Three-dimensional Workstation Research Articles

Subcutaneous air entrapment after subcutaneous implantable cardioverter defibrillator implantation evaluated by computed tomography.

Inappropriate shock (IAS) caused by subcutaneous air entrapment (AE) in an early period after subcutaneous implantable cardioverter defibrillator (S-ICD) implantation has been reported, however, no detailed data on air volume are available. We evaluated the subcutaneous air volume after implantation and its absorption rate one week after implantation. Patients who underwent S-ICD implantation in our hospital received chest CT scans immediately after implantation and followed up 1 week later. The total subcutaneous air volume, air around the generator, the distal electrode, and the proximal electrode within 3cm were calculated using a three-dimensional workstation. Fat areas at the level of the lower edge of the generator were also analyzed. Fifteen patients received CT immediately after implantation. The mean age was 45.6±17.9 (66.7% of men), and the mean body mass index was 24.3±3.3. The three-incision technique was applied in seven patients and two-incision technique was in the latter eight patients. The mean total subcutaneous air volume was 18.54±7.50mL. Air volume around the generator, the distal electrode, and the proximal electrode were 11.05±5.12, 0.72±0.72, and 0.88±0.87mL, respectively. Twelve patients received a follow-up CT 1 week later. The mean total subcutaneous air was 0.25±0.45mL, showing a 98.7% absorption rate. Although subcutaneous air was observed in all patients after S-ICD implantation, most of the air was absorbed within 1 week, suggesting a low occurrence of AE-related IAS after a week postoperation.

Novel Three-Dimensional Workstation System for Intraoperative Navigation in Robot-Assisted Partial Nephrectomy: A Single-Arm Study

Abstract Detailed knowledge of the anatomical relationships between renal tumors, vascular structures, and the urinary tract is required to perform robot-assisted partial nephrectomies (RAPNs) successfully. Recent improvements in imaging modalities include computed tomography and magnetic resonance imaging. In addition, 3-dimensional (3D) workstation systems for intraoperative navigation have also been developed. This report introduces a novel 3D workstation system for intraoperative navigation while performing RAPN called “Atrena.” Atrena is equipped with multiple methods for the stereoscopic viewing of 3D images. Furthermore, Atrena operates on a tablet. Therefore, using Atrena in RAPN enables the rotation and enlargement of stereoscopic 3D images through manipulations on the tablet's screen. Atrena was successfully used for intraoperative navigation in initial 15 cases of RAPN with high trifecta achievement ratios. We believe that this novel 3D workstation system, “Atrena,” is beneficial in performing RAPN and enhances its success. We also believe that Atrena may be useful as an educational tool for medical staff.

The significance of evaluating sphenoid sinus fluid by postmortem computed tomography in cases of drowning

PurposeIn cases of drowning, the presence of sphenoid sinus fluid is a non-specific autopsy finding. However, studies have reported that fluid accumulation in the paranasal sinuses is more commonly observed in drowning victims. Furthermore, some laboratory tests, such as diatom and electrolyte analysis, can serve as supplementary diagnostic tools for diagnosing drowning. Therefore, accurate sphenoid sinus fluid sampling is an important aspect of an autopsy in suspected drowning cases. The aim of this study was to identify the significance of evaluating sphenoid sinus fluid by PMCT images in cases of drowning. MethodsWe retrospectively reviewed 54 drowning victims who underwent PMCT and forensic autopsy. Fluid volume in the sphenoid sinus was measured using a graduated syringe during autopsy and a three-dimensional (3D) workstation based on PMCT images was used for the purpose of comparison. The Mann–Whitney U test and Spearman's rank correlation coefficient was used to evaluate statistically significant differences and correlations. Additionally, a Bland-Altman plot was employed to assess the agreement between PMCT and autopsy. ResultsThe median volume was 1.65 (range 0.00–12.4) ml and 1.55 (range 0.00–7.00) ml in the PMCT and autopsy, respectively, showing a statistically insignificant difference (p = 0.294) and a significant correlation (Rs = 0.896). In 35 cases, the PMCT overestimated the fluid volume more than the autopsy, whereas in 14 cases, the PMCT underestimated the fluid volume. No fluid was identified in seven cases during the autopsy, whereas in five patients, no fluid was found in both PMCT and autopsy. By analyzing the Bland-Altman plot, a bias of 0.73 ± 1.4 ml and limits of agreement ranging from −2.04 to 3.51 ml were observed for sphenoid sinus fluid volume measurements. ConclusionsBased on the limitations of traditional fluid volume measurement in the sphenoid sinus during autopsy, we propose the utilization of PMCT volumetric analysis prior to autopsy as a means to enhance the detection of sphenoid sinus fluid in cases of drowning.

Epicardial adipose tissue volume is associated with abdominal aortic aneurysm expansion.

The epicardial adipose tissue volume (EATV) is associated with cardiovascular diseases such as coronary artery disease. However, no information is available regarding the relationship between the EATV and abdominal aortic aneurysm (AAA) expansion. In the present study, we evaluated the association between the EATV and AAA growth and sought to identify the predictors of AAA expansion. Between June 2009 and December 2019, 906 patients had undergone endovascular or open repair of AAAs at our institution. Patients with previous cardiac surgery, previous ascending thoracic aortic surgery, a ruptured AAA, an infected AAA, an inflammatory AAA, a saccular aneurysm, a solitary iliac aneurysm, or reintervention after treatment of the AAA were excluded. A total of 237 patients with at least two preoperative computed tomography (CT) scans performed >180days apart were included in the present study. The EATV within the pericardium was retrospectively quantified from the preoperative non-contrast-enhanced CT images using a three-dimensional workstation. The EATV index was defined as the EATV divided by the body surface area. The AAA expansion rate was defined as an increase in the AAA diameter annually, and the patients were divided into the slow-expansion group (expansion rate,<5mm/y) and the fast-expansion group (expansion rate, ≥5mm/y). The correlation between the expansion rate and the EATV index was analyzed, and the cutoff value for the EATV index was determined using a receiver operating characteristics curve. Multivariate analysis was used to assess the predictors of the AAA expansion rate. The expansion rate of AAA correlated positively with the EATV index (R= 0.237; P< .001). The initial aneurysm diameter (P< .001) and EATV index (P= .009) differed significantly between the two groups. The cutoff for the EATV index was 60.3cm3/m2 (area under the curve, 0.658; 95% confidence interval [CI], 0.568-0.749; sensitivity, 1.000; specificity, 0.309). Multivariate analysis revealed that the initial aneurysm diameter and an EATV index of >60.3cm3/m2 were significantly associated with the AAA expansion rate. The results of the present study have demonstrated that the EATV index is associated with AAA expansion.

Clinical utility of psoas muscle volume in assessment of sarcopenia in patients with early-stage non-small cell lung cancer.

Sarcopenia influences postoperative outcomes of patients with non-small cell lung cancer (NSCLC). Imaging tools for evaluating and diagnosing sarcopenia have developed, and a novel method of psoas volume index (PVI) obtained by measuring bilateral psoas major muscle volume has been reported. However, the relationship between sarcopenia based on PVI and clinical outcomes has not been fully investigated for patients with early-stage NSCLC. This study aimed to clarify the utility of PVI values in assessing the relationshipe between sarcopenia and clinical outcomes. This study included 645 patients with stage I-II NSCLC who underwent curative lung resection between 2012 and 2017. Bilateral psoas major muscle volumes were calculated semi-automatically using a three-dimensional workstation. The cutoff value of PVI for defining sarcopenia was < 60.5cm3/m3 for men and < 43.6cm3/m3 for women. The avrage time to obtaine PVI was only 25s with the 3D system, and interobserver agreements for evauating sarcopenia on PVI was 1. A total of 159 patients (24.7%) were preoperatively diagnosed with sarcopenia. On multivariate analysis, sarcopenia was an independent prognostic factor for overall survival (OS, p < 0.001), recurrence-free survival (RFS, p < 0.001), and lung cancer-specific survival (LCS, p < 0.001). The 5-year OS, RFS, and LCS were significantly worse in sarcopenic patients than non-sarcopenic patients (88.8 vs. 72.4%, p < 0.001; 80.1 vs. 65.0%, p < 0.001; 92.4 vs. 78.9%, p < 0.001, respectively). Sarcopenia diagnosed using PVI is an independent prognostic predictor of OS, RFS, and LCS in early-stage NSCLC.

Computed tomography angiography-derived area stenosis calculations overestimate degree of carotid stenosis compared with North American Symptomatic Carotid Endarterectomy Trial-derived diameter stenosis calculations

ObjectiveThe degree of carotid artery stenosis, calculated using catheter-based angiography and the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method, has been shown to predict the stroke risk in several, large, randomized controlled trials. In the present era, patients have been increasingly evaluated using computed tomography (CT) angiography (CTA) before carotid artery revascularization, especially as the use of transcarotid artery revascularization has increased. Interpretation of CTA findings regarding the degree of carotid stenosis has not been standardized, with both NASCET methods and the area stenosis used. We performed a single-institution, blinded, retrospective analysis of CTA studies using both the NASCET method and the CT-derived area stenosis to assess the concordance and discordance between the two methods when evaluating ≥70% and ≥80% stenosis. MethodsThe UMass Memorial Medical Center vascular laboratory database was queried for all carotid duplex ultrasound scans performed from 2008 to 2017. The included patients were limited to those with duplex-defined ≥70% stenosis (defined as a peak systolic velocity of ≥125 cm/s and an internal carotid artery/common carotid artery ratio of ≥4), and a correlative CTA study performed within 1 year of the duplex ultrasound examination. A blinded review of all correlative CTA studies using centerline measurements on a three-dimensional workstation (Aquarius iNtuition Viewer; Terarecon, Durham, NC) was performed to characterize the degree of carotid stenosis using the NASCET method and the area stenosis method. Patients were excluded if revascularization had been performed between the two imaging studies. ResultsOf the 37,204 carotid duplex ultrasound scans reviewed (performed from 2008 to 2017), 3480 arteries met the criteria for duplex ultrasound-defined ≥70% stenosis. A correlative CTA study within 1 year of the duplex ultrasound examination was identified in 460 arteries, of which 320 were adequate quality for blinded review. The median interval between the duplex ultrasound and CTA examinations was 9.5 days. Concordance between the area stenosis and NASCET methods was poor for both ≥70% (κ = 0.32) and ≥80% (κ = 0.25) stenosis. Of the 247 arteries considered to have ≥70% area stenosis, 127 (51.4%) were considered to have ≥70% stenosis using the NASCET method. Of the 169 arteries considered to have ≥80% area stenosis, 44 (26.0%) were considered to have ≥80% stenosis using the NASCET method. ConclusionsThe area stenosis CTA calculations of carotid artery stenosis dramatically overestimated the degree of carotid stenosis compared with that calculated using the NASCET method. Given that stroke risk estimates have been determined from trials that used the NASCET method, the area stenosis method likely overestimates the risk of stroke. Therefore, area stenosis calculations could lead to unnecessary carotid revascularization procedures. This model highlights the need for standardized usage of the NASCET method when using CTA as the imaging modality to determine the threshold for carotid revascularization.

Increase in visceral adipose tissue and subcutaneous adipose tissue thickness in children with acute pancreatitis. A case-control study

AimThe aim of this study was to investigate the relationship between the development of acute pancreatitis in children and their body mass index (BMI), waist circumference (WC), visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) thickness. MethodThis was a case-control study carried out in a tertiary hospital between October and November 2019. The diagnosis of acute pancreatitis was based on the presence of at least two of three criteria of the International Study Group of Pediatric Pancreatitis (INSPPIRE) guidelines. AC, VAT, and SAT measurements of patients and controls were performed by using a three-dimensional workstation (Aquarius 3D Workstation, TeraRecon Inc., San Mateo, Calif., USA) through cross sections of the L2 vertebra level after examining previous abdominal computerized tomography (CT) records. ResultsA total of 25 patients diagnosed with acute and acute recurrent pancreatitis who underwent abdominal CT were included in the study and 38 healthy, sex- and age-matched children formed the control group. There were no differences between the patients and healthy children in terms of age, sex and BMI-for-age z-scores. Besides, measurements of WC, SAT, and VAT thickness were found to be higher in the patient group (P=0.007, P=0.021, P=0.016, respectively). ConclusionIn this study, WC, VAT, and SAT were found to be thicker in children with acute pancreatitis compared with healthy children without any difference in BMI. Further studies are needed to clarify whether adipose tissue thickness is an etiological cause or a secondary finding in patients with acute pancreatitis.

Increased Aortic Sac Regression and Decreased Infrarenal Aortic Neck Dilation After Fenestrated Endovascular Aneurysm Repair Compared With Standard Endovascular Aneurysm Repair

Aortic neck dilation (AND) can occur in nearly 25% of patients after EVAR, resulting in loss of proximal seal and aortic rupture. Fenestrated endovascular aneurysm repair (FEVAR) affords increased treatment options for patients with shorter infrarenal aortic necks; however, AND has not been well characterized in these patients. This study sought to compare AND in patients undergoing FEVAR vs standard endovascular aneurysm repair (EVAR). Retrospective review was conducted of prospectively collected data of 20 consecutive FEVAR patients (Cook Zenith fenestrated; Cook Medical, Bloomington, Ind) and 20 EVAR patients (Cook Zenith). Demographic and anatomic characteristics, procedural details, and clinical outcome were analyzed. Preoperative, 1-month postoperative, and longest follow-up computed tomography scans were analyzed using a dedicated three-dimensional workstation. Abdominal aortic aneurysm (AAA) neck diameter was measured in 5-mm increments from the lowest renal artery. Standard statistical analysis was performed. Demographic characteristics did not differ significantly between the two cohorts. The FEVAR group had larger mean aortic diameter at the lowest renal artery, shorter infrarenal aortic neck length, increased prevalence of nonparallel neck shape, and longer AAA length (Table). On follow-up imaging, the suprarenal aortic segment dilated significantly more at all suprarenal locations in the FEVAR cohort, whereas the infrarenal aortic neck segment dilated significantly less compared with the EVAR group (Table). The FEVAR group demonstrated significantly greater sac regression vs the EVAR group. Positive aortic remodeling, as evidenced by increased distance from the celiac axis to the most cephalad margin of the AAA, occurred to a more significant degree in the FEVAR cohort. Device migration, endoleak occurrence, and need for reintervention were similar in both groups. Compared with EVAR, patients undergoing FEVAR had greater extent of suprarenal AND, consistent with a more diseased native proximal aorta. However, the infrarenal neck, which is shorter and also more diseased in FEVAR patients, appears more stable in the postoperative period compared with EVAR cases. Moreover, the FEVAR cohort had significantly greater sac shrinkage and improved aortic remodeling. The suprarenal seal zone in FEVAR may confer a previously undescribed increased level of protection against infrarenal neck dilation and lessen endotension, resulting in more rapid and dramatic sac shrinkage and contributing to a more durable aortic repair.TableDemographics, radiographic data, and outcomes of fenestrated endovascular aneurysm repair (FEVAR) vs endovascular aneurysm repair (EVAR)FEVAREVARP valueDemographics No. of patients20201 Longest CT follow-up, months29.3 ± 16.129.8 ± 16.1.922 Age at procedure, years75.4 ± 9.6775.35 ± 7.07.985 Male85100.231 CAD55501 COPD2510.407 DM1025.407 HTN80801 Active smoker2510.407 Preoperative creatinine level, mg/dL1.06 ± 0.191.07 ± 0.22.88Baseline radiographic data Diameter at lowest renal, mm29.2 ± 7.1924.6 ± 2.94.012 Mean device diameter, mm30.1 ± 3.728.1 ± 3.8.098 Mean device oversizing11.614.3.354 Infrarenal neck length, mm6.65 ± 5.0435.32 ± 14.77<.0001 Nonparallel neck shape8550.041 Severe neck thrombus2010.661 Severe neck calcification551 Length of proximal sealing, mm33.37 ± 9.4531.21 ± 9.19.496 AAA maximum diameter, mm60.44 ± 10.2358.95 ± 11.09.662 AAA length, mm97.12 ± 27.5173.96 ± 18.43.003Diameter changes CA42.22 SMA93.5.0098 +20 mm9.92.7.0008 +15 mm9.92.3.001 +10 mm12.46.2.002 +5 mm13.15.9.002 Lowest renal10.45.9.26 −5 mm9.911.1.77 −10 mm6.712.9.13 −15 mm1.714.3.0009 −20 mm2.116.6.03 AAA maximum diameter−15.7−4.9.04Distance changesCA to aneurysm29.93.4.0167CA to TOG11.713.4.85Outcomes Type IA endoleak on follow-up00N/A Type II endoleak on follow-up3545.748 Branch vessel occlusion00N/A Device-related reintervention1051 All-cause mortality10151 Aorta-related mortality00N/AAAA, Abdominal aortic aneurysm; CA, celiac artery; CAD, coronary artery disease; COPD, chronic obstructive pulmonary disease; CT, computed tomography; DM, diabetes mellitus; HTN, hypertension; N/A, not applicable; SMA, superior mesenteric artery; TOG, top of graft.Categorical variables are presented as percentage. Continuous variables are presented as mean ± standard deviation. Open table in a new tab

Low-density vulnerable thrombus/plaque volume on preoperative computed tomography predicts for spinal cord ischemia after endovascular repair for thoracic aortic aneurysm

BackgroundSimilar to open surgical repair, thoracic endovascular aortic repair (TEVAR) carries a risk of spinal cord ischemia (SCI). However, the generally lower incidence of SCI after TEVAR compared with that after open surgical repair, despite the inability to preserve the intercostal arteries, indicates different pathophysiologic mechanisms with the two procedures. We hypothesized that a microembolism from an aortic mural thrombus is the main cause of SCI. Thus, we evaluated the association between the density of a mural thrombus in the descending thoracic aorta and the development of SCI. MethodsA retrospective review of a prospectively assembled database was performed for all patients who had undergone surgery at a single institution from October 2008 to December 2018. Patient demographics and procedure-related variables were collected. The volume and Hounsfield unit (HU) value of mural thrombi in the whole descending thoracic aorta were estimated on preoperative computed tomography using a three-dimensional workstation. Logistic regression analysis was performed to identify the risk factors for SCI development. ResultsOf the 367 patients who had undergone TEVAR during the study period, 155 were excluded because of previous arch surgery (n = 59), previous descending thoracic aortic surgery (n = 6), previous TEVAR (n = 6), unavailability of optimal preoperative computed tomography data (n = 17), double-barreled dissection (n = 40), and other reasons. The mean ± standard deviation age of the remaining 212 patients was 75.8 ± 6.4 years, and 42 (19.8%) were women. Of the 212 patients, 14 (6.6%) developed SCI after TEVAR. The low mean density of the mural thrombus, total thrombus volume, low-density (≥−100 HU but <30 HU) thrombus volume, intermediate-density (≥30 HU but <150 HU) thrombus volume, treatment length, urgent surgery, and baseline dialysis differed significantly between patients with and without SCI. Although subsequent multivariate analysis could not be performed owing to the small number of SCI events, vulnerable low-density thrombus/plaque was a stronger predictor among the aneurysm-related factors of SCI after TEVAR on univariate analysis. Well-known risk factors, such as distal coverage between T8 and L1, left subclavian artery coverage, previous abdominal aortic surgery, and prophylactic spinal drainage, did not show significant differences. ConclusionsThe results from the present study have demonstrated that among aneurysm-related factors, a lower density mural thrombus/plaque in the descending thoracic aorta is a predictor of SCI development after TEVAR. These results suggest that microembolism is one of the important mechanisms of SCI after TEVAR, which might change the prophylactic strategy.

Computed Tomography Angiogram Area Stenosis Calculations Overestimate the Degree of Carotid Stenosis

Degree of carotid artery stenosis, as calculated by catheter-based angiography using North American Symptomatic Carotid Endarterectomy Trial (NASCET) methodology, has been shown to predict stroke risk in several large randomized controlled trials. In the current era, patients are increasingly being evaluated with computed tomography angiography (CTA) before carotid artery revascularization, especially as transcarotid artery revascularization (TCAR) adoption grows. Interpretation of CTA for degree of carotid stenosis has not been standardized, with both NASCET methodology and area stenosis being used. We performed a single-institution, blinded, retrospective analysis of CTA using both NASCET methodology and area stenosis to assess concordance/discordance between the two methods when evaluating ≥70% and ≥80% stenosis. The University of Massachusetts vascular laboratory database was queried for all carotid duplex ultrasounds performed from 2008 to 2017. The dataset was winnowed to patients with peak systolic velocity of ≥125 cm/s, internal carotid-to-common carotid ratio of ≥4, and a correlative CTA performed <1 year from duplex. A blinded review of all correlative CTA, using centerline measurements on a three-dimensional workstation (Terarecon, Redmond, Calif) was performed to characterize the degree of carotid stenosis by NASCET methodology and by area stenosis (Fig). Patients were excluded if revascularization was performed between the two imaging studies. Of 37,204 carotid duplex ultrasound examinations reviewed (2008-2017), 3480 arteries met criteria for peak systolic velocity of ≥125 cm/s and internal carotid-to-common carotid ratio of ≥4. A correlative CTA within 1 year of the duplex examination was identified in 460 arteries, of which 320 were adequate quality for blinded review. The median number of days between ultrasound examination and CTA was 9.5. Using NASCET methodology, 44 patients were calculated to have ≥80% stenosis and 128 patients were calculated to have ≥70% stenosis. Using area stenosis, 167 patients were calculated to have ≥80% stenosis (3.8-fold increase compared to NASCET methodology) and 247 patients were calculated to have ≥70% stenosis (1.9-fold increase compared to NASCET methodology). Area stenosis CTA calculations of carotid artery stenosis dramatically overestimate the degree of carotid stenosis compared to that calculated by NASCET methodology. Given that stroke risk estimates are based on trials that used NASCET methodology, area stenosis likely overestimates the risk of stroke. Therefore, area stenosis calculations may lead to unnecessary carotid revascularization procedures. This model highlights the need for standardized use of NASCET methodology when using CTA as the imaging modality to determine threshold for carotid revascularization.

Calcifications of the Medial Choroid in the Velum Interpositum: An Unrecognized Site of Physiologic Calcifications Evident on Multidetector Computed Tomography

In adult patients undergoing multidetector computed tomography (CT) of the brain, we observed linear calcification along the deep venous system on thin (<3 mm) sagittal reconstructions. We found no reports of this finding in the velum interpositum (VI) in the imaging literature. We performed a focused examination of the VI on 2 autopsy cases and retrospectively reviewed sagittal, thin-section reconstructions of CT scans of 273 consecutive adult patients. On 2 routine autopsies of the brain, sampling and histologic evaluation was performed of structures within the VI. A series of 273 unselected, sequentially acquired clinical head CT scans of patients ≥60 years old were retrospectively reviewed on a three-dimensional workstation to determine the incidence of this finding and its correlation with patient age. In 1 of the autopsy cases, calcified choroid plexus was identified in the region of the VI; this was also visible on the patient's premorbid CT. In the series of CT scans, linear calcification of ≥9 mm along the deep venous system was evident in 24.5% of cases. The median age of the cases without calcifications was 72 years, while the median age of the cases with calcification was 82; this difference was statistically significant (χ2, P < 0.0005). Evidence supports that linear midline calcification along the internal cerebral veins represents age-related, physiologic calcification of extraventricular choroid plexus within the VI. Awareness of this previously unreported finding on CT will prevent mistaking these physiologic calcifications on CT for evidence of underlying venous pathology. This finding provides additional support that the midline choroid plexus lies within the VI rather than in the third ventricle and expands our understanding of the detailed anatomy of the VI.

Time-Enhancement Curve of Four-Dimensional Computed Tomography Predicts Aneurysm Enlargement with Type-II Endoleak after Endovascular Aneurysm Repair.

Objective We investigated the hemodynamic features of Type-II endoleaks after endovascular aneurysm repair (EVAR) using four-dimensional (4D) computed tomography (CT) to identify patients with aneurysm enlargement. Methods During a 13-month period (January 2017–January 2018) at our institution, we performed 4D-CT examinations in 13 patients after EVAR because of suspected Type-II endoleaks. Three patients were excluded from the study because of other endoleaks or absence of detectable endoleaks. The ramaining 10 patients were divided into two groups: enlargement group ( n = 4), in which the aneurysm volume increased, and stable group ( n = 6), in which the aneurysm remained stable or shrank. A CT scanner and three-dimensional workstation were used. All images were obtained using a consistent protocol (22 phase scans using the test bolus tracking method). We analyzed the hemodynamics of the endoleak cavity (EC) relative to those of the aorta and evaluated the time-enhancement curves (TECs) using measurement protocols. The strengths of correlations between these factors in the two groups were analyzed statistically. Results TECs in the enlargement group showed a more gradual curve, and the upslope, the gradient of TEC in the ascending phase and the upslope index were significantly more gradual than those in the stable group ( p = 0.0247, 0.0243). The EC washout and the EC washout index were also more gradual than in the stable group's ( p = 0.019, 0.019). The enhancement duration was longer in the former than in the latter (80%, p = 0.0195; 70%, p = 0.0159; 60%, p = 0.0159). The CT number in the equilibrium phase was larger in the enlargement group than in the stable group ( p = 0.019). Conclusion The 4D-CT is useful for predicting aneurysm enlargement with Type-II endoleaks after EVAR.

Anatomic Suitability of Iliac Branched Devices for Chinese Patients with Abdominal-Iliac Aortic Aneurysm

Preserving internal iliac flow is the key to preventing ischemic complications during endovascular aneurysm repair (EVAR). The aim of this study is to determine the morphological features of abdominal aortic aneurysms (AAAs) that have been reported in clinical trials in Chinese patients to identify unique features of iliac branched systems. The data for patients who had common iliac aneurysms suitable for imaging review from 2014 to 2017 at 1 institution in China were reviewed. Three-dimensional workstations were used to measure the centerline diameters and lengths of aortoiliac structures, which were screened for suitability for both Cook iliac branch devices (IBD) and Gore iliac branch endoprosthesis (IBE). A total of 102 lesions of common iliac aneurysms were suitable for imaging review. The anatomic standards for the Gore IBE and Cook IBD were met by 13.7% (14/102) and 9.8% (10/102) of the cases, respectively, and 3 cases were suitable for both devices. The most common cause of not meeting the criteria was the same for both the Cook IBD (78.4%) and Gore IBE (48.03%), which was a limitation of the diameter of the target internal iliac artery. Of the 92 lesions excluded from the Cook IBD trial, 11 (11.9%) were eligible for the Gore IBE trial. Likewise, 7.95% (7/88) of the lesions excluded from the Gore IBE trial would have been eligible for the Cook IBD graft. In a practice that is able to enroll patients in both trials, a total of 20.6% (21/102) of the patients would be eligible for treatment, based on the anatomic criteria. The high incidence of iliac artery involvement in AAAs makes EVAR more complicated. Cook IBD and Gore IBE are only suitable for the treatment of a total of 20.6% Chinese patients based on the anatomic criteria. A limitation in the diameter of the target internal iliac artery is the most common cause of failure to meet the criteria for both devices. Future generations of iliac branch technologies should be designed with diameter accommodations for the hypogastric branch stent to reach a wider group of patients with aortoiliac aneurysmal disease.

Volume Measurements of Post-transplanted Liver of Pediatric Recipients Using Workstations and Deep Learning

The purpose of this study was to propose a method for segmentation and volume measurement of graft liver and spleen of pediatric transplant recipients on digital imaging and communications in medicine (DICOM) -format images using U-Net and three-dimensional (3-D) workstations (3DWS) . For segmentation accuracy assessments, Dice coefficients were calculated for the graft liver and spleen. After verifying that the created DICOM-format images could be imported using the existing 3DWS, accuracy rates between the ground truth and segmentation images were calculated via mask processing. As per the verification results, Dice coefficients for the test data were as follows: graft liver, 0.758 and spleen, 0.577. All created DICOM-format images were importable using the 3DWS, with accuracy rates of 87.10±4.70% and 80.27±11.29% for the graft liver and spleen, respectively. The U-Net could be used for graft liver and spleen segmentations, and volume measurement using 3DWS was simplified by this method.

Introduction of EOS imaging system and its current research status in evaluating clinical value of lower limb force line

The principle and technical background of EOS imaging system are introduced. Combining with the publicity of this technology and the existing literature reports, it is known that low dose EOS technology can reduce radiation dose by 5 to 10 times in the course of examination, and micro dose EOS can even reduce radiation dose by 45 times. The image quality is only high or low; the system has EOS 2D and 3D workstations, which can help clinicians to measure and evaluate coronal and sagittal force lines of lower limbs easily. The tilt and torsion of limbs can be measured three-dimensional after three-dimensional model reconstruction in the three-dimensional workstation. Using these results, preoperative evaluation can be carried out. It is helpful for clinicians to evaluate and improve preoperative planning and post-operative measurement and evaluation of surgical effect. In terms of measurement accuracy, a large number of literatures reported that the accuracy of EOS 2D measurement is comparable to that of general radiology measurement, while the accuracy of EOS 3D reconstruction measurement is comparable to that of CT and MRI. Based on the technical characteristics and advantages of EOS, this paper reviews the literature reports and research progress of EOS in evaluating the accuracy of lower limb alignment.

Use of a Custom-made Four-Vessel Fenestrated Endograft to Repair an Enlarging Juxtarenal Aneurysm With Type IA Endoleak After Prior ZFEN Repair

A 73-year-old woman with a history of a 6-cm juxtarenal abdominal aortic aneurysm who underwent a fenestrated endovascular aortic repair using the Zenith fenestrated endovascular (ZFEN) device (Cook Medical, Bloomington, Ind) presented with a type IA endoleak found on routine surveillance computed tomography angiography (CTA). The previously placed ZFEN device included a scallop for the superior mesenteric artery (SMA) and bilateral stented fenestrations to the renal arteries. A custom-made fenestrated endovascular aortic endograft was designed on the basis of measurements obtained from high-resolution CTA images on a three-dimensional workstation using standard centerline flow orthogonal techniques (TeraRecon, Foster City, Calif). The graft design included fenestrations to the celiac artery, SMA, and bilateral renal arteries. The main body fenestrated graft was designed with a modified preloaded delivery system using a preloaded cannulation catheter for the bilateral renal artery fenestrations. Balloon-expandable bridging stent grafts were deployed through the fenestrations to the SMA and bilateral renal arteries. The celiac artery was found to be occluded and covered with an aortic cuff to eliminate the potential for an endoleak. Completion angiography showed excellent stent graft architecture with no kinks or component separations, no evidence of endoleak, and patent visceral branches. The 1-month surveillance imaging demonstrated elimination of the type IA endoleak, patent stent grafts, and a small type II endoleak arising from a lumbar artery. Type IA endoleak from prior ZFEN repair can be successfully treated with a custom-designed fenestrated endovascular aortic endograft.

Aortic neck dilation is not associated with adverse outcomes after fenestrated endovascular aneurysm repair

ObjectiveLong-term outcomes after endovascular aneurysm repair (EVAR) are threatened by aortic neck dilation (AND), graft migration, and subsequent endoleak development. The aim of this study was to determine the rate of AND and the occurrence of endoleaks after fenestrated EVAR of juxtarenal aneurysms with physician-modified endovascular grafts (PMEGs). MethodsThe study included 77 patients presenting with asymptomatic and ruptured juxtarenal abdominal aortic aneurysms treated with PMEGs who received radiologic follow-up. Analysis of computed tomography images took place on a three-dimensional workstation (TeraRecon, San Mateo, Calif). Aortic neck diameter was measured before and after EVAR at the lowest patent renal artery outer wall to outer wall. Significant AND was defined as >3-mm increase between baseline and follow-up, and sac regression >5 mm was considered significant. The patient's 1-month initial postoperative computed tomography measurement was considered baseline. The rate of AND was measured by comparing the baseline measurement with measurements at 6 months, 12 months, and annually thereafter up to 4 years. ResultsIn this cohort of patients, 75% were men with a mean age of 74 ± 7.9 years. Median preoperative aneurysm size was 62 (57-73) mm, and median follow-up was 12 (3.5-30) months. Mean endograft oversizing was 17% ± 12.5%, and mean seal zone length was 41 ± 11 mm. At 1-year follow-up, the median aortic neck increase was 1.7 (0-3) mm. Maximum aneurysm size decreased dramatically during the first postoperative year, with significant sac regression in 65% of the patients. Aortic neck diameter at 1 year did correlate positively with the percentage of device oversizing. No other correlations were found. During the 4-year follow-up, there were no cases of type IA endoleaks. ConclusionsAND does not influence outcome after endovascular repair of juxtarenal aneurysms using PMEGs. These midterm results support the applicability of PMEGs in juxtarenal aneurysm repair.

Sarcopenia Predicts Prognosis in Patients with Newly Diagnosed Hepatocellular Carcinoma, Independent of Tumor Stage and Liver Function.

PurposeThe purpose of this study was to demonstrate the prognostic significance of changes in body composition in patients with newly diagnosed hepatocellular carcinoma (HCC).Materials and MethodsPatients (n=178) newly diagnosed with HCC participated in the study between 2007 and 2012. Areas of skeletal muscle and abdominal fat were directly measured using a three-dimensional workstation. Cox proportional-hazards modes were used to estimate the effect of baseline variables on overall survival. The inverse probability of treatmentweighting (IPTW) method was used to minimize confounding bias.ResultsCutoff values for sarcopenia, obtained from receiver-operating characteristic curves, were defined as skeletal muscle index at the third lumbar vertebra of ≤ 45.8 cm/m2 for males and ≤ 43.0 cm/m2 for females. Sarcopenia patients were older, more likely to be female, and had lower body mass index. Univariable analysis showed that the presence of sarcopenia and visceral to subcutaneous fat area ratio (VSR) were significantly associatedwith prognosis. The multivariable analyses revealed that VSR was predictive of overall survival. However, in the multivariable Cox model adjusted by IPTW, sarcopenia, not VSR, were associated with overall survival.ConclusionThe presence of sarcopenia at HCC diagnosis is independently associated with survival.

Comparison of intravascular ultrasound- and centerline computed tomography-determined aortic diameters during thoracic endovascular aortic repair

BackgroundAccurate sizing of stent grafts during thoracic endovascular aortic repair (TEVAR) is critical for a successful outcome. Centerline measurements using three-dimensional reconstruction of preoperative computed tomography angiography (CTA) is the current standard for stent graft sizing. However, this technique is predicated on an idealized straightened aorta and does not account for the variability in the aortic diameter during the cardiac cycle or the overall status of the patient's volume. Intravascular ultrasound (IVUS) offers real-time cross-sectional imaging of the aorta orthogonal to the support wire, thereby providing an adjunctive method for aortic diameter determination at the time of TEVAR. MethodsA retrospective review was performed on all patients who underwent TEVAR for nontraumatic aortic pathology from July 2015 to December 2015. Preoperative CTA images were reconstructed on a dedicated three-dimensional workstation. CTA centerline aortic diameter measurements were performed in major and minor axes at 1-cm intervals from the left subclavian origin to 20 cm distally. The IVUS images were acquired intraoperatively through 1-cm stepwise pullback along the aorta from the left subclavian origin to 20 cm. IVUS aortic diameters were measured at the maximum phase during the cardiac cycle. The average values of major and minor axes diameters from both modalities were calculated at each location for comparison. Linear regression analysis was performed to evaluate correlation, and Bland-Altman plots assessed agreement between different imaging modalities. ResultsDuring the study period, 26 patients underwent TEVAR. Of these, 20 patients had adequate CTA and IVUS images, providing 355 paired measurements. There was a high correlation between CTA- and IVUS-determined aortic diameters (R = 0.62; P < .001). However, Bland-Altman analysis showed that, compared with CT, IVUS resulted in larger aortic diameters, with the mean difference of 3.09 mm. There was a significant variability between IVUS and CTA with the standard deviation of difference (SD diff) of 4.56 mm. When stratified by the aortic position, a high degree of agreement was observed at the base of the left subclavian (position 0), with a mean difference of –2.69 mm and an SD diff of 4 mm. The agreement was the lowest at the angulated aortic segments (2 cm to 7 cm distal to the subclavian origin) with a mean difference up to 7.96 mm and an SD diff up to 8.27 mm. ConclusionsIVUS imaging and centerline CTA may provide significantly different aortic diameter measurements, particularly in angulated aortic segments. Caution must be taken when sizing a stent graft using CTA alone, particularly in an angulated proximal landing zone.

IP031. Retroperitoneal Hematoma Volume Is a Good Predictor of Perioperative Mortality After Endovascular Aneurysm Repair for Ruptured Abdominal Aortic Aneurysm

The purpose of this study was to analyze the anatomical characteristics of ruptured abdominal aortic aneurysm (rAAA) in the Japanese prospective multicenter registry and validate the usefulness of retroperitoneal hematoma volume as a predictor of perioperative mortality after endovascular aneurysm repair (EVAR) for rAAA. Consecutive rAAA patients at three institutions with unified EVAR-first protocol (SRAP protocol) from 2012 to 2016 were prospectively registered and reviewed. Patients receiving EVAR with preoperative computed tomography (CT) scan adequate for the analysis using three-dimensional workstation were included and analyzed. To validate the retroperitoneal hematoma volume as a predictor of perioperative mortality, volumetry was used for the measurement. For the adjustment of body size differences, retroperitoneal hematoma volume was divided by the abdominal cavity volume, and the calculated ratio was used for the validation under appropriate statistical methods. Of 114 rAAA patients, 101 patients (88.6%) received EVAR, 9 patients (7.9%) received open surgical repair, and 4 patients (3.5%) did not receive any repair during the study period. From 101 EVAR patients, 82 patients were included for the analysis. Perioperative mortality for all 101 EVAR patients and 82 patients included in the analysis was 25.7% and 24.4%, respectively, without statistically significant difference. Calculated mean retroperitoneal hematoma volume ratio of survivors and nonsurvivors was 3.59% ± 2.46% and 7.63% ± 3.45%, respectively (P < .001). Univariate analysis of other preoperative demographic and anatomical data are reported in the Table, and factors that were statistically significant (P < .05) were Glasgow Aneurysm Score (GAS) >85, systolic blood pressure <90 mm Hg, loss of consciousness, and mean minimum right external iliac artery diameter. To compare the usefulness as a predictor of perioperative mortality, receiver operating characteristics curves were drawn for retroperitoneal hematoma volume ratio and GAS for patients with Fitzgerald classification >3 (Fig), since mortality rate of patients with Fitzgerald classification <2 was low (2 of 21 [9.5%]). Area under curve for retroperitoneal hematoma volume ratio and GAS was 0.880 and 0.587, respectively, suggesting retroperitoneal hematoma volume ratio as a good predictor of perioperative mortality. Maximum value of Youden’s index for retroperitoneal hematoma volume ratio indicating best cutoff value was 6.97% (sensitivity, 0.833; specificity, 0.860). Our study suggests that retroperitoneal hematoma volume is a good predictor of perioperative mortality after EVAR for rAAA, especially in FC >3 group with best cutoff value of 6.97%.Table IBaseline characteristics and demographics of patientsVariableNonsurvivor (n = 20)Survivors (n = 62)P valueAgea80.3 (8.4)77.9 (11.8).326Male sex17 (85.0)46 (74.2).319Aneurysm sizea (mm)74.2 (12.5)71.0 (17.1).382Hypertension12 (60.0)38 (61.3).918Diabetes3 (15.0)7 (11.3).659Coronary artery disease6 (30.0)13 (21.0).405Cerebrovascular disease3 (15.0)10 (16.1).904COPD2 (10.0)4 (6.5).596CRI (eGFR <59)16 (80.0)50 (80.6).950Fitzgerald classification >318 (90.0)43 (69.4).066SBP <90 mm Hg17 (85.0)32 (51.6).008Loss of consciousness11 (55.0)10 (16.1).001Anemia (Hb <10 mg/dL)11 (55.0)21 (33.9).092GAS >8520 (100.0)50 (80.6).033Aneurysm neck length (mm)a29.7 (16.9)28.1 (15.5).719Proximal neck anglea52.0 (33.4)53.3 (34.0).879Right iliac diametera (mm) Maximum21.3 (13.4)20.4 (8.9).783 Minimum6.05 (1.57)7.14 (1.66).012Left iliac diametera (mm) Maximum21.6 (13.8)19.9 (9.7).621 Minimum5.89 (2.16)6.98 (1.86).051RHV ratioa (%)7.62 (3.45)3.59 (2.46)<.001COPD, Chronic obstructive pulmonary disease; CRI, chronic renal insufficiency; eGFR, estimated glomerular filtration rate; GAS, Glasgow Aneurysm Score; Hb, hemoglobin; RHV, retroperitoneal hematoma volume; SBP, systolic blood pressure.aContinuous data are shown as the mean (standard deviation), and categoric data are shown as number (%). Open table in a new tab