Acute Fatty Liver of Pregnancy Complicated With Mild Encephalitis/Encephalopathy With a Reversible Splenial Lesion: A Case Report.

Acute fatty liver of pregnancy (AFLP) is a rare complication of pregnancy that may result in fulminant hepatic failure. A 28-year-old woman, at 36 weeks of gestation, presented to a maternal-fetal outpatient clinic with fever and headache. She was prescribed analgesics and was planned for follow-up.

Ovarian torsion due to ovarian hyperstimulation syndrome diagnosed by sonographic whirlpool sign in the first trimester of pregnancy: A case report.

Ovarian torsion during pregnancy is a rare condition that needs prompt diagnosis and detorsion in order to preserve ovarian function. Diagnosing ovarian torsion is a difficult procedure especially in pregnant cases since radiation exposure should be avoided. Detecting the whirlpool sign by ultrasonography is a highly useful technique as it is noninvasive, less time-consuming, and radiation-free.

Step-by-step instructions for detecting whirlpool sign in adnexal torsion.

Adnexal torsion is a common gynecological emergency whose prompt diagnosis is essential because a delay may lead to ovarian dysfunction. Although the whirlpool sign is reliable for diagnosing ovarian cyst torsion, technical difficulties hinder its use by sonographers. Here we developed a systematic approach to visualizing this sign by focusing on the fact that torsion arises from the space between the uterus and the pelvic wall.

Educational Effect of Remote Lectures for Students Aiming to Become Radiologic Technologists: Questionnaire on Nuclear Medicine Examinations.

In the latter half of 2019, coronavirus disease 2019 (COVID-19) began spreading worldwide. To prevent COVID-19 infection, all teaching at Suzuka University of Medical Sciences from April to June 2020 took place as remote lectures, not in the face-to-face format. This study analyzed postlecture questionnaire responses regarding face-to-face and remote teaching on the subject of nuclear medicine technology examinations.

Application of a variable filter for presampled modulation transfer function analysis with the edge method.

We devised a new noise filtering method to reduce the noise in the line spread function (LSF) for presampled modulation transfer function (MTF) analysis with the edge method. A filter was designed to reduce noise effectively using a position-dependent filter controlled by the boundary frequency b for low-pass filtering, which is calculated by 1/2d (d: distance from the LSF center). In this filtering process, strong filters with very low b can be applied to regions distant from the LSF center, and the region near the LSF center can be maintained simultaneously by a correspondingly high b.

[Investigation of measurement accuracy of factors used for detective quantum efficiency measurement in digital radiography].

In the detective quantum efficiency (DQE) evaluation of detectors for digital radiography (DR) systems, physical image quality indices such as modulation transfer function (MTF) and normalized noise power spectrum (NNPS) need to be accurately measured to obtain highly accurate DQE evaluations. However, there is a risk of errors in these measurements. In this study, we focused on error factors that should be considered in measurements using clinical DR systems.

Examination of the optimal temporal resolution required for computed tomography coronary angiography.

Sub-second multidetector-row computed tomography systems provide great potential for the further improvement of CT coronary angiography (CTCA). However, because the temporal resolution (TR) of such CT systems is insufficient, blurring and artifacts produced by fast cardiac motion remain as unresolved issues. Previous TR investigations of CTCA were based on the retrospective electrocardiogram-gated multisegment reconstruction technique.

[Physical image properties of digital radiography systems in low dose range].

We measured physical image properties of a flat panel detector (FPD) system and a computed radiography (CR) system, targeting to a low dose range (reference dose: 2.58×10(-7) C/kg: to 1/20 dose). Input-output properties, pre-sampled modulation transfer functions (pre-sampled MTFs), and normalized noise power spectra for an FPD system equipped with a CsI scintillator (FPDcsi) and a CR system with an imaging plate coated with storage phosphor (CR) were measured at the low dose range for radiation quality of RQA3 (≍50 skV) and RQA5 (≍70 kV), and detective quantum efficiencies (DQEs) were calculated.

[Study of appropriate dosing in consideration of image quality and patient dose on the digital radiography].

Recently about 90% of radiographs have been taken by the digital radiographic system in Japan, but the exposure dose of the patients are about ten-times different among the systems. We understood it by a surveytaken in 2007. We studied the visual evaluation with varying exposure doses using the image phantom of the lumber AP, lumber lateral and hip AP.

[A comparative study of electrocardiogram multi-segment reconstruction and dual source computed tomography using a computer controlled coronary phantom].

Currently, there are two main methods for improving temporal resolution of coronary computed tomography (CT): electrocardiogram-gated multi-segment reconstruction (EMR) and dual source scanning using dual source CT (DSCT). We developed a motion phantom system for image quality assessment of cardiac CT to evaluate these two methods. This phantom system was designed to move an object at arbitrary speeds during a desired phase range in cyclic motion.

[Investigation of error factors in analysis of digital noise power spectrum].

The noise power spectrum (NPS) measurement is important for assessing noise properties of digital radiography systems, and its measurement method was standardized in International Electrotechnical Commission 62220-1 (IEC). However, improvement of its accuracy is not easy due to random data analysis. In this study, regarding error factors in the NPS measurement using 2-dimensional (2D) Fast Fourier transform, we investigated effects of overlap of region of interests (ROIs), number of average lines in 2D frequency space, directional dependence of frequency property, and detrending techniques.

[Influence of angle-measurement error on pre-sampled MTF and proposal of an optimal technique of angle measurement].

The presampled modulation transfer function (MTF) is recognized as the established metric for characterizing the resolution performance of a digital imaging system. In the past, the three general approaches for assessing the presampled MTF were using the angulated slit, angulated edge, and angulated square-wave test pattern all of which are tilted slightly against the column direction of the detector. In all methods, it is important to determine the exact angle of the respective test devices.

[Proposal and verification of presampled MTF measurement by simple analysis using the edge method].

The edge method adopted by the International Electrotechnical Commission (IEC) for presampled modulation transfer function (presampled MTF) measurement has the advantage that the complexity and limitations of image acquisition are less than those of the slit method. On the other hand, it has the disadvantage that the maintenance of accuracy is difficult because of the noise amplification caused by the differentiation. In order to reduce this disadvantage, we proposed an effective method in which many edge profiles are synthesized and then the synthesized edge profiles are bound into regular interval bins.