Dynamic contrast-enhanced MRI of ocular melanoma.

Dynamic contrast-enhanced MRI is used for the assessment of microvasculature in several tumours. We aimed to assess the contrast signal enhancement characteristics of ocular melanoma. Forty patients with ocular melanoma were prospectively investigated with ocular MRI including dynamic contrast-enhanced sequences over a 13-month period.

Topographic analysis and evaluation of anatomical landmarks for placement of central venous catheters based on conventional chest X-ray and computed tomography.

Background: Positioning central venous catheters (CVCs) in the proper part of the superior vena cava (SVC) is difficult. The aim of this exploratory study was to analyse topographic relationships of the extrapericardial SVC using chest X-ray (CXR) and computed tomography (CT). This included an appraisal of rules for optimal CVC tip placement.

Hypertensive heart disease: quantitative evaluation of response to therapy with cine MR imaging.

Rationale And Objectives: To assess the ability of cine magnetic resonance (MR) imaging to help detect and quantity changes in left ventricular parameters in patients receiving antihypertensive therapy.

Materials And Methods: After undergoing baseline cine MR imaging of the heart, 16 (12 men, four women) hypertensive patients participating in a prospective drug trial began isradipine therapy. Follow-up serial cine MR imaging was performed at 3 months and 6 months.

[Diagnosis and follow-up of muscle injuries by means of plain and contrast-enhanced MRT: experimental and clinical studies].

Purpose: To clarify the value of plain and contrast-enhanced MRI for the diagnosis and follow-up of muscle injuries, by means of experimental and clinical studies.

Method: 24 Wistar rats were studied following standardized division of the calf muscles by means of MRI carried out on the first day, and also after one, two, three and four weeks. In addition, 16 patients with muscle injuries were examined (32 examinations), first between the first and fifth day of trauma, and subsequently over a period of two to seven weeks (average: four weeks).

[Value of endoscopic ultrasound examination of the mediastinum in Hodgkin's and non-Hodgkin's lymphomas].

Aim: The applicability of ultrasound for diagnosing mediastinal diseases is limited by the surrounding thorax containing air and bone, permitting only restricted echo windows. Transoesophageal endoscopic ultrasound circumvents this problem and provides good visualisation of nearly all parts of the mediastinum. We evaluated the value of endoscopic ultrasonography for mediastinal staging of Hodgkin's and non-Hodgkin lymphoma patients.

[Endoscopic ultrasound of pathological mediastinal findings].

Introduction: Mediastinal diseases are mostly diagnosed by CT and MRI. The applicability of ultrasound is limited by the surrounding air- and bone-containing thorax, which permits only restricted echo windows. Transesophageal endoscopic ultrasonography circumvents this problem and ensures visualization of parts of the mediastinum.

Enhancement of thoracic masses using nonionic MR contrast agents.

Objective: This study evaluated the effect of a new nonionic MR contrast medium, gadodiamide injection (Omniscan; Sanofi-Winthrop), on enhancement of thoracic masses on T1-weighted SE images.

Materials And Methods: Gadodiamide injection was administered intravenously at a dose of 0.2 mmol/kg to 26 patients with thoracic masses.

Effect of magnetic susceptibility contrast medium on myocardial signal intensity with fast gradient-recalled echo and spin-echo MR imaging: initial experience in humans.

Purpose: To show the effect of dysprosium diethylenetriaminepentaacetic acid bis-methylamine injection on the images of normal human myocardium.

Materials And Methods: T2-sensitive fast gradient-recalled echo (GRE) (repetition time [TR], 10.8 msec; echo time [TE], 4.

Quantification of the left ventricular volumes and function with cine MR imaging: comparison of geometric models with three-dimensional data.

Acquisition and measurement of left ventricular (LV) volumes with a three-dimensional data set of cine magnetic resonance (MR) images from apex to base is a time-consuming process. Results of a study with 10 healthy volunteers and 10 patients with LV hypertrophy were prospectively evaluated. The heart was shown in the anatomic short- and horizontal long-axis planes with cine MR imaging.

Flow pattern analysis in the abdominal aorta with velocity-encoded cine MR imaging.

The sites of deposition of atherosclerotic plaque on the aortic wall are considered to be influenced by secondary and retrograde flow patterns that cause regions of altered shear stress. To detect secondary flow patterns and areas of retrograde flow in the abdominal aorta, velocity-encoded cine (VEC) magnetic resonance (MR) imaging was performed at five different levels of the abdominal aorta in nine healthy volunteers. Net retrograde flow (expressed as a percentage of antegrade flow) increased from proximal to distal levels and was maximal (13.

MR imaging of the myocardium using nonionic contrast medium: signal-intensity changes in patients with subacute myocardial infarction.

Objective: Gadodiamide injection (Omniscan, Sanofi Winthrop Pharmaceuticals, New York) is a new nonionic MR contrast medium that has been shown in animal studies to provide persistent differential enhancement of myocardial infarction. Because differential enhancement of normal and infarcted myocardium may be useful for the diagnosis and sizing of myocardial infarctions, we assessed the effectiveness of gadodiamide injection in enhancing signal-intensity differences between infarcted and normal myocardium on spin-echo T1-weighted images.

Subjects And Methods: Signal intensity of normal and infarcted myocardium, contrast ratio, contrast-to-noise ratio, and signal-to-noise ratio were measured in 12 patients with subacute myocardial infarction (mean, 16 days after diagnosis) before and after injection of contrast medium.

Velocity-encoded cine MRI in the evaluation of left ventricular diastolic function: measurement of mitral valve and pulmonary vein flow velocities and flow volume across the mitral valve.

Left ventricular diastolic function has been evaluated by means of analysis of the flow pattern through the mitral valve. Velocity-encoded cine magnetic resonance imaging (VEC-MR) is a new method for characterizing flow patterns in the heart. The feasibility of using VEC-MR to measure early diastolic (E) and atrial systolic (A) peak flow velocities and E/A ratios in the mitral inflow, as well as systolic (X), early diastolic (Y), and atrial systolic (Z) peak flow velocities and X/Y ratios in the pulmonary vein, was evaluated in 10 normal volunteers.

Right ventricular diastolic filling: evaluation with velocity-encoded cine MRI.

Abnormal flow velocity curves across the tricuspid valve (TV) and in the superior vena cava have been described in patients with abnormal right ventricular (RV) relaxation or restriction and with pericardial diseases by means of Doppler echocardiography. In this study, various imaging planes and strategies of velocity-encoded cine (VEC) MR for measurement of peak E and peak A velocities and the E/A ratio across the TV were evaluated and compared to Doppler measurements in 10 normal volunteers. In addition, VEC-MR velocity measurements were performed in the superior vena cava.

Contrast media for cardiothoracic MR imaging.

Contrast media have been used for the study of disease of the thorax. Most experience has consisted of the use of MR contrast media for improving the delineation of acute myocardial infarction, for demarcating the area of acute myocardial ischemia, and for demonstrating the area of potentially jeopardized myocardium after acute coronary occlusion. Contrast agents demonstrate the ischemic or jeopardized area as a zone of decreased signal intensity to normal myocardium.

Airway obstruction by right aortic arch with right-sided patent ductus arteriosus: demonstration by MRI.

An unusual cause of airway obstruction was demonstrated by MRI in two infants with congenital heart disease. The two infants experienced airway obstruction caused by a right aortic arch with right-sided patent ductus arteriosus. The diagnosis was established by MRI prior to surgery; angiography did not demonstrate the critical relationship between the large ductus and the airway.

Quantification of left to right atrial shunts with velocity-encoded cine nuclear magnetic resonance imaging.

Objectives: The purpose of this study was to evaluate the ability of velocity-encoded nuclear magnetic resonance (NMR) imaging to quantify left to right intracardiac shunts in patients with an atrial septal defect.

Background: Quantification of intracardiac shunts is clinically important in planning therapy.

Methods: Velocity-encoded NMR imaging was used to quantify stroke flow in the aorta and in the main pulmonary artery in a group of patients who were known to have an increased pulmonary to systemic flow ratio (Qp/Qs).

Severity of aortic regurgitation: interstudy reproducibility of measurements with velocity-encoded cine MR imaging.

The interstudy reproducibility of velocity-encoded cine (VEC) magnetic resonance (MR) imaging for quantification of regurgitant volume (RV) and regurgitant fraction (RF) was studied in 10 patients with chronic aortic regurgitation. Each patient underwent two VEC MR imaging studies. RV and RF were measured on the aortic flow curve by quantifying antegrade and retrograde flow per cardiac cycle.

[Experiences with intraoperative radiotherapy in gastric carcinoma (Berlin method)].

The aim of our pilot study is to determine whether intraoperative radiotherapy in gastric cancer cannot only prevent a local relapse but also improve the survival rate. Since November 1987, 26 patients with resectable gastric cancer were irradiated intraoperatively with the linear accelerator using fast electrons (single dose: 12 to 16 Gy). Percutaneous radiotherapy was performed postoperatively with 24 to 38 Gy (4 x 2 Gy per week).

[Variability and reproducibility in the determination of left-ventricular heart volume by cine-MR. A comparison of measurement methods].

Sixteen normal individuals were examined on a 1.5 T instrument using gradient echo sequences (cine-MR). The results of various computations were tested with respect to agreement and reproducibility of the methods.

[A semiquantitative assessment of aortic valve insufficiency by cine-MR compared to Doppler color echocardiography and cardioangiography].

A simple, reliable semiquantitative method for evaluating aortic valve insufficiency by means of cine MR is described. Ten normal persons and 36 patients with aortic valve abnormalities were examined in a 1.5 Tesla apparatus using ECG-triggered gradient echo sequences.