Combined pulmonary fibrosis and emphysema: 3D time-resolved MR angiographic evaluation of pulmonary arterial mean transit time and time to peak enhancement.

PURPOSE: To correlate conventional invasive pressure indexes of pulmonary circulation with pulmonary first-order arterial mean transit time (MTT) and time to peak enhancement (TTP) measured by means of three-dimensional time-resolved magnetic resonance (MR) angiography in patients with combined pulmonary fibrosis and emphysema (CPFE). MATERIALS AND METHODS: The study was institutional review board approved. All subjects involved in the study provided written informed consent. Eighteen patients with CPFE were enrolled in this study. Thirteen healthy individuals matched for age and sex served as control subjects. Three-dimensional time-resolved MR angiography was performed by using a 3.0-T MR imager. Regions of interest (ROIs) were drawn manually on first-order pulmonary arteries. Within the ROIs, signal intensity-versus-time curves reflecting the first pass of the contrast agent bolus in the pulmonary vessels were obtained. MTT and TTP were calculated. Pulmonary arterial pressure and pulmonary capillary wedge pressure were measured with a double-lumen, balloon-tipped catheter that was positioned in the pulmonary artery. The mean pulmonary arterial pressure (mPAP) and the pulmonary vascular resistance (PVR) were determined. RESULTS: MTT and TTP values were prolonged significantly in patients with CPFE compared with those in the control subjects (P < .001). Mean TTP and mean MTT correlated directly with mPAP and PVR index (P < .005). At multiple linear regression analysis, MTT was the only factor independently associated with PVR index and mPAP. CONCLUSION: Three-dimensional time-resolved MR angiography enables determination of pulmonary hemodynamic parameters that correlate significantly with the pulmonary hemodynamic parameters obtained with invasive methods and may represent a complementary tool for evaluating pulmonary hypertension in patients with CPFE.

A hand-held ultrasound machine vs. conventional ultrasound machine in the bedside assessment of post-liver transplant patients.

The purpose was to assess the diagnostic accuracy of a hand-held Doppler ultrasound (US) machine for the bedside detection of liver and vascular abnormalities after liver transplantation in the intensive care unit. The IRB approved this study, and written informed consent was obtained from all patients or the patient's legal representative. Any liver transplant recipient at our institution who needed a bedside Doppler US examination in the intensive care unit was eligible. Patients underwent routine grey-scale, colour, and spectral Doppler US examinations of the liver with a conventional machine, which was taken as the reference method, and with a hand-held machine on the same day. Examinations followed one another and were performed in a blinded fashion by two radiologists. Over a 4-month period, 24 consecutive patients (16 men, median age 54 years old; 16 cadaveric and 8 living related right liver transplantations) underwent 43 examinations with both conventional and hand-held machines. Image quality and overall satisfaction scores of grey-scale were lower with the hand-held than with the conventional machine. The hand-held was similar to the conventional machine for assessing the patency of portal veins, hepatic veins and the IVC in all patients but one. The hand-held machine failed to detect signals in the right branch of the hepatic artery and in the hilum in two and one cases, respectively. There was no abnormal hepatic arterial flow with the conventional machine in any of the patients, and the results were the same with the hand-held machine. Total examination time was significantly longer with the hand-held machine. The hand-held US machine had a high diagnostic accuracy for both parenchymal and vascular analyses compared with a conventional US machine in the bedside assessment of post-liver transplant patients.