Computed tomography findings of intersigmoid hernia.

Purpose: To evaluate the computed tomography findings of intersigmoid hernias. Material and methods: Between April 2010 and March 2018, 7 patients who were surgically diagnosed with intersigmoid hernia in 3 institutions were enrolled in this study. Two radiologists evaluated imaging findings for the herniated small bowel, the distance between the occlusion point and bifurcation of the left common iliac artery, and the anatomic relationship with adjacent organs. Results: All patients were male, and their mean age (standard deviation, range) was 61.0 (13.5, 36-85) years. The mean size of the bowel loops was 5.2 (1.3, 4.0-8.3) cm in the caudal direction, 3.6 (0.8, 2.5-5.1) cm in the lateral, and 3.4 (0.6, 2.5-4.7) cm in the anterior-posterior direction. The volume was 37.9 (27.8, 15.6-103.0) cm3 approximated by an ellipse, and 24.0 (17.7, 9.9-65.6) cm3 approximated by a truncated cone. The obstruction point was located 3.6 (0.6, 2.8-4.7) cm inferior to the bifurcation of the left common iliac artery. In all cases, the small bowel ran under the point at which the inferior mesenteric vessels bifurcated to the superior rectal vessels and the sigmoid vessels and formed a sac-like appearance between the left psoas muscle and the sigmoid colon. The ureter ran dorsal to the point of the bowel stenosis, and the left gonadal vein ran outside the small bowel loops. Conclusions: All cases showed common imaging findings, which may be characteristic of men's intersigmoid hernia. In addition, the fossa's position was lower, and the size was larger than in the previous study, which may be a risk factor.

Collateral pulmonary vein after catheter ablation therapy for atrial fibrillation.

A patient with previous catheter ablation therapy for atrial fibrillation was examined for an abnormal shadow on a chest radiograph. ECG-gated multidetector CT clearly showed the left upper pulmonary vein connected with the left inferior pulmonary vein. We hypothesize an intrapulmonary venous connection as a collateral.

Thoracic endovascular repair for retrograde acute type A aortic dissection as an alternative choice.

OBJECTIVE: The purpose of this study was to determine the clinical outcomes of thoracic endovascular aortic repair in 8 patients with acute type A aortic dissection with an entry tear in the descending aorta. SUBJECTS AND METHODS: From January 2016 to December 2018, eight patients (mean age 76 years; range 54-92 years) were treated by thoracic endovascular aortic repair due to high operative risk for conventional open repair. All patients had significant comorbidities, and two had critical organ malperfusion due to aortic dissection. Surgical outcomes were retrospectively reviewed. RESULTS: All procedures were technically successful with complete coverage of the entry tear. The proximal landing zone was Zone 1 in 2, Zone 2 in 1, Zone 3 in 4, and Zone 4 in 1 patient. Patients requiring Zone 1 and 2 thoracic endovascular aortic repair underwent aortic arch bypass simultaneously. Mean operation time was 132 min. There were no hospital deaths and no serious complications, including stroke and spinal cord ischemic injury. All patients had complete thrombosis and shrinkage of the false lumen in the ascending aorta before discharge. During up to 36-month follow-up (mean 20 ± 12 months), there were no adverse aortic events except one who died due to ischemic colitis 4 months after the procedure. CONCLUSION: Thoracic endovascular aortic repair could be a useful alternative surgical option for patients with retrograde acute type A aortic dissection with an entry in the descending aorta who are not suitable for conventional open surgery. Careful follow-up of such patients is mandatory.

Does Endovascular Abdominal Aortic Repair Change Psoas Muscle Volume?

BACKGROUND: Because endovascular abdominal aortic repair (EVAR) lowers the lumbar arterial blood flow, we hypothesized that the volume of the psoas muscle decreases after surgery. When internal iliac artery (IIA) embolization is performed, the lumbar arterial blood flow further decreases; therefore, we also hypothesized that the decrease in the volume of the psoas muscle becomes more significant. This study was performed to assess the volume change in the psoas muscle after EVAR. METHODS: Fifty-three consecutive patients who underwent EVAR from January 2016 to December 2016 were included. The psoas muscle volume was measured by preoperative and postoperative computed tomography (CT). Postoperative CT scans were performed 6-12 months after EVAR. Axial CT images with a 2-mm slice thickness were used to measure the psoas muscle volume. Data were transferred to a 3-dimensional workstation, and the psoas muscle volume was measured. RESULTS: In the EVAR group, the volume of the psoas muscle decreased by an average of 5.8 mL (4.6%) from 114.8 ± 32.0 mL preoperatively to 109.0 ± 30.3 mL postoperatively (P < 0.01). There was a significant difference in the change in the psoas muscle volume between patients with and without IIA embolization (embolization group: preoperative 118.1 ± 31.0 mL, postoperative 107.5 ± 29.2 mL, mean volume change rate -8.8%; nonembolization group: preoperative 114.0 ± 32.3 mL, postoperative 109.4 ± 30.7 mL, mean volume change rate -3.6%; P < 0.05). CONCLUSIONS: The psoas muscle volume is reduced with EVAR. Moreover, when the IIA is embolized, the psoas muscle volume is further reduced.

Is debranching thoracic endovascular aortic repair acceptable as the first choice for arch aneurysm in the elderly?

OBJECTIVES: This study aimed to assess differences in midterm outcomes between total arch replacement (TAR) and debranching thoracic endovascular aortic repair (d-TEVAR) and to evaluate the validity of d-TEVAR as the preferred treatment choice for aortic arch aneurysm in the elderly. METHODS: We reviewed the case histories of 86 patients who had undergone TAR (64 men; mean age 78 ± 2.9 years) and 121 patients who had undergone d-TEVAR (90 men; mean age 82 ± 4.5 years) between 2007 and 2017; of these patients, 50 from each group were matched based on propensity scores to adjust for differences in patient characteristics. RESULTS: Rates of freedom from all-cause mortality at 2 and 4 years were similar between the 2 groups (88% and 77% in the TAR group vs 82% and 64% in the d-TEVAR group, P = 0.11), but rates of freedom from reintervention at 2 and 4 years were significantly higher in the TAR group (100% and 96%) than in the d-TEVAR group (97% and 88%) (P = 0.004). Propensity score matching yielded similar survival rates of 88% and 85% for TAR vs 86% and 71% for d-TEVAR (P = 0.53) and comparable freedom from reintervention rates (100% and 97% in TAR, 98% and 90% in d-TEVAR, P = 0.16) at 2 and 4 years. Cox regression analysis identified previous cerebral infarction [hazard ratio (HR) 3.9; P = 0.005 in TAR/HR 3.1; P = 0.002 in d-TEVAR] as an independent positive predictor of overall mortality in both groups. CONCLUSIONS: Midterm outcomes after TAR and d-TEVAR were satisfactory and propensity score matching-based evaluation revealed no significant differences in outcomes, implying that d-TEVAR is an acceptable first-choice procedure for aortic arch aneurysm in patients older than 75 years.

Filtered back projection revisited in low-kilovolt computed tomography angiography: sharp filter kernel enhances visualization of the artery of Adamkiewicz.

PURPOSE: The reliability of assessment of the artery of Adamkiewicz before the aortic repair is highly dependent on the display of the continuity of this artery with the aorta, mainly around the vertebral pedicle, by computed tomography angiography (CTA). We hypothesized that the sharp filter kernel can improve visualization of this continuity of the vessel structure because of its edge enhancement and high-spatial resolution. This study was performed to compare the subjective and objective image quality of spinal CTA reconstructed with sharp and smooth filter kernels. METHODS: We retrospectively reviewed 40 consecutive patients who had undergone 80-kV CTA to detect the artery of Adamkiewicz before aortic repair. We measured the CT number and the contrast-to-noise ratio of the anterior spinal artery to the spinal cord. Furthermore, the continuity of the artery of Adamkiewicz was evaluated using a 3-point scale (2 points, absolute; 0 points, undetectable). RESULTS: CTA with the sharp filter kernel showed a significantly higher CT number and contrast-to-noise ratio of the spinal artery than did CTA with the smooth filter kernel (P < .001 for both). Moreover, the sharp filter kernel showed a significantly higher continuity of the artery of Adamkiewicz with the aorta than did the smooth filter kernel (P < .001). CONCLUSIONS: The sharp filter kernel significantly improved the image quality in low-tube-voltage CTA for the assessment of the artery of Adamkiewicz. Thus, CTA with the sharp filter kernel can generate a high-confidence level in the evaluation of the artery of Adamkiewicz.

Cardiac Sarcoidosis Mimicking Septal Tumor with Intermittent Complete Atrioventricular Block.

A 52-year-old woman with intermittent complete atrioventricular (AV) block detected on exercise was admitted to the hospital. Echocardiography revealed lesions on the right ventricular side of the interventricular septum and free wall of the basal inferolateral area. Gadolinium-enhanced cardiovascular magnetic resonance (CMR) imaging revealed the mass and wall thickening at the same locations with late gadolinium enhancement (LGE). Focal uptake at the septal lesion was detected using 67Ga scintigraphy. Focal on diffuse intense uptake in the lesions was observed on Fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) imaging. Whole-body CT and laboratory evaluations uncovered no signs of malignant tumors in other organs. Ophthalmologic evaluation revealed ophthalmologic sarcoidosis. Although the result of endomyocardial biopsy was negative, the presence of cardiac sarcoidosis was strongly suggested on the basis of the new Japanese guidelines published in 2017. AV conduction disturbance and tracer accumulation on 67Ga scintigraphy completely disappeared after 2 weeks of steroid therapy. The size of mass, inferolateral wall thickness in echocardiography and CMR, and standardized uptake value (SUV) of the masses on 18F-FDG PET also decreased over time.

[Successful Emergency Management of an Infected Thoracic Aortic Aneurysm Rupture Using a Pedicled Latissimus Dorsi Flap after Stent-graft Implantation;Report of a Case].

We report a case of ruptured mycotic thoracic aortic aneurysm treated with a pedicled latissimus dorsi flap after stent-graft implantation. The patient was a 64-year-old woman with diabetes mellitus that had developed septicemia as a result of pyelonephritis and a perinephric abscess. The patient required emergency stent-graft implantation due to rupture of an infected thoracic aortic aneurysm on hospital day 10. On hospital day 19, the abscess cavity was debrided and irrigated, and a pedicled latissimus dorsi flap was created. No recurrence of the inflammatory reaction was observed at 1 year postoperatively.

Analysis of decrease in lung perfusion blood volume with occlusive and non-occlusive pulmonary embolisms.

PURPOSE: The aim of this study was to determine if lung perfusion blood volume (lung PBV) with non-occlusive pulmonary embolism (PE) differs quantitatively and visually from that with occlusive PE and to investigate if lung PBV with non-occlusive PE remains the same as that without PE. MATERIALS AND METHODS: Totally, 108 patients suspected of having acute PE underwent pulmonary dual-energy computed tomography angiography (DECTA) between April 2011 and January 2012. Presence of PE on DECTA was evaluated by one radiologist. Two radiologists visually evaluated the PE distribution (segmental or subsegmental) and its nature (occlusive or non-occlusive) on DECTA and classified perfusion in lung PBV as "decreased," "slightly decreased," and "preserved". Two radiologists used a lung PBV application to set a region of interest (ROI) in the center of the lesion and measured HU values of an iodine map. In the same slice as the ROI of the lesion and close to the lesion, another ROI was set in the normal perfusion area without PE, and HUs were measured. The proportion of lesions was compared between the occlusive and non-occlusive groups. HUs were compared among the occlusive, non-occlusive, and corresponding normal groups. RESULTS: Twenty-five patients had 80 segmental or subsegmental lesions. There were 37 and 43 lesions in the occlusive and non-occlusive groups, respectively. The proportion of decreased lesions was 73.0% (27/37) in the occlusive group, while that of preserved lesions in the non-occlusive group was 76.7% (33/43). There was a significant difference in the proportion of lesions (P<0.001) between the two groups. HUs of the iodine map were significantly higher in the non-occlusive group than in the occlusive group (33.8 ± 8.2 HU vs. 11.9 ± 6.1 HU, P<0.001). There was no significant difference in HUs for the entire lesion between the non-occlusive (33.8 ± 8.2 HU) and corresponding normal group (34.5 ± 6.8 HU; P=0.294). CONCLUSION: Iodine perfusion tended to be visually and quantitatively preserved in lungs with nonocclusive PE. Lung PBV is required to evaluate pulmonary blood flow.

Where is the most common site of DVT? Evaluation by CT venography.

PURPOSE: Our aim was to clarify the common site of deep venous thrombosis (DVT) in patients suspected of having pulmonary embolism using computed tomography pulmonary angiography with computed tomography venography (CTV). MATERIALS AND METHODS: We evaluated 215 patients. For all studies, 100 ml of 370 mg I/ml nonionic contrast material was administered. CTV were scanned with helical acquisition starting at 3 min in four-slice multidetector-row computed tomography (MDCT) or 5 min in 64-MDCT after the start of contrast material injection. The site of DVT was divided into iliac vein, femoral vein, popliteal vein, or calf vein. Calf vein was divided into muscular (soleal and gastrocnemius) and nonmuscular (anterior/posterior tibial and peroneal) veins. The 2 × 2 chi-square test was used. RESULTS: One hundred and thirty-seven patients showed DVT; the muscular calf vein was more prevalent than other veins (P < 0.01). CONCLUSIONS: Our study showed that the most common site of DVT was the muscular calf vein.

Lung perfused blood volume images with dual-energy computed tomography for chronic thromboembolic pulmonary hypertension: correlation to scintigraphy with single-photon emission computed tomography.

OBJECTIVE: The purpose of this study was to evaluate the feasibility and diagnostic utility of lung perfused blood volume (LPBV) images generated by dual-energy computed tomography (CT), as compared with pulmonary perfusion scintigraphy, for patients with chronic thromboembolic pulmonary hypertension. METHODS: Patients (n = 51) with chronic pulmonary thromboembolic embolism were examined by dual-source CT in dual-energy mode. Lung perfused blood volume images were generated by analysis of the iodine content of the lung parenchyma using dual-energy data. Pulmonary perfusion defects were evaluated on a segment-by-segment basis in images obtained by both LPBV and pulmonary scintigraphy. Findings suggestive of chronic thromboembolic pulmonary hypertension in CT pulmonary angiography were analyzed. RESULTS: All examinations were acquired without complications, and the contrast enhancement of the pulmonary artery was sufficient for diagnosis of vascular thromboses. In the LPBV images, in 76 (8.3%) of 918 segments, it was difficult to assess perfusion because of artifacts. The agreement between the 2 modalities was good (κ = 0.70). The sensitivity of LPBV in detecting perfusion defects was 96%; the specificity was 76%; the positive predictive value was 94%, and the negative predictive value was 29%. CONCLUSIONS: Lung perfused blood volume imaging by dual-energy CT is feasible for the evaluation of pulmonary perfusion and is comparable to pulmonary scintigraphy. It is possible to evaluate vessels and pulmonary perfusion with CT pulmonary angiography and LPBV images and to assess pulmonary perfusion more definitively in diagnosing chronic pulmonary thromboembolic embolism.

Correlation between the site of pulmonary embolism and the extent of deep vein thrombosis: evaluation by computed tomography pulmonary angiography and computed tomography venography.

PURPOSE: The aim of this study was to evaluate the relation between the sites of pulmonary embolism (PE) and deep vein thrombosis (DVT) by computed tomography pulmonary angiography (CTPA) and CT venography (CTV) of the pelvis and lower extremities. MATERIALS AND METHODS: We retrospectively reevaluated CTPA-CTV data sets for 227 consecutive patients suspected of having a PE. The PEs were divided into proximal (located at the lobar artery or proximal to it) and distal groups. DVTs were divided into proximal (located above the knee) and distal groups. Cohen's kappa statistic and chi-squared tests were performed. RESULTS: The incidence of PE was significantly higher in patients with a proximal DVT than with a distal DVT (P < 0.01). In patients with a proximal DVT, the incidence of proximal PE was significantly higher than that of distal PE (P < 0.05). In patients with a proximal DVT, the incidence of PE was significantly higher in patients with a right-side DVT than with a left-side DVT (P < 0.05). CONCLUSION: Proximal PEs were correlated with proximal DVTs. Patients with a proximal DVT tended to have a PE, especially with a right-proximal DVT. Hence, the presence of a right-proximal DVT has the potential for serious complications, and carefully diagnosis is required for PE and DVT.

Relationship between heart rate and optimal reconstruction phase in dual-source CT coronary angiography.

RATIONALE AND OBJECTIVES: To evaluate reconstruction image quality at the systolic and diastolic cardiac phases and determine the optimal phase for reconstruction according to heart rate when using dual-source computed tomography (CT) with 75 ms temporal resolution. MATERIALS AND METHODS: We retrospectively reviewed the CT datasets of 35 patients with regular heartbeats who underwent coronary CT angiography. Images were reconstructed in 2% steps between 32 and 78% of the beat-to-beat interval. Two experienced radiologists determined the reconstruction interval with the fewest motion artifacts and the motion score of each vessel for the systolic and diastolic phases. Subgroup analysis was performed in patients having heart rates of <70, 70-80, and >80 beats per minute (bpm). RESULTS: In the subgroup with heart rates of <70 bpm, the diastolic phase reconstruction image quality was significantly better than for the systolic phase (P < .01). In the 70-80 bpm and >80 bpm subgroups, no significant difference was observed. In the diastolic phase, the image quality of the <70 bpm subgroup was significantly better than for the >80 bpm subgroup (P < .05). In all systolic phase subgroups and other diastolic phase subgroups, no significant difference was observed. CONCLUSIONS: Using a DSCT scanner with 75 ms temporal resolution, reconstruction at the diastolic phases should be used for patients with heart rates <70 bpm. For heart rates >70 bpm, larger studies are necessary to determine whether reconstruction at the systolic, diastolic, or both phases should be used.

Comparison of magnetic resonance imaging with transthoracic echocardiography in the diagnosis of ventricular septal defect-associated coronary cusp prolapse.

PURPOSE: To compare magnetic resonance imaging (MRI) with transthoracic echocardiography (TTE) in the diagnosis of coronary cusp prolapse (CCP) as a complication of ventricular septal defect (VSD). MATERIALS AND METHODS: Twenty-three patients (10 males, 13 females, mean age 9 years) with clinically suspected CCP were included in a retrospective study. Long and short axis cine images and electrocardiogram (ECG)-gated axial T1-weighted image MRI images were evaluated for deformity and protrusion of right and noncoronary cusps. We compared MRI and TTE results. We compared the agreement between MRI and TTE in outlet VSD and membranous VSD. RESULTS: On MRI, 19 patients had right coronary cusp prolapse (RCCP), three had noncoronary cusp prolapse (NCCP), and one patient had RCCP and NCCP on MRI. Twenty-two patients had RCCP on TTE and none had NCCP. Seventeen patients had outlet defects and six patients had a membranous defect at operation. All patients with an outlet VSD had RCCP on both MRI and TTE. The agreement between MRI and TTE in outlet VSD was better than in membranous VSD. CONCLUSION: MRI results corresponded with TTE results in patients with outlet VSDs, but discordant results were observed in patients with membranous VSDs.

Multidetector computed tomography venography: optimum dose of contrast material.

PURPOSE: The aim of this study was to determine the optimum dose of contrast material for evaluating veins in the lower limbs. MATERIALS AND METHODS: A total of 134 patients who underwent multidetector computed tomography (MDCT) due to suspected deep vein thrombosis (DVT) or pulmonary embolism (PE) were included in this study. One hundred milliliters of iopamidol 100 ml, with 370 mg I/ml was administered. The degree of contrast enhancement of veins in the lower limbs was classified on a 4-point scale (grade 1, poor --> 4, excellent). Regions of interest (ROIs) were positioned in the femoral vein and the popliteal vein to measure CT numbers in these veins. Correlations between the CT number in each ROI and body weight were examined. RESULTS: The mean +/- SD body weights of patients by contrast-enhancement grade were as follows: grade 1, 86.3 +/- 10.2 kg; grade 2, 72.6 +/- 10.7 kg; grade 3, 59.7 +/- 8.7 kg; grade 4, 51.3 +/- 7.9 kg. Negative correlations were found between body weight and CT number for both the femoral vein and the popliteal vein. Grade 3 or better contrast enhancement was obtained in 79 of 81 patients (97.5%) weighing <60 kg. CONCLUSION: For patients weighing <60 kg, 100 ml of contrast material (370 mg I/ml) is considered sufficient for evaluating veins in the lower limbs.

Dual-energy CT head bone and hard plaque removal for quantification of calcified carotid stenosis: utility and comparison with digital subtraction angiography.

We evaluated quantification of calcified carotid stenosis by dual-energy (DE) CTA and dual-energy head bone and hard plaque removal (DE hard plaque removal) and compared the results to those of digital subtraction angiography (DSA). Eighteen vessels (13 patients) with densely calcified carotid stenosis were examined by dual-source CT in the dual-energy mode (tube voltages 140 kV and 80 kV). Head bone and hard plaques were removed from the dual-energy images by using commercial software. Carotid stenosis was quantified according to NASCET criteria on MIP images and DSA images at the same plane. Correlation between DE CTA and DSA was determined by cross tabulation. Accuracies for stenosis detection and grading were calculated. Stenosis could be evaluated in all vessels by DE CTA after applying DE hard plaque removal. In contrast, conventional CTA failed to show stenosis in 13 out of 18 vessels due to overlapping hard plaque. Good correlation between DE plaque removal images and DSA images was observed (r (2) = 0.9504) for stenosis grading. Sensitivity and specificity to detect hemodynamically relevant (>70%) stenosis was 100% and 92%, respectively. Dual-energy head bone and hard plaque removal is a promising tool for the evaluation of densely calcified carotid stenosis.

Dual-energy direct bone removal CT angiography for evaluation of intracranial aneurysm or stenosis: comparison with conventional digital subtraction angiography.

Dual-energy CT can be applied for bone elimination in cerebral CT angiography (CTA). The aim of this study was to compare the results of dual-energy direct bone removal CTA (DE-BR-CTA) with those of digital subtraction angiography (DSA). Twelve patients with intracranial aneurysms and/or ICA stenosis underwent a dual-source CT in dual-energy mode. Post-processing software selectively removed bone structures using the two energy data sets. Three-dimensional images with and without bone removal were reviewed and compared to DSA. Dual-energy bone removal was successful in all patients. For 10 patients, bone removal was good and CTA maximum-intensity projection (MIP) images could be used for vessel evaluation. For two patients, bone removal was moderate with some bone remnants, but this did not inhibit the three-dimensional visualization. Three aneurysms adjacent to the skull base were only partially visible in conventional CTA but were fully visible in DE-BR-CTA. In five patients with ICA stenosis, DE-BR-CTA revealed the stenotic lesions on the MIP images. The correlation between DSA and DE-BR-CTA was good (R (2)=0.822), but DE-BR-CTA led to an overestimation of stenosis. DE-BR-CTA was able to eliminate bone structure using only a single CT data acquisition and is useful to evaluate intracranial aneurysms and stenosis.