Perfusion scanning

About: Perfusion scanning is a research topic. Over the lifetime, 9496 publications have been published within this topic receiving 223860 citations. The topic is also known as: perfusion imaging.

Pulmonary disorders: ventilation-perfusion MR imaging with animal models.

Abstract: PURPOSE: To demonstrate the capability of magnetic resonance (MR) imaging to assess alteration in regional pulmonary ventilation and perfusion with animal models of airway obstruction and pulmonary embolism. MATERIALS AND METHODS: Airway obstruction was created by inflating a 5-F balloon catheter into a secondary bronchus. Pulmonary emboli were created by injecting thrombi into the inferior vena cava. Regional pulmonary ventilation was assessed with 100% oxygen as a T1 contrast agent. Regional pulmonary perfusion was assessed with a two-dimensional fast low-angle shot, or FLASH, sequence with short repetition and echo times after intravenous administration of gadopentetate dimeglumine. RESULTS: Matched ventilation and perfusion abnormalities were identified in all animals with airway obstruction. MR perfusion defects without ventilation abnormalities were seen in all animals with pulmonary emboli. CONCLUSION: Ventilation and perfusion MR imaging are able to provide regional pulmonary functional informatio...

Dose Exposure of Patients Undergoing Comprehensive Stroke Imaging by Multidetector-Row CT: Comparison of 320-Detector Row and 64-Detector Row CT Scanners

Abstract: BACKGROUND AND PURPOSE: Recently introduced 320-detector row CT enables whole brain perfusion imaging compared to a limited scanning area in 64-detector row CT. Our aim was to evaluate patient radiation exposure in comprehensive stroke imaging by using multidetector row CT consisting of standard CT of the head, CTA of cerebral and cervical vessels, and CTP. MATERIAL AND METHODS: Organ doses were measured by using LiF-TLDs located at several organ sites in an Alderson-Rando phantom. Effective doses were derived from these measurements. Stroke protocols including noncontrast head CT, CTA of cerebral and cervical vessels, and CTP were performed on 320- and 64-detector row scanners. RESULTS: Measured effective doses for the different scanning protocols ranged between 1.61 and 4.56 mSv, resulting in an effective dose for complete stroke imaging of 7.52/7.54 mSv (m/f) for 64-detector row CT and 10.56/10.6 mSv (m/f) for 320-detector row CT. The highest organ doses within the area of the primary beam were measured in the skin (92 mGy) and cerebral hemispheres (69.91 mGy). Use of an eye-protection device resulted in a 54% decrease of the lens dose measured for the combo protocol for whole-brain perfusion with the 320-detector row CT scanner. CONCLUSIONS: Phantom measurements indicate that comprehensive stroke imaging with multidetector row CT may result in effective radiation doses from 7.52 mSv (64-detector row CT) to 10.6 mSv (320-detector row CT). The technique of 320-detector row CT offers additional information on the time course of vascular enhancement and whole-brain perfusion. Physicians should weigh the potential of the new technique against the higher radiation dose that is needed. Critical doses that would cause organ damage were not reached.

Coronary Microvascular Dysfunction Is Associated With Myocardial Ischemia and Abnormal Coronary Perfusion During Exercise.

Abstract: Background: Coronary microvascular dysfunction (MVD) is defined by impaired flow augmentation in response to a pharmacological vasodilator in the presence of nonobstructive coronary artery disease....

Improved identification of coronary artery disease in patients with left bundle branch block by use of dobutamine stress echocardiography and comparison with myocardial perfusion tomography

Abstract: This study compared the efficacy of dobutamine stress testing using 2-dimensional echocardiography and perfusion tomography for the noninvasive identification of coronary artery disease (CAD) in patients with left bundle branch block (LBBB). Twenty-four patients with permanent, complete LBBB (11 with previous myocardial infarction) were studied prospectively with dobutamine echocardiography and perfusion tomography. The presence of > 50% luminal diameter coronary stenosis was compared with the presence of dobutamine-induced fixed or reversible perfusion defects, and with resting or dobutamine-induced abnormalities of wall thickening. For each test, the left anterior coronary artery territory was compared with the circumflex and/or right coronary artery. Significant CAD was found in the left anterior descending coronary artery in 12 patients; all (100%) were identified by perfusion imaging, and 10 (83%, p = NS) by 2-dimensional stress echocardiography. In the 12 patients without left anterior descending CAD, scintigraphy was also positive in all (specificity: 0%), and echocardiography in only 1 (specificity: 92%, p < 0.01). The diagnostic accuracy was 50% and 87% (p < 0.05), respectively. This low specificity of perfusion tomography was improved by requiring an associated apical defect to indicate left anterior descending CAD and was corrected by restricting the diagnosis of coronary disease to those patients with partially reversible defects. In the circumflex and/or right coronary artery territory, sensitivity and specificity were similar using both techniques. We conclude that dobutamine-stress echocardiography is a specific and accurate test for the noninvasive identification of CAD, even in the left anterior descending artery territory of patients with LBBB.