. Association between sex and T2 relaxation times was tested using the Mann-Whitney U test. Correlation between…
Evaluation of breast tumor blood flow with dynamic first-pass 18F-FDG PET/CT: comparison with angiogenesis markers and prognostic factors
2012
The purpose of this study was to prospectively evaluate the relationship between tumor blood flow and glucose metabolism as evaluated by dynamic first-pass (18)F-FDG PET and by proliferation and endothelial pathologic markers in the setting of newly diagnosed breast cancer.Forty patients were prospectively included. Biopsy samples of each tumor were used to assess the Ki67 index of proliferation and immunostaining for CD34 (a panendothelial cell marker) and CD105 (a proliferation-related endothelial cell marker). All patients underwent (18)F-FDG PET/CT at least 1 wk after sample biopsy and before any treatment. A dynamic 2-min acquisition was performed immediately after intravenous injectio…
Renal endometriosis mimicking complicated cysts of kidney: report of two cases
2017
Endometriosis is a common gynecologic disorder characterized by ectopic endometrial tissue growth outside the uterine cavity. Although usually occurring in pelvic organs, endometrial lesions may involve urinary tract. Renal endometriosis is extremely rare and it has only occasionally been reported in the past. We report two cases of patients with renal cystic lesions, incidentally found at imaging techniques during oncologic follow-up for gastric sarcoma and melanoma, initially misinterpreted as complicated haemorrhagic cysts and then histologically characterized as renal localizations of extragenital endometriosis.
External validation of a prognostic model estimating the survival of patients with recurrent high-grade gliomas after reirradiation
2015
PURPOSE: We aimed to validate a controversial prognostic model for the survival of relapsed malignant glioma patients after reirradiation with an independent, multicentric patient cohort.METHODS AND MATERIALS: A total of 165 malignant glioma patients underwent reirradiation at 4 different institutions between 1994 and 2012. Twenty-two patients had a good (score 1), 44 had a moderate (score 2), and 99 had a poor prognosis (score 3 or 4). Four statistical methods were used to validate the prognostic model: First, we compared survival according to prognostic group in the construction and the validation cohort by visual comparison of the respective Kaplan-Meier plots. Second, discrimination was…
Imaging findings of primary breast sarcoma : results of a first multicenter study
2016
Abstract Purpose To investigate imaging findings in patients with primary breast sarcoma (PBS). Materials and methods A retrospective search in the databases of 10 radiological departments in Germany from 2000 to 2011 was performed. Only histologically proven cases of PBS were included into the study. Mammography was available in 31 patients (33 lesions), ultrasound images in 24 patients (24 lesions), and for 10 patients (14 lesions) magnetic resonance imaging (MRI) of the breast was performed. The breast findings were classified according to the American College of Radiology Breast Imaging Reporting and Data Systems (BI-RADS) 5th edition categories. Collected data were evaluated by means o…
Virtopsy and Living Individuals Evaluation Using Computed Tomography in Forensic Diagnostic Imaging
2019
The applications of forensic radiology involve both Virtopsy both studies on living people - to demonstrate bone age, search for foreign bodies, such as voluntary injection of drug ovules or surgical sponges accidentally forgotten, to assess gunshot wounds, to evaluate injuries by road accidents, and cases of violence or abuse (both in adults and in children). Computed tomography is the most used imaging tool used in forensic pathology and its indications are mainly focused on cases of unnatural deaths or when a crime is suspected. It is preferred over the standard autopsy in selected cases, such as in putrefied, carbonized or badly damaged bodies; or as a preliminary evaluation in mass dis…
Endovascular Embolization of a Large High-Flow Splenic Arteriovenous Fistula and Aneurysm Using the Amplatzer Vascular Plug II.
2015
We describe the use of an Amplatzer Vascular Plug (AVP) II for embolizing a large high-flow splenic arteriovenous fistula and an aneurysm in a young patient. This patient presented to our center with persistent mild abdominal discomfort, 5 years after open splenectomy. Contrast-enhanced computed tomography angiography showed the presence of a fistula between the splenic arterial and splenic venous remnants and a resultant fusiform aneurysmal dilatation of the residual splenic vein. We decide to embolize the splenic artery with a 12-mm diameter AVP II with an oversizing by 70% of the vessel diameter. Celiac angiography performed 5 min postembolization revealed complete obliteration of the sp…
Impact of Thoracic Endografting on the Hemodynamics of the Native Aorta: Pre- and Postoperative Assessments of Wall Shear Stress and Vorticity Using …
2021
Purpose To quantify the hemodynamic consequences of thoracic endovascular aortic repair (TEVAR) by comparing the preoperative and postoperative wall shear stress (WSS) and vorticity profiles on computational fluid dynamics (CFD) simulations. Materials and Methods The pre- and postoperative computed tomography (CT) scans from 20 consecutive patients (median age 69 years, range 20–87) treated for different thoracic aortic pathologies (11 aneurysms, 5 false aneurysms, 3 penetrating ulcers, and 1 traumatic aortic rupture) were segmented to construct patient-specific CFD models using a meshless code. The simulations were run over the cardiac cycle, and the WSS and vorticity values measured at th…
A simplified framework to optimize MRI contrast preparation
2018
PURPOSE This article proposes a rigorous optimal control framework for the design of preparation schemes that optimize MRI contrast based on relaxation time differences. METHODS Compared to previous optimal contrast preparation schemes, a drastic reduction of the optimization parameter number is performed. The preparation scheme is defined as a combination of several block pulses whose flip angles, phase terms and inter-pulse delays are optimized to control the magnetization evolution. RESULTS The proposed approach reduces the computation time of B 0 -robust preparation schemes to around a minute (whereas several hours were required with previous schemes), with negligible performance loss. …