Value of Latest-generation Cone-beam Computed Tomography for Post Lipiodol-embolization Imaging in Hepatic Transarterial Chemoembolization in Comparison with Multi-detector Computed Tomography.

RATIONALE AND OBJECTIVES: To evaluate image quality, radiation dose (phantom study) and tumor volumetry of intraprocedural cone-beam computed tomography (CBCT) compared to postprocedural multidetector computed tomography (MDCT) in patients undergoing hepatic conventional transarterial chemoembolization (cTACE). MATERIALS AND METHODS: One hundred fourteen patients (64/50 female/male; mean age, 57 ± 14 years) who had undergone cTACE including intraprocedural-CBCT and postprocedural-MDCT were retrospectively enrolled. Subjective image quality (IQ) and suitability for assessing Lipiodol distribution were compared using 4-point Likert scales; additionally, lesion to liver contrast (LLC) and contrast-to-noise-ratio (CNR) were compared. Tumor volumes were measured semi-automatically and compared to magnetic resonance imaging (MRI). Effective doses were measured using an anthropomorphic phantom. RESULTS: The suitability of CBCT for assessing Lipiodol distribution during cTACE was comparable to MDCT (mean score, 3.2 ± 0.6) and CBCT (3.4 ± 1.0, p = 0.29). Subjective overall IQ was rated with a mean score of 3.2 ± 0.7 (κ = 0.66) in CBCT and 3.1 ± 0.4 (κ = 0.57, p = 0.15) in MDCT. Evaluation of LLC showed significant differences between CBCT and MDCT (mean scores 3.6 ± 1.2 and 2.6 ± 1.5, respectively). CNR analysis demonstrated comparable mean values for CBCT and MDCT (3.5 ± 1.3 vs. 3.4 ± 1.8, p = 0.31). No significant differences were found regarding tumor volumetry (mean volumes: CBCT, 27.0 ± 17.4 mm3; MDCT: 26.8 ± 16.0 mm3; p = 0.66) in comparison to T2-weighted MRI (25.9 ± 17.6 mm3). Effective doses were 3.2 ± 0.6 mSv (CBCT) and 2.5 ± 0.3 mSv (MDCT) (p < 0.001). No cTACE-related complications (bleeding, non-target embolization) were missed on intraprocedural CBCT in comparison to postprocedural MDCT. CONCLUSION: Latest-generation intraprocedural CBCT provides suitable assessment of Lipiodol distribution and similar image quality compared to MDCT while allowing for robust volumetric tumor measurements and immediate complication control by visualizing non-target embolization and hematoma. Therefore, it may improve patient safety and outcome as well as clinical workflow compared to postprocedural MDCT in hepatic cTACE in certain cases.

Significant Asymmetry of the Bilateral Upper Extremities of a Skeleton Excavated from the Mashiki-Azamabaru Site, Okinawa Island, Japan.

The human skeleton of a young adult male with marked asymmetry of the bilateral upper extremities was excavated from the Mashiki-Azamabaru site (3000-2000 BCE) on the main island of Okinawa in the southwestern archipelago of Japan. The skeleton was buried alone in a corner of the cemetery. In this study, morphological and radiographic observations were made on this skeleton, and the pathogenesis of the bone growth disorder observed in the left upper limb was discussed. The maximum diameter of the midshaft of the humerus was 13.8 mm on the left and 21.2 mm on the right. The long bones comprising the left upper extremity lost the structure of the muscle attachments except for the deltoid tubercle of the humerus. The bone morphology of the right upper extremity and the bilateral lower extremities was maintained and was close to the mean value of females from the Ohtomo site in northwestern Kyushu, Japan, during the Yayoi period. It is assumed that the anomalous bone morphology confined to the left upper extremity was secondary to the prolonged loss of function of the muscles attached to left extremity bones. In this case, birth palsy, brachial plexus injury in childhood, and acute grey matter myelitis were diagnosed. It was suggested that this person had survived into young adulthood with severe paralysis of the left upper extremity due to injury or disease at an early age.

Effect of icosapent ethyl on progression of coronary atherosclerosis in patients with elevated triglycerides on statin therapy: a prospective, placebo-controlled randomized trial (EVAPORATE): interim results.

AIMS: Though statin therapy is known to slow coronary atherosclerosis progression and reduce cardiovascular (CV) events, significant CV risk still remains. In the REDUCE-IT study, icosapent ethyl (IPE) added to statin therapy reduced initial CV events by 25% and total CV events by 30%, but its effects on coronary atherosclerosis progression have not yet been fully investigated. Therefore, this study is to determine whether IPE 4 g/day will result in a greater change from baseline in plaque volume measured by serial multidetector computed tomography than placebo in statin-treated patients. METHODS AND RESULTS: EVAPORATE is a randomized, double-blind, placebo-controlled trial. Patients had to have coronary atherosclerosis by coronary computed tomographic angiography (CCTA) (≥1 angiographic stenoses with ≥20% narrowing), on stable statin therapy with low-density lipoprotein cholesterol levels 40-115 mg/dL, and persistently high triglyceride levels (135-499 mg/dL). Patients underwent an interim scan at 9 months and were followed for an additional 9 months with CCTA at 0, 9, and 18 months. Here, we present the protocol-specified interim efficacy results. A total of 80 patients were enrolled, with 67 completing the 9-month visit and having interpretable CCTA at baseline and at 9 months (age = 57 ± 6 years, male = 36, 63%). At the 9-month interim analysis, there was no significant change in low attenuation plaque (LAP) between active and placebo groups (74% vs. 94%, P = 0.469). However, there was slowing of total non-calcified plaque (sum of LAP, fibrofatty, and fibrous plaque) (35% vs. 43%, P = 0.010), total plaque (non-calcified + calcified plaque) (15% vs. 26%, P = 0.0004), fibrous plaque (17% vs. 40%, P = 0.011), and calcified plaque (-1% vs. 9%, P = 0.001), after adjustment by baseline plaque, age, sex, diabetes, baseline triglyceride levels, and statin use. CONCLUSION: EVAPORATE is the first study using CCTA to evaluate the effects of IPE as an adjunct to statin therapy on atherosclerotic plaque characteristics in a high-risk CV population with persistently high triglyceride levels. It provides important mechanistic data in regards to the reduction in CV events in the REDUCE-IT clinical trial. CLINICALTRIALS. GOVIDENTIFIER: NCT029226027.

Incorporating SULF1 polymorphisms in a pretreatment CT-based radiomic model for predicting platinum resistance in ovarian cancer treatment.

OBJECTIVE: Early detection of platinum resistance for ovarian cancer treatment remains challenging. This study aims to develop a machine learning model incorporating genomic data such as Single-Nucleotide Polymorphisms (SNPs) of Human Sulfatase 1 (SULF1) with a CT radiomic model based on pre-treatment CT images, to predict platinum resistance for ovarian cancer (OC) treatment. METHODS: A cohort of 102 patients with pathologically confirmed OC was retrospectively enrolled into this study from January 2006 to February 2018. All patients had platinum-based chemotherapy after maximal cyto-reductive surgery. This cohort was separated into two groups according to treatment response, i.e., the group with platinum-resistant disease (PR group) and the group with platinum-sensitive disease (PS group). We genotyped 12 SNPs of SULF1 for all OC patients using Mass Array Method. Radiomic features, SNP data and clinicopathological data of the 102 patients were used to build the differentiation models. The study participants were divided into two cohorts: the training cohort (n = 71) and the validation cohort (n = 31). Feature selection and predictive modeling were performed using least absolute shrinkage and selection operator (LASSO), Random Forest Classifier and Support Vector Machine methods. Model performance for predicting platinum resistance was assessed with respect to its calibration, discrimination, and clinical application. RESULTS: For prediction of platinum resistance, the approach combining the radiomics, clinicopathological data and SNP data demonstrated higher classification efficiency, with an AUC value of 0.993 (95 % CI: 0.83 to 0.98) in the training cohort and 0.967 (95 % CI: 0.83 to 0.98) in validation cohort, than the performance with only the SNPs of SULF1 model (AUC: training, 0.843 [95 %CI: 0.738-0.948]; validation, 0.815 [0.601-1.000]), or with only the radiomic model (AUC: training, 0.874 [95 %CI: 0.789-0.960]; validation, 0.832 [95 %CI: 0.687-0.976]). This integrated approach also showed good calibration and favorable clinical utility. CONCLUSIONS: A predictive model combining pretreatment CT radiomics with genomic data such as SNPs of SULF1 could potentially help to predict platinum resistance in ovarian cancer treatment.

Method of Surgical Treatment of Spine Injury with the Use of Extracorporeal Navigation System Based on Additive Technologies.

We present a method of minimally invasive transcutaneous insertion of screws using a prefabricated extracorporeal navigation system using additive technologies (based on primary data obtained from the DICOM package in multi-detector computed tomography of the affected spine segment) according to the principle of personalized medicine. The method was tested on 10 dogs of different breeds with generally similar mechanism of trauma and typical consequences that led to fracture and dislocation of one of the lumbar vertebrae. In all animals, a positive treatment outcome of different degrees was achieved. Regression of the neurological deficit without significant postoperative inflammatory reaction was noted. The proposed method of treatment reduces the risk of malposition in pedicular and interbody pins and reduces radiation intraoperative exposure.

Computed tomography-derived left atrial volume index, sex, and age to predict the presence and the extent of left atrial low-voltage zones in patients with atrial fibrillation: The ZAQ score.

BACKGROUND: Pulmonary vein isolation is the cornerstone of catheter ablation in patients with atrial fibrillation (AF). However, with advanced left atrial (LA) structural changes, additional targeted catheter ablation of low-voltage zones (LVZs) has produced favorable results. Therefore, with the advent of single-shot techniques, it would be helpful to predict the presence of LVZs before an ablation procedure. OBJECTIVE: We hypothesized that computed tomography (CT)-derived left atrial volume index (LAVI), in combination with other objective parameters, could be used to develop a score able to predict the presence of LVZs. METHODS: In a large cohort of patients undergoing their first AF ablations, comprehensive echocardiographic evaluations and cardiac CT were performed. During the electrophysiological studies, LA geometry and electroanatomic voltage maps were created. LVZs were defined as areas ≥1 cm2 with bipolar peak-to-peak voltage amplitudes ≤0.5 mV. RESULTS: In a derivation cohort of 374 patients, predictors of LVZs were identified by regression analysis and used to build the Zentralklinik Bad Berka and University of L'Aquila (ZAQ) score (age ≥65 years; female sex; and CT-LAVI ≥57 mL/m2 ). The ZAQ score of 2 points accurately identified the presence and the extent of LVZs (area under the curve [AUC], 0.809; 95% confidence interval [CI], 0.758-0.861; P < .001 and 3 [interquartile range, IQR, 1.5-4.5] vs 7 cm2 [IQR 4-9]; P = .001). In a validation cohort of 103 patients, the predictive value of the score was confirmed (AUC, 0.793; 95% CI, 0.709-0.878; P < .001 and 4 [IQR, 2-7] vs 11.5 cm2 [IQR, 8-16.5]; P = .001). CONCLUSIONS: The ZAQ score identifies LVZs and may be useful for planning the ablation strategy ahead of time.

Spectrum of Early Postoperative Multidetector Computed Tomography Findings Following Cytoreductive Surgery With Hyperthermic Intraperitoneal Chemotherapy.

OBJECTIVE: To review and describe imaging findings on multidetector computed tomography in the early postoperative period after cytoreductive surgery with concomitant hyperthermic intraperitoneal chemotherapy (CRS + HIPEC). METHODS: This was a retrospective review of consecutive patients undergoing early (≤60 days) postoperative abdominopelvic multidetector computed tomography scans after CRS + HIPEC from 2014 to 2018 at a single institution. Two radiologists separately assessed bowel wall thickening, bowel wall enhancement, bowel dilation, ascites, and pleural effusion(s) and identified any other significant finding(s). RESULTS: Thirty-two patients met the inclusion criteria. The majority of patients demonstrated bowel wall thickening (53%; n = 17) and ascites (72%; n = 23), whereas postoperative ileus (35%; n = 10), pleural effusion(s) (24%; n = 7), and bowel wall hyperenhancement (6%; n = 1) were less common. Significant findings included anastomotic leak/perforation (13%; n = 4), fistula (13%; n = 4), abscess (13%; n = 4), and bladder leak (6%; n = 2). CONCLUSIONS: Multidetector computed tomography is an excellent imaging modality to identify common postoperative findings as well as complications following CRS + HIPEC.

Epicardial Conduction Speed, Electrogram Abnormality, and Computed Tomography Attenuation Associations in Arrhythmogenic Right Ventricular Cardiomyopathy.

OBJECTIVES: This study sought to evaluate the association between contrast-enhanced multidetector computed tomography (CE-MDCT) attenuation and local epicardial conduction speed (ECS) and electrographic abnormalities in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and ventricular tachycardia (VT). BACKGROUND: CE-MDCT is a widely available and fast imaging technology with high spatial resolution that is less prone to defibrillator generator-related safety issues and image artifacts. However, the association between hypoattenuation on MDCT and VT substrates in ARVC remains unknown. METHODS: Patients with ARVC who underwent CE-MDCT followed by endocardial (n = 30) and epicardial (n = 21) electroanatomical mapping (EAM) and VT ablation were prospectively enrolled. Right ventricular (RV) mid-myocardial attenuation was calculated from 3-dimensional MDCT images and registered to EAM. Local ECS was calculated by averaging the ECS between each point and 5 adjacent points with concordant wave front direction. RESULTS: A total of 17,311 epicardial and 5,204 endocardial points were included. In multivariable regression analysis clustered by patient, RV myocardial attenuation was associated with epicardial bipolar voltage amplitude (2.5% decrease in amplitude per 10 HU decrease in attenuation; p < 0.001), with endocardial unipolar voltage amplitude (0.9% decrease in amplitude per 10 HU decrease in attenuation; p < 0.001), and with ECS (0.4% decrease in ECS per 10 HU decrease in attenuation; p = 0.001). CONCLUSIONS: CE-MDCT attenuation distribution is associated with regional ECS and electrographic amplitude in ARVC. Regions with low attenuation likely reflect fibro-fatty involvement in the RV and may serve as important VT substrates in patients with ARVC who are undergoing VT ablation.

[The Optimal Start Timing of Helical Scan for Coronary CT Angiography and CT Myocardial Perfusion Scan Using 64-MDCT].

PURPOSE: Ichihara et al. (Fujita Med J 2015; 1(1): 9-14) developed a method to simultaneously obtain both coronary computed tomography (CT) angiography and CT myocardial perfusion (CTP) using 64-multi detector CT (MDCT). An input-function (time enhancement curve, TEC) of the ascending aorta (Ao) and myocardial CT density are necessary to calculate absolute myocardial blood flow (ml/g/min) using a two-compartment model. Helical scan starting timing is important to capture the peak (P) of Ao time enhancement curve (TEC). The purpose is to search the optimal timing of starting helical scan to capture the P. METHODS: We performed 14 CTPs using Definition AS+ (SIEMENS). A dynamic scan at the Ao level was started at 7 s after contrast injection and helical scan was started at various trigger on bolus tracking. Definition AS+ needs 2 s (other scanner may need 4 s) for changing from a dynamic to helical scan mode. We created TECs of pulmonary artery (PA) and Ao using the fifth function fitting. We measured the time from trigger point to the P (t200, t250, t300 and tCP). RESULTS: Mean t200, t250, t300 and tCP were 9.1±1.9, 7.9±2.0, 6.6±1.9 and 3.9±1.2 s, respectively. In additional other 16 CTP studies using the cross point method, we can capture the P in all (100%) examinations. CONCLUSION: Scan starting at the cross point is best for Definition AS+, and the Ao=300 HU may be best for other scanner that needs 4 s for changing scan mode to obtain a fine input function for calculating absolute myocardial blood flow.

State of the art: utility of multi-energy CT in the evaluation of pulmonary vasculature.

Multi-energy computed tomography (MECT) refers to acquisition of CT data at multiple energy levels (typically two levels) using different technologies such as dual-source, dual-layer and rapid tube voltage switching. In addition to conventional/routine diagnostic images, MECT provides additional image sets including iodine maps, virtual non-contrast images, and virtual monoenergetic images. These image sets provide tissue/material characterization beyond what is possible with conventional CT. MECT provides invaluable additional information in the evaluation of pulmonary vasculature, primarily by the assessment of pulmonary perfusion. This functional information provided by the MECT is complementary to the morphological information from a conventional CT angiography. In this article, we review the technique and applications of MECT in the evaluation of pulmonary vasculature.

Postinfarction Myocardial Calcifications on Cardiac Computed Tomography: Implications for Mapping and Ablation in Patients With Nontolerated Ventricular Tachycardias.

BACKGROUND: Postinfarction ventricular tachycardia (VT) generally involves myocardial fibers surrounded by scar. Calcification of scar tissue has been described, but the relationship between calcifications within endocardial scar and VTs is unclear. The purpose of this study was to assess the prevalence of myocardial calcifications as detected by cardiac computed tomography (CT) and the benefit for mapping and ablation focusing on nontolerated VTs. METHODS: Fifty-six consecutive postinfarction patients had a cardiac CT performed before a VT ablation procedure. Another 56 consecutive patients with prior infarction without VT who had cardiac CTs served as a control group. RESULTS: Myocardial calcifications were identified in 39 of 56 patients (70%) in the postinfarction group with VT, compared with 6 of 56 patients (11%) in the control group without VT. Calcifications were associated with VT when compared with a control group. A calcification volume of 0.538 cm3 distinguished patients with calcification-associated VT from patients without calcification-associated VTs (area under the curve, 0.87; sensitivity, 0.87; specificity, 0.88). Myocardial calcifications corresponded to areas of electrical nonexcitability and formed a border for reentry circuits for 49 VTs (33% of all VTs for which target sites were identified) in 24 of 39 patients (62%) with myocardial calcifications. A nonconfluent calcification pattern was associated with VT target sites independent of calcification volume ( P=0.01). CONCLUSIONS: Myocardial calcifications detected by cardiac CT in patients with prior infarction are associated with VT. The calcifications correspond to areas of unexcitability and represent a fixed boundary of reentry circuits that can be visualized by CT. Calcifications correspond to effective ablation sites in >1/3 of patients with postinfarction VT.

Age- and gender-adjusted percentiles for number of calcified plaques in coronary artery calcium scanning.

BACKGROUND: Age- and gender-adjusted percentiles of coronary artery calcium (CAC) score are commonly reported to compare a patient's coronary atherosclerosis burden to that of others of the same age and gender. The number of calcified plaques (numCP) detected on CAC scanning, a measure of plaque diffusivity, is associated with increased cardiovascular risk and, in the intermediate CAC range, adds to the CAC score in predicting mortality. This study aims to develop adjusted percentiles for numCP to provide a better context for understanding CAC scan findings. METHODS AND RESULTS: Using nonparametric modeling techniques, the distribution of numCP was analyzed in 70,320 consecutive, asymptomatic patients without prior clinically-diagnosed cardiovascular disease who were part of the Coronary Artery Calcium Consortium and supplemented by additional patients referred for clinical CAC scanning in a single center between 1998 and 2016. Nomograms for age-adjusted numCP percentiles for each gender were generated using quantile regression. The prevalence and average number of calcified coronary plaque were found to be higher in men than women. Distribution of numCP in women was found to closely mirror that of men approximately a decade younger. NumCP increased consistently across age groups in both men and women for each quantile category. CONCLUSIONS: A nomogram for age and gender-adjusted percentiles for the numCP on CAC scans has been developed in a large population of asymptomatic patients studied across multiple centers. This numCP nomogram may provide an additional tool for refining physician recommendations regarding treatment and expressing to patients how their CAC findings relate to others of similar age and gender. The numCP percentiles may also provide a meaningful way to evaluate and report the rate of progression of CAC on serial studies.

Prediction of premature ventricular complex origin in left vs. right ventricular outflow tract: a novel anatomical imaging approach.

AIMS: Left ventricular (LV) outflow tract ventricular arrhythmias (OTVA) are associated with hypertension (HT), older age, and LV dysfunction, suggesting that LV overload plays a role in the aetiopathogenesis. We hypothesized that anatomical modifications of the LV outflow tract (LVOT) could predict left vs. right OTVA site of origin (SOO). METHODS AND RESULTS: Fifty-six (32 men, 53 ± 18 years old) consecutive patients referred for OTVA ablation were included. Cardiac multidetector computed tomography was performed before ablation and then imported to the CARTO system to aid the mapping and ablation procedure. Anatomical characteristics of the aortic root as well as aortopulmonary valvular planar angulation (APVPA) were analysed. The LV was the OTVA SOO (LVOT-VA) in 32 (57%) patients. These patients were more frequently male (78% vs. 22%, P = 0.001), older (57 ± 18 vs. 47 ± 18 years, P = 0.055), and more likely to have HT (59% vs. 21%, P = 0.004), compared to right OTVA patients. Aortopulmonary valvular planar angulation was higher in LVOT-VA patients (68 ± 5° vs. 55 ± 6°, respectively; P < 0.001). Absolute size of all aortic root diameters was associated with LVOT origin. However, after indexing by body surface area, only sinotubular junction diameter maintained a significant association (P = 0.049). Multivariable analysis showed that APVPA was an independent predictor of LVOT origin. Aortopulmonary valvular planar angulation ≥62° reached 94% sensitivity and 83% specificity (area under the curve 0.95) for predicting LVOT origin. CONCLUSIONS: The measurement of APVPA as a marker of chronic LV overload is useful for the prediction of left vs. right ventricular OTVA origin.

Detailed comparison between the wall thickness and voltages in chronic myocardial infarction.

BACKGROUND: The relationship between the local electrograms (EGMs) and wall thickness (WT) heterogeneity within infarct scars has not been thoroughly described. The relationship between WT and voltages and substrates for ventricular tachycardia (VT) was examined. METHODS: In 12 consecutive patients with myocardial infarction and VT, WT, defined by a multidetector computed tomography, and voltage were compared. In multicomponent EGMs, amplitudes of both far- and near-field components were manually measured, and the performance of the three-dimensional-mapping system automatic voltage measurement was assessed. RESULTS: Of 15 748 points acquired, 2677 points within 5 mm of the endocardial surface were analyzed. In total, 909 (34.0%) multicomponent EGMs were identified; 785 (86.4%) and 883 (97.1%) were distributed in the WT less than 4 and 5 mm, respectively. Far-field EGM voltages increased linearly from 0.14 mV (0.08-0.28 mV) in the WT: 0 to 1 mm to 0.70 mV (0.43-2.62 mV) in the WT: 4 to 5 mm (ρ = 0.430; P < 0.001), and a significant difference was demonstrated between any two WT-groups (P ≤ 0.001). In contrast, near-field EGM voltages varied from 0.27 mV (0.11-0.44 mV) in the WT: 0 to 1 mm to 0.29 mV (0.17-0.53 mV) in the WT: 4 to 5 mm with a poorer correlation (ρ = 0.062, P = 0.04). The proportion of points where the system automatically measured the voltage on near-field EGMs increased from less than 10% in areas of WT: 4 to 5 mm to 50% in areas less than 2 mm. Of 21 VTs observed, seven hemodynamically stable VTs were mapped and terminated in WT: 1 to 4 mm area. CONCLUSIONS: Although far-field voltages gradually increase with the WT, near-field does not. The three-dimensional-mapping system preferentially annotates the near-field components in thinner areas (center of the scar) and the far-field component in thicker areas when building a voltage map. Critical sites of VT are distributed in WT: 1 to 4 mm areas.

Lymphangiography and Post-lymphangiographic Multidetector CT for Preclinical Lymphatic Interventions in a Rabbit Model.

PURPOSE: To describe the feasibility of lymphangiography and the visibility of the lymphatic system using post-lymphangiographic multidetector CT (MDCT) for preclinical lymphatic interventions in a rabbit model. MATERIALS AND METHODS: Lymphangiography via the popliteal lymph node or vessel after surgical exposure was performed, using six healthy female Japanese White rabbits. Lipiodol was manually injected for lymphangiography. Post-lymphangiographic MDCT examinations were performed in all rabbits. The dataset images were subjected to image processing analysis utilizing the three-dimensional maximum intensity projection technique. Three reviewers evaluated the degree of depiction of the lymphatic system using a four-point visual score (1, poor; 2, fair; 3, good; 4, excellent). The distance between the body surface and cisterna chyli was measured on post-lymphangiographic MDCT axial image. RESULTS: Lymphangiography was successfully performed in all rabbits. The popliteal lymph node was detectable in 90%. The visualization of lymphatic system via the popliteal node was achieved in 89%. Mean visual scores of > 3.0 were realized by the right femoral lymphatic vessel, left femoral lymphatic vessel, left iliac lymphatic vessel, left lumbar lymphatic trunks and cisterna chyli, whereas mean visual scores of < 3.0 were yielded by the right iliac lymphatic vessel, right lumbar lymphatic trunks and thoracic duct. The distance between the body surface and cisterna chyli on post-lymphangiographic MDCT axial images was 4.33 ± 0.14 cm. CONCLUSION: Lymphangiography is feasible, and the visibility of the lymphatic system on post-lymphangiographic MDCT in a rabbit model provides enough information for interventional radiologists to perform preclinical lymphatic interventions.

Fast personalized electrophysiological models from computed tomography images for ventricular tachycardia ablation planning.

AIMS: Clinical application of patient-specific cardiac computer models requires fast and robust processing pipelines that can be seamlessly integrated into clinical workflows. We aim at building such a pipeline from computed tomography (CT) images to personalized cardiac electrophysiology (EP) model. The simulation output could be useful in the context of post-infarct ventricular tachycardia (VT) radiofrequency ablation (RFA) planning for pre-operative targets prediction. METHODS AND RESULTS: The support for model personalization is a patient-specific virtual three-dimensional heart obtained from CT images. Here, the scar is identified as thinning of the myocardial wall on automatically computed thickness maps. We then use an Eikonal model of wave front propagation with reduced velocity in the damaged areas. An image-based vessel enhancement algorithm can automatically identify VT isthmuses. The personalized model is used for virtual pacing. We obtained a very fast pipeline that enables simulations in only a few minutes. It is fully automated starting from the semi-automated image segmentation phase. The computational time frame is compatible with the construction of a virtual pacing tool. In this tool, onset points and an optional directional block could be interactively selected. The directional block is a simple way to model tissue refractoriness. Output activation maps are compared with EP data acquired pre-operatively. We show that this framework allows the reproduction of recorded re-entrant VT activation patterns. CONCLUSION: Our simulation framework has an application in VT RFA intervention planning. It could be used to guide EP explorations and even predict ablation targets pre-operatively. This could reduce intervention duration and improve success rate.

Modified Rat Hepatocellular Carcinoma Models Overexpressing Vascular Endothelial Growth Factor.

PURPOSE: To compare tumor vascularity in 4 types of rat hepatocellular carcinoma (HCC) models: N1S1, vascular endothelial growth factor (VEGF)-transfected N1S1 (VEGF-N1S1), McA-RH7777, and VEGF-transfected McA-RH7777 (VEGF-McA-RH777) tumors. MATERIALS AND METHODS: The N1S1 and McA-RH7777 cell lines were transfected with expression vectors containing cDNA for rat VEGF. Eighty-eight male Sprague-Dawley rats (weight range, 400-450 g) were randomly divided into 4 groups (ie, 22 rats per model), and 4 types of tumor models were created by using the N1S1, VEGF-N1S1, McA-RH7777, and VEGF-McA-RH777 cell lines. Tumor vascularity was evaluated by perfusion computed tomography (CT), enzyme-linked immunosorbent assay of VEGF, CD34 staining, angiography, and Lipiodol transarterial embolization. Intergroup discrepancies were evaluated by Kruskal-Wallis test. RESULTS: Arterial perfusion (P < .001), portal perfusion (P = .015), total perfusion (P < .001), tumor VEGF level (P = .002), and microvessel density (MVD; P = .007) were significantly different among groups. VEGF-McA-RH7777 tumors showed the greatest arterial perfusion (46.7 mL/min/100 mL ± 15.5), total perfusion (60.7 mL/min/100 mL ± 21.8), tumor VEGF level (3,376.7 pg/mL ± 145.8), and MVD (34.5‰ ± 7.5). Whereas most tumors in the N1S1, VEGF-N1S1, and McA-RH7777 groups showed hypovascular staining on angiography and minimal Lipiodol uptake after embolization, 5 of 6 VEGF-McA-RH7777 tumors (83.3%) presented hypervascular tumor staining and moderate to compact Lipiodol uptake. CONCLUSIONS: McA-RH7777 tumors were more hypervascular than N1S1 tumors, and tumor vascularity was enhanced further by VEGF transfection. Therefore, the VEGF-McA-RH7777 tumor is recommended to mimic hypervascular human HCC in rats.

Field of view of mapping catheters quantified by electrogram associations with radius of myocardial attenuation on contrast-enhanced cardiac computed tomography.

BACKGROUND: Contrast-enhanced cardiac computed tomography (CE-CT) provides useful substrate characterization in patients with ventricular tachycardia (VT). OBJECTIVE: The purpose of this study was to describe the association between endocardial electrogram measurements and myocardial characteristics on CE-CT, in particular the field of view of electrogram features. METHODS: Fifteen patients with postinfarct VT who underwent catheter ablation with preprocedural CE-CT were included. Electroanatomic maps were registered to CE-CT, and myocardial attenuation surrounding each endocardial point was measured at a radius of 5, 10, and 15 mm. The association between endocardial voltage and attenuation was assessed using a multilevel random effects linear regression model, clustered by patient, with best model fit defined by highest log likelihood. RESULTS: A total of 4698 points were included. There was a significant association of bipolar and unipolar voltage with myocardial attenuation at all radii. For unipolar voltage, the best model fit was at an analysis radius of 15 mm regardless of the mapping catheter used. For bipolar voltage, the best model fit was at an analysis radius of 15 mm for points acquired with a conventional ablation catheter. In contrast, the best model fit for points acquired with a multipolar mapping catheter was at an analysis radius of 5 mm. CONCLUSION: Myocardial attenuation on CE-CT indicates a smaller myocardial field of view of bipolar electrograms using multipolar catheters with smaller electrodes in comparison to standard ablation catheters despite similar interelectrode spacing. Smaller electrodes may provide improved spatial resolution for the definition of myocardial substrate for VT ablation.

What the radiologist should know about postoperative MDCT evaluation of a patient treated with cytoreductive surgery with or without hyperthermic intraperitoneal chemotherapy.

Cytoreductive surgery (CRS), often associated with hyperthermic intraperitoneal chemotherapy (HIPEC), is now a well-recognised treatment for most peritoneal malignancies in selected patients. As imaging is frequently performed postoperatively, radiologists are increasingly confronted with postoperative multidetector-row computed tomography (MDCT) examinations in these cases. In this article, after briefly describing the procedures that are currently being performed for the treatment of peritoneal metastases, the normal postoperative MDCT changes that may be encountered after these procedures are described. We then highlight complications that may arise after CRS, depending on the surgery performed, and those related to HIPEC, and illustrate their MDCT features.