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1.
Objectives
To investigate the progression of coronary atherosclerosis burden by coronary CT angiography (CCTA) and to demonstrate its association with the incidence of major adverse cardiac events (MACE).Methods
We retrospectively studied patients with stable angina who had undergone repeat CCTA due to recurrent or worsening symptoms. Lipid-rich, fibrous, calcified and total plaque burden as well as coronary diameter stenosis were quantitatively analysed. The incidence of MACE during follow-up was determined.Results
The final cohort consisted of 268 patients (mean age 52.9 ± 9.8 years, 71 % male) with a mean follow-up period of 4.6 ± 0.9 years. Patients with lipid-rich, fibrous, calcified and total plaque burden (%) progression, as well as coronary diameter stenosis (%) progression had a significantly higher incidence of MACE than those without (all p < 0.05). The progression of lipid-rich plaque (HR = 1.601, p = 0.021), total plaque burden (HR = 2.979, p = 0.043) and coronary diameter stenosis (HR = 4.327, p <0.001) were independent predictors of MACE (all p < 0.05).Conclusions
Patients presenting with recurrent or worsening symptoms associated with coronary artery disease who have coronary atherosclerosis progression on CCTA are at an increased risk of future MACE.Key Points
? Repeat CCTA can provide information regarding the progression of coronary atherosclerosis. ? Coronary atherosclerosis progression at CCTA is independently associated with MACE. ? CCTA findings could serve as incremental predictors of MACE.2.
S.?Oebel S.?Hamada K.?Higashigaito J.?von?Spiczak E.?Klotz F.?Enseleit R.?Hinzpeter F.?Ruschitzka R.?Manka H.?Alkadhi
Objectives
We aimed to assess the diagnostic performance of a combined protocol with coronary computed tomography angiography (CCTA) and stress CT perfusion imaging (CTP) in heart transplant patients for comprehensive morphological and functional imaging.Methods
In this prospective study, 13 patients undergoing routine follow-up 8±6 years after heart transplantation underwent CCTA and dynamic adenosine stress CTP using a third-generation dual-source CT scanner, cardiac magnetic resonance (MR) adenosine stress perfusion imaging at 1.5 T, and catheter coronary angiography. In CCTA stenoses >50% luminal diameter narrowing were noted. Myocardial perfusion deficits were documented in CTP and MR. Quantitative myocardial blood flow (MBF) was calculated with CTP. Left ventricular ejection fraction was determined on cardiac MR cine images. Radiation doses of CT were determined.Results
One of the 13 patients had to be excluded because of severe motion artifacts. CCTA identified three patients with stenosis >50%, which were confirmed with catheter coronary angiography. CTP showed four patients with stress-induced myocardial hypoperfusion, which were confirmed by MR stress perfusion imaging. Quantitative analysis of global MBF showed lower mean values as compared to known reference values (MBF under stress 125.5 ± 34.5 ml/100 ml/min). Average left ventricular ejection fraction was preserved (56 ± 5%).Conclusions
In heart transplant patients, a comprehensive CT protocol for the assessment of morphology and function including CCTA and CTP showed good concordance to results from MR perfusion imaging and catheter coronary angiography.Key Points
? Stress CT perfusion imaging enables the detection of myocardial ischemia ? CT myocardial perfusion imaging can be combined with coronary computed tomography angiography ? Combining perfusion and coronary CT imaging is accurate in heart transplant patients ? CT myocardial perfusion imaging can be performed at a reasonable radiation dose3.
Christophe?T.?Arendt Patricia?Tischendorf Julian?L.?Wichmann Michael?Messerli Lucas?J?rg Niklas?Ehl Robin?F.?Gohmann Simon?Wildermuth Thomas?J.?Vogl Ralf?W.?Bauer
Objectives
We investigated the potential reduction of patient exposure during invasive coronary angiography (ICA) if the procedure had only been directed to the vessel with at least one ≥ 50% stenosis as described in the CT report.Methods
Dose reports of 61 patients referred to ICA because of at least one ≥ 50% stenosis on coronary CT angiography (CCTA) were included. Dose–area product (DAP) was documented separately for left (LCA) and right coronary arteries (RCA) by summing up the single DAP for each angiographic projection. The study population was subdivided as follows: coronary intervention of LCA (group 1) or RCA (group 2) only, or of both vessels (group 3), or further bypass grafting (group 4), or no further intervention (group 5).Results
57.4% of the study population could have benefitted from reduced exposure if catheterization had been directly guided to the vessel of interest as described on CCTA. Mean relative DAP reductions were as follows: group 1 (n = 18), 11.2%; group 2 (n = 2), 40.3%; group 3 (n = 10), 0%; group 4 (n = 3), 0%; group 5 (n = 28), 28.8%.Conclusions
Directing ICA to the vessel with stenosis as described on CCTA would reduce intraprocedural patient exposure substantially, especially for patients with single-vessel stenosis.Key points
? Patients with CAD can benefit from decreased radiation exposure during coronary angiography. ? ICA should be directed solely to significant stenoses as described on CCTA. ? Severely calcified plaques remain a limitation of CCTA leading to unnecessary ICA referrals.4.
Amir Imanzadeh Elizabeth George Takeshi Kondo Shinichi Takase Makoto Amanuma Frank J. Rybicki Kanako K. Kumamaru 《Japanese journal of radiology》2016,34(2):140-147
Purpose
To evaluate the role of coronary artery calcium scoring (CACS) and/or coronary CT angiography (CCTA) in asymptomatic elderly patients with high pretest probability for coronary artery disease (CAD).Materials and methods
Forty-eight consecutive asymptomatic elderly (>65 years) subjects who had a high pretest probability and underwent CACS/CCTA were included. Each CCTA was evaluated for adequacy for assessment of coronary stenosis. Significant stenosis (>50 % diameter narrowing) was assessed on evaluable CT images and by invasive catheter angiography (ICA).Results
All subjects were men with mean CACS of 880 ± 1779. Among those with low (0–99), intermediate (100–399), and high (400–999) CACS, ICA-verified significant stenosis was present in 8 % (1/13), 23 % (2/13), and 67 % (8/12), respectively. Among those with very high CACS (≥1000) (n = 10), 90 % of CCTAs were not evaluable for stenosis.Conclusion
In asymptomatic elderly subjects with high pretest probability, CACS followed by CCTA may be considered for those with intermediate to high CACS.5.
Junghoon?Kim Hyon?Joo?Kwag Seung?Min?Yoo Jin?Young?Yoo In-Ho?Chae Dong-Ju?Choi Min-Jae?Park Mani?Vembar Eun?Ju?Chun
Objectives
To evaluate the clinical significance of discrepant lesions between coronary computed tomography angiography (CCTA) and invasive coronary angiography (ICA) in a longitudinal study.Methods
In 220 patients with suspected coronary artery disease (CAD) who underwent both 256-row CCTA and ICA, the obstructive CAD (≥ 50% stenosis) on CCTA was compared with that on ICA as the reference standard. We analysed the causes of the discrepancy between CCTA and ICA. During a 40-month follow-up period, major adverse cardiac events (MACE) were assessed.Results
Discordance between CCTA and ICA was observed in 121 of the 3166 coronary artery segments (3.8%). Common causes were calcification (45.9%) and positive remodelling (PR) (29.6%) in 83 false positive lesions, and noise (40.0%) and motion artefact (37.8%) in 38 false negative lesions. MACE occurred in seven lesions among the discrepant lesions; six among the 29 PR lesions (20.7%) and one among the 53 calcified lesions (1.9%). With respect to the prediction power of MACE in an intermediate stenosis, the CCTA-related value including PR was higher than the ICA-related value.Conclusions
PR was a frequent cause of MACE among the false positive lesions on CCTA. Therefore, the presence of PR on CCTA may suggest clinical significance, although it can be missed by ICA.Key Points
? Compared to ICA, PR in CCTA may be cause of false positive lesion. ? CCTA-related value including PR shows higher prediction power of MACE than ICA-related value. ? PR reflects atherosclerotic burden that can be related to cardiac events. ? PR in CCTA should be observed carefully, even if it is false positive.6.
Stefanie Mangold Julian L. Wichmann U. Joseph Schoepf Sheldon E. Litwin Christian Canstein Akos Varga-Szemes Giuseppe Muscogiuri Stephen R. Fuller Andrew C. Stubenrauch Konstantin Nikolaou Carlo N. De Cecco 《European radiology》2016,26(9):2937-2946
Objectives
To evaluate the image quality of coronary CT angiography (CCTA) in obese patients using a 3rd generation, dual-source CT scanner.Methods
We retrospectively evaluated 102 overweight and obese patients who had undergone CCTA. Studies were performed with 3rd generation dual-source CT, prospectively ECG-triggered acquisition at 120 kV, and automated tube current modulation. Advanced modeled iterative reconstruction was used. Patients were divided into three BMI groups: 1)25–29.9 kg/m2; 2)30–39.9 kg/m2; 3)?≥?40 kg/m2. Vascular attenuation in the coronary arteries was measured. Contrast-to-noise ratio (CNR) was calculated. Image quality was subjectively evaluated using five-point scales.Results
Image quality was considered diagnostic in 97.6 % of examinations. CNR was consistently adequate in all groups but decreased for groups 2 and 3 in comparison to group 1 as well as for group 3 compared to group 2 (p?=?0.001, respectively). Subjective image quality was significantly higher in group 1 compared to group 3 (attenuation proximal: 4.8?±?0.4 vs. 4.4?±?0.6, p?=?0.011; attenuation distal: 4.5?±?0.7 vs. 4.0?±?0.8, p?=?0.019; noise: 4.7?±?0.6 vs. 3.8?±?0.7, p?<?0.001). The mean effective dose was 9.5?±?3.9 mSv for group 1, 11.4?±?4.7 mSv for group 2 and 14.0?±?6.4 mSv for group 3.Conclusion
Diagnostic image quality can be routinely obtained at CCTA in obese patients with 3rd generation DSCT at 120 kV.Key Points
? Diagnostic CCTA can be routinely performed in obese patients with 3 rd generation DSCT.? 120-kV tube voltage allows diagnostic image quality in patients with BMI?>?40 kg/m 2 .? 80-ml contrast medium can be administered without significant decline in vascular attenuation.7.
Objectives
To validate a method for performing myocardial segmentation based on coronary anatomy using coronary CT angiography (CCTA).Methods
Coronary artery-based myocardial segmentation (CAMS) was developed for use with CCTA. To validate and compare this method with the conventional American Heart Association (AHA) classification, a single coronary occlusion model was prepared and validated using six pigs. The unstained occluded coronary territories of the specimens and corresponding arterial territories from CAMS and AHA segmentations were compared using slice-by-slice matching and 100 virtual myocardial columns.Results
CAMS more precisely predicted ischaemic area than the AHA method, as indicated by 95% versus 76% (p?<?0.001) of the percentage of matched columns (defined as percentage of matched columns of segmentation method divided by number of unstained columns in the specimen). According to the subgroup analyses, CAMS demonstrated a higher percentage of matched columns than the AHA method in the left anterior descending artery (100% vs. 77%; p?<?0.001) and mid- (99% vs. 83%; p?=?0.046) and apical-level territories of the left ventricle (90% vs. 52%; p?=?0.011).Conclusions
CAMS is a feasible method for identifying the corresponding myocardial territories of the coronary arteries using CCTA.Key Points
? CAMS is a feasible method for identifying corresponding coronary territory using CTA ? CAMS is more accurate in predicting coronary territory than the AHA method ? The AHA method may underestimate the ischaemic territory of LAD stenosis8.
Antoine Hutt Alain Duhamel Valérie Deken Jean-Baptiste Faivre Francesco Molinari Jacques Remy Martine Remy-Jardin 《European radiology》2016,26(6):1521-1528
Purpose
To investigate the reliability of ungated, high-pitch dual-source CT for coronary artery calcium (CAC) screening.Materials and methods
One hundred and eighty-five smokers underwent a dual-source CT examination with acquisition of two sets of images during the same session: (a) ungated, high-pitch and high-temporal resolution acquisition over the entire thorax (i.e., chest CT); (b) prospectively ECG-triggered acquisition over the cardiac cavities (i.e., cardiac CT).Results
Sensitivity and specificity of chest CT for detecting positive CAC scores were 96.4 % and 100 %, respectively. There was excellent inter-technique agreement for determining the quantitative CAC score (ICC = 0.986). The mean difference between the two techniques was 11.27, representing 1.81 % of the average of the two techniques. The inter-technique agreement for categorizing patients into the four ranks of severity was excellent (weighted kappa?=?0.95; 95 % CI 0.93–0.98). The inter-technique differences for quantitative CAC scores did not correlate with BMI (r?=?0.05, p?=?0.575) or heart rate (r?=?–0.06, p?=?0.95); 87.2 % of them were explained by differences at the level of the right coronary artery (RCA: 0.8718; LAD: 0.1008; LCx: 0.0139; LM: 0.0136).Conclusion
Ungated, high-pitch dual-source CT is a reliable imaging mode for CAC screening in the conditions of routine chest CT examinations.Key points
? CAC is an independent risk factor for major cardiac events.? ECG-gated techniques are the reference standard for calcium scoring.? Great interest is directed toward calcium scoring on non-gated chest CT examinations.? Reliable calcium scoring can be obtained with dual-source CT in a high-pitch mode.9.
Amanda Formosa Denise May Santos Daniel Marcuzzi Andrew A. Common Vikramaditya Prabhudesai 《Cardiovascular and interventional radiology》2016,39(4):606-610
Purpose
Catheter-directed computed tomography angiography (CCTA) has been shown to reduce the contrast volumes required in conventional CTA, thus minimizing the risk of contrast-induced nephropathy (CIN).Materials and Methods
A retrospective analysis was performed on cases where CCTA was used to assess access vessels prior to transfemoral aortic valve implantation (TAVI, n = 53), abdominal aortic aneurysm assessment for endovascular aneurysm repair (EVAR, n = 11), and peripheral vascular disease (PVD, n = 24).Results
We show that CCTA can image vasculature with adequate diagnostic detail to allow assessment of lower extremity disease, anatomic suitability for EVAR, as well as potential contraindications to TAVI. Average contrast volumes for pre-TAVI, pre-EVAR, and PVD cases were 7, 11, and 28 mL, respectively.Conclusion
This study validates the use of CCTA in obtaining diagnostic images of the abdominal and pelvic vessels and in imaging lower extremity vasculature.10.
Purpose
To investigate diagnostic accuracy of 3rd-generation dual-source CT (DSCT) coronary angiography in obese and non-obese patients.Methods
We retrospectively analyzed 76 patients who underwent coronary CT angiography (CCTA) and invasive coronary angiography. Prospectively ECG-triggered acquisition was performed with automated tube voltage selection (ATVS). Patients were dichotomized based on body mass index in groups A (<30 kg/m2, n?=?37) and B (≥30 kg/m2, n?=?39) and based on tube voltage in groups C (<120 kV, n?=?46) and D (120 kV, n?=?30). Coronary arteries were assessed for significant stenoses (≥50 % luminal narrowing) and diagnostic accuracy was calculated.Results
Per-patient overall sensitivity, specificity, positive predictive value, negative predictive value (NPV) and accuracy were 96.9 %, 95.5 %, 93.9 %, 97.7 % and 96.1 %, respectively. Sensitivity and NPV were lower in groups B and D compared to groups A and C, but no statistically significant differences were observed (group A vs. B: sensitivity, 100.0 % vs. 93.3 %, p?=?0.9493; NPV, 100 % vs. 95.5 %, p?=?0.9812; group C vs. D: sensitivity, 100.0 % vs. 92.3 %, p?=?0.8462; NPV, 100.0 % vs. 94.1 %, p?=?0.8285).Conclusion
CCTA using 3rd-generation DSCT and (ATVS) provides high diagnostic accuracy in both non-obese and obese patients.Key Points
? Coronary CTA provides high diagnostic accuracy in non-obese and obese patients. ? Diagnostic accuracy between obese and non-obese patients showed no significant difference.? <120 kV studies were performed in 44 % of obese patients. ? Current radiation dose-saving approaches can be applied independent of body habitus.11.
Objectives
Multi-detector-row computed tomography angiography (MDCTA) plays an important role in the assessment of patients with suspected coronary artery disease. However, MDCTA tends to overestimate stenosis in calcified coronary artery lesions. The aim of our study was to evaluate the diagnostic performance of calcification-suppressed material density (MD) images produced by using a single-detector single-source dual-energy computed tomography (ssDECT).Methods
We enrolled 67 patients with suspected or known coronary artery disease who underwent ssDECT with rapid kilovolt-switching (80 and 140 kVp). Coronary artery stenosis was evaluated on the basis of MD images and virtual monochromatic (VM) images. The diagnostic performance of the two methods for detecting coronary artery disease was compared with that of invasive coronary angiography as a reference standard.Results
We evaluated 239 calcified segments. In all the segments, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for detecting significant stenosis were respectively 88%, 88%, 75%, 95% and 88% for the MD images, 91%, 71%, 56%, 95% and 77% for the VM images. PPV was significantly higher on the MD images than on the VM images (P?<?0.0001).Conclusions
Calcification-suppressed MD images improved PPV and diagnostic performance for calcified coronary artery lesions.Key Points
? Computed tomography angiography tends to overestimate stenosis in calcified coronary artery. ? Dual-energy CT enables us to suppress calcification of coronary artery lesions. ? Calcification-suppressed material density imaging reduces false-positive diagnosis of calcified lesion.12.
Objectives
The purpose of this study was to assess the efficacy of the renewed dynamic collimator in a third-generation dual source CT (DSCT) scanner and to determine the improvements over the second-generation scanner.Methods
Collimator efficacy is defined as the percentage overranging dose in terms of dose–length product (DLP) that is blocked by the dynamic collimator relative to the total overranging dose in case of a static collimator. Efficacy was assessed at various pitch values and different scan lengths. The number of additional rotations due to overranging and effective scan length were calculated on the basis of reported scanning parameters. On the basis of these values, the efficacy of the collimator was calculated.Results
The second-generation scanner showed decreased performance of the dynamic collimator at increasing pitch. Efficacy dropped to 10% at the highest pitch. For the third-generation scanner the efficacy remained above 50% at higher pitch. Noise was for some pitch values slightly higher at the edge of the imaged volume, indicating a reduced scan range to reduce the overranging dose.Conclusions
The improved dynamic collimator in the third-generation scanner blocks the overranging dose for more than 50% and is more capable of shielding radiation dose, especially in high pitch scan modes.Key points
? Overranging dose is to a large extent blocked by the dynamic collimator ? Efficacy is strongly improved within the third-generation DSCT scanner ? Reducing the number of additional rotations can reduce overranging with increased noise13.
Stefan B. Puchner Maros Ferencik Pal Maurovich-Horvat Masataka Nakano Fumiyuki Otsuka Hans-Ulrich Kauczor Renu Virmani Udo Hoffmann Christopher L. Schlett 《European radiology》2015,25(1):15-23
Objectives
To evaluate whether iterative reconstruction algorithms improve the diagnostic accuracy of coronary CT angiography (CCTA) for detection of lipid-core plaque (LCP) compared to histology.Methods and materials
CCTA and histological data were acquired from three ex vivo hearts. CCTA images were reconstructed using filtered back projection (FBP), adaptive-statistical (ASIR) and model-based (MBIR) iterative algorithms. Vessel cross-sections were co-registered between FBP/ASIR/MBIR and histology. Plaque area <60 HU was semiautomatically quantified in CCTA. LCP was defined by histology as fibroatheroma with a large lipid/necrotic core. Area under the curve (AUC) was derived from logistic regression analysis as a measure of diagnostic accuracy.Results
Overall, 173 CCTA triplets (FBP/ASIR/MBIR) were co-registered with histology. LCP was present in 26 cross-sections. Average measured plaque area <60 HU was significantly larger in LCP compared to non-LCP cross-sections (mm2: 5.78?±?2.29 vs. 3.39?±?1.68 FBP; 5.92?±?1.87 vs. 3.43?±?1.62 ASIR; 6.40?±?1.55 vs. 3.49?±?1.50 MBIR; all p?<?0.0001). AUC for detecting LCP was 0.803/0.850/0.903 for FBP/ASIR/MBIR and was significantly higher for MBIR compared to FBP (p?=?0.01). MBIR increased sensitivity for detection of LCP by CCTA.Conclusion
Plaque area <60 HU in CCTA was associated with LCP in histology regardless of the reconstruction algorithm. However, MBIR demonstrated higher accuracy for detecting LCP, which may improve vulnerable plaque detection by CCTA.Key Points
? A low attenuation plaque area is associated with the presence of lipid-core plaque ? MBIR leads to higher diagnostic accuracy for detecting lipid-core plaque ? The benefit of MBIR is mainly due to increased sensitivity at high specificities ? Semiautomated CCTA assessment can detect vulnerable plaques non-invasively14.
Objectives
To evaluate the accuracy of reduced-dose CT scans reconstructed using a new generation of model-based iterative reconstruction (MBIR) in the imaging of urinary tract stone disease, compared with a standard-dose CT using 30% adaptive statistical iterative reconstruction.Methods
This single-institution prospective study recruited 125 patients presenting either with acute renal colic or for follow-up of known urinary tract stones. They underwent two immediately consecutive scans, one at standard dose settings and one at the lowest dose (highest noise index) the scanner would allow. The reduced-dose scans were reconstructed using both ASIR 30% and MBIR algorithms and reviewed independently by two radiologists. Objective and subjective image quality measures as well as diagnostic data were obtained.Results
The reduced-dose MBIR scan was 100% concordant with the reference standard for the assessment of ureteric stones. It was extremely accurate at identifying calculi of 3 mm and above. The algorithm allowed a dose reduction of 58% without any loss of scan quality.Conclusions
A reduced-dose CT scan using MBIR is accurate in acute imaging for renal colic symptoms and for urolithiasis follow-up and allows a significant reduction in dose.Key points
? MBIR allows reduced CT dose with similar diagnostic accuracy ? MBIR outperforms ASIR when used for the reconstruction of reduced-dose scans ? MBIR can be used to accurately assess stones 3 mm and above15.
Valeria Cantoni Roberta Green Wanda Acampa Mario Petretta Domenico Bonaduce Marco Salvatore Alberto Cuocolo 《Journal of nuclear cardiology》2016,23(2):185-197
Background
We conducted a meta-analysis to compare the long-term prognostic value of stress single-photon emission computed tomography myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CCTA) for adverse cardiovascular events in subjects with suspected or known coronary artery disease.Methods and Results
We searched PubMed, Cochrane, Web of Science, and Scopus database between January 2000 and December 2014 for stress MPI and CCTA studies that followed up ≥ 100 subjects for ≥ 2.5 years and provided the unadjusted and/or adjusted hazard ratio (HR) at Cox regression analysis. Summary risk estimates for abnormal perfusion at MPI or ≥ 50% coronary stenosis at CCTA were derived in random effect regression analysis, and causes of heterogeneity were determined in meta-regression analysis. We identified 21 eligible articles (10 MPI and 11 CCTA) including 25,258 participants (13,484 in MPI and 11,774 in CCTA studies) with suspected or known coronary artery disease. Among the included publications, 8 MPI and 8 CCTA studies reported the HR for the occurrence of hard events (death and nonfatal myocardial infarction). The pooled HR was comparable for MPI and CCTA studies. The HR for the occurrence of a combined endpoint including revascularization as event was reported in 4 MPI and 6 CCTA studies. The pooled HR was higher for CCTA compared to MPI (P < .05) also when only MPI and CCTA studies with limited representation of prior CAD were considered.Conclusions
The long-term prognostic value of MPI and CCTA for the occurrence of hard events is similar. However, the association between event-free survival and CCTA is higher than MPI when coronary revascularization is included in the endpoint.16.
Onur Taydas Emre Unal Ali Devrim Karaosmanoglu Mehmet Ruhi Onur Erhan Akpinar 《Japanese journal of radiology》2018,36(2):151-158
Purpose
To investigate whether computed tomography (CT)-based scoring systems obtained within 72 h of symptoms onset can predict disease course in acute pancreatitis.Methods
Between October 2007 and December 2015, 189 patients (age range 21–93 years) who underwent abdominopelvic CT for the diagnosis of acute pancreatitis were included in the study. Balthazar grade and original and modified versions of CT severity index (CTSI) measurements were carried out for each patient.Results
There were significant associations between each CT based scoring system and development of pancreatic and extrapancreatic complications (p < 0.001). A cutoff value of > 6 for CTSI and > 9 for the modified version of CTSI achieved a specificity of 98.7 and 99.2% for predicting pancreatic and extrapancreatic complications with areas under the curve (AUC) of 0.96 and 0.96, respectively. Balthazar grade of > C yielded a sensitivity of 98.4% for predicting pancreatic and extrapancreatic complications with an AUC of 0.95. The modified version of CTSI had the most significant association with pancreatic and extrapancreatic complications (HR: 3.22; p = 0.002, HR: 2.99, p = 0.003, respectively). Pancreatic necrosis was the only parameter significantly associated with mortality (HR: 5.83, p = 0.045).Conclusion
Early CT scan has an important role in prediction of complications and the management of acute pancreatitis.17.
Objectives
To determine if identifiable hepatic textural features are present at abdominal CT in patients with colorectal cancer (CRC) prior to the development of CT-detectable hepatic metastases.Methods
Four filtration–histogram texture features (standard deviation, skewness, entropy and kurtosis) were extracted from the liver parenchyma on portal venous phase CT images at staging and post-treatment surveillance. Surveillance scans corresponded to the last scan prior to the development of CT-detectable CRC liver metastases in 29 patients (median time interval, 6 months), and these were compared with interval-matched surveillance scans in 60 CRC patients who did not develop liver metastases. Predictive models of liver metastasis-free survival and overall survival were built using regularised Cox proportional hazards regression.Results
Texture features did not significantly differ between cases and controls. For Cox models using all features as predictors, all coefficients were shrunk to zero, suggesting no association between any CT texture features and outcomes. Prognostic indices derived from entropy features at surveillance CT incorrectly classified patients into risk groups for future liver metastases (p < 0.001).Conclusions
On surveillance CT scans immediately prior to the development of CRC liver metastases, we found no evidence suggesting that changes in identifiable hepatic texture features were predictive of their development.Key Points
? No correlation between liver texture features and metastasis-free survival was observed. ? Liver texture features incorrectly classified patients into risk groups for liver metastases. ? Standardised texture analysis workflows need to be developed to improve research reproducibility.18.
Objectives
To investigate the effect of iodine uptake on tissue/organ absorbed doses from CT exposure and its implications in CT dosimetry.Methods
The contrast-induced CT number increase of several radiosensitive tissues was retrospectively determined in 120 CT examinations involving both non-enhanced and contrast-enhanced CT imaging. CT images of a phantom containing aqueous solutions of varying iodine concentration were obtained. Plots of the CT number increase against iodine concentration were produced. The clinically occurring iodine tissue uptake was quantified by attributing recorded CT number increase to a certain concentration of aqueous iodine solution. Clinically occurring iodine uptake was represented in mathematical anthropomorphic phantoms. Standard 120 kV CT exposures were simulated using Monte Carlo methods and resulting organ doses were derived for non-enhanced and iodine contrast-enhanced CT imaging.Results
The mean iodine uptake range during contrast-enhanced CT imaging was found to be 0.02-0.46% w/w for the investigated tissues, while the maximum value recorded was 0.82% w/w. For the same CT exposure, iodinated tissues were found to receive higher radiation dose than non-iodinated tissues, with dose increase exceeding 100% for tissues with high iodine uptake.Conclusions
Administration of iodinated contrast medium considerably increases radiation dose to tissues from CT exposure.Key-points
? Radiation absorption ability of organs/tissues is considerably affected by iodine uptake ? Iodinated organ/tissues may absorb up to 100?% higher radiation dose ? Compared to non-enhanced, contrast-enhanced CT may deliver higher dose to patient tissues ? CT dosimetry of contrast-enhanced CT imaging should encounter tissue iodine uptake19.
Dong Wook Kim Hyoung Jung Kim Kyung Won Kim Jae Ho Byun So Yeon Kim Ki Byung Song Nikhil H. Ramaiya Sree Harsha Tirumani Seung-Mo Hong 《European radiology》2016,26(5):1320-1329
Objectives
To evaluate the prognostic value of CT to predict recurrence-free and overall survival in patients with pancreatic neuroendocrine neoplasms (PanNENs).Methods
Between January 2004 and December 2012, 161 consecutive patients who underwent preoperative triphasic CT and surgical resection with curative intent for PanNENs were identified. The tumour consistency, margin, presence of calcification, pancreatic duct dilatation, bile duct dilatation, vascular invasion, and hepatic metastases were evaluated. The tumour size, arterial enhancement ratio, and portal enhancement ratio were measured. The Cox proportional hazard model was used to determine the association between CT features and recurrence-free survival and overall survival.Results
By multivariate analysis, tumour size (>3 cm) (hazard ratio, 3.314; p?=?0.006), portal enhancement ratio (≤1.1) (hazard ratio, 2.718; p?=?0.006), and hepatic metastases (hazard ratio, 4.374; p?=?0.003) were independent significant variables for worse recurrence-free survival. Portal enhancement ratio (≤1.1) (hazard ratio, 5.951; p?=?0.001) and hepatic metastases (hazard ratio, 4.122; p?=?0.021) were independent significant variables for worse overall survival.Conclusions
Portal enhancement ratio (≤1.1) and hepatic metastases assessed on CT were common independent prognostic factors for worse recurrence-free survival and overall survival in patients with PanNENs.Key points
? CT is useful to predict survival outcomes in patients with PanNENs.? Survival outcomes are associated with portal enhancement ratio and hepatic metastases.? Portal enhancement ratio is prognostic CT biomarker in patients with PanNENs.20.