CT-based total vessel plaque analyses improves prediction of hemodynamic significance lesions as assessed by fractional flow reserve in patients with stable angina pectoris

BackgroundCoronary stenosis and plaque evaluation by coronary computed tomography angiography (CTA) may contribute to identify hemodynamically relevant lesions. We evaluated the most stenotic lesion including plaques proximal to it versus a total vessel analyses combined with stenosis for ischemia.MethodsPatients scheduled for clinically indicated invasive coronary angiography (ICA) for suspected coronary artery disease underwent coronary CTA and ICA including fractional flow reserve (FFR) as part of the NXT trial (clinicaltrials.gov NCT01757678). Stenoses were visually graded ≤50%, 51–70%, and >70% on coronary CTA. Semi-automated plaque analyses were performed using a proximal to the FFR pressure sensor location (including the most severe lesion to the coronary ostium) versus a total vessel (vessel diameter ≥2 mm) approach. Coronary stenosis and plaque parameters were evaluated for discrimination of ischemia by logistic regressions and combined models analyzed using receiver operating characteristics (ROC) with invasive FFR≤ 0.80 as reference standard.ResultsIn 254 patients, mean (±SD) age 64 (±10) years, 64% male, a coronary CTA stenosis >50% was present in 239 (49%) vessels. Invasive FFR was ≤0.80 in 100 (21%) vessels. Coronary stenosis severity and low-density non-calcified plaque (LD-NCP) volume were independent predictors of ischemia in the “proximal” and “total-vessel” analyses. Stenosis severity + total vessel LD-NCP assessment performed better than stenosis severity + proximal LD-NCP evaluation (Area under curve [AUC] (95%CI): 0.83 (0.78–0.87) vs 0.81 (0.76–0.86), p-value = 0.009), whereas stenosis severity + proximal LD-NCP performed better than stenosis alone (AUC (95%CI): 0.81 (0.76–0.86) vs 0.78 (0.73–0.83), p-value = 0.019).ConclusionAdding total vessel high-risk plaque volume to stenosis severity improves discrimination of ischemia in coronary CTA performed in patients with stable angina pectoris.     

Incidence and predictors of lesion-specific ischemia by FFRCT: Learnings from the international ADVANCE registry

BackgroundTo date, the clinical utility of coronary computed tomography angiography (CTA)-derived fractional flow reserve (FFRCT) has been limited to trials and single center experiences. We herein report the incidence of abnormal FFRCT (≤0.80) and the relationship of lesion-specific ischemia to subject demographics, symptoms, and degree of stenosis in the multicenter, prospective ADVANCE registry.MethodsOne thousand patients with suspected angina having documented coronary artery disease on coronary CTA and clinically referred for FFRCT were prospectively enrolled in the registry. Patient demographics, symptom status, coronary CTA and FFRCT findings were recorded. Univariate and multivariate analyses were performed to investigate the predictors related to abnormal FFR_CT.ResultsFFR_CT data were analyzed in 952 patients (95.2%). Overall, 51.1% patients had a positive FFR_CT value (≤0.80). Patients with ≥3 risk factors had a significantly higher rate of abnormal FFR_CT than those with <3 risk factors (60.2% vs. 43.9%, p = 0.0001). On multivariate analysis, baseline diabetes (odds ratio [OR] 1.52, 95% confidence interval [CI] 1.04–2.21, p = 0.030) and hypertension (OR 1.56, 95%CI 1.14–2.14, p = 0.005) were both predictive of abnormal FFR_CT. In addition, >70% stenosis was significantly associated with low FFR_CT (OR 31.16, 95%CI 12.25–79.22, p < 0.0001) vs. <30% stenosis. Notably, stenosis 30–49% vs. <30% had an increased likelihood of ischemia (OR 3.74, 95%CI 1.52–9.17, p < 0.0001).ConclusionsIn this real-world registry, CT angiographic stenosis severity in addition to baseline cardiovascular risk factors conferred an increased likelihood of an abnormal FFR_CT. Importantly, however, mild CT angiographic stenoses were noted to have an increased hazard for ischemia and the converse holding true for more severe stenoses as well.     

Hypertrophic Cardiomyopathy (HCM): New insights into Coronary artery remodelling and ischemia from FFRCT

IntroductionAngina, myocardial ischemia, and coronary artery physiology in hypertrophic cardiomyopathy (HCM) are poorly understood. However, coronary computed tomography angiography (CCTA) with fractional flow reserve from CT (FFRCT) analysis offers a non-invasive method for evaluation of coronary artery volume to myocardial mass ratio (V/M) that may provide insight into such mechanisms. Thus, we sought to investigate changes in V/M in HCM.MethodsA retrospective analysis was performed on 37 HCM patients and 37 controls matched for age, sex, and cardiovascular risk factors; CCTA-derived coronary artery lumen volume (V) and myocardial mass (M) were used to determine V/M. FFR_CT values were calculated for the left anterior descending (LAD), left circumflex (LCx) and right coronary (RCA) arteries as well as the 3-vessel cumulative FFR_CT values.ResultsHCM patients had significantly increased myocardial mass (176 ± 84 vs. 119 ± 27 g, p < 0.0001) and total coronary artery luminal volume (4112 ± 1139 vs. 3290 ± 924 mm³, p < 0.0001) that resulted from increases in segmented luminal volumes of both the left and right coronary artery systems. However, HCM patients had significantly decreased V/M (23.8 ± 5.9 vs. 26.5 ± 5.3 mm³/g; p = 0.026) which was further decreased when restricting V/M analysis to those HCM patients with septal hypertrophy (22.4 mm³/g, p = 0.01) that was mild-moderately predictive of HCM (AUC = 0.68). HCM patients also showed significantly lower nadir FFR_CT values in the LCx (0.87 ± 0.06 vs. 0.91 ± 0.06, p = 0.02), and cumulative 3-vessel FFR_CT values (2.58 ± 0.18 vs. 2.63 ± 0.14, p = 0.006).ConclusionsHCM patients demonstrate significantly greater coronary volume. Despite this, HCM patients suffer from decreased V/M. Further prospective studies evaluating the relationship between V/M, angina, and heart failure in HCM are needed.     

Relationship of the Duke jeopardy score combined with minimal lumen diameter as assessed by computed tomography angiography to the hemodynamic relevance of coronary artery stenosis

ObjectivesTo study the diagnostic performance of the ratio between the Duke jeopardy score (DJS) and the minimal lumen diameter (MLD) (DJS/MLDCT ratio) as assessed by coronary computed tomographic angiography (CTA) for differentiating functionally significant from non-significant coronary artery stenoses, with reference to invasive fractional flow reserve (FFR).MethodsPatients who underwent both coronary CTA and FFR measurement during invasive coronary angiography (ICA) within 2 weeks were retrospectively included in the study. Invasive FFR measurement was performed in patients with intermediate to severe coronary stenoseis. DJS/MLDCT ratio and anatomical parameters were recorded. Lesions with FFR ≤0.80 were considered to be functionally significant.ResultsOne hundred and sixty-one patients with 175 lesions were included into the analysis. Diameter stenosis in CT, area stenosis, plaque burden, lesion length (LL), ICA-based stenosis degree, DJS, LL/MLD⁴ ratio, DJS/MLA ratio as well as DJS/MLD ratio were all significantly different between hemodynamically significant and non-significant lesions (p<0.05 for all). ROC curve analysis determined the optimal cut-off value for DJS/MLD_CT ratio to be 1.96 (area under curve = 0.863, 95 % confidence interval = 0.803–0.910), yielding a high diagnostic accuracy (86.9%, 152/175).ConclusionsIn coronary artery stenoses detected by coronary CTA, the DJS/MLD ratio is able to predict hemodynamic relevance.     

Optimized energy of spectral coronary CT angiography for coronary plaque detection and quantification

BackgroundTo optimize spectral coronary computed tomography angiography (CTA) for quantification of coronary artery plaque components.Materials and methodsFifty-one subjects were prospectively enrolled (88.2% male) (NCT02740699). Dual energy coronary CTA was performed at 90/Sn150 kVp using a 3rd generation dual-source CT scanner (SOMATOM Force, Siemens Healthcare). Dual energy images were reconstructed with a) linear mixed blending of 90 and Sn150 kVp data, b) virtual monoenergetic algorithm from 40 to 150 keV (at 10- keV intervals), and c) noise-optimized virtual monoenergetic algorithm from 40 to 150 keV. Image noise, iodine signal-to-noise-ratio (SNR), and contrast-to-noise ratio (CNR) for calcified and non-calcified plaque were measured. Qualitative readings of image quality were performed. Semi-automated software (QAngioCT, Medis) was used to quantify coronary plaque. Linear mixed-models that account for within-subject correlation of plaques were used to compare the results.Results100–150 keV noise-optimized virtual monoenergetic images had lower image noise than linear mixed images (all P < 0.05). The highest iodine SNR was achieved in 40 keV noise-optimized virtual monoenergetic images (33.3 ± 0.6 vs 23.3 ± 0.7 for linear mixed images, P < 0.001). 40–70 keV noise-optimized virtual monoenergetic images and 70 keV virtual monoenergetic images had superior coronary plaque CNR versus linear mixed images (all P < 0.01) with a maximum improvement of 20.1% and 22.7% for calcified plaque and non-calcified plaque (38.8 ± 2.2 vs 32.3 ± 2.3 and 17.3 ± 1.3 vs 14.1 ± 1.4, respectively). Using 90/Sn150 kVp linear mixed images as a reference, the plaque quantity was similar for 70 keV noise-optimized virtual monoenergetic images whereas low keV images (e.g. 40 keV) yielded significantly higher coronary plaque volumes (all P < 0.001).ConclusionSpectral coronary CTA with low energy (40–70 keV) post-processing can improve the CNR of coronary plaque components. However, low energies (such as 40 keV) resulted in different absolute volumes of coronary plaque compared to “conventional” mixed 90/Sn150 kVp images.     

Incidentally detected atherosclerosis in the abdominal aorta or its major branches on computed tomography is highly associated with coronary heart disease in asymptomatic adults

BackgroundAtherosclerotic lesions in the abdominal aorta or its major branches are often incidentally detected on abdominal CT. However, clinical implications and optimal subsequent management are mostly left undetermined.MethodsConsecutive, asymptomatic adults (age≥30) who underwent both abdominal CT and coronary computed tomography angiography as part of a self-referred health check-up were investigated (n = 1494).ResultsAdjusted for cardiovascular risk factors, abdominal atherosclerotic lesions with stenosis<25% were associated with significant coronary stenosis, especially in the abdominal aorta (adjusted odds ratio [aOR] 3.37, 95% confidence interval [CI] 0.99–11.45) and any common iliac artery (aOR 2.99, 95% CI 1.43–6.26). The association was higher in atherosclerotic lesions with stenosis≥25%, respectively (aOR 16.39, 95% CI 4.00–67.11; aOR 7.32, 95% CI 2.84–18.86). Furthermore, any major abdominal artery stenosis added predictive value to significant coronary stenosis (area under the receiver operating curve: 0.7598 vs. 0.8019, P < 0.001). The extent of arterial territory involvement was associated with the presence of significant coronary stenoses (P for trend <0.001).ConclusionStenotic atherosclerotic lesions in the abdominal aorta or its major branches incidentally detected on abdominal CT are relatively prevalent and carry high risk for asymptomatic coronary arterial disease.     

Prospective Evaluation of Optical Coherence Tomography in Lower Limb Arteries Compared with Intravascular Ultrasound

PurposeTo compare in a prospective noninferiority study optical coherence tomography (OCT) and intravascular ultrasound (IVUS) in popliteal and infrapopliteal vessels.Materials and MethodsOCT and IVUS images of 112 popliteal and infrapopliteal arterial segments were prospectively obtained from 16 patients with peripheral arterial occlusive disease. Three observers evaluated the corresponding OCT and IVUS images for image quality, artifact frequency, discriminability of vessel wall layers, and plaque composition. Measurements of the lumen, vessel, and plaque areas were compared for both modalities.ResultsThe intrareader and interreader reproducibility of plaque tissue discrimination (0.88 vs 0.75), overall image quality, and vessel wall layer discriminability were significantly higher for OCT (all P < .001). Artifact frequency was higher in OCT, constraining the imaging of the tibioperoneal trunk. The results of measurements of the lumen and vessel area were comparable for both modalities (correlation > 0.9, P < .001). Plaque area measurements differed (correlation 0.8, P < .01) because OCT underestimated it. The OCT procedure caused vessel spasms in two patients.ConclusionsOCT imaging of infrapopliteal arteries is feasible and safe and provides high image quality. It enables an accurate assessment of vessel lumen, wall, and plaque. Compared with IVUS, OCT images provide excellent image quality and superior visualization of vessel wall layers and different plaque components. The penetration depth of OCT restricts its use to suitable vessel regions.     

Coronary plaque characteristics in computed tomography and 2-year outcomes: The PREDICT study

BackgroundCoronary computed tomography angiography (CCTA) not only provides information regarding luminal stenoses but also allows for visualization of mural atheromatous changes (coronary plaques).ObjectiveWe sought to elucidate whether plaques seen on CCTA enable prediction of 2-year outcomes in patients with suspected and known coronary artery disease (CAD).MethodsOf 3015 patients who underwent CCTA, the images and 2-year clinical courses of 2802 patients were independently analyzed. The primary endpoint was the composite of all-cause death and acute coronary syndrome.ResultsDuring the 2-year observation period, 49 (1.7%) patients developed the primary outcome. The 2-year rates of the primary outcome in the normal (n = 515, no mural lesions), calcium (n = 654, calcified lesion alone), and plaque groups (n = 1633, presence of noncalcified or partially calcified plaques) were 0.2%, 2.0%, and 2.1%, respectively (P = 0.0028). Adverse plaque features such as low attenuation, positive remodeling, spotty calcification, and the napkin-ring sign (low-attenuation core with a higher-attenuation rim) were assessed by an independent core laboratory. Stepwise multivariate Cox proportional hazard analysis showed that a plaque with two or more characteristics (adjusted hazard ratio, 1.98; 95% confidence interval, 1.09–3.60; P = 0.0254), age of ≥67 years (mean), statin treatment after CCTA, and obstructive stenosis remained independent predictors of the primary outcome.ConclusionsPlaque imaging in CCTA has predictive value for the 2-year outcome and is a useful identifier for high-risk patients among those with known and suspected CAD.     

Risk Factors for Pneumothorax Complicating Radiofrequency Ablation for Lung Malignancy: A Systematic Review and Meta-Analysis

PurposeTo assess the potential risk factors for pneumothorax secondary to pulmonary radiofrequency (RF) ablation.Materials and MethodsSix electronic databases were searched from inception to February 2014 for studies assessing potential patient-related, tumor-related, or treatment-related risk factors for pneumothorax during pulmonary RF ablation. Study selection, data collection, and quality assessment were done by three independent reviewers.ResultsAmong 771 studies identified in the search, 10 retrospective cohort studies met inclusion criteria. There were 981 patients (61.5% male) with a mean age of 64.2 years included (259 primary lung tumors, 722 metastatic tumors). The prevalence of pneumothorax was 37% (95% confidence interval [CI], 29%–46%) in 1,916 RF ablation sessions. The potential patient-related and tumor-related risk factors for pneumothorax were increased age (mean difference [MD], 2.09; 95% CI [0.11–4.06]; I² = 0%), male gender (unadjusted odds ratio [OR], 2.20; 95% CI [1.49-3.27]; I² = 0%), no history of lung surgery (unadjusted OR, 0.29; 95% CI [0.19–0.44]; I² = 0%), and a greater number of tumors ablated (MD, 0.50; 95% CI [0.27–0.73]; I² = 0%).ConclusionBased on available observational studies, the results suggest risk factors for pneumothorax secondary to pulmonary RF ablation may include increased age, male gender, no history of lung surgery, number of tumors ablated, and increased length of the aerated lung traversed by the electrode. The findings from this systematic review should be interpreted with caution because of the inherent limitations of the retrospective observational design.     

Apparent Diffusion Coefficient of Uterine Leiomyoma as a Predictor of the Potential Response to Uterine Artery Embolization

PurposeTo determine the utility of the apparent diffusion coefficient (ADC) of uterine leiomyoma for prediction of the potential response to uterine artery embolization (UAE).Materials and MethodsThis prospective study included 49 patients with uterine leiomyomas who underwent diffusion-weighted magnetic resonance (MR) imaging before UAE between May 2011 and January 2012. All patients also underwent 3-month follow-up MR imaging after UAE. Using conventional and diffusion-weighted MR imaging sequences, 72 uterine leiomyomas ≥ 3 cm were prospectively evaluated. The volume of each leiomyoma was calculated, and quantitative measurement of ADC was performed. Regression analysis was used to evaluate the relationship between ADC and volumetric response after UAE. Receiver operating characteristic curve analysis was performed to determine the sensitivity and specificity of ADC for prediction of the potential response to UAE. Interclass correlation coefficient analysis was used to assess interobserver variability between two radiologists.ResultsVolume reduction rates of leiomyomas after UAE ranged from 0.2%–89.1% (mean, 44.1%). ADC ranged from 0.559 × 10^?3 mm²/s to 1.814 × 10^?3 mm²/s (mean, 1.170 × 10^?3 mm²/s). ADC was statistically significantly related to volumetric response of leiomyomas (P = .014). Using a threshold of 1.092 × 10^?3 mm²/s, the sensitivity and specificity of ADC for prediction of > 50% volume reduction of the leiomyoma after UAE were 82.6% and 52.3%, respectively. Using a threshold of 1.023 × 10^?3 mm²/s, the sensitivity and specificity of ADC for prediction of < 30% volume reduction were 80.8% and 33.3%, respectively. The interclass correlation coefficient for measuring ADC of uterine leiomyomas between two radiologists was 0.98.ConclusionsADC of uterine leiomyomas was significantly related to the volume reduction after UAE. ADC may be useful in predicting the potential response to UAE. A high ADC of the uterine leiomyoma may be associated with a greater volume reduction after UAE.     

Rationale and design of advantage (additional diagnostic value of CT perfusion over coronary CT angiography in stented patients with suspected in-stent restenosis or coronary artery disease progression) prospective study

BackgroundRecent studies demonstrated a significant improvement in the diagnostic performance of coronary CT angiography (CCTA) for the evaluation of in-stent restenosis (ISR). However, coronary stent assessment is still challenging, especially because of beam-hardening artifacts due to metallic stent struts and high atherosclerotic burden of non-stented segments. Adenosine-stress myocardial perfusion assessed by CT (CTP) recently demonstrated to be a feasible and accurate tool for evaluating the functional significance of coronary stenoses in patients with suspected coronary artery disease (CAD). Yet, scarce data are available on the performance of CTP in patients with previous stent implantation.Aim of the studyWe aim to assess the diagnostic performance of CCTA alone, CTP alone and CCTA plus CTP performed with a new scanner generation using quantitative invasive coronary angiography (ICA) and invasive fractional flow reserve (FFR) as standard of reference.MethodsWe will enroll 300 consecutive patients with previous stent implantation, referred for non-emergent and clinically indicated invasive coronary angiography (ICA) due to suspected ISR or progression of CAD in native coronary segments. All patients will be subjected to stress myocardial CTP and a rest CCTA. The first 150 subjects will undergo static CTP scan, while the following 150 patients will undergo dynamic CTP scan. Measurement of invasive FFR will be performed during ICA when clinically indicated.ResultsThe primary study end points will be: 1) assessment of the diagnostic performance (diagnostic rate, sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy) of CCTA, CTP, combined CCTA-CTP and concordant CCTA-CTP vs. ICA as standard of reference in a territory-based and patient-based analysis; 2) assessment of sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of CCTA, CTP, combined CCTA-CTP and concordant CCTA-CTP vs. invasive FFR as standard of reference in a territory-based analysis.ConclusionsThe ADVANTAGE study aims to provide an answer to the intriguing question whether the combined anatomical and functional assessment with CCTA plus CTP may have higher diagnostic performance as compared to CCTA alone in identifying stented patients with significant ISR or CAD progression.     

Comparison of quantitative atherosclerotic plaque burden from coronary CT angiography in patients with first acute coronary syndrome and stable coronary artery disease

BackgroundCoronary CTA allows characterization of non-calcified and calcified plaque and identification of high-risk plaque features.ObjectiveWe aimed to quantitatively characterize and compare coronary plaque burden from CTA in patients with a first acute coronary syndrome (ACS) and controls with stable coronary artery disease.Materials and methodsWe retrospectively analyzed consecutive patients with non-ST-segment elevation myocardial infarction (NSTEMI) or unstable angina with a first ACS, who underwent CTA as part of their initial workup before invasive coronary angiography and age- and gender-matched controls with stable chest pain; controls also underwent CTA with subsequent invasive angiography (total n = 28). Culprit arteries were identified in ACS patients. Coronary arteries were analyzed by automated software to quantify calcified plaque (CP), noncalcified plaque (NCP), and low-density NCP (LD-NCP, attenuation <30 Hounsfield units) volumes, and corresponding burden (plaque volume × 100%/vessel volume), stenosis, remodeling index, contrast density difference (maximum percent difference in attenuation/cross-sectional area from proximal cross-section), and plaque length.ResultsACS patients had fewer lesions (median, 1), with higher total NCP and LD-NCP burdens (NCP: 57.4% vs 41.5%; LD-NCP: 12.5% vs 8%; P ≤ .04), higher maximal stenoses (85.6% vs 53.0%; P = .003) and contrast density differences (46.1 vs 16.3%; P < .006). Per-patient CP burden was not different between ACS and controls. NCP and LD-NCP plaque burden was higher in culprit vs nonculprit arteries (NCP: 57.8% vs 9.5%; LD-NCP: 8.4% vs 0.6%; P ≤ .0003); CP was not significantly different. Culprit arteries had increased plaque lengths, remodeling indices, stenoses, and contrast density differences (46.1% vs 10.9%; P ≤ .001).ConclusionNoninvasive quantitative coronary artery analysis identified several differences for ACS, both on per-patient and per-vessel basis, including increased NCP, LD-NCP burden, and contrast density difference.     

A Novel Resorbable Embolization Microsphere for Transient Uterine Artery Occlusion: A Comparative Study with Trisacryl-Gelatin Microspheres in the Sheep Model

PurposeTo evaluate angiographic recanalization, inflammatory reaction, and uterine damage after sheep uterine artery embolization (UAE) with a novel calibrated resorbable embolization microsphere (REM) and compare the results with control nonresorbable microspheres.Materials and MethodsSix hormonally artificially cycled sheep underwent bilateral UAE until stasis with either REM or trisacryl-gelatin microspheres (TGMS). At 7 days, control angiograms were obtained to assess the residual vascularization at arterial and parenchymal phases. The animals were then sacrificed for analysis of the presence of microspheres, inflammatory foreign body reaction, and surface areas of uterine damage.ResultsMean volume of microspheres injected per uterine artery (UA) or per animal did not differ between groups. At day 7, the flow was normal for six of six UAs that received embolization with REM versus only three of six UAs with TGMS (P = .0455, χ² test). Uterine parenchymography showed no defects in six UAs in the REM group versus five defects in six UAs in the TGMS group (P = .0060, χ² test). No REM or residual fragments of microspheres were observed on histologic analysis. TGMS were observed in tissues and accompanied by a mild inflammatory response. Necrosis rates were not significantly different between the two products, either in endometrium (REM 23.5% ± 28.8% [median 8.1%] vs TGMS 21.8% ± 23.7% [median 14.6%]) or in myometrium (REM 8.2% ± 22.7% [median 0.0%] vs TGMS 8.8% ± 20.8% [median 0.9%]). Endometrium alteration rate was lower with REM than with TGMS (39.7% ± 25.7% [median 34%] vs 60.6% ± 27.1% [median 71%]; P = .0060, Mann-Whitney test). Myometrium alteration rates were not significantly different between REM (45.7% ± 37.1% [median 63.0%]) and TGMS (37.8% ± 34.0% [median 19.1%]).ConclusionsAt 1 week after sheep UAE with REM, the recanalization was complete, the microspheres were completely degraded, and there was no remnant inflammatory response.     

Percutaneous Angioplasty Using a Paclitaxel-Coated Balloon Improves Target Lesion Restenosis on Inflow Lesions of Autogenous Radiocephalic Fistulas: A Pilot Study

PurposeTo determine whether the use of a paclitaxel-coated balloon (PCB) improves patency in patients undergoing percutaneous transluminal angioplasty (PTA) for recurrent juxtaanastomotic stenosis of radiocephalic arteriovenous fistulas (RCAVFs).Material and MethodsThis prospective study recruited hemodialysis patients with two short (< 2 cm) and separated inflow RCAVF lesions. After dilation of lesions using a 4-mm plain balloon (PB), half of the lesions were randomly selected for treatment with PTA using PCB (size, 4 mm; length, 2 cm) and PB (size, 5-mm or 6-mm) (group 1), and the other half were treated with PTA using PB alone (group 2). After the index PTA, dysfunction-driven angiography was performed to confirm target lesion restenosis (TLR). TLR and lesion patency were compared in the two groups by χ² test, t test, and Kaplan-Meier analysis.ResultsThe analysis of 20 lesions in 10 patients revealed that the TLR-free duration in group 1 was significantly longer than the TLR-free duration in group 2 (251.2 d vs 103.2 d; P < .01). The patency rate of the target lesion was significantly higher in group 1 than in group 2 at 6 months (70% vs 0%; P < .01) but not at 12 months (20% vs 0%; P > .05).ConclusionsThis early study suggests that, for improving short-term patency, PTA with PCB and PB is more effective than PTA with PB alone, warranting further study.     

Long-term Outcomes of Coil Packing for Visceral Aneurysms: Correlation between Packing Density and Incidence of Coil Compaction or Recanalization

PurposeTo evaluate the correlation between packing density and the incidence of coil compaction or recanalization of visceral artery aneurysms (VAAs) after coil packing.Materials and MethodsBetween July 2004 and April 2012, coil packing was performed for 46 true visceral aneurysms (16 splenic, 11 pancreaticoduodenal, eight renal, six hepatic, three superior mesenteric, one right gastric, and one gastroepiploic) in 42 patients. The size and volume of the aneurysm, packing density, and the incidences of compaction and recanalization were evaluated retrospectively.ResultsThe mean follow-up period was 37 months ± 8 (range, 11–80 mo). The mean packing density was 19% ± 8 (range, 5%–42%), mean aneurysm size was 19 mm ± 8 (range, 5–40 mm), and mean volume was 4,108 mm³ ± 5,435 (range, 72–26,235 mm³). Compaction and recanalization occurred in two (4%) and 12 aneurysms (26%), respectively. The mean packing density was significantly lower in aneurysms with compaction or recanalization than in unaffected aneurysms (12% vs 22%; P = .00014). There was a significant difference in mean packing density between small (< 20 mm; 22%) and large (≥ 20 mm) aneurysms (15%; P = .0045). The mean size and volume were significantly larger for coil-compacted or recanalized aneurysms than for unaffected aneurysms (P < .05). In aneurysms with a packing density of at least 24%, no compaction or recanalization occurred.ConclusionsCoil compaction or recanalization after coil packing for VAAs more often occurs after insufficient embolization with low packing density and in patients with large aneurysms.     

Pilot Study of Angiogenic Response to Yttrium-90 Radioembolization with Resin Microspheres

PurposeTo investigate the impact of radioembolization with yttrium-90 resin microspheres on the regulation of angiogenesis through observation of serial changes in a spectrum of angiogenic markers and other cytokines after therapy.Materials and MethodsThis prospective pilot study enrolled 22 patients with liver-dominant disease deriving from biopsy-proven hepatocellular carcinoma (HCC) (n = 7) or metastatic colorectal carcinoma (mCRC) (n = 15). Circulating angiogenic markers were measured from serum samples drawn at baseline and at time points after therapy ranging from 6 hours to 120 days. Using multiplex enzyme-linked immunosorbent assay, several classic angiogenesis factors (vascular endothelial growth factor [VEGF], angiopoietin-2 [Ang-2], basic fibroblast growth factor [bFGF], platelet-derived growth factor subunit BB [PDGF-BB], thrombospondin-1 [Tsp-1]) and nonclassic factors (follistatin, leptin, interleukin [IL]-8) were evaluated.ResultsIncreases in cytokine levels ≥ 50% over baseline were observed in more than half of all patients studied for many cytokines, including classic angiogenic factors such as VEGF, Ang-2, and Tsp-1 as well as nonclassic factors IL-8 and follistatin (range, 36%–82% for all cytokines). Baseline cytokine levels in patients with overall survival (OS) < 6 months differed significantly from patients with longer survival for Ang-2 (P = .033) and IL-8 (P = .041). Patients with OS ≤ 6 months exhibited transient increases in VEGF and PDGF-BB after therapy compared with patients with OS > 6 months.ConclusionsRadioembolization is associated with early transient increases in many angiogenic cytokines. In this small sample size, some of these changes were associated with worse OS. This research has important implications for future studies of radioembolization with antiangiogenic therapy performed during and after the procedure.     

Respiration-induced Deformations of the Superior Mesenteric and Renal Arteries in Patients with Abdominal Aortic Aneurysms

PurposeTo quantify respiration-induced deformations of the superior mesenteric artery (SMA), left renal artery (LRA), and right renal artery (RRA) in patients with small abdominal aortic aneurysms (AAAs).Materials and MethodsSixteen men with AAAs (age 73 y ± 7) were imaged with contrast-enhanced magnetic resonance angiography during inspiratory and expiratory breath-holds. Centerline paths of the aorta and visceral arteries were acquired by geometric modeling and segmentation techniques. Vessel translations and changes in branching angle and curvature resulting from respiration were computed from centerline paths.ResultsWith expiration, the SMA, LRA, and RRA bifurcation points translated superiorly by 12.4 mm ± 9.5, 14.5 mm ± 8.8, and 12.7 mm ± 6.4 (P < .001), and posteriorly by 2.2 mm ± 2.7, 4.9 mm ± 4.2, and 5.6 mm ± 3.9 (P < .05), respectively, and the SMA translated rightward by 3.9 mm ± 4.9 (P < .01). With expiration, the SMA, LRA, and RRA angled upward by 9.7° ± 6.4, 7.5° ± 7.8, and 4.9° ± 5.3, respectively (P < .005). With expiration, mean curvature increased by 0.02 mm^?1 ± 0.01, 0.01 mm^?1 ± 0.01, and 0.01 mm^?1 ± 0.01 in the SMA, LRA, and RRA, respectively (P < .05). For inspiration and expiration, RRA curvature was greater than in other vessels (P < .025).ConclusionsWith expiration, the SMA, LRA, and RRA translated superiorly and posteriorly as a result of diaphragmatic motion, inducing upward angling of vessel branches and increased curvature. In addition, the SMA exhibited rightward translation with expiration. The RRA was significantly more tortuous, but deformed less than the other vessels during respiration.     

Comparison of Intravascular Ultrasound with Conventional Venography for Detection of Extracranial Venous Abnormalities Indicative of Chronic Cerebrospinal Venous Insufficiency

PurposeTo investigate prevalence of extracranial abnormalities in azygos and internal jugular (IJ) veins using conventional venography and intravascular ultrasound (IVUS) in patients with multiple sclerosis (MS) being evaluated for chronic cerebrospinal venous insufficiency, a condition of vascular hemodynamic dysfunction.Materials and MethodsPREMiSe (Prospective Randomized Endovascular therapy in Multiple Sclerosis) is a venous angioplasty study that enrolled 30 patients with relapsing MS. The patients fulfilled two or more venous hemodynamic extracranial Doppler sonography screening criteria. Phase I of the study included 10 patients and was planned to assess safety and standardize venography, IVUS, and angioplasty and blinding procedures; phase II enrolled 20 patients and further validated diagnostic assessments using the two invasive techniques. Venography was considered abnormal when ≥ 50% lumen-diameter restriction was detected. IVUS was considered abnormal when ≥ 50% lumen-diameter restriction, intraluminal defects, or reduced pulsatility was detected.ResultsNo venography-related or IVUS-related complications, including vessel rupture, thrombosis, or side effects of contrast media were recorded among the 30 study patients. IVUS-detected venous abnormalities, including chronic, organized, thrombus-like inclusions were observed in 85% of azygos, 50% of right IJ, and 83.3% of left IJ veins, whereas venography demonstrated stenosis of ≥ 50% in 50% of azygos, 55% of right IJ, and 72% of left IJ veins. Sensitivity of venography for detecting IVUS abnormalities was 52.9%, 73.3%, and 80% for the azygos, left IJ, and right IJ veins, respectively.ConclusionsIVUS assessment of azygos and IJ veins showed a higher rate of venous abnormalities than venography. IVUS provides a diagnostic advantage over conventional venography in detecting extracranial venous abnormalities indicative of chronic cerebrospinal venous insufficiency.     

High-Frequency Jet Ventilation under General Anesthesia Facilitates CT-Guided Lung Tumor Thermal Ablation Compared with Normal Respiration under Conscious Analgesic Sedation

PurposeTo determine whether technical difficulty of computed tomography (CT)–guided percutaneous lung tumor thermal ablations is altered with the use of high-frequency jet ventilation (HFJV) under general anesthesia (GA) compared with procedures performed with normal respiration (NR) under conscious sedation (CS).Materials and MethodsThermal ablation treatment sessions performed with NR under CS or HFJV under GA with available anesthesia records and CT fluoroscopic images were retrospectively reviewed; 13 and 33 treatment sessions, respectively, were identified. One anesthesiologist determined the choice of anesthesiologic technique independently. Surrogate measures of procedure technical difficulty—time duration, number of CT fluoroscopic acquisitions, and radiation dose required for applicator placement for each tumor—were compared between anesthesiologic techniques. The anesthesiologist time and complications were also compared. Parametric and nonparametric data were compared by Student independent-samples t test and χ² test, respectively.ResultsPatients treated with HFJV under GA had higher American Society of Anesthesiologists classifications (mean, 2.66 vs 2.23; P = .009) and smaller lung tumors (16.09 mm vs 27.38 mm; P = .001). The time duration (220.30 s vs 393.94 s; P = .008), number of CT fluoroscopic acquisitions (10.31 vs 19.13; P = .023), and radiation dose (60.22 mGy·cm vs 127.68 mGy·cm; P = .012) required for applicator placement were significantly lower in treatment sessions performed with HFJV under GA. There was no significant differences in anesthesiologist time (P = .20), rate of pneumothorax (P = .62), or number of pneumothoraces requiring active treatment (P = .19).ConclusionsHFJV under GA appears to reduce technical difficulty of CT-guided percutaneous applicator placement for lung tumor thermal ablations, with similar complication rates compared with treatment sessions performed with NR under CS. The technique is safe and may facilitate treatment of technically challenging tumors.     

Quantitative Assessment of Lipiodol Deposition after Chemoembolization: Comparison between Cone-Beam CT and Multidetector CT

PurposeTo evaluate the ability of cone-beam computed tomography (CBCT) performed directly after transarterial chemoembolization to assess ethiodized oil (Lipiodol) deposition in hepatocellular carcinoma (HCC) and compare it with unenhanced multidetector computed tomography (CT).Materials and MethodsConventional transarterial chemoembolization was used to treat 15 patients with HCC, and CBCT was performed to assess Lipiodol deposition directly after transarterial chemoembolization. Unenhanced multidetector CT was performed 24 hours after transarterial chemoembolization. Four patients were excluded because the margin of tumor or area of Lipiodol deposition was unclear. The image enhancement density of the entire tumor and liver parenchyma was measured by ImageJ software, and tumor-to-liver contrast (TLC) was calculated. In addition, volumetric measurement of tumor and Lipiodol was performed by semiautomatic three-dimensional volume segmentation and compared using linear regression to evaluate consistency between the two imaging modalities.ResultsThe mean value of TLC on CBCT was not significantly different from TLC on multidetector CT (337.7 HU ± 233.5 vs 283.0 HU ± 152.1, P = .103).The average volume of the whole tumor and of only the regions with Lipiodol deposition and the calculated average percentage of Lipiodol retention on CBCT were not significantly different compared with multidetector CT (tumor volume, 9.6 cm³ ± 11.8 vs 10.8 cm³ ± 14.2, P = .142; Lipiodol volume, 6.3 cm³ ± 7.7 vs 7.0 cm³ ± 8.1, P = .214; percentage of Lipiodol retention, 68.9% ± 24.0% vs 72.2% ± 23.1%, P = .578). Additionally, there was a high correlation in the volume of tumor and Lipiodol between CBCT and multidetector CT (R² = 0.919 and 0.903).ConclusionsThe quantitative image enhancement and volume analyses demonstrate that CBCT is similar to multidetector CT in assessing Lipiodol deposition in HCC after transarterial chemoembolization.