Different methodologies have been used to assess the role of AV calcification (AVC) on TAVI outcomes.This systematic review aims to describe the burden of AVC, synthesize the different methods of calcium score quantification, and evaluate the impact of AVC on outcomes after TAVI. We included studies of TAVI patients who had reported AV calcium scoring by contrast-enhanced multidetector CT and the Agatston method. The impact of calcification on TAVI outcomes without restrictions on follow-up time or outcome type was evaluated. Results were reported descriptively, and a meta-analysis was conducted when feasible.Sixty-eight articles were included, with sample sizes ranging from 23 to 1425 patients. Contrast-enhanced calcium scoring was reported in 30 studies, calcium volume score in 28 studies, and unique scoring methods in two. All studies with calcium volume scores had variable protocols, but most utilized a modified Agatston method with variable attenuation threshold values of 300-850 HU. Eight studies used the Agatston method, with the overall mean AV calcium score in studies published from 2010 to 2012 of 3342.9 AU [95%CI: 3150.4; 3535.4, I2 = 0%]. The overall mean score was lower and heterogenous in studies published from 2014 to 2020 (2658.9 AU [95% CI: 2517.3; 2800.5, I2 = 79%]. Most studies reported a positive association between calcium burden and increased risk of adverse outcomes, including implantation of permanent pacemaker (7/8 studies), paravalvular leak (13/13 studies), and risk of aortic rupture (2/2 studies).AVC quantification methodology with contrast-enhanced CT is still variable. AVC negatively impacts TAVI outcomes independently of the quantification method.

BACKGROUND. Current guidelines recommend visual evaluation of coronary artery calcium (CAC) on all nongated noncontrast chest CT examinations. However, chest CT examinations are often performed with contrast material administration. OBJECTIVE. The purpose of our study was to evaluate diagnostic performance, prognostic utility, and interobserver agreement of visual CAC assessment on chest CT performed for other indications. METHODS. This retrospective study included 260 patients (158 men, 102 women; mean age, 60 ± 11 [SD] years) who underwent both nongated chest CT (contrast-enhanced in 116 patients; noncontrast in 144 patients) and cardiac calcium score CT within a 12-month interval. A cardiothoracic radiologist visually assessed CAC on chest CT using an ordinal scale (absent, mild, moderate, or severe). Cardiac CT Agatston calcium scores were quantified according to established guidelines and were categorized as CAC absent (0), mild CAC (1-99), moderate CAC (100-299), or severe CAC (≥ 300). The diagnostic performance of chest CT for the presence of CAC was assessed using cardiac CT as the reference standard. Major adverse cardiac events (MACE) were assessed as a composite of cardiovascular death and myocardial infarction and were evaluated using Cox proportional hazards models. A second cardiothoracic radiologist performed visual CAC assessments in a random subset of 50 chest CT examinations to assess interob-server agreement. RESULTS. For the presence of any CAC on cardiac CT, contrast-enhanced and non-contrast chest CT had sensitivity of 83% (62/75) and 89% (85/95) (p = .20) and specificity of 100% (41/41) and 100% (49/49) (p = .99). CAC present on cardiac CT was misclassified as absent on 13 contrast-enhanced and 10 noncontrast chest CT examinations; Agatston score was less than 30 in all such patients, and none experienced any MACE. The visual ordinal CAC score was associated with MACE for contrast-enhanced chest CT (hazard ratio [HR] = 4.5 [95% CI, 1.2-16.4], p = .02) and noncontrast chest CT (HR = 3.4 [95% CI, 1.5-7.8], p = .003). Interobserver agreement was excellent for contrast-enhanced (κ = 0.89) and noncontrast (κ = 0.95) chest CT. CONCLUSION. Visual ordinal CAC assessment on both contrast-enhanced and non-contrast chest CT has high diagnostic performance, prognostic utility, and interobserver agreement. CLINICAL IMPACT. Routine reporting of CAC on all chest CT examinations regardless of clinical indication and contrast material administration could identify a large number of patients with previously unknown CAC who might benefit from preventive treatment.

The 2019 Society of Cardiovascular Computed Tomography (SCCT) Annual Scientifi c Meeting (ASM) was perhaps the most impactful meeting in recent memory for the fi eld of cardiovascular CT.Beyond just being the highest attended ASM meeting in the society's history, the virtual impact of the meeting extended farther than ever before due to coordinated social media coverage and participation.Bound through the hashtag #SCCT2019 from Twitter as a prism of interests and response of the global cardiovascular CT community, this article presents the topics with the highest social media engagement from the 14 th ASM.

Introduction Coronary artery calcification is a significant contributor to reduced accuracy of coronary computed tomographic angiography (CTA) in the assessment of coronary artery disease severity. The aim of the current study is to assess the impact of a prototype calcium deblooming algorithm on the diagnostic accuracy of CTA. Methods 40 patients referred for invasive catheter angiography underwent CTA and invasive catheter angiography. CTA studies were read with and without the deblooming algorithm blinded to the invasive coronary angiogram findings. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value for the detection of stenosis ≥50% were evaluated using quantitative coronary angiography as the reference standard. Results All studies were diagnostic with 581 segments available for evaluation. Image score was 3.64±0.72 with CTADEBLOOM, versus 3.56±0.72 with CTASTAND (p=0.38). CTADEBLOOM had significantly less calcium blooming artifact than CTASTAND (12.5% vs. 47.5%, p=0.001). The Sensitivity/Specificity/PPV/NPV/Accuracy were 64.4/85.2/27.6/96.5/83.5 for CTADEBLOOM and 75.0/81.6/25.8/97.5/81.1 for CTASTAND. CTADEBLOOM specificity was significantly higher than CTASTAND (85.2% vs. 81.6%, p=0.017), with no difference between the algorithms in sensitivity (p=0.22), or accuracy (p= 0.09). Interobserver agreement was fair with both techniques (CTADEBLOOMk= 0.38, CTASTAND k= 0.37). Conclusion Coronary calcification deblooming using a prototype post-processing algorithm is feasible and significantly reduces calcium blooming with an improvement of the specificity of the CTA exam.

PurposeTo examine the prognostic implication of fractional flow reserve (FFR) derived from coronary CT (FFRCT) in routine clinical practice.Materials and MethodsPatients referred for FFRCT analysis at a single center between October 2015 and June 2017 were retrospectively included and followed up for rates of invasive angiography and clinical events. Two hundred seven patients underwent successful FFRCT analysis with seven lost to follow-up, leaving 200 (mean age ± standard deviation, 62.4 years ± 10.0; 49 [24.5%] women) patients for analysis. At coronary CT angiography, patients were categorized as having significant stenosis (SS) in the presence of a diameter stenosis greater than or equal to 50% (hereafter, SS positive) and flow limitation in the presence of a postlesion (that is, FFRCT measured 2 cm to the distal aspect of the lesion) FFRCT less than 0.80 (hereafter, FFRCT positive). Vessel-oriented clinical events (VOCEs) were defined as vessel-related late revascularization (>90 days), myocardial infarction, and cardiac mortality.ResultsAt CT angiography, 130 (65%) studies were SS positive and 63 (31.5%) were FFRCT positive. At median follow-up of 477 days (range, 252-859 days), there were 26 VOCE end points in 22 patients: 22 revascularizations and four nonfatal myocardial infarctions. VOCE end points occurred in zero of 58 (0%) of SS-negative and FFRCT negative patients, in eight of 79 (10.1%) of SS-positive and FFRCT-negative patients, in zero of 12 (0%) of SS-negative and FFRCT-positive patients, and in 18 of 51 (35.3%) of SS-positive and FFRCT-positive patients (log-rank χ2 = 30.1; P < .001). At multivariable Cox regression, both FFRCT (hazard ratio per 0.1 decrease, 1.54 [95% confidence interval: 1.1, 2.2] P = .013) and stenosis (hazard ratio per unit increase, 2.16 [95% confidence interval: 1.25, 3.72] P = .006) were independently associated with VOCE.ConclusionStenosis and FFRCT are independent predictors of intermediate-term outcomes. In the absence of a stenosis greater than 50%, a positive FFRCT result is not associated with an increased intermediate risk.© RSNA, 2019Supplemental material is available for this article.See also commentary by Fairbairn and Bull in this issue.

Introduction: Coronary artery calcification is detrimental to the accuracy of coronary computed tomographic angiography (CTA) in the assessment of stenosis severity. The aim of the current study is to examine the diagnostic accuracy of a prototype calcium deblooming algorithm on detection of significant stenosis on CTA.

OBJECTIVE::To describe dynamic 18F-flumethycholine PET (dPET) and dynamic contrast enhancement MR (DCE MR) parameters in localized high-risk prostate cancer (PCa), and determine whether these differ from normal prostate. Furthermore, to determine whether a correlation exists between dPET and DCE MR parameters.METHODS::41 consenting patients who underwent prostate DCE MR and dPET were included in this institutionally approved study. Intraprostatic lesions on MR were assigned a PI-RADS v2 score, and focal lesions on PET were documented. All lesions were correlated with pathology. Quantitative and semi-quantitative DCE MR and two-tissue compartmental model dPET parameters were determined and tumor-to-normal gland ratios (T/N) for these parameters were calculated. Finally, dPET and DCE MR correlation was estimated using Spearman correlation coefficients.RESULTS::There were 46 malignant lesions per standard of reference. On dPET, peripheral zone (PZ) tumors had higher K1 (p < 0.001), and a T/N ratio ≥2 was significant (p < 0.001). On DCE MR, the parameters in, kep, Ktrans and quantitative iAUC were higher for PZ and non-PZ tumors than corresponding normal tissue (p < 0.001); for PZ tumors, a T/N ratio ≥ 1.5 for Ktrans and pei was significant (p = 0.0019 and 0.0026, respectively). Moderate Spearman correlation (0.40 < ρ < 0.59) was found between dPET K1 and DCE MR Ktrans and pei.CONCLUSION::In patients with high-risk PCa, quantitative dPET and DCE-MR parameters in primary tumors differ from normal tissue. Only moderate correlation exists between K1 (dPET) and Ktrans and pei (DCE MR). The incremental value of any of these parameters to PI-RADS v2 warrants further investigation.ADVANCES IN KNOWLEDGE::Unique quantitative and semi-quantitative FCH PET/MR parameters in PCa differ from normal gland, and should be further investigated to determine their potential contribution to PI-RADS v2 in the detection of clinically significant PCa.

OBJECTIVE:The purpose of this study was to determine whether integrated 18F-fluorocholine (FCH) PET whole-body MRI (PET/WBMRI) depicts lymph node and distant metastases in patients with high-risk prostate cancer more frequently than does conventional staging.SUBJECTS AND METHODS:A prospective study included 58 patients with untreated high-risk prostate cancer. After conventional staging (CT and bone scintigraphy), patients underwent FCH PET/WBMRI (n = 10) or FCH PET/CT and WBMRI (n = 48). Metastatic sites and disease stage were recorded for each modality (conventional imaging, PET, WBMRI, and PET/WBMRI) and compared with a standard of reference (histopathologic examination, imaging, and clinical follow-up) and early clinical outcomes.RESULTS:In the detection of metastases, PET had significantly higher sensitivity (72/77 [93.5%]) than conventional imaging (49/77 [63.6%]; p < 0.001) and WBMRI (56/77 [72.7%]; p = 0.002). There was a trend toward improved detection with PET/WBMRI (77/77 [100%]) compared with PET alone (p = 0.059). For correct NM staging, PET and PET/WBMRI performed better than conventional imaging (p = 0.002) and WBMRI (p = 0.008). Twelve of 56 patients (21.4%) had early biochemical failure after radical treatment (median, 7 months; range, 1-20 months). This rate was higher for patients with M1a or M1b disease at PET/WBMRI than for others, but this finding did not reach statistical significance (4/8 [50%] vs 8/48 [16.7%]; p = 0.055).CONCLUSION:In patients with high-risk prostate cancer, FCH PET and FCH PET/WBMRI depict significantly more metastatic lesions than do conventional imaging and WBMRI. Stage determined with PET/WBMRI may correlate with early outcomes.

PURPOSE:After chemotherapy, approximately 50% of patients with metastatic testicular germ cell tumors (GCTs) who undergo retroperitoneal lymph node dissections (RPNLDs) for residual masses have fibrosis. Radiomics uses image processing techniques to extract quantitative textures/features from regions of interest (ROIs) to train a classifier that predicts outcomes. We hypothesized that radiomics would identify patients with a high likelihood of fibrosis who may avoid RPLND.PATIENTS AND METHODS:Patients with GCT who had an RPLND for nodal masses > 1 cm after first-line platinum chemotherapy were included. Preoperative contrast-enhanced axial computed tomography images of retroperitoneal ROIs were manually contoured. Radiomics features (n = 153) were used to train a radial basis function support vector machine classifier to discriminate between viable GCT/mature teratoma versus fibrosis. A nested 10-fold cross-validation protocol was used to determine classifier accuracy. Clinical variables/restricted size criteria were used to optimize the classifier.RESULTS:Seventy-seven patients with 102 ROIs were analyzed (GCT, 21; teratoma, 41; fibrosis, 40). The discriminative accuracy of radiomics to identify GCT/teratoma versus fibrosis was 72 ± 2.2% (area under the curve [AUC], 0.74 ± 0.028); sensitivity was 56.2 ± 15.0%, and specificity was 81.9 ± 9.0% ( P = .001). No major predictive differences were identified when data were restricted by varying maximal axial diameters (AUC range, 0.58 ± 0.05 to 0.74 ± 0.03). The prediction algorithm using clinical variables alone identified an AUC of 0.76. When these variables were added to the radiomics signature, the best performing classifier was identified when axial masses were limited to diameter < 2 cm (accuracy, 88.2 ± 4.4; AUC, 0.80 ± 0.05; P = .02).CONCLUSION:A predictive radiomics algorithm had a discriminative accuracy of 72% that improved to 88% when combined with clinical predictors. Additional independent validation is required to assess whether radiomics allows patients with a high predicted likelihood of fibrosis to avoid RPLND.

Although a common occurrence, cystic lesions of the pancreatico-biliary tree (PBT) may pose a diagnostic dilemma because they encompass a large number of neoplastic and benign processes with varied clinical symptoms. Knowledge of lesion classification and characterization are essential in making an accurate prospective diagnosis. This is necessary for identifying clinically significant cystic masses, which at times may require invasive intervention from indolent, nonneoplastic lesions, for which surveillance may suffice. Today, there is an arsenal of modalities for assessing the PBT, however, magnetic resonance imaging (MRI) remains at the forefront for characterizing cystic morphology and fluid content, internal septations, solid component, enhancement patterns, as well as assessing the surrounding normal structures. This pictorial review aims to review the spectrum of MRI features, which will aid in the differential diagnoses of cystic lesions of the PBT and mimickers, enabling the radiologist to reach a more confident diagnosis.

4559 Background: After chemotherapy, > 50% of patients (pts) with metastatic testicular GCT who undergo retroperitoneal lymph node dissection (RPNLD) for residual masses are found to have fibrosis (F) alone on pathological examination. To minimize overtreatment, better prediction algorithms are needed to identify pts with F who can avoid RPLND. Radiomics uses image processing techniques to extract quantitative textures/features from tumor regions of interest (ROI) to train a classifier that predicts pathological findings. We hypothesized that radiomics may identify pts with a high predicted likelihood of F who may avoid RPLND. Methods: Pts with GCT who had an RPLND for nodal masses > 1cm after first line platinum chemotherapy were included. Preoperative contrast enhanced axial CT images of retroperitoneal ROI were manually contoured. 153 radiomics features trained a radial basis function support vector machine classifier to discriminate between viable GCT /Mature Teratoma (T) vs F. Nested ten-fold cross-validation protocol was employed to determine classifier accuracy. Clinical variables and restricted size criteria were used to optimize the classifier. Results: A total of 82 pts with 102 ROI were analyzed (GCT: 21; T: 41; F: 40). The discriminative accuracy of radiomics to identify GCT/T vs F was 72%(±2.2)(AUC: 0.74 (±0.028); positive predictive value: 67% (48-92%); negative predictive value: 74% (62-84%)(p = 0.001)). No major predictive differences were identified when data was restricted by varying maximal axial diameters (AUC range: 0.58(±0.05) - 0.74(±0.03)). Prediction algorithm using clinical variables alone identified an AUC of 0.71 (±0.15). When these variables were added to the radiomic signature, the best performing classifier was identified when axial tumors were limited to diameter < 2cm (accuracy: 88.2 (±4.4); AUC: 0.80 (±0.05)(p = 0.02)). Conclusions: A predictive radiomics algorithm had an overall discriminative accuracy of 72% that improved to 88% when combined with clinical details. Further independent validation is required to assess whether radiomics, in conjunction with standard clinical predictors, may allow pts with a high predicted likelihood of F to avoid RPLND.

© www.appliedradiology.com March 2017 Adnexal masses often are indeterminate at ultrasound, the diagnostic imaging modality of choice in the workup of women with symptoms of such entities, and confirming ovarian etiology can be difficult. Additional diagnostic imaging is frequently indicated, as a common benign diagnosis may obviate the need for surgery, while prompt identification of malignant features requires intervention by subspecialist oncological surgeons. Magnetic resonance imaging (MRI) is useful in the workup of complex adnexal masses. The modality has several problem-solving utilities that can be correlated with ultrasound findings, clinical history, physical examination and laboratory investigations when a diagnosis remains indeterminate. MR imaging also is more reproducible than sonography, and it can help determine additional diagnostic information, such as the presence of fat, blood products, fibrosis and enhancement pattern or diffusion restriction. DWI, for example, has been beneficial in differentiating benign from malignant tumors with high sensitivity. Ovarian neoplasms range from benign to malignant and may be primary or secondary. Usually, they are classified by tissue of origin (surface epithelial, germ cell and sex-cord stromal) and metastatic (one secondary) (Table 1). In this article, however, we classify ovarian masses into three main MR imaging categories: Cystic neoplasms (with septations), Complex neoplasms (solid-cystic) and Solid neoplasms (predominantly solid). These three categories are further subdivided according to specific MR imaging features, such as the presence of calcifications, fat, blood, proteinaceous content and signal intensities. To the authors’ knowledge this is a novel approach. This MRI classification can help to narrow the differential diagnosis and add to the diagnostic confidence needed to guide the type and extent of definitive surgical management prior to a pathological tissue diagnosis. Indeed, the ultimate aim of this review is to help the radiologist to arrive at a narrow differential diagnosis and, in some cases, a specific diagnosis (Flowchart 1). MRI classification and characterization of complex ovarian masses

The largest randomized controlled trial (RCT) on the effect of FDG-PET on surgical management for metastatic colorectal adenocarcinoma to liver (“PET-CAM”) reported only a modest change in surgical management (8%).

Purpose: Patients with locally advanced rectal cancer (LARC) achieving pathologic complete response (pCR) to neoadjuvant chemoradiotherapy (CRT) have significantly improved long term survival. Preoperative detection of pCR may enable a conservative therapeutic approach in some patients. The purpose of the current prospective pilot study was to assess multiparametric qualitative and quantitative MR, PET, PET-MR and tumor texture features in predicting pCR to CRT in patients with LARC. Material and Methods: Eighteen LARC patients underwent staging with FDG-PET and MR-rectum and 15 had post-CRT restaging. Response was assessed qualitatively and quantitatively. SUV (tumor/background), SUV/ADC, and tumor texture parameters derived via machine learning algorithms (MLA) from PET and multiple MR sequences and were correlated with histopathology. Results: A third of patients had pCR. Sensitivity, specificity & accuracy of PET, MR and combined PET-MR were 90, 60, & 80; 90, 20 & 66.7; 90, 80 & 86.7, respectively. Differences did not reach statistical significance. Quantitatively, only tumor-muscle (SUV/ADC) ratio improved prediction of pCR. Of all texture features assessed using MLA, only the classifier trained on pre-treatment PET was significant (p = 0.034; accuracy, 92.8%). Combined PET and MR texture features did not improve performance. Conclusion: Combined PET-MR may improve specificity compared with PET or MR alone, although this needs to be validated in a larger cohort. Tumor to muscle SUV/ADC ratios post-therapy and texture features on baseline PET show promise in improving prediction of pCR post-CRT in LARC.

PURPOSETo investigate whether volumetrically derived apparent diffusion coefficient (ADC) from pretreatment diffusion-weighted (DW) magnetic resonance (MR) imaging is associated with disease recurrence in women with locally advanced cervical cancer treated with chemotherapy and radiation therapy.MATERIALS AND METHODSAn ethics board-approved, retrospective study was conducted in 85 women with stage IB-IVA cervical cancer treated with chemo- and radiation therapy in 2009-2013. All patients underwent MR imaging for staging, including T2-weighted and DW MR imaging series, by using a 1.5- or 3.0-T imager. The mean, median, 75th, 90th, and 95th percentile ADCs (ADCmean, ADC50, ADC75, ADC90, and ADC95, respectively) of all voxels that comprised each tumor were extracted and normalized to the mean urine ADC (nADCmean, nADC50, nADC75, nADC90, and nADC95, respectively) to reduce variability. The primary outcome was disease-free survival (DFS). Uni- and multivariable Cox regression analyses were used to evaluate the association of ADC parameters and relevant clinical variables with DFS.RESULTSOf the 85 women included, 62 were free of disease at last follow-up. Median follow-up was 37 months (range, 5-68 months). Significant variables at univariable analysis included T2-weighted derived tumor diameter, para-aortic nodal involvement, advanced stage, ADC90 and ADC95, nADC75, nADC90, and nADC95. Normalized parameters were more highly associated (hazard ratio per 0.01 increase in normalized ADC, 0.91-0.94; P < .04). Because nADC75, nADC90, and nADC95 were highly correlated, only nADC95 (which had the lowest P value) was included in multivariable analysis. At multivariable analysis, absolute and normalized ADC95 remained associated with DFS (hazard ratio, 0.90-0.98; P < .05).CONCLUSIONThe volumetric ADC95 may be a useful imaging metric to predict treatment failure in patients with locally advanced cervical cancer treated with chemo- and radiation therapy.

OBJECTIVE:The objective of our study was to assess the association between colorectal liver metastases and intrahepatic bile duct dilatation and compare its frequency with the frequency of intrahepatic bile duct dilatation in other common noncolorectal metastases and hepatocellular carcinoma (HCC).MATERIALS AND METHODS:A retrospective review of the radiology database was performed to obtain the records of patients who underwent CT for staging of histologically proven colorectal carcinoma (n = 1,000), noncolorectal carcinomas (n = 1,000), and HCC (n = 226). The CT scans of the 2,226 patients were reviewed for the presence of liver metastases and masses, the presence of intrahepatic bile duct dilatation directly related to the masses, the size of the largest lesion, and the associated caliber of the dilated intrahepatic bile duct.RESULTS:Of the 297 patients with colorectal liver metastases, 49 (16.5%) had intrahepatic bile duct dilatation, whereas of the 263 patients with noncolorectal liver metastases, only eight (3%) had dilated ducts. Thirteen (5.7%) of the 226 patients with HCC had intrahepatic bile duct dilatation. Intrahepatic bile duct dilatation was present in significantly more patients with colorectal liver metastases (p < 0.05) than those with noncolorectal and HCC metastases. The mean sizes of the lesions and mean caliber of the dilated bile duct from colorectal metastases, noncolorectal metastases, and HCC were 5.3, 3.9, and 5.6 cm, respectively, and 5.1, 4.6, and 4.8 mm, respectively. Overall lesion size irrespective of diagnosis had no significant correlation with the probability of bile duct dilatation (p = 0.16; odds ratio = 1.08; 95% CI, 0.97-1.20). Lesion size also did not have a significantly different effect on the probability of dilatation for the three diagnoses (p = 0.71). The caliber of bile duct dilatation did not significantly differ among the three groups of patients by diagnosis (p = 0.70).CONCLUSION:Colorectal liver metastases have a significantly higher tendency to cause intrahepatic bile duct dilatation than noncolorectal metastases and HCC due to the characteristic features, such as cholangiocarcinoma, of intrabiliary growth. This association has important diagnostic, surgical, and prognostic implications that make it necessary to highlight this finding while communicating with clinical colleagues.