Yutaka Imai

Objective: We investigated the efficacy and exposure to radiation in 320-detector row computed tomography fluoroscopy-guided (CTF-guided) interventions. Methods: We analysed 231 320-detector row CTF-guided interventions (207 patients over 2 years and 6 months) in terms of technical success rates, clinical success rates, complications, scanner settings, overall radiation doses (dose–length product, mGy*cm), patient doses of peri-interventional CT series, and interventional CT (including CTF), as a retrospective cohort study. The relationships between patient radiation dose and interventional factors were assessed using multivariate analysis. Results: Overall technical success rate was 98.7% (228/231). The technical success rates of biopsies, drainages, and aspirations were 98.7% (154/156), 98.5% (66/67), and 100% (8/8), respectively. The clinical success rate of biopsies was 93.5% (146/156). All three major complications occurred in chest biopsies. The median total radiation dose was 522.4 (393.4–819.8) mGy*cm. Of the total radiation dose, 87% was applied during the pre- and post-interventional CT series. Post-interventional CT accounted for 24.4% of the total radiation dose. Only 11.4% of the dose was applied by CTF-guided intervention. Multilinear regression demonstrated that male sex, body mass index, drainage, intervention time, and helical scan as post-interventional CT were significantly associated with higher dose. Conclusion: The 320-detector row CTF interventions achieved a high success rate. Dose reduction in post-interventional CT provides patient dose reduction without decreasing the technical success rates. Advances in knowledge: This is the first study on the relationship between various interventional outcomes and patient exposure to radiation in 320-detector row CTF-guided interventions, suggesting a new perspective on dose reduction.

The original article can be found online.

Purpose To reveal that a computed tomography surveillance program (CT-surveillance) could demonstrate the epidemiologic features of COVID-19 infection and simultaneously investigate the type and frequency of CT findings using clinical CT data. Materials and methods We targeted individuals with possible CT findings of viral pneumonia. Using an online questionnaire, we asked Japanese board-certified radiologists to register their patients’ information including patient age and sex, the CT examination date, the results of PCR test for COVID-19 infection, CT findings, and the postal code of the medical institution that performed the CT. We compared the diurnal patient number and the cumulative regional distribution map of registrations in CT-surveillance to those of the PCR-positive patient surveillance (PCR-surveillance). Results A total of 637 patients was registered from January 1 to April 17, 2020 for CT-surveillance. Their PCR test results were positive (n = 62.5–398%), negative (n = 8.9–57%), unknown (n = 26.2–167%), and other disease (n = 2.4–15%). An age peak at 60–69 years and male dominance were observed in CT-surveillance. The most common CT finding was bilaterally distributed ground-glass opacities. The diurnal number and the cumulative regional distribution map by CT-surveillance showed tendencies that were similar to those revealed by PCR-surveillance. Conclusion Using clinical CT data, CT-surveillance program delineated the epidemiologic features of COVID-19 infection.

Our hypothesis in the study is that post–chemotherapy and radiation therapy skewness of the apparent diffusion coefficient histogram and percentage change in apparent diffusion coefficient can help predict a favorable response to neoadjuvant chemotherapy and radiation therapy in patients with locally advanced rectal cancer. PurposeTo determine response to neoadjuvant chemotherapy and radiation therapy in patients with locally advanced rectal cancer (LARC) by using magnetic resonance (MR) apparent diffusion coefficient (ADC) histogram analysis.Materials and MethodsNinety-two patients with LARC underwent MR imaging with rectal barium before and after chemotherapy and radiation therapy (CRT). Rectal expansion with barium expanded the lumen, provided similar imaging geometry before and after CRT, and eliminated fecal matter, air, and residual fluid. T2-weighted images, the percentage change in ADC, and ADC histogram skewness and kurtosis were assessed. The histopathologic tumor regression grade (TRG) ranged from 1a (66%–99% residual tumor cells) to 3 (no residual cells). The Wilcoxon signed-rank test, the Spearman correlation test, multivariable linear regression, and one-way analysis of variance were used to determine post- and pretreatment differences and correlations between tumor size and ADC.ResultsOf the 92 patients, 16 (1...

We evaluated radiological findings and clinical significance of right aortic arch with mirror-image branching (RAMI) in adults using data from computed tomography (CT) examinations. We reviewed recorded reports and CT images obtained from university and branch hospitals for RAMI in adults. The RAMI incidence in adults found on CT was assessed. Associated congenital and acquired cardiovascular diseases were evaluated. A total of 27 cases (14 men, 13 women; mean age, 59.4 ± 18.3 years) of RAMI were found. Among 107,014 cases in three hospitals, the RAMI incidence in the first, second, and third Tokai University hospitals were 0.018%, 0.012%, and 0.012%, respectively. Eight cases had high aortic arches and four cases had aortic diverticulum (AD) in proximal descending aorta. Three cases had a history of tetralogy of Fallot. One case with an absent left pulmonary artery and three cases with an aberrant left brachiocephalic vein were found incidentally. Two cases were associated with AD aneurysm and vascular ring formation. One case had stenosis of the left subclavian artery due to injury. Cases of RAMI found in CT examinations in adults were extremely rare. Some cases were associated with congenital anomalies and/or acquired cardiovascular disease.

To assess the feasibility of apparent diffusion coefficient analysis in evaluating the inflammatory severity of extracranial abscesses. This retrospective study included 23 patients with solitary body abscesses (except those in the brain) who underwent 1.5-T diffusion-weighted magnetic resonance imaging (DWI) at b-values of 0 and 1000 s/mm2. Three types of the Apparent Diffusion Coefficient (ADC) measurements of abscesses were performed: the mean ADC value in region of interest (ROI), volume of interest (VOI), and histogram analysis of the ADC distribution in the VOI. Furthermore, two different areas were used: high-intensity area on b = 0 and b = 1000 s/mm2 images. Subsequently, correlations between ADC data and C-reactive protein (CRP) levels were assessed using Pearson's correlation coefficient (R) analyses. The strongest correlation was observed between the mean ADC value in VOI and CRP level (R = 0.78, P < 0.01), followed by ROI (R = 0.77, P < 0.01) by using the high-intensity area on the b = 0 s/mm2 images. The mean ADC value in the ROI encompassing the abscess at a b-value of 0 s/mm2 may be useful to assess the inflammatory activity of an abscess in daily practice.

Objection: To evaluate of Kommerell diverticulum (KD) in adults during routine CT examinations. Eighty-seven cases of left aortic arch with aberrant right subclavian artery (LAARS) and 28 cases of right aortic arch with aberrant left subclavian artery (RAALS) were found on routine CT examinations using 64-128 multidetector CT. We assessed the incidence of KD and measured the size of KD, and compared the results between both groups. We evaluated associated congenital and acquired cardiovascular diseases on both groups. The incidence of KD in each group was as follows: RAALS 100 % and LAARS 48.3 % and incidence of KD in RAALS group was significant higher than in LAARS group. The mean KD size was as follows: RAALS 32.8 mm and LAARS 17.8 mm and, the size of KD in RAALS group was larger than that in LAARS group. Two cases were associated with congenital heart disease. Several cases were associated with acquired aortic diseases including aortic aneurysm, dissection, severe atherosclerosis and aortitis. KD was common among adults with an ASA and some adults were associated with aortic diseases.

A 58-year-old Japanese female was admitted to our hospital for treatment of ovarian cancer. She had no urinary tract symptoms at the time of presentation. Preoperative CT (Computed Tomography) was performed for surgical planning, and it revealed two left-sided ureters including a short ureter with a blind, cystic ending and a short ureter joined to the main ureter before entering into the bladder. On CT urography, these radiological findings were compatible with a blind-ending bifid ureter. Preoperatively, a double J stent was inserted into the normal left ureter, and then the blind-ending bifid ureter was resected before an ovarian cancer operation.

T2 mapping is an MRI method particularly reflective of the collagen arrangement in the cartilage, and diffusion tensor (DT) imaging captures the diffusion of water molecules. Laser-induced photoacoustic measurement (LIPA) makes it possible to assess not only the thickness of the cartilage layer but also its viscoelastic properties. By assessing cartilage damage assessment using LIPA and 3.0 Tesla MRI (T2 mapping and DT imaging), this study investigates the usefulness of the various methods. The International Cartilage Repair Society (ICRS) classification was used to classify 29 bone cartilage pieces excised during surgical procedures. At the same time, LIPA was performed at sites matching the area of cartilage damage. MRI was performed preoperatively to measure the T2 and the apparent diffusion coefficient. In addition, tissue sections for histological assessment using the Mankin score were prepared for each ICRS grade, and the results with the various methods were compared. With DT imaging, significant differences were observed in all grades (P < 0.01). With T2 mapping, significant differences were observed in all grades except for grade 1 versus grade 2 (P < 0.01). With LIPA, significant differences were observed in ICRS grade 1 versus grade 3 (P < 0.05), grade 1 versus grade 4 (P < 0.01), grade 2 versus grade 4 (P < 0.01), and grade 3 versus grade 4 (P < 0.05). With the Mankin score, significant differences were observed in ICRS grade 1 versus grade 3 (P < 0.01), grade 1 versus grade 4 (P < 0.01), grade 2 versus grade 4 (P < 0.01), and grade 3 versus grade 4 (P < 0.01). Correlations were observed in all combinations of ICRS grade with DT imaging, T2 mapping, LIPA, and Mankin score. Correlations were observed between the degree of histological degeneration and DT imaging, T2 mapping, and ICRS grade, but LIPA had a weaker correlation than MRI. In the assessment of knee osteoarthritis, there are instances where it is difficult to assess the damaged cartilage site with MRI alone, and we believe that it is desirable to use a combination of LIPA and MRI.

A 29-year-old female with ulcerative colitis was found to have advanced sigmoid colon cancer on colonoscopy. Computed tomography (CT) was performed after colonoscopy for the evaluation of metastasis. CT colonography (CTC) could be understood adding carbon dioxide because of soon after colonoscopic examination. Images of CTC were evaluated by two- and three-dimensional images including virtual endoscopic, virtual colon dissection and air images, and then compared with conventional endoscopic images. Virtual endoscopic images of flat elevated cancer with shallow ulcer were similar to those findings by conventional endoscopy. This lesion could be depicted by computer-aided detection.