[Usefulness of Delay Time Setting in Computed Tomography Pulmonary Angiography].

Purpose: During computed tomography pulmonary angiography (CTPA), a decrease in the CT value of the pulmonary artery may be observed due to poor contrast enhancement, even though the imaging is performed at the optimum timing while continuously injecting a contrast medium. This study focused on the increase in blood flow in the superior and inferior vena cava during inspiration that affects the decrease in the CT value of the pulmonary artery and investigated a radiography method in which a delay time was set after inspiration in clinical cases.

Methods: A total of 50 patients who underwent CTPA for suspected pulmonary thromboembolism were included.

Effects of Model-Based Iterative Reconstruction in Low-Dose Paranasal Computed Tomography: A Comparison with Filtered Back Projection and Hybrid Iterative Reconstruction.

Iterative reconstruction (IR) improves image quality compared with filtered back projection (FBP). This study investigated the usefulness of model-based IR (forward-projected model-based iterative reconstruction solution [FIRST]) in comparison with FBP and hybrid IR (adaptive iterative dose reduction three-dimensional processing [AIDR 3D]) in low-dose paranasal CT. Twenty-four patients with paranasal sinusitis who underwent standard-dose CT (120 kV) and low-dose CT (100 kV) scanning before and after medical treatment were enrolled.

[Usefulness of low kilovoltage settings in computed tomography venography of lower limbs].

It has been reported that a reduction in tube kilovoltage during computed tomography (CT) angiography results in an average reduction of the effective radiation dose. Furthermore, a lower kilovoltage has been shown as a technique dose. However, there is no fundamental data in a low-kilovoltage protocol for CT venography.

The Roles of Regulatory Science Research in Drug Development at the Pharmaceuticals and Medical Devices Agency of Japan.

Recently, it is becoming increasingly difficult to develop innovative drugs. Thus, the role of regulatory science research in drug development and postmarketing settings has become more important. In this article, the authors discuss the roles of regulatory science research at the Pharmaceuticals and Medical Devices Agency (PMDA), which aims to improve public health in Japan.

Vascular enhancement and image quality of CT venography: comparison of standard and low kilovoltage settings.

Objective: The objective of our study was to investigate the vascular enhancement and image quality of CT venography (CTV) with a lower peak kilovoltage (kVp) setting than the standard setting.

Materials And Methods: In this retrospective study, the clinical records of 100 consecutive patients with suspected pulmonary embolism were analyzed. All patients underwent pulmonary CT angiography and CTV of the abdomen, pelvis, and lower extremities using 64-MDCT with automatic tube current modulation: 50 patients underwent CT at 120 kVp, the standard kVp setting, and 50 patients were scanned at 100 kVp; we refer to these groups as the "standard-kVp group" and the "low-kVp group," respectively.