Assessing antiviral treatment efficacy and risk factors for severe COVID-19 in kidney transplant recipients during the Omicron subvariant-dominant period: a retrospective study.

BACKGROUND: Kidney transplant recipients (KTRs) are at risk of severe coronavirus disease 2019 (COVID-19), and even now that Omicron subvariants have become dominant, cases of severe disease are certain to occur. The aims of this retrospective study were to evaluate the efficacy of antiviral treatment for COVID-19 and to identify risk factors for severe disease in KTRs during Omicron subvariant-dominant periods. METHODS: A total of 65 KTRs diagnosed with COVID-19 who received antiviral treatment between July 2022 and September 2023 were analyzed. Mild cases received oral molnupiravir (MP) as outpatient therapy, while moderate or worse cases received intravenous remdesivir (RDV) as inpatient therapy. In principle, mycophenolate mofetil was withdrawn and switched to everolimus. We investigated the efficacy of antiviral treatment and compared the clinical parameters of mild/moderate and severe/critical cases to identify risk factors for severe COVID-19. RESULTS: Among 65 cases, 49 were mild, 6 were moderate, 9 were severe, and 1 was of critical severity. MP was administered to 57 cases; 49 (86%) improved and 8 (14%) progressed. RDV was administered to 16 cases; 14 (87%) improved and 2 (13%) progressed. Seventeen (26%) cases required hospitalization, and none died. Comparisons of the severe/critical group (n = 10) with the mild/moderate group (n = 55) demonstrated that the severe/critical group had a significantly higher median age (64 vs. 53 years, respectively; p = 0.0252), prevalence of diabetes (70% vs. 22%, respectively; p = 0.0047) and overweight/obesity (40% vs. 11%, respectively; p = 0.0393), as well as a significantly longer median time from symptom onset to initial antiviral therapy (3 days vs. 1 day, respectively; p = 0.0026). Multivariate analysis showed that a longer time from symptom onset to initial antiviral treatment was an independent risk factor for severe COVID-19 (p = 0.0196, odds ratio 1.625, 95% confidence interval 1.081-2.441). CONCLUSION: These findings suggest that a longer time from symptom onset to initial antiviral treatment is associated with a higher risk of severe COVID-19 in KTRs. Initiating antiviral treatment as early as possible is crucial for preventing severe outcomes; this represents a valuable insight into COVID-19 management in KTRs.

LncRNA BCYRN1 as a Potential Therapeutic Target and Diagnostic Marker in Serum Exosomes in Bladder Cancer.

Bladder cancer (BC) is a common genitourinary malignancy that exhibits silent morbidity and high mortality rates because of a lack of diagnostic markers and limited effective treatments. Here, we evaluated the role of the lncRNA brain cytoplasmic RNA 1 (BCYRN1) in BC. We performed loss-of-function assays to examine the effects of BCYRN1 downregulation in T24 and BOY BC cells. We found that BCYRN1 downregulation significantly inhibited the proliferation, migration, invasion, and three-dimensional spheroid formation ability and induced apoptosis in BC cells. Additionally, gene set enrichment analysis (GSEA) using RNA sequences from tumor fractions showed that BCYRN1 downregulation decreased the expression of mRNAs associated with the cell cycle. These findings were supported by observations of G2/M arrest in flow cytometry assays. Finally, we examined the expression of serum exosomal BCYRN1 as a biomarker. Clinically, BCYRN1 expression in serum exosomes from patients with BC (n = 31) was significantly higher than that in healthy donors (n = 19; mean difference: 4.1-fold higher, p < 0.01). Moreover, in patients who had undergone complete resection of BC, serum exosomal BCYRN1 levels were significantly decreased (n = 8). Thus, serum exosomal BCYRN1 may be a promising diagnostic marker and therapeutic target in patients with BC.

Perioperative proximal splenic artery embolization in cirrhotic patients with splenomegaly.

INTRODUCTION: The purpose of this study was to determine the effect of proximal splenic artery embolization (SAE) in cirrhotic patients with splenomegaly who underwent surgical laparotomy. MATERIAL AND METHODS: This retrospective observational study included 8 cirrhotic patients with splenomegaly. They underwent proximal SAE before- (n = 6) or after (n = 2) laparotomy. Vascular plugs or coils were placed in the proximal splenic artery. The diameter of the portal vein and the splenic volume were recorded. Clinical outcome assessments included platelet counts, the model for end-stage liver disease (MELD) score, and complications. RESULTS: After embolization, the portal venous diameter was significantly smaller (pre: 13.6 ± 2.7 mm, post: 12.5 ± 2.3 mm, p = 0.023), the splenic volume was significantly decreased (pre: 463.2 ± 145.7 ml, post: 373.3 ± 108.5 ml, p = 0.008) and the platelet count was significantly higher (pre: 69.6 ± 30.8 × 103/µl, post: 86.8 ± 27.7 × 103/µl, p = 0.035). Before embolization, the median MELD score was 12; after embolization, it was 11 (p = 0.026). No patient developed post-treatment complications after embolization. CONCLUSIONS: The reduction of hypersplenism by perioperative proximal SAE may be safe and reduce the surgical risk in cirrhotic patients with splenomegaly.

Potential therapeutic target secretogranin II might cooperate with hypoxia-inducible factor 1α in sunitinib-resistant renal cell carcinoma.

Multitargeted receptor tyrosine kinase inhibitors, including vascular endothelial growth factor (VEGF) inhibitors, such as sunitinib, have been used as the primary targeted agents for patients with recurrent or distant metastasis of advanced renal cell carcinoma (RCC). However, endogenous or acquired sunitinib resistance has become a significant therapeutic problem. Therefore, we focused on mechanisms of sunitinib resistance in RCC. First, we undertook RNA sequencing analysis using previously established sunitinib-resistant RCC (SUR-Caki1, SUR-ACHN, and SUR-A498) cells. The results showed increased expression of secretogranin II (SCG2, chromogranin C) in SUR-RCC cells compared to parental cells. The Cancer Genome Atlas database showed that SCG2 expression was increased in RCC compared to normal renal cells. In addition, the survival rate of the SCG2 high-expression group was significantly lower than that of the RCC low-expression group. Thus, we investigated the involvement of SCG2 in sunitinib-resistant RCC. In vitro analysis showed that migratory and invasive abilities were suppressed by SCG2 knockdown SUR cells. As SCG2 was previously reported to be associated with angiogenesis, we undertook a tube formation assay. The results showed that suppression of SCG2 inhibited angiogenesis. Furthermore, coimmunoprecipitation assays revealed a direct interaction between SCG2 and hypoxia-inducible factor 1α (HIF1α). Expression levels of VEGF-A and VEGF-C downstream of HIF1α were found to be decreased in SCG2 knockdown SUR cells. In conclusion, SCG2 could be associated with sunitinib resistance through VEGF regulation in RCC cells. These findings could lead to a better understanding of the VHL/HIF/VEGF pathway and the development of new therapeutic strategies for sunitinib-resistant RCC.

Characteristics of the pulmonary opacities on chest CT associated with difficulty in short-term liberation from veno-venous ECMO in patients with severe ARDS.

BACKGROUND: It is clinically important to predict difficulty in short-term liberation from veno-venous extracorporeal membrane oxygenation (V-V ECMO) in patients with severe acute respiratory distress syndrome (ARDS) at the time of initiation of the support. The aim of this study was to identify the characteristics of pulmonary opacities on chest CT that is associated with difficulty in short-term liberation from V-V ECMO (< 14 days). METHODS: This multicenter retrospective study was conducted in adult patients initiated on V-V ECMO for severe ARDS between January 2014 and June 2022. The pulmonary opacities on CT at the time of initiation of the ECMO support were evaluated in a blinded manner, focusing on the following three characteristics of the opacities: (1) their distribution (focal/diffuse on the dorso-ventral axis or unilateral/bilateral on the left-right axis); (2) their intensity (pure ground glass/pure consolidation/mixed pattern); and (3) the degree of fibroproliferation (signs of traction bronchiectasis or reticular opacities). RESULTS: Among the 153 patients, 72 (47%) were successfully liberated from ECMO in the short term, while short-term liberation failed in the remaining 81 (53%) patients. Multivariate logistic regression analysis showed that the presence of mixed-pattern pulmonary opacities and signs of traction bronchiectasis, but not the distribution of the opacities, were independently associated with difficulty in short-term liberation (OR [95% CI]; 4.8 [1.4-16.5] and 3.9 [1.4-11.2], respectively). CONCLUSIONS: The presence of a mixed pattern of the pulmonary opacities and signs of traction bronchiectasis on the chest CT were independently associated with difficulty in short-term liberation from V-V ECMO in severe ARDS patients.

Targeting of the glutamine transporter SLC1A5 induces cellular senescence in clear cell renal cell carcinoma.

In recent years, cancer metabolism has attracted attention as a therapeutic target, and glutamine metabolism is considered one of the most important metabolic processes in cancer. Solute carrier family 1 member 5 (SLC1A5) is a sodium channel that functions as a glutamine transporter. In various cancer types, SLC1A5 gene expression is enhanced, and cancer cell growth is suppressed by inhibition of SLC1A5. However, the involvement of SLC1A5 in clear cell renal cell carcinoma (ccRCC) is unclear. Therefore, in this study, we evaluated the clinical importance of SLC1A5 in ccRCC using The Cancer Genome Atlas database. Our findings confirmed that SLC1A5 was a prognosis factor for poor survival in ccRCC. Furthermore, loss-of-function assays using small interfering RNAs or an SLC1A5 inhibitor (V9302) in human ccRCC cell lines (A498 and Caki1) showed that inhibition of SLC1A5 significantly suppressed tumor growth, invasion, and migration. Additionally, inhibition of SLC1A5 by V9302 in vivo significantly suppressed tumor growth, and the antitumor effects of SLC1A5 inhibition were related to cellular senescence. Our findings may improve our understanding of ccRCC and the development of new treatment strategies for ccRCC.

Exosomal microRNA-1 and MYO15A as a target for therapy and diagnosis in renal cell carcinoma.

Exosomes are 40-100 nm nano-sized extracellular vesicles and are receiving increasing attention as novel structures that participate in intracellular communication. We previously found that miRNA-1 (miR-1) functions as a tumor suppressor in renal cell carcinoma (RCC). In this study, we investigated the function of exosomal miR-1 and the possibility that the exosome constitutes a tumor maker in RCC. First, we established the method to collect exosomes from cell lysates and human serum by a spin column-based method. Next, we assessed exosomes using Nanosight nanoparticle tracking analysis and Western blot analysis with exosome marker CD63. We confirmed that exosomes labeled with PKH26 fused with recipient cells. Moreover, miR-1 expression was elevated in RCC cells treated with exosomes derived from miR-1-transfected cells. Functional analyses showed that exosomal miR-1 significantly inhibited cell proliferation, migration and invasion compared to control treatment. Our analyses with TCGA database of RCCs showed that miR-1 expression was significantly downregulated in clinical RCC samples compared to that in normal kidney samples, and patients with low miR-1 expression had poorer overall survival in comparison to patients with high expression. Furthermore, RNA sequence analyses showed that expression levels of several genes were altered by exposure to exosomal miR-1. The analyses with TCGA database indicated that high expression of MYO15A was associated with a poorer outcome in RCC. In addition, RT-qPCR analysis of exosomes from clinical patients' sera showed that MYO15A was significantly upregulated in RCC patients compared to that in healthy controls. This study showed that treatment with exosomal miR-1 might be an effective approach to treating RCCs. In addition, exosomal MYO15A could be a diagnostic tumor marker in RCCs.

Triaging of COVID-19 patients using low dose chest CT: Incidence and factor analysis of lung involvement on CT images.

INTRODUCTION: Despite an increase in CT studies to evaluate patients with coronavirus disease 2019 (COVID-19), their indication in triage is not well-established. The purpose was to investigate the incidence of lung involvement and analyzed factors related to lung involvement on CT images for establishment of the indication for CT scans in the triaging of COVID-19 patients. METHODS: Included were 192 COVID-19 patients who had undergone CT scans and blood tests for triaging. Two radiologists reviewed the CT images and recorded the incidence of lung involvement. The prediction model for lung involvement on CT images using clinico-laboratory variables [age, gender, body mass index, oxygen saturation of the peripheral artery (SpO2), comorbidities, symptoms, and blood data] were developed by multivariate logistic regression with cross-validation. RESULTS: In 120 of the 192 patients (62.5%), CT revealed lung involvement. The patient age (odds ratio [OR]; 4.95, 95% confidence interval [CI]; 0.93-26.49), albumin (OR; 4.66, 95%CI; 1.37-15.84), lactate dehydrogenase (OR; 5.79, 95%CI; 1.43-23.38) and C-reactive protein (OR; 8.93, 95%CI; 4.13-19.29) were selected for the final prediction model for lung involvement on CT images. The cross-validated area under the receiver operating characteristics (ROC) curve was 0.83. CONCLUSIONS: The high incidence of lung involvement (62.5%) was confirmed on CT images. The proposed prediction model that includes the patient age, albumin, lactate dehydrogenase, and C-reactive protein may be useful for predicting lung involvement on CT images and may assist in deciding whether triaged COVID-19 patients should undergo CT.

Cranio-caudal puncture with computed tomography-guided drainage of a deep pelvic abscess.

Purpose: Computed tomography (CT)-guided percutaneous drainage has been used to address pelvic abscesses because it is safe and minimally invasive. However, CT-guided drainage has the limitation that the puncture route should be on the same axial slice. A technique for puncturing in the cranio-caudal direction under CT fluoroscopy is needed. Case report: An 82-year-old man with an abscess due to rectal cancer was scheduled for CT-guided drainage to improve his general condition before radical surgery. Drainage was performed via a perineal approach to localize the drainage tract in the resection area to avoid dissemination of cancer cells. To perform a puncture in the cranio-caudal direction we controlled the needle like a joystick and advanced it under CT fluoroscopy while moving the CT gantry cranially to follow the needle tip throughout the puncture. Our unique technique yielded successful CT-guided puncture in the cranio-caudal direction. Conclusions: Our unique technique overcomes the limitations of CT-guided cranio-caudal puncture and may allow the drainage of abscesses whose treatment was heretofore difficult.

Incidence and factor analysis of laryngohyoid fractures in hanging individuals-computed tomography study.

OBJECTIVES: Although laryngohyoid fracture indicates the applied neck pressure and is an important finding in hanging individuals, the reported rate varies widely and its true incidence remains controversial. We used computed tomography (CT) studies to investigate the incidence of laryngohyoid fracture in hanging individuals and identify factors contributing to such fractures. METHODS: Considered for inclusion in this study were 107 attempted or successful hanging individuals subjected to CT studies between 2005 and 2019. After excluding 19 whose images were inadequate for evaluation, 88 subjects were included. Body suspension was complete in 20, partial in 49, and unknown in 19; 54 (61.4%) individuals died. Two radiologists performed image analysis and recorded the presence and site of laryngohyoid fractures. Multiple logistic regression analysis was used for factor analysis of laryngohyoid fractures; it included the gender, the age (< or ≧ 40 years), the type of suspension (complete or incomplete), and the outcome (death or survival). RESULTS: Of the 88 subjects, 35 (39.8%) presented with laryngohyoid fractures on CT images; the superior horn of the thyroid cartilage was fractured in 32 (91.4%) of the 35. Age was the only factor significantly related to laryngohyoid fracture (odds ratio = 2.85, 95% confidence interval = 1.08-7.52). CONCLUSIONS: In hanging individuals, the incidence of laryngohyoid fracture on CT images was 39.8%. The superior horn of the thyroid cartilage was the most frequent fracture site. KEY POINTS: • The incidence of laryngohyoid fracture on CT images of hanging individuals was almost 40%; the superior horn of the thyroid cartilage was the most frequent fracture site. • In older hanging individuals, attention must be paid to laryngohyoid fractures on CT images.

Potential benefits of volumetric modulated arc therapy to reduce the incidence of ≥ grade 2 radiation pneumonitis in radiotherapy for locally advanced non-small cell lung cancer patients.

BACKGROUND: The use of volumetric modulated arc therapy is gradually widespread for locally advanced non-small cell lung cancer. The purpose of this study was to identify the factors that caused ≥ grade 2 radiation pneumonitis and evaluate the impact of using volumetric modulated arc therapy on the incidence of ≥ grade 2 radiation pneumonitis by comparing three-dimensional conformal radiation therapy. METHODS: We retrospectively evaluated 124 patients who underwent radical radiotherapy for locally advanced non-small cell lung cancer in our institution between 2008 and 2019. The following variables were analysed to detect the factors that affected ≥ grade 2 radiation pneumonitis; age, sex, the presence of interstitial lung disease, pulmonary emphysema, tumour location, stage, PTV/lung volume, lung V20Gy, total dose, concurrent chemoradiotherapy, adjuvant immune checkpoint inhibitor, radiotherapy method. Radiation pneumonitis was evaluated using the common terminology criteria for adverse events (version 5.0). RESULTS: A total of 84 patients underwent three-dimensional conformal radiation therapy (3D-CRT group) and 40 patients underwent volumetric modulated arc therapy (VMAT group). The cumulative incidence of ≥ grade 2 radiation pneumonitis at 12 months was significantly lower in the VMAT group than in the 3D-CRT group (25% vs. 49.1%). The use of volumetric modulated arc therapy was a significant factor for ≥ grade 2 radiation pneumonitis (HR:0.32, 95% CI: 0.15-0.65, P = 0.0017) in addition to lung V20Gy (≥ 24%, HR:5.72 (95% CI: 2.87-11.4), P < 0.0001) and total dose (≥ 70 Gy, HR:2.64 (95% CI: 1.39-5.03), P = 0.0031) even after adjustment by multivariate analysis. CONCLUSIONS: We identified factors associated with ≥ grade 2 radiation pneumonitis in radiotherapy for patients with locally advanced non-small cell lung cancer. Volumetric modulated arc therapy has potential benefits to reduce the risk of ≥ grade 2 radiation pneumonitis.

Advanced CT techniques for assessing hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the sixth-most common cancer in the world, and hepatic dynamic CT studies are routinely performed for its evaluation. Ongoing studies are examining advanced imaging techniques that may yield better findings than are obtained with conventional hepatic dynamic CT scanning. Dual-energy CT-, perfusion CT-, and artificial intelligence-based methods can be used for the precise characterization of liver tumors, the quantification of treatment responses, and for predicting the overall survival rate of patients. In this review, the advantages and disadvantages of conventional hepatic dynamic CT imaging are reviewed and the general principles of dual-energy- and perfusion CT, and the clinical applications and limitations of these technologies are discussed with respect to HCC. Finally, we address the utility of artificial intelligence-based methods for diagnosing HCC.

Biological Effects of Low-Dose Chest CT on Chromosomal DNA.

Background Although the National Lung Screening Trial reported a significant reduction in lung cancer mortality when low-dose (LD) CT chest examinations are used for a diagnosis, their biologic effects from radiation exposure remain unclear. Purpose To compare LD CT and standard-dose (SD) CT for DNA double-strand breaks and chromosome aberrations (CAs) in peripheral blood lymphocytes. Materials and Methods Between March 2016 and June 2018, 209 participants who were referred to a respiratory surgery department for chest CT studies were prospectively enrolled in this study. Individuals were excluded if they had undergone radiography examinations within the last 3 days or had undergone chemotherapy or radiation therapy. Peripheral blood samples were obtained before and 15 minutes after CT. The number of γ-H2AX foci and unstable CAs in lymphocytes was quantified by immunofluorescent staining of γ-H2AX and by fluorescence in situ hybridization by using peptide nucleic acid probes for centromeres and telomeres, respectively. The Wilcoxon signed rank test was used for statistical analysis. Bonferroni correction was applied for multiple comparisons. Results Of the 209 participants (105 women, 104 men; mean age, 67.0 years ± 11.3 [standard deviation]), 107 underwent chest LD CT and 102 underwent chest SD CT. Sex distribution, age, and body size metrics were similar between the two groups. The median effective dose of LD CT and SD CT was 1.5 and 5.0 mSv, respectively. The number of double-strand breaks and CAs increased after a SD CT examination (γ-H2AX, P < .001; CAs, P = .003); the number of double-strand breaks and CAs before and after LD CT was not different (γ-H2AX, P = .45; CAs, P = .69). Conclusion No effect of low-dose CT on human DNA was detected. In the same setting, DNA double-strand breaks and chromosome aberrations increased after standard-dose CT. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Brenner in this issue.

Individual Optimization of Contrast Media Injection Protocol at Hepatic Dynamic Computed Tomography Using Patient-Specific Contrast Enhancement Optimizer.

OBJECTIVE: We developed a patient-specific contrast enhancement optimizer (p-COP) that can exploratorily calculate the contrast injection protocol required to obtain optimal enhancement at target organs using a computer simulator. Appropriate contrast media dose calculated by the p-COP may minimize interpatient enhancement variability. Our study sought to investigate the clinical utility of p-COP in hepatic dynamic computed tomography (CT). METHODS: One hundred thirty patients (74 men, 56 women; median age, 65 years) undergoing hepatic dynamic CT were randomly assigned to 1 of 2 contrast media injection protocols using a random number table. Group A (n = 65) was injected with a p-COP-determined iodine dose (developed by Higaki and Awai, Hiroshima University, Japan). In group B (n = 65), a standard protocol was used. The variability of measured CT number (SD) between the 2 groups of aortic and hepatic enhancement was compared using the F test. In the equivalence test, the equivalence margins for aortic and hepatic enhancement were set at 50 and 10 Hounsfield units (HU), respectively. The rate of patients with an acceptable aortic enhancement (250-350 HU) for the diagnosis of hypervascular liver tumors was compared using the χ test. RESULTS: The mean ± SD values of aortic and hepatic enhancement were 311.0 ± 39.9 versus 318.7 ± 56.5 and 59.0 ± 11.5 versus 58.6 ± 11.8 HU in groups A and B, respectively. Although the SD for aortic enhancement was significantly lower in group A (P = 0.006), the SD for hepatic enhancement was not significantly different (P = 0.871). The 95% confidence interval for the difference in aortic and hepatic enhancement between the 2 groups was within the range of the equivalence margins. The number of patients with acceptable aortic enhancement was significantly greater in group A than in group B (P < 0.01). CONCLUSIONS: The p-COP software reduced interpatient variability in aortic enhancement and obtained acceptable aortic enhancement at a significantly higher rate compared with the standard injection protocol for hepatic dynamic CT.

Quantification of the salivary volume flow rate in the parotid duct using the time-spatial labeling inversion pulse (Time-SLIP) technique at MRI: A feasibility study.

BACKGROUND: We developed a method to quantify the volume flow rate (VFR) using the time-spatial labeling inversion pulse (Time-SLIP) technique to evaluate salivary function. PURPOSE/HYPOTHESIS: To investigate the accuracy of quantification of the salivary VFR using the Time-SLIP technique in phantoms and to examine the feasibility of its use in human subjects. STUDY TYPE: This was a prospective phantom and volunteer study. POPULATION/SUBJECTS/PHANTOM/SPECIMEN/ANIMAL MODEL: A phantom and 23 normal volunteers who fasted at least 2 hours study was performed. FIELD STRENGTH/SEQUENCE: Flow images of the phantom and the parotid duct of 23 volunteers were acquired on a 3T-MRI scanner using the Time-SLIP technique. ASSESSMENT: Hypothesizing that flow aggregates in the conducting duct, we measured the VFR on flow images. In the phantom study, the actual VFR (slow, medium, fast flow) was controlled by an automatic pump system and the measured VFR was compared with the actual VFR on flow images. In the human study we injected citric acid into the mouth of healthy volunteers to stimulate saliva secretion and recorded the VFR. STATISTICAL TESTS: As this study was a feasibility study, statistical tests were not performed. RESULTS: In the phantom study, the VFR at slow, medium, and fast flow was 5.7 ± 0.4 (SD), 8.4 ± 0.3, and 12.2 ± 1.1 mm3 /sec, respectively. The error between the measured and actual VFR values was 2.8-3.7%. Salivary flow in the parotid duct was visualized in 22 of the 23 volunteers. The mean VFR was 8760 mm3 /10 min. DATA CONCLUSION: When salivary flow was stimulated with citric acid in normal volunteers, the salivary VFR could be obtained using the Time-SLIP technique. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:928-935.

DNA damage in lymphocytes induced by cardiac CT and comparison with physical exposure parameters.

OBJECTIVES: To investigate whether physical exposure parameters such as the dose index (CTDI), dose length product (DLP), and size-specific dose estimate (SSDE) are predictive of DNA damage. METHODS: In vitro, we scanned a phantom containing blood samples from five volunteers at CTDI 50, 100, and 150 mGy. One sample was not scanned. We also scanned samples in three different-size phantoms at CTDI 100 mGy. In vivo, we enrolled 45 patients and obtained blood samples before and after cardiac CT. The γ-H2AX foci were counted. RESULTS: In vitro, in the control and at CTDI 50, 100, and 150 mGy, the number of γ-H2AX was 0.94 ± 0.24 (standard error, SE), 1.28 ± 0.30, 1.91 ± 0.47, and 2.16 ± 0.20. At SSDE 180, 156, and 135 mGy, it was 2.41 ± 0.20, 1.91 ± 0.47, and 1.42 ± 0.20 foci/cell. The γ-H2AX foci were positively correlated with the radiation dose and negatively correlated with the body size. In vivo, the γ-H2AX foci were significantly increased after CT (from 1.21 ± 0.19 to 1.92 ± 0.22 foci/cell) and correlated with CTDI, DLP, and SSDE. CONCLUSIONS: DNA damage was induced by cardiac CT. There was a correlation between the physical exposure parameters and γ-H2AX. KEY POINTS: • DNA damage was induced by radiation exposure from cardiac CT. • The γ-H2AX foci number was correlated with the CT radiation dose. • Physical exposure parameters reflect the DNA damage by CT radiation exposure.

Retrograde venography during balloon-occluded retrograde transvenous obliteration of gastric varices.

PURPOSE: The purpose of this study was to evaluate changes in thrombosis in gastric varices. MATERIAL AND METHODS: Fourteen patients were studied who underwent balloon-occluded retrograde transvenous obliteration (B-RTO) for gastric varices with a gastrorenal shunt. The B-RTO catheter was retained overnight in all patients. Balloon-occluded retrograde venography (B-RTV) was performed to evaluate the degree of thrombus formation. This evaluation was done twice during the overnight B-RTO procedure: A few hours after the procedure and on the following day. Investigated were the degree of thrombus formation observed by the first and second B-RTV, change in the degree of thrombus between the first and second B-RTV, and whether and how much sclerosing agent was administered on the second day. RESULTS: The first B-RTV showed entire or partial enhancement of the gastric varix in seven (50%) cases and complete or almost complete lack of enhancement in the remaining seven cases. In four of the former seven cases, the second B-RTV showed entire or partial enhancement of the gastric varix, and the sclerosing agent was added. However, in the remaining ten cases, enhancement was almost or completely lacking. CONCLUSION: When complete thrombosis is shown on B-RTV obtained a few hours after B-RTO, the addition of a sclerotic agent would be unnecessary.

CT fluoroscopy-guided percutaneous drainage: comparison of the one step and the Seldinger techniques.

OBJECTIVE: To evaluate the one step technique compared with the Seldinger technique in computed tomography (CT) fluoroscopy-guided percutaneous drainage of abdominal and pelvic abscess. MATERIAL AND METHODS: Seventy-six consecutive patients (49 men, 27 women; mean age 63.5 years, range 19-87 years) with abdominal and pelvic abscess were included in this study. Drainages were performed with the one step (n = 46) and with the Seldinger (n = 48) technique between September 2012 and June 2014. RESULTS: The technical success and clinical success rates were 95.8% and 93.5%, respectively, for the one step group, and 97.8% and 95.7%, respectively, for the Seldinger group. The mean procedure time was significantly shorter with the one step than with the Seldinger method (15.0 ± 4.3 min, range 10-29 min vs. 21.0 ± 9.5 min, range 13-54 min, p < .01). The mean abscess size and depth were 73.4 ± 44.0 mm and 42.5 ± 19.3 mm, respectively, in the one step group, and 61.0 ± 22.8 mm and 35.0 ± 20.7 mm in the Seldinger group. CONCLUSION: The one step technique was easier and faster than the Seldinger technique. The effectiveness of both techniques was similar for the CT fluoroscopy-guided percutaneous drainage of abdominal and pelvic abscess.

Effect of the Motion Correction Technique on Image Quality at 320-Detector Computed Tomography Coronary Angiography in Patients With Atrial Fibrillation.

OBJECTIVE: Adaptive motion correction (AMC) is a new technique that can suppress blurring of the coronary arteries. We evaluated its effect on the image quality of coronary computed tomography angiography in patients with atrial fibrillation (AF). METHODS: Twenty-five patients with persistent AF underwent coronary computed tomography angiography. Axial image data sets were reconstructed with and without AMC and the image noise in the perivascular tissue of the coronary arteries was measured. Two radiologists visually evaluated the overall image quality of the coronary artery segment using a 4-point scale (1, uninterpretable; 4, good). RESULTS: The mean image noise in the perivascular tissue of the right, but not the left coronary artery, was reduced by AMC (43.8 vs 52.5 Hounsfield units; P < 0.01) and the mean image quality score for the right, but not the left coronary artery, was improved by AMC (3.01 vs 2.74; P < 0.01). The image quality scores in patients with a heart rate of 75 to 114 beats per minute tended to be improved by AMC (75-94 beats per minute: P = 0.06; 95-114 beats per minute: P < 0.01); in patients with a heart rate up to 74 or above 115 beats per minute, they were not improved (P = 0.46 and P = 0.13, respectively). CONCLUSIONS: Adaptive motion correction reduced motion artifacts and improved image quality of the right coronary artery in some patients with AF.

Preoperative Coil Embolization in Patients With a Replaced Hepatic Artery Scheduled for Pancreatectomy With Splanchnic Artery Resection Helps to Prevent Ischemic Organ Injury.

OBJECTIVE: The aim of this study was to evaluate the prevention of liver ischemic injury by preoperative coil embolization in patients with a replaced hepatic artery scheduled for pancreatectomy with splanchnic artery resection. METHODS: Between July 2009 and May 2012, 4 patients with replaced hepatic artery underwent pancreatectomy plus splanchnic artery resection. The replaced right hepatic artery was preoperatively embolized in 2 patients. In the other 2 patients, the common hepatic artery was embolized preoperatively. We evaluated the complications encountered in the perioperative period. RESULTS: There were no embolization-related complications. Although 2 patients presented with small liver infarcts, the aspartate aminotransferase and alanine aminotransferase levels did not exceed 1000 IU/L in any of the patients, and none experienced severe liver injury. CONCLUSIONS: Coil embolization before pancreatectomy with splanchnic artery resection in patients with a replaced hepatic artery may help to prevent severe ischemic liver injury in the perioperative period.