Swallowing computed tomography and virtual reality as novel imaging modalities for the diagnosis of clicking larynx: Two case reports.

Globus sensation and pain causes are difficult to identify by conventional examination methods. With technology advances, new imaging methods including swallowing computed tomography (CT) and virtual reality (VR) have emerged and are contributing to definite diagnoses. We report two cases of cervical discomfort diagnosed as clicking larynx using swallowing CT/VR . Case 1 is a 55-year-old man. There were no findings on laryngoscopy or swallowing examinations, but swallowing CT/VR showed that the thyroid cartilage collided with the hyoid bone during swallowing, leading to the diagnosis of a clicking larynx. The patient was obese and is under observation hoping that weight loss will improve symptoms. Case 2 is a 32-year-old transgender man. He is receiving male hormones for gender identity disorder. He was diagnosed with a clicking larynx using swallowing CT/VR. Hormonal therapy may have increased the size of the thyroid cartilage, likely causing the symptoms. As they didn't choose surgical treatment, no symptomatic relief was achieved, but identifiying the cause contributed to improved patient satisfaction. Swallowing CT/VR is useful not only for evaluating the swallowing function, but also the underlying etiology of globus sensation and pain upon swallowing. Further clinical applications of this technique are expected for motion induced cervical symptoms.

Detection of left ventricular dysfunction on axial non-contrast chest CT.

PURPOSE: To evaluate the performance of axial non-contrast CT images in detecting systolic and diastolic left ventricular (LV) dysfunction. METHOD: This single-center retrospective study assessed 178 participants who underwent transthoracic ultrasonography and had non-contrast chest CT data within three months of ultrasonography. The patients were divided into LV systolic dysfunction (<52% ejection fraction in men and <54% in women), LV diastolic dysfunction (at least three of the following four criteria were met: average E/e' ratio >14; septal e' <7 cm/s or lateral e' <10 cm/s; peak tricuspid regurgitation velocity >2.8 m/s; or left atrial maximum volume index >34 ml/m2), and normal LV function groups. CT parameters were evaluated as predictive factors for LV dysfunction. These parameters were: I, maximum minor axis diameter of the LV lumen; II, I plus myocardial wall thickness; III, maximum left atrium anteroposterior diameter; IV, maximum transverse cardiac diameter; V, myocardial wall thickness; I-IV divided by maximum medial thoracic diameter; and I-IV divided by anteroposterior thoracic diameter. All parameters were measured on axial images: diameters were maximized. RESULTS: LV systolic dysfunction was indicated when parameter IV exceeded 131.2 mm with sensitivity and specificity of 71.8% and 77.0%, respectively. Moreover, LV diastolic dysfunction was indicated when parameter III divided by anteroposterior thoracic diameter exceeded 0.165 with sensitivity and specificity of 77.8% and 83.0%, respectively. CONCLUSIONS: Axial non-contrast chest CT is useful for detecting LV dysfunction. Even CT scans for other purposes provide LV function information that may lead to appropriate examination.

Automatic Aortic Valve Cusps Segmentation from CT Images Based on the Cascading Multiple Deep Neural Networks.

Accurate morphological information on aortic valve cusps is critical in treatment planning. Image segmentation is necessary to acquire this information, but manual segmentation is tedious and time consuming. In this paper, we propose a fully automatic aortic valve cusps segmentation method from CT images by combining two deep neural networks, spatial configuration-Net for detecting anatomical landmarks and U-Net for segmentation of aortic valve components. A total of 258 CT volumes of end systolic and end diastolic phases, which include cases with and without severe calcifications, were collected and manually annotated for each aortic valve component. The collected CT volumes were split 6:2:2 for the training, validation and test steps, and our method was evaluated by five-fold cross validation. The segmentation was successful for all CT volumes with 69.26 s as mean processing time. For the segmentation results of the aortic root, the right-coronary cusp, the left-coronary cusp and the non-coronary cusp, mean Dice Coefficient were 0.95, 0.70, 0.69, and 0.67, respectively. There were strong correlations between measurement values automatically calculated based on the annotations and those based on the segmentation results. The results suggest that our method can be used to automatically obtain measurement values for aortic valve morphology.

SIMPLE METHOD OF MEASURING SSDE FOR HEAD CT: FACILITATING PRE-CT SCAN DOSE CALCULATION USING SPECIALIZED HEAD SCAN BAND.

In this study, scaled scan band was developed to provide size-specific dose estimation (SSDE) values based on head circumference of patients undergoing computed tomography (CT) scans. The scan band was tested in 40 consecutive head CT examinations. The accuracy of the specialized scan band method was determined by comparing SSDEband with SSDE293,forehead, SSDEmean and SSDEcenter. SSDE293,forehead was used as the control value. The results of the linear fit of SSDEband, SSDEmean and SSDEcenter against SSDE293, forehead, were R2 = 0.958, R2 = 0.984 and R2 = 0.936, respectively. There was no significant difference between SSDEband, SSDEmean and SSDEcenter for SSDE293,forehead. Use of the proposed scan band method makes it possible to accurately determine the required radiation dose before a CT examination is performed.

Pediatric Cardiothoracic CT Guideline Provided by the Asian Society of Cardiovascular Imaging Congenital Heart Disease Study Group: Part 2. Contemporary Clinical Applications.

The use of pediatric cardiothoracic CT for congenital heart disease (CHD) was traditionally limited to the morphologic evaluation of the extracardiac thoracic vessels, lungs, and airways. Currently, the applications of CT have increased, owing to technological advancements in hardware and software as well as several dose-reduction measures. In the previously published part 1 of the guideline by the Asian Society of Cardiovascular Imaging Congenital Heart Disease Study Group, we reviewed the prerequisite technical knowledge for clinical applications in a user-friendly and vendor-specific manner. Herein, we present the second part of our guideline on contemporary clinical applications of pediatric cardiothoracic CT for CHD based on the consensus of experts from the Asian Society of Cardiovascular Imaging CHD Study Group. This guideline describes up-to-date clinical applications effectively in a systematic fashion.

Prospective Study of Spatial Distribution of Missed Lung Nodules by Readers in CT Lung Screening Using Computer-assisted Detection.

PURPOSE: To evaluate the spatial patterns of missed lung nodules in a real-life routine screening environment. MATERIALS AND METHODS: In a screening institute, 4,822 consecutive adults underwent chest CT, and each image set was independently interpreted by two radiologists in three steps: (1) independently interpreted without computer-assisted detection (CAD) software, (2) independently referred to the CAD results, (3) determined by the consensus of the two radiologists. The locations of nodules and the detection performance data were semi-automatically collected using a CAD server integrated into the reporting system. Fisher's exact test was employed for evaluating findings in different lung divisions. Probability maps were drawn to illustrate the spatial distribution of radiologists' missed nodules. RESULTS: Radiologists significantly tended to miss lung nodules in the bilateral hilar divisions (p < 0.01). Some radiologists had their own spatial pattern of missed lung nodules. CONCLUSION: Radiologists tend to miss lung nodules present in the hilar regions significantly more often than in the rest of the lung.

Four immunoglobulin isotypes and IgD splice variants in urodele amphibians.

Until recently, different families of urodele amphibians were thought to express distinct subsets of immunoglobulin (Ig) isotypes. In this study, we explored cDNAs encoding Ig heavy-chains (H-chains) in three species of urodele amphibians. We found that Cynops pyrrhogaster, Pleurodeles waltl, and Ambystoma mexicanum each carry genes encoding four Ig H-chain isotypes, including IgM, IgY, IgD, and IgX, similar to those found in anuran amphibians. We also found that urodele IgDs have a long constant region similar to those found in anuran, reptiles, and bony fishes. We also found several putative IgD splice variants. Our findings indicated that P. waltl IgP is not a novel isotype but an IgD splice variant. Altogether, our findings indicate that IgD splice variants may be universally expressed among amphibian species.

Forward-projected Model-based Iterative Reconstruction SoluTion in Temporal Bone Computed Tomography: A Comparison Study of All Reconstruction Modes.

OBJECTIVE: Identify appropriate reconstruction modes of Forward-projected model-based Iterative Reconstruction SoluTion (FIRST) in temporal bone computed tomography (CT) and investigate the contribution of spatial resolution and noise to the visual assessment. METHODS: Sixteen temporal bone CT images were reconstructed. Two blinded radiologists assessed 8 anatomical structures and classified the visual assessment. These visual scores were compared across reconstruction modes among each anatomical structure. Visual scores and contrast-to-noise ratio, noise power spectrum (NPS) at low (NPSLow) and high (NPSHigh) spatial frequencies, and 50% modulation transfer function relationships were evaluated. RESULTS: Visual scores differed significantly for the stapedius muscle and osseous spiral lamina, with CARDIAC SHARP, BONE, and LUNG modes for the osseous spiral lamina scoring highest. Visual scores significantly positively correlated with NPSLow, NPSHigh, and 50% modulation transfer function but negatively with contrast-to-noise ratio. CONCLUSIONS: Modes providing higher spatial resolution and lower noise reduction showed an improved visual assessment of CT images reconstructed with FIRST.

Evaluation of peripheral bronchiole visualization using model-based iterative reconstruction in quarter-detector computed tomography.

This study aimed to evaluate the visualization of peripheral bronchioles in normal lungs via quarter-detector computed tomography (QDCT). Visualization of bronchioles within 10 mm from the pleura is considered a sign of bronchiectasis. However, it is not known peripheral bronchioles how close to the pleura in normal lungs can be tracked using QDCT. This study included 228 parts in 76 lungs from 38 consecutive patients who underwent QDCT. Reconstruction was performed with different thicknesses, increments, and matrix sizes: 0.5-mm thickness and increment with 512 and 1024 matrixes (Group5 and Group10, respectively) and 0.25-mm thickness and increment with 1024 matrix (Group10Thin). The distance between the most peripheral bronchiole visible and the pleura was determined in the three groups. The distance between the peripheral bronchial duct ends and the nearest pleural surface were significantly shorter in the order of Group10Thin, Group10, and Group5, and the mean distances from the pleura in Group10Thin and Group10 were shorter than 10 mm. These findings suggest the visualization of peripheral bronchioles in QDCT was better with a 1024 axial matrix than with a 512 matrix, and with a 0.25-mm slice thickness/increment than with a 0.5-mm slice thickness/increment. Our study also indicates bronchioles within 10 mm of the pleura do not necessarily indicate pathology.

Sleep-Induced Glottis Closure in Multiple System Atrophy Evaluated by Four-Dimensional Computed Tomography.

Multiple system atrophy (MSA) is a progressive neurodegenerative disorder. Since patients with MSA often have sleep-related respiratory disorders including upper-airway obstruction and/or central sleep disturbance, appropriate evaluation of the upper airway especially during sleep may be indispensable. Fiberoptic laryngoscopy during diazepam-induced sleep has been reported for upper-airway obstruction verification. However, some patients cannot endure the uncomfortable sensation of the fiberscope. To address these issues, we devised a protocol of four four-dimensional computed tomography (4D-CT) for upper-airway evaluation during sleep. Here, we report the case of patient with MSA who was evaluated for upper-airway obstruction during sleep using 4D-CT. A 46-year-old man (height 1.60 m, weight 79 kg) was admitted to our neurological department for tracheal intubation because of a sudden onset of respiratory failure occurring at night. At the age of 45 years, he was diagnosed as MSA with predominant parkinsonism. As pulmonary disease had been excluded and his swallowing was normal, our differential diagnoses were central sleep apnea or obstructive sleep apnea related to his MSA or obstructive sleep apnea (SA) related to his obesity. A tracheostomy was done to maintain the airway after extubation. Polysomnography showed obstructive SA and not central SA. Awake fiberoptic laryngoscopy showed no upper airway obstruction but bilateral vocal abduction impairment (BVAI) during inspiration. To assess the spatial and temporal conditions of the upper respiratory tract-the patient could not tolerate sleep laryngoscopy-we carried out a 4D-CT. Reconstructed 4D-CT images of respiration during sleep showed clear abnormalities: glottis closure at the terminal stage of inspiration and subsequent velopharyngeal closure. As glottis closure does not occur normally in obesity patients, the cause of the respiratory failure in this patient was considered MSA-related sleep-induced airway obstruction. We decided to keep the tracheostoma, because BVAI in patients with MSA may be getting worse, although central apnea after tracheostomy may cause sudden central origin-related death; 4 months postoperatively, the patient had experienced no further airway-related complications. This report indicates that 4D-CT sequential upper-airway assessment during sleep is useful for determining the abnormalities causing obstructive SA in patients with MSA.

Computed tomography findings of early-stage TAFRO syndrome and associated adrenal abnormalities.

OBJECTIVES: To compare CT findings of early (within 3 weeks post-onset)- and later (within 1 month before or after diagnostic criteria were satisfied, and later than 3 weeks post-onset) stage thrombocytopenia, anasarca, fever, reticulin fibrosis, renal dysfunction, and organomegaly (TAFRO) syndrome. METHODS: Between 2014 and 2019, 13 patients with TAFRO syndrome (8 men and 5 women; mean age, 54.9 years) from nine hospitals were enrolled. The number of the following CT findings (CT factors) was recorded: the presence of anasarca, organomegaly, adrenal ischaemia, anterior mediastinal lesion, bony lesion, and lymphadenopathy. Records of adrenal disorders (adrenomegaly, ischaemia, and haemorrhage) throughout the disease course were also collected. Differences in CT factors at each stage were statistically compared between remission and deceased groups. RESULTS: Para-aortic oedema and mild lymphadenopathy were observed in all patients, whereas pleural effusion, ascites, and subcutaneous oedema were found in 5/13, 7/13, and 7/13 cases, respectively, at the early stage. CT factors at the early stage were significantly higher in the deceased than in the remission group (mean, 11 vs 6.5; p = 0.04), while they were nonsignificant at the later stage. Adrenal disorders were present in 7/13 cases throughout the course including 6 of adrenomegaly and 4 of ischaemia at the early stage. CONCLUSIONS: Para-aortic oedema and mild lymphadenopathy are most common at the early stage. Anasarca, organomegaly, lymphadenopathy, and adrenal disorders on early-stage CT are useful for unfavourable prognosis prediction. Moreover, adrenal disorders are frequent even at the early stage and are useful for early diagnosis of TAFRO syndrome. KEY POINTS: • CT findings facilitate early diagnosis and prognosis prediction in TAFRO syndrome. • Adrenal disorders are frequently observed in TAFRO syndrome. • Adrenal disorders are useful for differential diagnosis of TAFRO syndrome.

Pilot study of eruption forecasting with muography using convolutional neural network.

Muography is a novel method of visualizing the internal structures of active volcanoes by using high-energy near-horizontally arriving cosmic muons. The purpose of this study is to show the feasibility of muography to forecast the eruption event with the aid of the convolutional neural network (CNN). In this study, seven daily consecutive muographic images were fed into the CNN to compute the probability of eruptions on the eighth day, and our CNN model was trained by hyperparameter tuning with the Bayesian optimization algorithm. By using the data acquired in Sakurajima volcano, Japan, as an example, the forecasting performance achieved a value of 0.726 for the area under the receiver operating characteristic curve, showing the reasonable correlation between the muographic images and eruption events. Our result suggests that muography has the potential for eruption forecasting of volcanoes.

Uterine adenomyosis with extensive glandular proliferation: case series of a rare imaging variant.

PURPOSE: We aimed to investigate the clinical and magnetic resonance imaging (MRI) characteristics of uterine adenomyosis, in which there is an extensive area of high signal intensity in the myometrium on T2-weighted MRI. METHODS: This retrospective radiographic study reviewed a case series of six patients (mean age, 36 years) with adenomyosis. These patients were selected because, unlike in classical adenomyosis, T2-weighted images showed a larger area of high signal intensity than that of low signal intensity in the myometrium. The morphology of the myometrial lesions, patterns of contrast enhancement (n=4), intramyometrial hemorrhaging, diffusion restriction (n=5), endometrial lesions, and imaging findings after treatment (n=3) were evaluated on MRI. RESULTS: The patients' clinical symptoms included vaginal bleeding and severe anemia. Four were administered hormonal therapy, one underwent hysterectomy, and one underwent enucleation. On T2-weighted images, all showed endometrial thickening and a high signal intensity area in the myometrium that was divided up by a mesh of low signal intensity bands, with an appearance reminiscent of a fish caught in a net. Other findings included gradual centripetal enhancement with contrast defects in multicystic areas (4/4), an intramyometrial hemorrhage (1/6), and increased diffusion (5/5). Following hormonal therapy, the uteruses decreased in size and were similar to those of classical adenomyosis on MRI (3/3). The lesions were diagnosed as adenomyosis with a proliferation of adenomyotic glandular tissue and a proliferative endometrial polyp. CONCLUSION: This case series suggests that there is a subgroup of uterine adenomyosis that shows a characteristic "fish-in-a-net" appearance on T2-weighted images.

Comparison of image quality between synthetic and patients' electrocardiogram-gated 320-row pediatric cardiac computed tomography.

BACKGROUND: Pediatric cardiac computed tomography (CT) can be acquired without electrode placement by using synthetic electrocardiogram (ECG). OBJECTIVE: To determine whether the depiction of gross cardiac structures and coronary arteries in 320-row pediatric CT is not inferior when CT is gated with synthetic ECG at 150 beats per minute (bpm), compared to the patients' own ECG. MATERIALS AND METHODS: Sixty 320-row CT examinations performed in children younger than 3 years old with congenital cardiac anomaly were enrolled in this retrospective study. Thirty examinations were scanned using the children's own ECG for gating and 30 examinations were scanned using synthetic ECG at 150 bpm. The image quality was compared between the two gating modes using a 3-point scale to delineate the following anatomical structures: atrial septum, ventricular septum, right atrium, right ventricle, left atrium, left ventricle, main pulmonary artery, ascending aorta, aortic arch including the patent ductus arteriosus, descending aorta, right coronary artery and left main trunk. Beam-hardening artifacts from contrast enhancement material were evaluated using a 3-point scale, and the overall image quality was evaluated using a 5-point scale. RESULTS: Synthetic ECG was not inferior to the patients' ECG in depicting each structure, beam-hardening artifact and overall image quality. Average indices were clinically acceptable imaging quality, except for subjective image quality of mid and distal coronary arteries. CONCLUSION: Pediatric cardiac CT in patients younger than 3 years old can be acquired using synthetic ECG gating, with image quality not inferior to the patients' ECG.

Evaluation of the depiction ability of the microanatomy of the temporal bone in quarter-detector CT: Model-based iterative reconstruction vs hybrid iterative reconstruction.

Little is known regarding differences between model-based iterative reconstruction (MBIR) and hybrid iterative reconstruction (HIR) in temporal bone computed tomography (CT). This study compared the ability to depict microstructures in temporal bone in quarter-detector CT (QDCT) between MBIR and HIR.Sixty-two temporal bones in 31 consecutive adult patients who underwent QDCT were included. Reconstruction was performed with Forward projected model-based Iterative Reconstruction SoluTion (FIRST) BONE mild mode and Adaptive Iterative Dose Reduction 3D (AIDR3D) enhanced mild mode. Imaging quality was graded for 3 microstructures (spiral osseous lamina, tympanic membrane, and singular canal).Spiral osseous lamina was significantly well-delineated in the AIDR3D enhanced group, compared with the FIRST group. In nearly all cases with FIRST, spiral osseous lamina was poorly defined. Although there was no significant difference, depiction of the tympanic membrane and singular canal tended to be better with AIDR3D enhanced mode.Routine reconstruction for preoperative temporal bone CT should be performed with HIR, rather than MBIR.

Multidisciplinary clinical approach by sharing oral examination information to treat a diabetes patient with dysgeusia.

Taste alteration is one of the complications of severe diabetes. It is important in diabetes treatment to assess taste alteration and perform dietary counseling, therapeutic exercise, and oral care. In this case, multidisciplinary clinical approach by medical staff was successful for a severely diabetic patient with dysgeusia.

Effect of bolus tracking region-of-interest position within the descending aorta on luminal enhancement of coronary arteries in coronary computed tomography angiography.

To compare coronary artery luminal enhancement in coronary computed tomography angiography (CCTA) between ventral and dorsal region-of-interest (ROI) bolus tracking in the descending aorta.The records of 165 consecutive patients who underwent CCTA with non-helical acquisition from July 2017 to March 2018 were retrospectively examined. We performed 320-row CCTA with bolus tracking [scan triggered at 260 HU in the descending aorta] and 133 patients were finally included. ROI was set in the ventral and dorsal halves of the descending aorta in 68 and 65 patients, respectively.Contrast arrival time was significantly shorter in the dorsal group (ventral: 21.8 ±â€Š0.372 s; dorsal: 20.7 ±â€Š0.369; P = .0295). The mean density of the proximal and distal RCA was significantly higher in the ventral group (proximal: ventral, 428.1 ±â€Š6.95 HU; dorsal, 405.5 ±â€Š7.72 HU, P = .0318; distal: ventral, 418.0 ±â€Š9.29 HU; dorsal, 393.2 ±â€Š9.46 HU, P = .0133).Dorsal bolus tracking ROI in the descending thoracic aorta significantly reduced preparation time and RCA CT values.

User-Friendly Vendor-Specific Guideline for Pediatric Cardiothoracic Computed Tomography Provided by the Asian Society of Cardiovascular Imaging Congenital Heart Disease Study Group: Part 1. Imaging Techniques.

Optimal performance of pediatric cardiothoracic computed tomography (CT) is technically challenging and may need different approaches for different types of CT scanners. To meet the technical demands and improve clinical standards, a practical, user-friendly, and vendor-specific guideline for pediatric cardiothoracic CT needs to be developed for children with congenital heart disease (CHD). In this article, we have attempted to describe such guideline based on the consensus of experts in the Asian Society of Cardiovascular Imaging CHD Study Group. This first part describes the imaging techniques of pediatric cardiothoracic CT, and it includes recommendations for patient preparation, scan techniques, radiation dose, intravenous injection protocol, post-processing, and vendor-specific protocols.

Vaginal delivery-related changes in the pelvic organ position and vaginal cross-sectional area in the general population.

PURPOSE: Evaluate the effect of vaginal delivery on pelvic organ positions and vaginal cross-sectional areas. METHODS: MRI of 119 premenopausal women were grouped according to the number of deliveries. The distances from the three 3-reference points (bladder, uterus, and rectum) to two 2-lines (pubococcygeal-line (PCL) and midpubic-line (MPL)), length of H- and M-lines and vaginal cross-sectional area were compared between the groups. RESULTS: With increasing parity, distance from the rectum to PCL tended to increase (nullipara vs. bipara; p<0.01). Vaginal cross-sectional area was larger in bipara and tripara than in nullipara (p<0.01). CONCLUSIONS: Rectal position is more caudally located and vaginal cross-sectional area is larger in bipara than in nullipara.

Deep neural network-based computer-assisted detection of cerebral aneurysms in MR angiography.

BACKGROUND: The usefulness of computer-assisted detection (CAD) for detecting cerebral aneurysms has been reported; therefore, the improved performance of CAD will help to detect cerebral aneurysms. PURPOSE: To develop a CAD system for intracranial aneurysms on unenhanced magnetic resonance angiography (MRA) images based on a deep convolutional neural network (CNN) and a maximum intensity projection (MIP) algorithm, and to demonstrate the usefulness of the system by training and evaluating it using a large dataset. STUDY TYPE: Retrospective study. SUBJECTS: There were 450 cases with intracranial aneurysms. The diagnoses of brain aneurysms were made on the basis of MRA, which was performed as part of a brain screening program. FIELD STRENGTH/SEQUENCE: Noncontrast-enhanced 3D time-of-flight (TOF) MRA on 3T MR scanners. ASSESSMENT: In our CAD, we used a CNN classifier that predicts whether each voxel is inside or outside aneurysms by inputting MIP images generated from a volume of interest (VOI) around the voxel. The CNN was trained in advance using manually inputted labels. We evaluated our method using 450 cases with intracranial aneurysms, 300 of which were used for training, 50 for parameter tuning, and 100 for the final evaluation. STATISTICAL TESTS: Free-response receiver operating characteristic (FROC) analysis. RESULTS: Our CAD system detected 94.2% (98/104) of aneurysms with 2.9 false positives per case (FPs/case). At a sensitivity of 70%, the number of FPs/case was 0.26. DATA CONCLUSION: We showed that the combination of a CNN and an MIP algorithm is useful for the detection of intracranial aneurysms. LEVEL OF EVIDENCE: 4 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:948-953.