Search results for "030218 nuclear medicine & medical imaging"

Performance of morphologic criteria for the diagnosis of cirrhosis in patients with non-alcoholic steatohepatitis compared to other etiologies of chr…

2020

Purpose To compare the diagnostic performance of morphologic criteria for detection of cirrhosis in patients with alcoholic liver disease (ALD), hepatitis C (HCV), and non-alcoholic steatohepatitis (NASH). Methods One hundred patients (53 male) with different etiologies of chronic liver disease (NASH,n = 41; HCV,n = 39; and ALD,n = 20) and with different degrees of fibrosis on histopathologic examination (74 with cirrhosis) were retrospectively evaluated. Four readers (R1: fellowship-trained abdominal radiologist, R2: community attending radiologist, R3: senior radiology resident/research fellow, R4: junior radiology resident) analyzed the contrast-enhanced CTs for presence of commonly acce…

Uncommon imaging evolutions of focal liver lesions in cirrhosis.

2019

Objective: The purpose of this article is to describe and illustrate uncommon imaging evolutions of benign (i.e., cyst, hemangioma, focal nodular hyperplasia-like nodules, and hepatic angiomyolipoma) and malignant (i.e., HCC and non HCC malignancies) lesions in a cirrhotic liver. The content highlights relevant pathogenesis and imaging clues for proper differential diagnosis. Revision of prior imaging and knowledge of these scenarios may help the abdominal radiologist to reach a noninvasive diagnosis and direct the patient to the most appropriate clinical management. Conclusion: Uncommon imaging evolutions of focal liver lesions in cirrhosis may represent a challenge for the abdominal radio…

Liver stiffness measurement in patients with nodular regenerative hyperplasia undergoing magnetic resonance elastography

2020

Purpose Nodular regenerative hyperplasia (NRH) may mimic cirrhosis at imaging. We aim to investigate the effect of NRH on liver stiffness measurement (LSM) obtained with magnetic resonance elastography (MRE).Methods This retrospective, Institutional Review Board-approved study included 37 subjects with NRH (Group 1) and no or minimal fibrosis (F0-F1), a control group (Group 2) made of 30 subjects with non-advanced fibrosis (F0-F2), and a control group (Group 3) made of 30 subjects with advanced fibrosis (F3-F4), all with available MRE. LSM was measured in each subject along with assessment of hepatic morphological features of cirrhosis and signs of portal hypertension. The significance of t…

Color Doppler Ultrasound in Portal Hypertension

2020

Portal hypertension is one of the most important causes of morbidity and mortality in cirrhotic patients. A color Doppler evaluation of the left gastric vein (LGV) has proven utility in the prediction of esophageal varices and variceal bleeding in patients with portal hypertension. The purpose of this review is to discuss the ultrasound evaluation, imaging findings, and clinical application of Doppler ultrasound in the assessment of the LGV. Knowledge of the color Doppler technique and imaging findings of the LGV may help clinicians improve the monitoring of portal hypertension and predict patients with a high risk of esophageal varices.

Congenital Cystic Lesions of the Bile Ducts: Imaging-Based Diagnosis

2020

Congenital cystic lesions of the bile ducts represent a spectrum of liver and biliary system lesions, resulting from abnormal embryologic development of the ductal plate. These disorders include Caroli disease, choledochal cysts, autosomal dominant polycystic liver disease, congenital hepatic fibrosis, and biliary hamartomas. Each disorder carries a peculiar clinical presentation, prognosis, and risk of complications. Knowledge of radiological findings of fibropolycystic liver diseases is crucial for their appropriate detection and for differential diagnosis with other similar hepatic cystic lesions, in order to avoid relevant misdiagnosis. The aim of this review is to provide an illustrati…

A smart and operator independent system to delineate tumours in Positron Emission Tomography scans

2018

Abstract Positron Emission Tomography (PET) imaging has an enormous potential to improve radiation therapy treatment planning offering complementary functional information with respect to other anatomical imaging approaches. The aim of this study is to develop an operator independent, reliable, and clinically feasible system for biological tumour volume delineation from PET images. Under this design hypothesis, we combine several known approaches in an original way to deploy a system with a high level of automation. The proposed system automatically identifies the optimal region of interest around the tumour and performs a slice-by-slice marching local active contour segmentation. It automa…

Comparison of different segmentation approaches without using gold standard. Application to the estimation of the left ventricle ejection fraction fr…

2011

International audience; A statistical method is proposed to compare several estimates of a relevant clinical parameter when no gold standard is available. The method is illustrated by considering the left ventricle ejection fraction derived from cardiac magnetic resonance images and computed using seven approaches with different degrees of automation. The proposed method did not use any a priori regarding with the reliability of each method and its degree of automation. The results showed that the most accurate estimates of the ejection fraction were obtained using manual segmentations, followed by the semiautomatic methods, while the methods with the least user input yielded the least accu…

Pulmonary infiltrate with characteristic “reversed halo” and “air crescent” signs

2016

18F-Florbetaben PET/CT to Assess Alzheimer's Disease: A new Analysis Method for Regional Amyloid Quantification.

2019

Background and purpose While AD can be definitively confirmed by postmortem histopathologic examination, in vivo imaging may improve the clinician's ability to identify AD at the earliest stage. The aim of the study was to test the performance of amyloid PET using new processing imaging algorithm for more precise diagnosis of AD. Methods Amyloid PET results using a new processing imaging algorithm (MRI-Less and AAL Atlas) were correlated with clinical, cognitive status, CSF analysis, and other imaging. The regional SUVR using the white matter of cerebellum as reference region and scores from clinical and cognitive tests were used to create ROC curves. Leave-one-out cross-validation was carr…

Cerebral metabolism after transient ischemic attack. A 1H MR spectroscopy study

1999

International audience; Abstract: Metabolic changes induced by cerebral infarction or by stenosis and occlusion of the internal carotid artery have been previously described in 1H Magnetic Resonance Spectroscopy (1H MRS). These changes are essentially characterized by decreased N-acetyl-aspartate (NAA) and increased lactate concentration. Little is known about the metabolic changes observed in the three days following a transient ischemic attack (TIA) in the absence of stenosis or occlusion of the internal carotid artery, and without visible infarction on Magnetic Resonance imaging (MRI). We studied five patients with a TIA lasting between 30 min and 3 h, affecting the sensory and motor fun…