Search results for " Enhancement"
showing 10 items of 521 documents
Evaluation of texture analysis for the differential diagnosis of focal nodular hyperplasia from hepatocellular adenoma on contrast-enhanced CT images
2018
PurposeTo explore the value of CT texture analysis (CTTA) for differentiation of focal nodular hyperplasia (FNH) from hepatocellular adenoma (HCA) on contrast-enhanced CT (CECT).MethodsThis is a retrospective, IRB-approved study conducted in a single institution. A search of the medical records between 2008 and 2017 revealed 48 patients with 70 HCA and 50 patients with 62 FNH. All lesions were histologically proven and with available pre-operative CECT imaging. Hepatic arterial phase (HAP) and portal venous phase (PVP) were used for CTTA. Textural features were extracted using a commercially available research software (TexRAD). The differences between textural parameters of FNH and HCA wer…
Assessment of the distal anastomosis of coronary artery bypass grafts with a 2D T2-weighted turbo spin echo sequence and correlation to conventional …
2005
Abstract Objective The aim of the study was to evaluate the patensies of the distal anastomoses of coronary artery bypass grafts and to detect graft stenoses and occlusions with a magnetic resonance (MR) spin echo sequence. Patients and methods One hundred and eighty-five patients with 481 distal anastomoses were examined with a 1.5 T MR scanner and coronary angiography. A 2-dimensional T2-weigthed breath-hold half-Fourier acquisition single-shot turbo spin echo sequence (Haste) was performed. All images were evaluated independently by a radiologist and cardiologist and compared to the conventional coronary angiography. The observers were blinded to the coronary angiography findings, but in…
Accuracy of SWI sequences compared to T2*-weighted gradient echo sequences in the detection of cerebral cavernous malformations in the familial form
2016
Purpose The purpose of this study was to assess the accuracy of susceptibility-weighted imaging (SWI), compared with T2*-weighted gradient echo (GRE) imaging in assessing cerebral cavernous malformations. Materials and methods We retrospectively evaluated 21 patients with a familial form of cavernous malformation. Magnetic resonance (MR) protocol included non-enhanced and contrast-enhanced fast-spin echo (FSE) T1-weighted sequences, FSE T2-weighted sequences, fluid-attenuated inversion-recovery (FLAIR), GRE T2*-weighted and SWI sequences. Images were reviewed in consensus by two expert neuroradiologists to assess the location, number, size and conspicuity of the lesions on T2*-weighted GRE …
Single region of interest versus multislice T2* MRI approach for the quantification of hepatic iron overload.
2011
Purpose To evaluate the effectiveness of the single ROI approach for the detection of hepatic iron burden in thalassemia major (TM) patients in respect to a whole liver measurement. Materials and Methods Five transverse hepatic slices were acquired by a T2* gradient-echo sequence in 101 TM patients and 20 healthy subjects. The T2* value was calculated in a single region of interest (ROI) defined in the medium-hepatic slice. Moreover, the T2* value was extracted on each of the eight ROIs defined in the functionally independent segments. The mean hepatic T2* value was calculated. Results For patients, the mean T2* values over segments VII and VIII were significantly lower. This pattern was su…
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…
CT-guided intratumoral gene therapy in non-small-cell lung cancer.
1999
The objective of this study was to prove the principle of CT-guided gene therapy by intratumoral injection of a tumor suppressor gene as an alternative treatment approach of incurable non-small-cell lung cancer. In a prospective clinical phase I trial six patients with non-small-cell lung cancer and a mutation of the tumor suppressor gene p53 were treated by CT-guided intratumoral gene therapy. Ten milliliters of a vector solution (replication-defective adenovirus with complete wild-type p53 cDNA) were injected under CT guidance. In four cases the vector solution was completely applied to the tumor center, whereas in two cases 2 ml aliquots were injected into different tumor areas. For the …
A phase I study of adenovirus-mediated wild-type p53 gene transfer in patients with advanced non-small cell lung cancer.
1998
Mutations of the tumor suppressor gene p53 are the most common genetic alterations observed in human cancer. Loss of wild-type p53 function impairs cell cycle arrest as well as repair mechanisms involved in response to DNA damage. Further, apoptotic pathways as induced by radio- or chemotherapy are also abrogated. Gene transfer of wild-type p53 was shown to reverse these deficiencies and to induce apoptosis in vitro and in preclinical in vivo tumor models. A phase I dose escalation study of a single intratumoral injection of a replication-defective adenoviral expression vector encoding wild-type p53 was carried out in patients with incurable non-small cell lung cancer. All patients enrolled…
Contrast-Enhanced Ultrasonography With SonoVue
2009
Objective. We investigated the ability of contrast-enhanced ultrasonography with SonoVue (Bracco SpA, Milan, Italy), a sulfur hexafluoride microbubble contrast agent, to reveal differences between benign and malignant focal splenic lesions. Methods. In a prospective study we investigated 35 lesions in 35 patients (24 male and 11 female; mean age ± SD, 54 ± 15 years) with focal splenic lesions detected by B-mode ultrasonography. After intravenous injection of 1.2 to 2.4 mL of SonoVue, the spleen was examined continuously for 3 minutes using low–mechanical index ultrasonography with contrastspecific software. The final diagnosis was established by histologic examination, computed tomography, …
Feasibility, reproducibility, and reliability for the T*2 iron evaluation at 3 T in comparison with 1.5 T
2012
This study aimed to determine the feasibility, reproducibility, and reliability of the multiecho T * 2 Magnetic resonance imaging technique at 3 T for myocardial and liver iron burden quantification and the relationship between T * 2 values at 3 and 1.5 T. Thirty-eight transfusion-dependent patients and 20 healthy subjects were studied. Cardiac segmental and global T * 2 values were calculated after developing a correction map to compensate the artifactual T * 2 variations. The hepatic T * 2 value was determined over a region of interest. The intraoperator and interoperator reproducibility for T * 2 measurements at 3 T was good. A linear relationship was found between patients' R (1000/T * …
Tumori gastrointestinali stromali: Aspetti con tomografia computerizzata multidetettore (40-strati)
2006
Purpose. The purpose of this study was to describe the findings and evaluate the role of multidetector (40-slice) computed tomography (MDCT) in the preoperative assessment of gastrointestinal stromal tumours (GISTs). Materials and methods. Thirteen patients with histologically proven GIST (size: 4-30 cm; mean: 9 cm) underwent 40-slice MDCT after the ingestion of 1,000 ml of water. Images were obtained before and 70 s after intravenous injection of 120 ml of iodinated contrast agent. Two experienced radiologists reviewed the CT findings to evaluate lesion site, size, margins, attenuation, growth pattern, enhancement pattern, ascites, lymphadenopathy, direct invasion to adjacent organs and di…