Detection of Pulmonary Embolism Using a Novel Dynamic Flat-Panel Detector System in Monkeys.

Background:Recently, dynamic chest radiography (DCR) was developed to evaluate pulmonary function using a flat-panel detector (FPD), which can evaluate blood flow in the pulmonary artery without injection of contrast agents. This study investigated the ability of a FPD to measure physiological changes in blood flow and to detect pulmonary embolism (PE) in monkeys.Methods and Results:DCR was performed in 5 monkeys using a FPD. Regions of interest (ROI) were placed in both lung fields of the image, and maximum changes in pixel value (∆pixel value) in the ROI were measured during 1 electrocardiogram cardiac cycle. Next, a PE model was induced using a Swan-Ganz catheter and additional images were taken. The ∆pixel value of the lungs in normal and PE models were compared in both supine and standing positions. The lung ∆pixel value followed the same cycle as the monkey electrocardiogram. ∆pixel values in the upper lung field decreased in the standing as compared to the supine position. In the PE model, the ∆pixel value decreased in the area of pulmonary blood flow occlusion and increased in the contralateral lung as compared to the normal model (normal model 1.287±0.385, PE model occluded side 0.428±0.128, PE model non-occluded side 1.900±0.431).Conclusions:A FPD could detect postural changes in pulmonary blood flow and its reduction caused by pulmonary artery occlusion in a monkey model

Vasovagal Reaction and Ischemic Colitis Following Blood Donation.

Vasovagal reactions are the most common type of adverse reaction after blood donation; however, there are no reports of ischemic colitis as an adverse reaction after blood donation. A previously healthy 55-year-old woman suffered loss of consciousness at the end of her first plasma donation. She was diagnosed with a vasovagal reaction and received hydration. However, she developed persistent left flank pain and watery diarrhea, followed by bloody diarrhea. Abdominal computed tomography confirmed ischemic colitis. She was asked to fast and was eventually discharged 7 days later. We should consider the possibility of ischemic colitis if patients develop persistent abdominal pain after transient hypotension, such as that observed during a vasovagal reaction