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Background: Voxel-based morphometry (VBM) using magnetic resonance imaging (MR) has been used to estimate cortical atrophy associated with various diseases. However, there are mis-segmentations of segmented gray matter image in VBM. Purpose: To study a twofold evaluation of single- and multi-channel segmentation using synthetic MR images: (1) mis-segmentation of segmented gray matter images in transverse and cavernous sinuses; and (2) accuracy and repeatability of segmented gray matter images. Material and Methods: A total of 13 healthy individuals were scanned with 3D quantification using an interleaved Look–Locker acquisition sequence with a T2 preparation pulse (3D-QALAS) sequence on a 1.5-T scanner. Three of the 13 healthy participants were scanned five consecutive times for evaluation of repeatability. We used SyMRI software to create images with three contrasts: T1-weighted (T1W), T2-weighted (T2W), and proton density-weighted (PDW) images. Manual regions of interest (ROI) on T1W imaging were individually set as the gold standard in the transverse sinus, cavernous sinus, and putamen. Single-channel (T1W) and multi-channel (T1W + T2W, T1W + PDW, and T1W + T2W + PDW imaging) segmentations were performed with statistical parametric mapping 12 software. Results: We found that mis-segmentations in both the transverse and cavernous sinuses were large in single-channel segmentation compared with multi-channel segmentations. Furthermore, the accuracy of segmented gray matter images in the putamen was high in both multi-channel T1W + PDW and T1W + T2W + PDW segmentations compared with other segmentations. Finally, the highest repeatability of left putamen volumetry was found with multi-channel segmentation T1WI + PDWI. Conclusion: Multi-channel segmentation with T1WI + PDWI provides good results for VBM compared with single-channel and other multi-channel segmentations. [ABSTRACT FROM AUTHOR]

Background: Atlas-based volumetry using three-dimensional T1-weighted (3D-T1W) magnetic resonance imaging (MRI) has been used previously to evaluate the volumes of intracranial tissues. Purpose: To evaluate the detectability of volume difference and accuracy for volumetry using smoothed data with an atlas-based method. Material and Methods: Twenty healthy individuals and 24 patients with idiopathic normal-pressure hydrocephalus (iNPH) underwent 3-T MRI, and sagittal 3D-T1W images were obtained in all participants. Signal values (as tissue probability) of voxels in five segmented data types (gray matter, white matter, cerebrospinal fluid [CSF], skull, soft tissue) derived from the 3D-T1W images with SPM 12 software were assigned simulated 3D-T1W signal intensities to each tissue image. The assigned data were termed "reference data." We created a reference 3 D-T1W image that included the reference data of all five tissue types. Standard volumes were measured for the reference CSF data with region of interest of lateral ventricle in native space, and measured volumes were obtained for non-smoothed and smoothed-modulated data. Detectability was evaluated between measured volumes in the healthy control and iNPH groups. Accuracy was evaluated as the difference between the mean measured and standard volumes. Results: In group comparison of measured volumes between the healthy control and iNPH groups, the lowest P value was for smoothed-modulated CSF data. In both groups, the largest difference from the standard volume was found for the mean of the measured volumes for smoothed-modulated CSF data. Conclusion: Our study shows that using smoothed data can improve detectability in group comparison. However, using smoothed data reduces the accuracy of volumetry. [ABSTRACT FROM AUTHOR]

The radioactivity in the organs adjacent to the heart causes interference with the quantitative assessment of myocardial uptake of tracer on scintigraphy. In order to investigate how much the functions of these organs affect myocardial uptake seen in imaging, we compared the myocardial uptake measured by means of a gamma camera with the actual activity in the excised organs. Methods: Thirty-three rats were imaged at 5, 10, 15, 30, 45, 60, 90 and 120 min after the administration of99mTc-tetrofosmin, and % injected dose per pixel (%ID/pixel) for each organ was assessed on planar images (PI measurement). Percent injected dose per gram of tissue (%ID/g) in the heart as well as lungs, liver, gastrointestines and blood was measured by means of a well scintillation counter (WC measurement). Comparison between PI and WC measurements was performed with % uptake, the PI-to-WC ratio and heart-to-organ ratios. Results: Our WC measurement showed an increase in cardiac uptake until 30 min (1.67±0.31%) postinjection and subsequent gradual decrease, whereas PI measurement showed maximum activity of 1.81±0.52% at 15 min postinjection. There was a prominent difference between the two measurements, particularly at 10 min, with a PI/WC ratio of about 1.6 times. Our WC measurement showed maximum pulmonary uptake at 15 min (0.87±0.31%) and a gradual decrease over 15 min, whereas PI measurement showed maximum uptake at 10 min (1.14±0.38%). There was hardly any variation in activity observed later than at 10 min. Our WC measurement showed hardly any variance in hepatic activity from 5 min (0.77±0.19%) to 30 min (0.69±0.27%) with a subsequent gradual decrease. The percent uptake in PI measurement was generally greater than that in WC measurement, and high values were found at 10 min and 15 min with PI/WC ratios of about 3.3 times and 2.3 times, respectively. Conclusion: Percent uptakes in PI measurement were greater than those in WC measurement. The difference between the two measurements was prominent in the early phases. The cardiac uptake in PI measurement was significantly greater than that in WC measurement at 10 min. It was considered that this discrepancy between the two measurements was caused by the Compton scatter from the organs adjacent to the heart. [ABSTRACT FROM AUTHOR]

SUMMARY General features are described and examples are provided of the radiological manifestations of postbulbar duodenal lesions, particularly the findings on hypotonic duodenograms. Hypotonic duodenography does not always reveal the characteristic findings of postbulbar duodenal lesions, but it helps to evaluate luminal stenosis and diagnose disease entities even in lesions that show non-specific findings. Radiologists should be familiar with the radiological findings of postbulbar duodenal lesions and know which kinds of lesions can affect the postbulbar duodenum. This is important in making a differential diagnosis and in preventing delays in diagnosis. [ABSTRACT FROM AUTHOR]

The importance of health literacy in medical imaging is well recognized, yet the current landscape remains inadequately understood. This study aims to explore the extent of health literacy studies contextualized to medical imaging. Scoping review. A scoping review was conducted using three online bibliographic databases namely, PubMed, ScienceDirect, and CINAHL. We have adopted the concept of health literacy, as a clinical risk and personal asset, to guide this review. Of 311 unique articles, 39 met our selection criteria. Five themes (categories) were identified by the authors: appropriate communication with patients who receive medical imaging test results, appropriate usage of medical imaging, classes and characteristics of eHealth literacy, disease/deterioration prevention, and patient education. Additionally, 17 health literacy assessment tools were identified, including 11 original creations. Finally, 11 recommendations have emerged from this scoping review, offering valuable insights into methods, considerations, and strategies for promoting health literacy. Health literacy studies in medical imaging cover both clinical and public health perspectives, benefiting diverse populations, regardless of underlying medical conditions. Notably, the majority of assessment tools used in these studies were author-generated, hindering cross-study comparisons. Given the innate capacity of medical images to convey intuitive information, those images do not solely benefit the patients who are given medical imaging examinations, but they also hold significant potential to enhance public health literacy. Health literacy and medical imaging are closely associated and mutually reinforce each other. [ABSTRACT FROM AUTHOR]

Purpose: We developed new deep learning-based hierarchical brain segmentation (DLHBS) method that can segment T1-weighted MR images (T1WI) into 107 brain subregions and calculate the volume of each subregion. This study aimed to evaluate the repeatability and reproducibility of volume estimation using DLHBS and compare them with those of representative brain segmentation tools such as statistical parametric mapping (SPM) and FreeSurfer (FS)., Methods: Hierarchical segmentation using multiple deep learning models was employed to segment brain subregions within a clinically feasible processing time. The T1WI and brain mask pairs in 486 subjects were used as training data for training of the deep learning segmentation models. Training data were generated using a multi-atlas registration-based method. The high quality of training data was confirmed through visual evaluation and manual correction by neuroradiologists. The brain 3D-T1WI scan-rescan data of the 11 healthy subjects were obtained using three MRI scanners for evaluating the repeatability and reproducibility. The volumes of the eight ROIs-including gray matter, white matter, cerebrospinal fluid, hippocampus, orbital gyrus, cerebellum posterior lobe, putamen, and thalamus-obtained using DLHBS, SPM 12 with default settings, and FS with the "recon-all" pipeline. These volumes were then used for evaluation of repeatability and reproducibility., Results: In the volume measurements, the bilateral thalamus showed higher repeatability with DLHBS compared with SPM. Furthermore, DLHBS demonstrated higher repeatability than FS in across all eight ROIs. Additionally, higher reproducibility was observed with DLHBS in both hemispheres of six ROIs when compared with SPM and in five ROIs compared with FS. The lower repeatability and reproducibility in DLHBS were not observed in any comparisons., Conclusion: Our results showed that the best performance in both repeatability and reproducibility was found in DLHBS compared with SPM and FS.

Background: The evolution of radiological technology is one of the most remarkable events of modern medical technology. Radiological examination has resulted in non-invasive, individual diagnostic imaging, which has contributed significantly to successful medical treatment of patients., Key Concepts: This review summarizes past and current Japanese educational systems for radiological technologists with a historical perspective focusing on three periods. The first period begins with Roentgen's discovery of X-rays (1895), the second period begins with the establishment of the Radiological X-ray Technologist Act (1951), and the third period begins with the launch of the first university course for radiological technologists (1987). It is conceivable that those periods are in accordance with the technological paradigm shifts, including the development of contrast radiography and the application of CT and MRI to clinical practice. To maintain awareness of the most recent available technologies and maximize safety, educational programs teaching the latest knowledge were offered during each period., Conclusions: The advanced technologies require highly skilled radiological technologists and highly established educational systems. At present, over 70% of Japanese educational programs for radiological technologists are university courses leading to a bachelor's degree. The increasing globalization of radiological technology requires future radiological education systems to have a global perspective., Competing Interests: The authors declare that they have no conflicts of interest regarding this review., (© 2022 The Juntendo Medical Society.)

Purpose: To determine the frequency and sonographic features of focal sparing of fatty liver at segment 2., Materials and Methods: The sonographic database was searched over the preceding three years. The criteria for sonographic diagnosis of focal sparing of fatty liver was an area of liver parenchyma of relatively low echogenicity with lack of mass effect., Results: Six (0.9%) of 686 patients with diffuse fatty liver showed focal sparing at segment 2. The areas showed spherical or ovoid hypoechoic mass-like lesions measuring 2 to 6 cm in longest diameter (average, 3.8 cm). These all abutted on the posterior surface of segment 2 adjacent to the ligamentum venosum. These were segmental in two cases and subsegmental in four., Conclusion: In diffuse fatty liver, segment 2 is infrequently spared, and this may be a helpful adjunct sign of fatty liver.