Syncope Due to Iatrogenic Cava Vein Obstruction: Rare Complication of Cardiac Implantable Electronic Device Leads.

A 77-year-old female patient with multiple pacemaker leads experienced hypotension and syncope during right heart catheterization. Imaging studies revealed a stenotic inferior vena cava with superior vena cava obstruction and well-developed retrograde collateral vessels, suggesting that balloon obstruction of the sole venous return site caused low cardiac output leading to syncope.

Laterality of CT-measured hepatic extracellular volume fraction in patients with chronic thromboembolic pulmonary hypertension.

PURPOSE: This study examines the hepatic extracellular volume fraction (ECV) disparity between the left and right lobes (ECV_left and ECV_right) in patients with chronic thromboembolic pulmonary hypertension (CTEPH), its association with right heart catheterization (RHC) metrics, and with intolerance to increased pulmonary hypertension (PH)-targeted medication dosages. METHODS: We retrospectively analyzed 72 CTEPH-diagnosed patients who underwent equilibrium-phase abdominal dual-energy CT (DECT) and RHC. Hepatic ECVs, derived from DECT's iodine maps using circular regions of interest in the liver and aorta, were correlated with RHC parameters via Spearman's rank correlation and lobe differences through the Wilcoxon signed-rank test. Logistic regression assessed cases with ECV_left exceeding ECV_right by > 0.05, while receiver operating characteristic curve analysis gauged ECVs' predictive power for medication intolerance. RESULTS: Of the 72 patients (57 females; median age 69), ECV_total (0.24, IQR 0.20-0.27) moderately correlated with RHC parameters (rs = 0.28, -0.24, 0.3 for mean pulmonary arterial pressure, cardiac index [CI], and pulmonary vascular resistance index, respectively). ECV_left significantly surpassed ECV_right (0.25 vs. 0.22, p < 0.001), with a greater ECV_left by > 0.05 indicating notably lower CI (p < 0.001). In 27 patients on PH medication, ECV_left effectively predicted medication intolerance (AUC = 0.84). CONCLUSION: In CTEPH patients, hepatic ECV correlated with RHC metrics, where elevated left lobe ECV suggested reduced CI and potential medication intolerance.

Side branch embolization before endovascular abdominal aortic aneurysm repair to prevent type II endoleak: A prospective multicenter study.

PURPOSE: The purpose of the study was to evaluate the efficacy and safety of pre-emptive transcatheter arterial embolization (P-TAE) of aortic side branches to prevent type II endoleak in patients with abdominal aortic aneurysm after endovascular abdominal aneurysm repair (EVAR). MATERIALS AND METHODS: This multicenter, prospective, single-arm trial enrolled 100 patients with abdominal aortic aneurysm from nine hospitals between 2018 and 2021. There were 85 men and 15 women, with a mean age of 79.6 ± 6.0 (standard deviation) years (range: 65-97 years). P-TAE was attempted for patent aortic side branches, including the inferior mesenteric artery, lumbar arteries, and other branches. The primary endpoint was late type II endoleak incidence at 6 months post-repair. Secondary endpoints included changes in aneurysmal sac diameter at 6- and 12 months, complications, re-intervention, and aneurysm-related mortality. Aneurysm sac changes at 6- and 12 months was compared between the late and no-late type II endoleak groups. RESULTS: Coil embolization was successful in 80.9% (321/397) of patent aortic side branches, including 86.3% of the inferior mesenteric arteries, 80.3% of lumbar arteries, and 55.6% of other branches without severe adverse events. Late type II endoleak incidence at 6 months was 8.9% (8/90; 95% confidence interval: 3.9-16.8%). Aneurysm sac shrinkage > 5 mm was observed in 41.1% (37/90) and 55.3% (47/85) of the patients at 6- and 12-months post-EVAR, respectively. Patients with late type II endoleak had less aneurysm sac shrinkage than those without type II endoleak at 12 months (-0.2 mm vs. -6.0 mm; P = 0.040). No patients required re-intervention for type II endoleak, and no aneurysm-related mortalities occurred. CONCLUSION: P-TAE is safe and effective in preventing type II endoleak, leading to early sac shrinkage at 12 months following EVAR.

Pre-emptive Aortic Side Branch Embolization during Endovascular Aneurysm Repair Using the Excluder Stent-Graft System: A Prospective Multicenter study.

PURPOSE: To evaluate the effectiveness and safety of pre-emptive transcatheter arterial embolization (P-TAE) for aortic side branches (ASBs) to prevent Type 2 endoleaks (EL2) before endovascular aneurysm repair (EVAR) using the Excluder stent-graft system (Excluder). MATERIALS AND METHODS: In this prospective, multicenter study, 80 patients (mean age, 79.1 years [SD ± 6.7]; 85.0% were men; mean aneurysmal sac diameter, 48.4 mm [SD ± 7.4]) meeting the eligibility criteria were prospectively enrolled from 9 hospitals. Before EVAR, P-TAE was performed to embolize the patent ASBs originating from the abdominal aortic aneurysm. Contrast-enhanced computed tomography (CT) was performed at 1 month and 6 months after EVAR. The primary endpoint was EL2 incidence at 6 months, and the secondary endpoints were aneurysmal sac diameter changes at 6 and 12 months, P-TAE outcomes, adverse events related to P-TAE, reintervention, and aneurysm-related mortality. RESULTS: All patients successfully underwent P-TAE without serious. Coil embolization was successful in 81.6% of ASBs. EL2 incidence at 6 months was identified in 18 of 70 (25.7%) patients. Aneurysmal sac diameter shrinkage (≥5 mm) was observed in 30.0% of patients at 6 months and in 40.9% at 12 months. Only 1 patient required reintervention for EL2 within 1 year of EVAR; aneurysm-related deaths were not observed. CONCLUSIONS: P-TAE for ASBs before EVAR using Excluder is a safe and effective strategy. It aids in achieving early aneurysmal sac shrinkage and reduces EL2 reintervention at 1 year after EVAR.

Deep Learning-based Post Hoc CT Denoising for the Coronary Perivascular Fat Attenuation Index.

RATIONALE AND OBJECTIVES: Coronary inflammation related to high-risk hemorrhagic plaques can be captured by the perivascular fat attenuation index (FAI) using coronary computed tomography angiography (CCTA). Since the FAI is susceptible to image noise, we believe deep learning (DL)-based post hoc noise reduction can improve diagnostic capability. We aimed to assess the diagnostic performance of the FAI in DL-based denoised high-fidelity CCTA images compared with coronary plaque magnetic resonance imaging (MRI) delivered high-intensity hemorrhagic plaques (HIPs). MATERIALS AND METHODS: We retrospectively reviewed 43 patients who underwent CCTA and coronary plaque MRI. We generated high-fidelity CCTA images by denoising the standard CCTA images using a residual dense network that supervised the denoising task by averaging three cardiac phases with nonrigid registration. We measured the FAIs as the mean CT value of all voxels (range of -190 to -30 HU) located within a radial distance from the outer proximal right coronary artery wall. The diagnostic reference standard was defined as HIPs (high-risk hemorrhagic plaques) using MRI. The diagnostic performance of the FAI in the original and denoised images was assessed using receiver operating characteristic curves. RESULTS: Of 43 patients, 13 had HIPs. The denoised CCTA improved the area under the curve (0.89 [95% confidence interval (CI) 0.78-0.99]) of the FAI compared with that in the original image (0.77 [95% CI, 0.62-0.91], p = 0.008). The optimal cutoff value for predicting HIPs in denoised CCTA was -69 HU with 0.85 (11/13) sensitivity, 0.79 (25/30) specificity, and 0.80 (36/43) accuracy. CONCLUSION: DL-based denoised high-fidelity CCTA improved the AUC and specificity of the FAI for predicting HIPs.

Optimization of null point in Look-Locker images for myocardial late gadolinium enhancement imaging using deep learning and a smartphone.

OBJECTIVES: To determine the optimal inversion time (TI) from Look-Locker scout images using a convolutional neural network (CNN) and to investigate the feasibility of correcting TI using a smartphone. METHODS: In this retrospective study, TI-scout images were extracted using a Look-Locker approach from 1113 consecutive cardiac MR examinations performed between 2017 and 2020 with myocardial late gadolinium enhancement. Reference TI null points were independently determined visually by an experienced radiologist and an experienced cardiologist, and quantitatively measured. A CNN was developed to evaluate deviation of TI from the null point and then implemented in PC and smartphone applications. Images on 4 K or 3-megapixel monitors were captured by a smartphone, and CNN performance on each monitor was determined. Optimal, undercorrection, and overcorrection rates using deep learning on the PC and smartphone were calculated. For patient analysis, TI category differences in pre- and post-correction were evaluated using the TI null point used in late gadolinium enhancement imaging. RESULTS: For PC, 96.4% (772/749) of images were classified as optimal, with under- and overcorrection rates of 1.2% (9/749) and 2.4% (18/749), respectively. For 4 K images, 93.5% (700/749) of images were classified as optimal, with under- and overcorrection rates of 3.9% (29/749) and 2.7% (20/749), respectively. For 3-megapixel images, 89.6% (671/749) of images were classified as optimal, with under- and overcorrection rates of 3.3% (25/749) and 7.0% (53/749), respectively. On patient-based evaluations, subjects classified as within optimal range increased from 72.0% (77/107) to 91.6% (98/107) using the CNN. CONCLUSIONS: Optimizing TI on Look-Locker images was feasible using deep learning and a smartphone. KEY POINTS: • A deep learning model corrected TI-scout images to within optimal null point for LGE imaging. • By capturing the TI-scout image on the monitor with a smartphone, the deviation of the TI from the null point can be immediately determined. • Using this model, TI null points can be set to the same degree as that by an experienced radiological technologist.

Patient positioning during pediatric cardiothoracic computed tomography using a high-resilience pad system and pre-scan measurement of chest thickness.

Patient positioning at the isocenter of the CT gantry is important for optimizing image quality and radiation dose, but accurate positioning is challenging in pediatric patients. We evaluated whether the high-resilience pad and pre-scan measurement of chest thickness allow accurate positioning in pediatric patients with congenital heart disease. Sixty-seven patients aged 7 years or younger who underwent cardiothoracic CT were enrolled. The ideal table height, defined as the position at which the scanner's and patient's isocenters coincided, was determined by radiographers either manually (manual group) or based on the pad's and chest's thickness (calculated group). The distance between the two isocenters and image quality were evaluated. The calculated group demonstrated smaller isocenter distance and standard deviation (distance: 0.2 ± 5.8 mm vs. - 8.3 ± 11.6 mm, p < 0.01; absolute value: 4.1 [1.9-8.0] mm vs. 12.3 [5.1-16.3] mm, p < 0.01), and higher signal-to-noise ratio (SNR) and dose-normalized SNR (SNRD) in the descending aorta than the manual group (SNR: 39.8 [31.0-53.7] vs. 31.9 [28.9-36.6], p = 0.048, SNRD: 39.8 [31.0-53.7] vs. 31.9 [28.9-36.6], p = 0.04). The system allowed for more accurate positioning in pediatric cardiothoracic CT, yielding higher image quality.

Balloon Pulmonary Angioplasty in the Management of Chronic Thromboembolic Pulmonary Hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH), which is classified as group 4 pulmonary hypertension (PH) in the 2015 European Society of Cardiology/European Respiratory Society guidelines for the diagnosis and treatment of PH, is regarded as a complication of pulmonary embolism and is caused by the transformation of incompletely resolved thrombi into fibrous tissue that occludes the pulmonary arteries. The current established reference standard curative therapy for CTEPH is pulmonary endarterectomy (PEA), which provides good long-term outcomes with a low mortality rate. For patients with inoperable disease with inaccessible lesions and risk factors for surgery or patients who are diagnosed with residual or recurrent PH after PEA, medical therapy with riociguat is recommended. Balloon pulmonary angioplasty (BPA) is an emerging alternative treatment option for patients with inoperable disease or those with residual or recurrent PH after PEA. BPA has been reported to improve hemodynamics, cardiac function, exercise capacity, and symptoms, as well as PEA. A detailed assessment of thromboembolic lesions in pulmonary arteries by using multiple imaging techniques and treatment strategies with multiple staged procedures based on the patient's condition is important for safe and effective BPA. However, this new technique may still induce life-threatening complications, such as reperfusion pulmonary edema, wire perforation, vessel dissection, and vessel rupture. Meticulous attention to technique is mandatory to minimize serious complications owing to the nature of the anatomic territory involved. The authors summarize the current roles, goals, and complications of BPA in patients with CTEPH and demonstrate ways to formulate an effective and safe treatment strategy. The future perspective of BPA is also discussed. Online supplemental material is available for this article. ©RSNA, 2022.

Deep Learning-based Post Hoc CT Denoising for Myocardial Delayed Enhancement.

Background To improve myocardial delayed enhancement (MDE) CT, a deep learning (DL)-based post hoc denoising method supervised with averaged MDE CT data was developed. Purpose To assess the image quality of denoised MDE CT images and evaluate their diagnostic performance by using late gadolinium enhancement (LGE) MRI as a reference. Materials and methods MDE CT data obtained by averaging three acquisitions with a single breath hold 5 minutes after the contrast material injection in patients from July 2020 to October 2021 were retrospectively reviewed. Preaveraged images obtained in 100 patients as inputs and averaged images as ground truths were used to supervise a residual dense network (RDN). The original single-shot image, standard averaged image, RDN-denoised original (DLoriginal) image, and RDN-denoised averaged (DLave) image of holdout cases were compared. In 40 patients, the CT value and image noise in the left ventricular cavity and myocardium were assessed. The segmental presence of MDE in the remaining 40 patients who underwent reference LGE MRI was evaluated. The sensitivity, specificity, and accuracy of each type of CT image and the improvement in accuracy achieved with the RDN were assessed using odds ratios (ORs) estimated with the generalized estimation equation. Results Overall, 180 patients (median age, 66 years [IQR, 53-74 years]; 107 men) were included. The RDN reduced image noise to 28% of the original level while maintaining equivalence in the CT values (P < .001 for all). The sensitivity, specificity, and accuracy of the original images were 77.9%, 84.4%, and 82.3%, of the averaged images were 89.7%, 87.9%, and 88.5%, of the DLoriginal images were 93.1%, 87.5%, and 89.3%, and of the DLave images were 95.1%, 93.1%, and 93.8%, respectively. DLoriginal images showed improved accuracy compared with the original images (OR, 1.8 [95% CI: 1.2, 2.9]; P = .011) and DLave images showed improved accuracy compared with the averaged images (OR, 2.0 [95% CI: 1.2, 3.5]; P = .009). Conclusion The proposed denoising network supervised with averaged CT images reduced image noise and improved the diagnostic performance for myocardial delayed enhancement CT. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Vannier and Wang in this issue.

Image Quality of Submillimeter High-Spatial-Resolution 2D Late Gadolinium-enhanced Images in Cardiac MRI: A Feasibility Study.

Purpose: To evaluate the image quality of high-spatial-resolution two-dimensional (2D) late gadolinium enhancement (LGE) cardiac MRI compared with conventional normal-resolution LGE MRI. Materials and Methods: This prospective study included participants suspected of having cardiomyopathy who underwent cardiac MRI between March 2021 and December 2021. Normal-resolution and high-resolution 2D LGE sequences (inversion recovery [IR] and phase-sensitive inversion recovery [PSIR]) were performed at 3 T. Resolution was compared between normal-resolution and high-resolution images obtained in a quality assurance phantom. In vivo image quality and resolution were evaluated qualitatively using a five-point scoring system. Receiver operating characteristic curve analysis was used for LGE detection performance. Border sharpness was assessed with profile curve measurement. The contrast-to-noise ratio (CNR) between hyperenhancement and remote myocardium and LGE detection performance were calculated using normal-resolution IR images as the reference. Results: In total, 120 participants were evaluated (mean age, 56 years ± 17 [SD]; 72 men). Features smaller than 1 mm were detectable only on high-resolution images of the phantom. In vivo, the image resolution score with high-resolution LGE was 4.14-4.24, which was higher than the normal-resolution LGE reference score of 2.99 (P < .05). Border sharpness was higher in high-resolution images (P < .001). Receiver operating characteristic curve analysis revealed no evidence of a difference in LGE detection between normal-resolution and high-resolution images. There was also no evidence of a change in CNR of LGE in IR and PSIR magnitude compared with reference images. Conclusion: Comparison of image quality in 2D high-resolution and normal-resolution LGE cardiac MRI demonstrated the highest resolution for high-resolution IR and high-resolution PSIR magnitude sequences.Keywords: Cartilage Imaging, MRI, Cardiac, Heart, Imaging Sequences, Comparative Studies Supplemental material is available for this article. © RSNA, 2022.

The feasibility of transcatheter arterial chemoembolization following radiation therapy for hepatocellular carcinoma.

BACKGROUND: Technological developments have led to an increased usage of external-body radiotherapy (RT) for the treatment of hepatocellular carcinoma (HCC). Transcatheter arterial chemoembolization (TACE) may be required later in patients treated with RT because of the high recurrence rate and multinodular presentation of HCC. However, despite the risk of liver function impairment, the cumulative liver damage correlated with TACE following a hepatic RT has not been adequately assessed. PURPOSE: To evaluate the feasibility of TACE following RT for HCC. MATERIALS AND METHODS: Sixty-seven patients with HCC who underwent TACE after RT were retrospectively evaluated between 2012 and 2018. We assessed increases in Child-Turcotte-Pugh (CTP) by ≥2 points at 1 month, the incidence of major complications, survival duration, and short-term mortality within 6 months after TACE. Furthermore, we evaluated the predictive factors for liver function impairment and short-term mortality. RESULTS: Eight patients experienced a CTP increase ≥2 points at 1 month. There were no cases of liver abscesses or bilomas. Nine patients died within 6 months following TACE. The mean liver dose (MLD) was a significant predictor of liver function impairment at 1 month (p = 0.042). Low liver functional reserve, distant metastasis (p = 0.037), MLD (p = 0.046), TACE type (p = 0.025), and TACE within 3 months following RT (p = 0.007) were significant predictors of short-term mortality. CONCLUSIONS: Despite the feasibility of TACE following RT, clinicians should pay attention to impaired pretreatment liver function, following high dose RT, and the short duration between RT and TACE.

A Real-World Clinical Implementation of Automated Processing Using Intelligent Work Aid for Rapid Reformation at the Orbitomeatal Line in Head Computed Tomography.

MATERIALS AND METHODS: We retrospectively reviewed 781 head CTs (median, 70 years; 441 men) collected by CT systems from 3 vendors. In addition to the orbitomeatal line image reformatted by a CT specialist as a reference, we obtained the fully automated orbitomeatal line image using the intelligent work aid. We calculated the offset angle from the reference of the automatically reformatted image. We defined the large offset angle groups as those with an offset angle greater than 3 degrees. Multivariate logistic regression was used to determine the independent factors for the large offset angle groups. We compared the postprocessing times measured using the intelligent work aid or by a CT specialist. RESULTS: With the intelligent work aid, 99.7% of CTs were automatically reformatted to the orbitomeatal line without error. Furthermore, 88.1% of CTs were within the 3 degrees' offset angle when compared with the reference produced by a CT specialist. The median offset angle from the reference was 1.41 degrees. Multivariate analysis showed that the offset angle of the positioning plane was an independent factor (odds ratio, 1.045; P = 0.005) for predicting the large offset angle group. Furthermore, this technique was 4 times faster (6.4 ± 0.7 seconds) than a CT specialist (25.6 ± 6.4 seconds). CONCLUSIONS: The intelligent work aid can generate a fast and precise head CT image aligned at the orbitomeatal line, even in real-world clinical CTs. However, precise positioning remains essential.

Severe intraluminal atheroma and iliac artery access affect spinal cord ischemia after thoracic endovascular aortic repair for degenerative descending aortic aneurysm.

OBJECTIVES: This study aimed to reveal additional factors potentially contributing to the multifactorial ethiopathogenesis of spinal cord ischemia (SCI) after thoracic endovascular aortic repair (TEVAR) for descending thoracic aortic aneurysm (TAA). METHODS: The medical records of 293 patients who underwent TEVAR without debranching procedures for descending TAA between 2011 and 2018 were retrospectively reviewed. We excluded the following cases from the study: 72 patients with aortic dissection; 15 with rupture; 14 with anastomotic pseudoaneurysm; 22 with re-TEVAR; 34 without evaluation of the artery of Adamkiewicz (AKA). Sufficient data were available for 136 patients (79% men; mean age of 76 ± 7.4 years). We conducted univariable and multivariable analyzes using the logistic regression analysis to assess the relationship between pre-/intraoperative factors and postoperative SCI. RESULTS: SCI was observed in nine patients (6.8%). Severe intraluminal atheroma [odds ratio (OR), 6.23; p = 0.014] and iliac artery access (OR 4.65; p = 0.043) were identified as the positive predictors of SCI by univariable analysis. Risk factors of SCI were determined additionally as follows: coverage of the intercostal artery branching AKA (ICA-AKA) (OR 4.89; p = 0.054); coverage of the ICA-AKA combined with iliac access (OR 10.1; p = 0.002); that combined with severe intraluminal atheroma (OR 13.7; p = 0.001). CONCLUSION: Severe intraluminal atheroma and iliac artery access were the independent predicting factors of SCI after TEVAR for degenerative descending TAA. In patients with complicated aortoiliofemoral access route, coverage of the ICA-AKA is associated with the risk of SCI.

Preoperative Magnetic Resonance Imaging (MRI) for Predicting Thromboembolic Complications during Endovascular Treatment for Iliac Artery Occlusions.

BACKGROUND: Preoperative prediction of thromboembolic complications using magnetic resonance imaging (MRI) in coronary arteries and carotid arteries has been established. However, the technique has not been applied in peripheral arteries. This study aimed to assess the relationship between thromboembolic complications during endovascular treatment (EVT) for iliac artery occlusion and signal intensity on MRI. METHODS: This single-institution study included 52 iliac artery occlusions in 51 patients (mean age, 70.4 years) who underwent successful EVT between January 2010 and March 2018. MRI using an inversion recovery-prepared, steady-state free precession technique was performed preoperatively. Thromboembolic complications were defined as distal embolization and in-stent protrusion greater than 25% of the stent cross-sectional area confirmed by angiography and intravascular ultrasonography, regardless of symptoms. The highest signal intensity of iliac artery occlusion divided by the signal intensity of adjacent iliopsoas muscle (target-to-muscle ratio, TMR) was measured on MR images. Multivariate analysis was performed to clarify the predictors of thromboembolic complications during EVT. RESULTS: Thromboembolic complications observed in 11 vessels (21.2%) from 11 patients comprised distal embolization (n = 4) and in-stent protrusion (n = 7). A TMR cutoff value > 2.57 had a sensitivity of 90.9%, specificity of 78.0%, positive predictive value of 52.6%, and negative predictive value of 97.0% for detecting thromboembolic complications during EVT. In the multivariate analysis, TMR >2.57 was the only independent factor associated with thromboembolic complications (odds ratio, 30.10; 95% confidence interval, 3.26-278.00; P = 0.003). CONCLUSIONS: The presence of higher signal intensity in iliac artery occlusion on MRI is useful for predicting thromboembolic complications during EVT.

Extraluminal recanalization for postoperative biliary obstruction using transseptal needle.

BACKGROUND: Postoperative biliary strictures are commonly related to accidental bile duct injuries or occur at the site of biliary anastomosis. The first-line treatment for benign biliary strictures is endoscopic therapy, which is less invasive and repeatable. However, recanalization for biliary complete obstruction is technically challenging to treat. The present report describes a successful case of treatment by extraluminal recanalization for postoperative biliary obstruction using a transseptal needle. CASE PRESENTATION: A 66-year-old woman had undergone caudal lobectomy for the treatment of hepatocellular carcinoma. The posterior segmental branch of the bile duct was injured and repaired intraoperatively. Three months after the surgery, the patient had developed biliary leakage from the right hepatic bile duct, resulting in complete biliary obstruction. Since intraluminal recanalization with conventional endoscopic and percutaneous approaches with a guidewire failed, extraluminal recanalization using a transseptal needle with an internal lumen via percutaneous approach was performed under fluoroscopic guidance. The left lateral inferior segmental duct was punctured, and an 8-F transseptal sheath was introduced into the ostium of right hepatic duct. A transseptal needle was advanced, and the right hepatic duct was punctured by targeting an inflated balloon that was placed at the end of the obstructed right hepatic bile duct. After confirming successful puncture using contrast agent injected through the internal lumen of the needle, a 0.014-in. guidewire was advanced into the right hepatic duct. Finally, an 8.5-F internal-external biliary drainage tube was successfully placed without complications. One month after the procedure, the drainage tube was replaced with a 10.2-F drainage tube to dilate the created tract. Subsequent endoscopic internalization was performed 5 months after the procedure. At the 1-year follow-up examination, there was no sign of biliary obstruction and recurrence of hepatocellular carcinoma. CONCLUSIONS: Recanalization using a transseptal needle can be an alternative technique for rigid biliary obstruction when conventional techniques fail.

Mid-term Outcomes and Predictors of Transarterial Embolization for Type II Endoleak After Endovascular Abdominal Aortic Aneurysm Repair.

PURPOSE: To evaluate the mid-term outcomes of transarterial embolization (TAE) for type II endoleak after endovascular abdominal aortic aneurysm repair (EVAR) and investigate the predictors of sac enlargement after embolization. MATERIALS AND METHODS: We conducted a retrospective analysis of 55 patients [48 men and 7 women, median age 79.0 (interquartile ranges 74-82) years] who underwent TAE for type II endoleak from 2010 to 2018. The aneurysmal sac enlargement, endoleaks, aneurysm-related adverse event rate, and reintervention rate were evaluated. Patients' characteristics and clinical factors were evaluated for their association with sac enlargement. RESULTS: Fifty-five patients underwent TAE with technical success and were subsequently followed for a median of 636 (interquartile ranges 446-1292) days. The freedom from sac enlargement rates at 1, 3, and 5 years was 73.2%, 32.0%, and 26.7%, respectively. After initial TAE, the recurrent type II, delayed type I, and occult type III endoleak were identified in 39 (71%), 5 (9%), and 3 (5%) patients, respectively. Although a patient had aorto-duodenal fistula, there was no aneurysm-related death. The freedom from reintervention rates was 84.6%, 35.7%, and 17.0%, respectively. In the multivariate analysis, sac diameter > 55 mm at initial TAE (hazard ratios, 3.23; 95% confidence intervals, 1.22-8.58; P < 0.05) was a significant predictor of sac enlargement. CONCLUSION: TAE for type II endoleak was not effective in preventing sac enlargement, and reinterventions were required among the mid-term follow-up. The sac diameter > 55 mm at initial TAE was a significant predictor of sac enlargement.

CT angiography with 15 mL contrast material injection on time-resolved imaging for endovascular abdominal aortic aneurysm repair.

PURPOSE: To assess the utility of whole-aorta CT angiography (CTA) with 15 mL contrast material (CM) on time-resolved imaging for endovascular abdominal aortic repair (EVAR). METHODS: Twenty-six patients with a high-risk of post-contrast acute kidney injury (PC-AKI) underwent CTA with 15 mL CM using temporal maximum intensity projection (tMIP-CTA) generated from time-resolved imaging. The aortoiliac CT values were measured. Two observers measured the arterial diameters in unenhanced CT and tMIP-CTA images, and image quality was evaluated on a 5-point scale. The presence of the accessory renal artery, inferior mesenteric artery (IMA) occlusion, and instructions for use (IFU) of EVAR were evaluated. RESULTS: CT examinations were successfully performed, and no patients developed PC-AKI. The mean CT values of the whole aorta were 267.5 ± 51.4 HU, which gradually decreased according to the distal levels of the aorta. Bland-Altman analysis revealed excellent agreement for the external arterial diameter measurements between unenhanced CT and tMIP-CTA. Excellent interobserver agreement was achieved for the measurements of the external (ICCs, 0.910-0.992) and internal arterial diameters (ICCs, 0.895-0.993). Excellent or good overall image quality was achieved in 24 (92 %) patients. The presence of the accessory renal artery, IMA occlusion and the assessment of IFU were in 100 % agreement. Multivariate analysis revealed aortic volume as the most significant independent factor associated with strong aortic enhancement (p = 0.004). CONCLUSIONS: Whole-aorta tMIP-CTA on time-resolved imaging is useful for maintaining contrast enhancement and image quality for EVAR planning, and can substantially reduce the amount of CM.

Improved Visualization and Identification of the Right Adrenal Vein in 70-kVp Contrast-Enhanced Computed Tomography.

OBJECTIVE: The aim of this study was to assess the utility of 70-kilovoltage-peak (kVp) contrast-enhanced computed tomography (CECT) for visualization and identification of the right adrenal vein (RAV) in comparison with that of conventional 120-kVp CECT. METHODS: This retrospective study included patients who underwent adrenal venous sampling with concurrent biphasic 120-kVp (120-kVp group, n = 43) or 70-kVp (70-kVp group, n = 47) CECT. Signal-to-noise ratios, contrast-to-noise ratios, longitudinal lengths, conspicuity scores, RAV detection rates, and size-specific dose estimates were compared between the 2 groups. RESULTS: In comparison with the 120-kVp group, the 70-kVp group had significantly higher signal-to-noise and contrast-to-noise ratios (P < 0.001-P = 0.033), greater longitudinal lengths (P < 0.001-P = 0.002), superior conspicuity scores for the RAV (P < 0.001), higher RAV detection rates (P = 0.015-P = 0.033), and lower size-specific dose estimates (P < 0.001). CONCLUSIONS: Seventy-kilovoltage-peak CECT has advantages over conventional 120-kVp CECT and is potentially useful for noninvasive assessment of the precise anatomy of the RAV.

The utility of transarterial embolization and computed tomography for life-threatening spontaneous retroperitoneal hemorrhage.

PURPOSE: To assess the safety and efficacy of transarterial embolization (TAE) and to evaluate the utility of contrast-enhanced computed tomography (CE-CT) for life-threatening spontaneous retroperitoneal hemorrhage (SRH). METHODS: Nineteen patients underwent TAE following CE-CT for life-threatening SRH. CE-CT and angiographic findings, technical successes, and clinical successes were evaluated. The diagnostic performance of CE-CT for the detection of active bleeding arteries was also assessed by two independent readers. RESULTS: Active extravasation of contrast material was accurately observed in 78.9‒84.2% of the patients on CE-CT. Angiograms revealed active extravasation in 37 arteries of 15 patients (78.9%), and 4 patients showed no sign of active bleeding. Sensitivity, positive predictive value, and accuracy rate of CE-CT for the detection of active bleeding vessels was 59.5%, 62.9‒71.0% and 55.6‒60.0% respectively. The successful embolization of 48 intended arteries was achieved in all the patients, including empirical TAE in four patients. Hemodynamic stabilization was achieved in 17 patients (89.5%) with a significant decrease in transfusion (p < 0.001). CONCLUSION: TAE is a technically safe and clinically effective treatment method for life-threatening SRH. CE-CT has moderate capability for accurate identification of active bleeding arteries. TAE including arteries that potentially distribute anatomic territory of the hematoma is essential.