Published papers

© 2015, The Japan Society of Ultrasonics in Medicine. A lateral cervical sinus, also known as a second pharyngeal or branchial cleft fistula/sinus, occurs when the second pharyngeal arch fails to grow caudally over the third and fourth arches, leaving remnants of the second branchial clefts in contact with the surface of the neck via a narrow canal. This type of sinus is detected on the lateral aspect of the neck directly anterior to the sternocleidomastoid muscle. We report two pediatric cases with lateral cervical sinus, and pathognomonic sonographic findings to confirm the diagnosis. The first case involved a 3-month-old boy with a sinus on the lateral neck and occasional drainage from a cervical sinus opening. Sonography revealed that the sinus tract extended between the external and internal carotid arteries. In case two, a 1-month-old girl presented with a sinus on the lateral neck and signs of acute infection at the site of a pinpoint opening. Sonography revealed an oval-shaped cystic lesion and sinus tract extending between the external and internal carotid arteries. Sonography does not require radiation or sedation for children. The best choice for the first examination for lateral cervical sinus is sonography, rather than CT, MRI, or contrast fistulograms.

Four-dimensional computed tomography (4DCT) provides a series of volume data and visualizes joint motions. However, numerical analysis of 4DCT data remains difficult because segmentation in all volumetric frames is time-consuming. We aimed to analyze joint kinematics using a sequential 3D-3D registration technique to provide the kinematics of the moving bone with respect to the fixed bone semiautomatically using 4DCT DICOM data and existing software. Surface data of the source bones are reconstructed from 3DCT. The trimmed surface data are respectively matched with surface data from the first frame in 4DCT. These trimmed surfaces are sequentially matched until the last frame. These processes provide positional information for target bones in all frames of the 4DCT. Once the coordinate systems of the target bones are decided, translation and rotation angles between any two bones can be calculated. This 4DCT analysis offers advantages in kinematic analyses of complex structures such as carpal or tarsal bones. However, fast or large-scale motions cannot be traced because of motion artifacts.

© The Author(s) 2020. Noonan syndrome is known to have various cardiovascular defects, which include pulmonary artery stenosis. Pulmonary artery stenosis is characterized by obstruction of pulmonary artery blood flow that can cause elevated pulmonary artery pressure and ventilation-perfusion inequality, which can cause dyspnea on exertion and eventually, heart failure. Although the etiology of pulmonary artery stenosis related to congenital diseases is still unknown, balloon pulmonary angioplasty has being reported to be effective to selected patients with Alagille and Williams syndromes, but not from Noonan syndrome despite of modest prevalence of pulmonary artery stenosis. Here, we report the first Noonan syndrome patient with pulmonary artery stenosis who underwent successful balloon pulmonary angioplasty. The strategy used in balloon pulmonary angioplasty was planned with careful morphologic evaluation by computed tomographic angiography, and performed with scoring balloons in a graded approach with multiple sessions. After balloon pulmonary angioplasty, we confirmed maintained dilation of lesions and symptom alleviation, suggesting that balloon pulmonary angioplasty can be performed safely on pulmonary artery stenosis in a Noonan syndrome patient.

Dynamic X-ray (DXR) is a functional imaging technique that uses sequential images obtained by a flat-panel detector (FPD). This article aims to describe the mechanism of DXR and the analysis methods used as well as review the clinical evidence for its use. DXR analyzes dynamic changes on the basis of X-ray translucency and can be used for analysis of diaphragmatic kinetics, ventilation, and lung perfusion. It offers many advantages such as a high temporal resolution and flexibility in body positioning. Many clinical studies have reported the feasibility of DXR and its characteristic findings in pulmonary diseases. DXR may serve as an alternative to pulmonary function tests in patients requiring contact inhibition, including patients with suspected or confirmed coronavirus disease 2019 or other infectious diseases. Thus, DXR has a great potential to play an important role in the clinical setting. Further investigations are needed to utilize DXR more effectively and to establish it as a valuable diagnostic tool.

We aimed to use upright computed tomography (CT) to depict posture-related changes in the brain tissue under normal gravity. Thirty-two asymptomatic volunteers underwent upright CT in the sitting position and conventional CT in the supine position on the same day. We compared the shift of the pineal body, cerebellar tonsil, the length of pituitary stalk, optic nerve sheath area and perimeter (ONSA and ONSP, respectively), and lateral ventricular volume between the supine and sitting positions. We also compared shape changes of the cerebrospinal fluid (CSF) spaces at different sites between both positions. In the sitting position, the pineal body shifted 0.68 ± 0.27 mm in the ventral direction and 0.76 ± 0.24 mm in the caudal direction, the length of pituitary stalk decreased by 1.23 ± 0.71 mm, the cerebellar tonsil descended by 2.10 ± 0.86 mm, the right ONSA decreased by 15.21 ± 6.54%, the left ONSA decreased by 15.30 ± 7.37%, the right ONSP decreased by 8.52 ± 3.91%, the left ONSP decreased by 8.20 ± 4.38%, and the lateral ventricular volume decreased by 5.07 ± 3.24% (all P < 0.001). We also observed changes in the shape of CSF spaces with changes in posture. We concluded that the intracranial structure of healthy subjects and volume of ventricles changed according to posture on Earth.

In the analysis of the shoulder complex, the sequential changes occurring in the sternoclavicular and acromioclavicular joints during active shoulder motion are challenging to track. This study aimed to investigate the in vivo sternoclavicular and acromioclavicular joint motions during active elevation, including the sequential changes in these joint spaces using upright four-dimensional computed tomography (4DCT). Bilateral shoulders of 12 healthy volunteers upright 4DCT were obtained during active elevation similar to a "hands up" motion. The sternoclavicular and acromioclavicular rotation angles, joint distances, and closest points on the clavicle relative to the thorax and scapula were evaluated during 10°-140° of humerothoracic elevation. During humerothoracic elevation, the clavicle elevated, retracted, and rotated posteriorly relative to the thorax, whereas the scapula rotated upwardly, internally, and posteriorly relative to the clavicle. All the sternoclavicular and acromioclavicular joint rotation angles were significantly different at ≥ 30°-50° of humerothoracic elevation compared with 10° of humerothoracic elevation. The mean sternoclavicular and acromioclavicular joint distances were 2.2 ± 1.1 mm and 1.6 ± 0.9 mm, respectively. The closest points were located on the anteroinferior part of the medial and lateral clavicle in the sternoclavicular and acromioclavicular joints, respectively. Significant differences were observed in the acromioclavicular joint distance and anterior/posterior movements of the closest points in the sternoclavicular and acromioclavicular joints compared with 10° of humerothoracic elevation. Our sternoclavicular and acromioclavicular closest point results indicate that the impingement tends to occur at the anteroinferior part of the medial and lateral aspects of the clavicle and may be related to osteoarthritis.

UNLABELLED: BACKGROUND ＆ AIMS: Muscle quantification using chest computed tomography (CT) is a useful prognostic biomarker for coronavirus disease 2019 (COVID-19). However, no studies have evaluated the clinical course through comprehensive assessment of the pectoralis and erector spinae muscles. Therefore, we compared the impact of the areas and densities of these muscles on COVID-19 infection outcome. METHODS: This multicenter retrospective cohort study was conducted by the COVID-19 Task Force. A total of 1410 patients with COVID-19 were included, and data on the area and density of the pectoralis and erector spinae muscles on chest CT were collected. The impact of each muscle parameter on the clinical outcome of COVID-19 was stratified according to sex. The primary outcome was the percentage of patients with severe disease, including those requiring oxygen supplementation and those who died. Additionally, 167 patients were followed up for changes in muscle parameters at three months and for the clinical characteristics in case of reduced CT density. RESULTS: For both muscles, low density rather than muscle area was associated with COVID-19 severity. Regardless of sex, lower erector spinae muscle density was associated with more severe disease than pectoralis muscle density. The muscles were divided into two groups using the receiver operating characteristic curve of CT density, and the population was classified into four (Group A: high CT density for both muscles, Group B: low CT density for pectoralis and high for erector spinae muscle. Group C: high CT density for pectoralis and low for erector spinae muscle, Group D: low CT density for both muscles). In univariate analysis, Group D patients exhibited worse outcomes than Group A (OR: 2.96, 95% CI: 2.03-4.34 in men; OR: 3.02, 95% CI: 2.66-10.4 in women). Multivariate analysis revealed that men in Group D had a significantly more severe prognosis than those in Group A (OR: 1.82, 95% CI: 1.16-2.87). Moreover, Group D patients tended to have the highest incidence of other complications due to secondary infections and acute kidney injury during the clinical course. Longitudinal analysis of both muscle densities over three months revealed that patients with decreased muscle density over time were more likely to have severe cases than those who did not. CONCLUSIONS: Muscle density, rather than muscle area, predicts the clinical outcomes of COVID-19. Integrated assessment of pectoralis and erector spinae muscle densities demonstrated higher accuracy in predicting the clinical course of COVID-19 than individual assessments.

Lumbar spinal alignment is crucial for spine biomechanics and is linked to various spinal pathologies. However, limited research has explored gender-specific differences using CT scans. The objective was to evaluate and compare lumbar spinal alignment between standing and sitting CT in healthy individuals, focusing on gender differences. 24 young and 25 elderly males (M) and females (F) underwent standing and sitting CT scans to assess lumbar spinal alignment. Parameters measured and compared between genders included lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), lordotic angle (LA), foraminal height (FH), and bony boundary area (BBA). Females showed significantly larger changes in SS and PT when transitioning from standing to sitting (p = .044, p = .038). A notable gender difference was also observed in the L4-S LA among the elderly, with females showing a significantly larger decrease in lordotic angle compared to males (- 14.1° vs. - 9.2°, p = .039*). Females consistently exhibited larger FH and BBA values, particularly in lower lumbar segments, which was more prominent in the elderly group (M vs. F: L4/5 BBA 80.1 mm2 [46.3, 97.8] vs. 109.7 mm2 [74.4, 121.3], p = .019 in sitting). These findings underline distinct gender-related variations in lumbar alignment and flexibility, with a focus on noteworthy changes in BBA and FH in females. Gender differences in lumbar spinal alignment were evident, with females displaying greater pelvic and sacral mobility. Considering gender-specific characteristics is crucial for assessing spinal alignment and understanding spinal pathologies. These findings contribute to our understanding of lumbar spinal alignment and have implications for gender-specific spinal conditions and treatments.

PURPOSE: DNA polymerase epsilon (POLE) exonuclease domain-mutated endometrial cancer (EC) is associated with a favorable prognosis and significant immune cell infiltration. Cancers with significant immune cell infiltration often exhibit higher maximum standardized uptake value (SUVmax) on 18F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT). This study aimed to evaluate the correlation between POLE status and FDG-PET/CT imaging in patients with EC. METHODS: This retrospective study enrolled 102 patients (mean age, 56.2 ± 11.8 years) with EC who underwent preoperative FDG-PET/CT between July 2018 and August 2023. Patients were categorized into molecular subtypes based on molecular profiling. SUVmax of the primary tumor and lymph nodes was measured, and correlations with molecular subtypes were examined. RESULTS: The SUVmax in the primary tumor of POLE-mutated ECs was higher than that in non-POLE-mutated ECs (mean ± SD, 13.21 ± 4.78 vs 9.82 ± 3.78; p = 0.001). Multiple regression analysis showed that POLE status was associated with SUVmax in primary tumors (B = 2.30, p = 0.031). The SUVmax in non-metastatic lymph nodes of POLE-mutated ECs was higher than that in non-POLE-mutated ECs (median SUVmax, 1.31 [IQR, 1.05-2.21] vs. 1.06 [IQR, 0.91-1.20]; p = 0.003). Multiple regression analysis revealed that POLE status was the only factor associated with SUVmax in non-metastatic lymph nodes (B = 0.339, p = 0.046), while age, BMI, blood glucose level, histological type, and primary tumor size showed no significant association. CONCLUSION: Patients with POLE-mutated EC exhibit high SUVmax in primary tumors and also tend to show elevated uptake in non-metastatic lymph nodes.

Background: Narrowing of the acromiohumeral distance (AHD) implies a rotator cuff tear. However, conventional AHD measurements using two-dimensional (2D) imaging or with the patient in the supine position might differ from that while standing during daily activity. This study aimed to evaluate the three-dimensional (3D) actual distance between the acromion and humeral head in the standing position and compare the AHD values with those obtained using conventional measuring methods. Methods: Computed tomography (CT) images of 166 shoulders from 83 healthy volunteers (31 male and 52 female; mean age 40.1 ± 5.8 years; age range, 30-49 years) were prospectively acquired in the supine and standing positions using conventional and upright CT scanners, respectively. The minimum distance between the acromion and humeral head on the 3D surface models was considered as the 3D AHD. We measured the 2D AHD on anteroposterior digitally reconstructed radiographs. The AHD values were compared between the supine and standing positions and between the 2D and 3D measurements. Results: The mean values of 2D AHD were 8.8 ± 1.3 mm (range, 5.9-15.4 mm) in the standing position and 8.1 ± 1.2 mm (range, 5.3-14.3 mm) in the supine position. The mean values of 3D AHD were 7.3 ± 1.4 mm (range, 4.7-14.0 mm) in the standing position and 6.6 ± 1.2 mm (range, 4.4-13.7 mm) in the supine position. The values of 3D AHD were significantly lower than those of 2D AHDs in both the standing and supine positions (P < 0.001). The values of 2D and 3D AHDs were significantly lower in the supine position than in the standing position (P < 0.001). Conclusions: This study evaluated the 3D AHD of normal shoulders in the standing position using an upright CT scanner. The present results indicated that assessments in the supine position can underestimate the value of the AHD compared with those made in the standing position and that assessments using 2D analysis can overestimate the value.

BACKGROUND: Posterior fossa arachnoid cysts are often asymptomatic, but can rarely cause postural headache, the mechanism of which remains unknown. CASE DESCRIPTION: We present a 40-year-old woman with an asymptomatic supracerebellar arachnoid cyst. Upright computed tomography (CT) showed enlargement of the arachnoid cyst and caudal descent of the cerebellum compared with supine CT with narrowing of the craniocervical junction cerebrospinal fluid space. CONCLUSIONS: This finding aids in understanding the association of posterior fossa arachnoid cysts with orthostatic headache. Clinicians should be aware of possible posture-related changes in intracranial structures.

Congenital dermoid fistulas of the anterior chest regions (CDFACRs) consist of a skin orifice at the anterior border of the sternocleidomastoid muscle with fistulas extending caudally in the subcutaneous tissue near the sternoclavicular joint. We report 2 pediatric CDFACR cases with pathognomonic sonography findings. By using sonography, we could diagnose the fistulas as CDFACRs by focusing on their location and direction and could reveal the distal side for complete resection. We suggest that sonography, which does not involve radiation or require sedation, is a better choice for the initial examination of CDFACRs than computed tomography or MRI.

Purpose: To investigate whether adaptive statistical iterative reconstruction (ASiR) or model-based iterative reconstruction (MBIR) improves the diagnostic performance of computed tomography angiography (CTA) for small-vessel calcified lesions relative to filtered back projection (FBP) using cadaver extremities and a calcified stenosis phantom. Methods: A cadaver was used in accordance with our institutional regulations, and a calcified stenosis phantom simulating 4 grades of stenosis was prepared. The phantom was inserted within the distal superficial femoral artery of the cadaver leg. Ten CT images per reconstruction type and stenosis grade were acquired using a 64-slice multidetector-row CTA. As an objective measurement, the first and second derivatives of the CT value function profiles were calculated. As a subjective measurement, 2 blinded reviewers measured the stenosis ratio using a quantitative scale. The Wilcoxon rank-sum test was used to evaluate the data. Results: Objective measurements of both 25% and 50% stenosis differed significantly (P <0.01) between MBIR (25/50%: 25.80/50.30 ± 3.88/3.86%) and FBP (25/50%: 35.60/83.80 ± 3.44/26.10%), whereas significant differences were not observed between ASiR and FBP. Reviewer 2's subjective measurements of 25% stenosis differed significantly (P <0.01) between MBIR (35.13 ± 3.25%) and ASiR (40.89 ± 3.14%), and the measurements of 50% stenosis differed significantly (P <0.01) between MBIR (reviewers 1/2, 62.36/54.78 ± 2.78/4.96%) and FBP (reviewers 1/2, 62.36/74.84 ± 2.78/18.10%). Significant differences in the subjective measurements were not observed between ASiR and FBP. Conclusion: MBIR improves the diagnostic performance of CTA for small-vessel calcified lesions relative to FBP.

© American Roentgen Ray Society. OBJECTIVE. The objective of our study was to evaluate the effects of radiation dose reduction and the reconstruction algorithm used-filtered back projection (FBP), adaptive statistical iterative reconstruction (ASIR), or model-based iterative reconstruction (MBIR)-on the measurement of abdominal visceral fat using CT. SUBJECTS AND METHODS. Standard-dose and low-dose abdominal CT examinations were performed simultaneously with automatic exposure control in 59 patients; the noise index for a 5-mm slice thickness was 12 for routine-dose CT and 24 for low-dose CT. The routine-dose CT images were reconstructed using FBP (reference standard), and the low-dose CT images were reconstructed using FBP, ASIR (so-called hybrid iterative reconstruction [IR]), and MBIR (so-called pure IR). In the 236 image series obtained, the visceral fat area was measured. Data were analyzed by the Pearson correlation coefficient test and a Bland-Altman difference analysis. RESULTS. The radiation dose of the low-dose abdominal CT examinations was 73.0% (mean) lower than that of routine-dose CT examinations. Excellent correlations were observed between the visceral fat areas measured on the routine-dose FBP images and those measured on the low-dose FBP, low-dose ASIR, and low-dose MBIR images (r = 0.998, 0.998, and 0.998, respectively; p < 0.001). A Bland-Altman difference analysis revealed excellent agreements, with mean biases of-0.47,-0.41, and 0.18 cm2 for the visceral fat area between the routine-dose FBP images and the low-dose FBP, low-dose ASIR, and low-dose MBIR images, respectively. CONCLUSION. A 73.0% reduction of the radiation dose would be possible in CT for the measurement of the abdominal visceral fat regardless of which reconstruction algorithm is used (i.e., FBP, hybrid IR, or pure IR).

© 2017 by the American Institute of Ultrasound in Medicine. OBJECTIVES: To compare the diagnostic accuracy for the low-type imperforate anus between prone cross-table radiography and sonography.METHODS: We included 20 neonates with imperforate anus: 13 with a surgically proven low type and 7 with an intermediate or high type. The distance between the distal rectal pouch and the perineum (pouch-perineum distance) was measured by both sonography and prone cross-table radiography. A previously established pouch-perineum distance of 10 mm was used as the cutoff for diagnosis of a low-type imperforate anus. The fistula location was also determined with sonography. We then compared the diagnostic accuracy of the imaging methods for a low-type imperforate anus using the cutoff value of the pouch-perineum distance alone and both the cutoff value of the pouch-perineum distance and fistula location. The McNemar test was used for statistical analysis.RESULTS: With the use of only the pouch-perineum distance, the diagnostic accuracy for the low-type imperforate anus based on sonographic measurements was comparable with the accuracy achieved by prone cross-table radiographic measurements (60.0% [12 of 20] versus 45.0% [9 of 20]; P = .625). With the use of the pouch-perineum distance and fistula location, the diagnostic accuracy of sonography was significantly better than the accuracy of prone cross-table radiography (90.0% [18 of 20] versus 45% [9 of 20]; P = .012).CONCLUSIONS: The diagnostic accuracy of sonography for the low-type imperforate anus based on both the pouch-perineum distance and fistula location is better than that of prone cross-table radiography. If the pouch-perineum distance on prone cross-table radiography is greater than 10 mm, a sonographic examination to determine the fistula location could be recommended.

© 2017 by the American Institute of Ultrasound in Medicine. Objectives: To evaluate the diagnostic accuracy of sonography for detection of an internal fistula on the birth day in neonates with an imperforate anus and to compare the diagnostic performance between the suprapubic and perineal approaches. Methods: We included 46 neonates with an imperforate anus (29 low type and 17 intermediate/high type) who underwent sonography by both the suprapubic and perineal approaches on the birth day. Thirty-nine neonates had internal fistulas, and 12 did not, as surgically proven. Two blinded radiologists evaluated the suprapubic and perineal sonograms for the presence of the internal fistula in consensus. A final diagnosis of the internal fistula was determined on the basis of the findings of both approaches. A receiver operating characteristic analysis was used to compare the diagnostic performance for detection of an internal fistula between the suprapubic and perineal approaches. Results: The sensitivity, specificity, and accuracy of the final diagnosis based on the findings of suprapubic, perineal, and both approaches were 52.9%, 79.4%, and 79.4%; 75.5%, 75.5%, and 75.5%; and 58.7%, 78.3%, and 78.3%, respectively. The diagnostic performance of the perineal approach was significantly better than that of the suprapubic approach (P <.0001). Conclusions: The diagnostic accuracy of sonography for detection of an internal fistula on the birth day exceeded 75% in neonates with an imperforate anus, and sonography on the birth day is feasible. The perineal approach had superior diagnostic performance over the suprapubic approach. Thus, when evaluating an internal fistula by sonography, we recommend using the perineal approach in addition to the suprapubic approach.

BACKGROUND: To our knowledge, no systematic study has been conducted on computed tomography (CT) imaging of mediastinitis in children post-cardiovascular surgery. We aimed to assess the CT findings of pediatric patients diagnosed with mediastinitis after cardiovascular surgery. METHODS: We included 28 pediatric patients with suspected mediastinitis after undergoing cardiovascular surgery and who underwent CT. Patients were divided into a group with mediastinitis requiring antibiotic therapy (n = 15) confirmed by positive bacterial culture from the mediastinum and a group without mediastinitis (n = 13). Fisher's exact test was used to compare the following CT findings between the two groups: (i) mediastinal fluid collection; (ii) free gas bubble within fluid collection; (iii) sternal destruction; and (iv) capsular ring enhancement. The enhancement extent was categorized into the following four grades: whole rim enhancement, >50% of the rim enhancement, <50% of the rim enhancement, and no rim enhancement. A receiver operating characteristic curve analysis was performed to establish a cut-off point for obtaining the maximum diagnostic accuracy. RESULTS: A significant difference was observed between patients, with and without mediastinitis in sternal destruction (73.6% vs 0%, P = <0.0001) and capsular ring enhancement (100.0% vs 38.5%, P = 0.0004). By using a cut-off grade of the whole rim enhancement, the estimated sensitivity and specificity for mediastinitis diagnosis were 100% and 92.3%, respectively. CONCLUSION: Computed tomography findings of sternal destruction and capsular ring enhancement were observed more in patients with mediastinitis than in those without mediastinitis, and should be assessed carefully to diagnose mediastinitis accurately in pediatric patients who have undergone cardiac surgery.

© 2020 Background: No clinical studies to date have compared unilateral lung or lobe volumes between the supine and standing positions. Objectives: To compare lung/lobe volumes on computed tomography (CT) between these two positions and evaluate the correlation between the total lung volume and total lung capacity (TLC) on pulmonary function tests (PFTs). Methods: Thirty-two asymptomatic volunteers underwent both conventional CT (supine position) and upright CT (standing position), during deep inspiration breath-hold, and PFTs on the same day. We measured lung/lobe volumes on CT in each position. Paired t tests were used for statistical analysis. Results: The volumes of the total lung (10.9% increase), right lung (10.3% increase), right upper lobe (8.6% increase), right lower lobe (14.6% increase), left lung (11.6% increase), left upper lobe (7.1% increase), and left lower lobe (16.0% increase) were significantly greater in the standing position than in the supine position (all p < 0.0001). The right middle lobe volume was similar between the two positions (p = 0.16). Intraclass correlation coefficients for agreement between total lung volumes on CT in the supine/standing positions and the TLC on PFT were 0.891/0.938, respectively. Conclusions: While the volumes of the bilateral upper and lower lobes and bilateral lungs were significantly greater in the standing than in the supine position, with lower lobes showing larger changes, the right middle lobe volume did not change significantly between positions. The total lung volume on upright CT in the standing position was more similar to TLC on PFT than that in the supine position.