Development of a computed tomography calcium scoring technique for assessing calcinosis distribution, pattern and burden in dermatomyositis.

OBJECTIVES: To utilize whole-body CT imaging and calcium scoring techniques as tools for calcinosis assessment in a prospective cohort of patients with adult and juvenile dermatomyositis (DM and JDM, respectively). METHODS: Thirty-one patients (14 DM and 17 JDM) who fulfilled Bohan and Peter Classification criteria as probable or definite DM, the EULAR-ACR criteria for definite DM, and with calcinosis identified by physical examination or prior imaging studies were included. Non-contrast whole-body CT scans were obtained using low-dose radiation procedures. Scans were read qualitatively and quantitated. We calculated the sensitivity and specificity of calcinosis detection of physician physical exam against CT. We quantified calcinosis burden using the Agatston scoring technique. RESULTS: We identified five distinct calcinosis patterns: Clustered, Disjoint, Interfascial, Confluent and Fluid-filled. Novel locations of calcinosis were observed, including the cardiac tissue, pelvic and shoulder bursa, and the spermatic cord. Quantitative measures using Agatston scoring for calcinosis were used in regional distributions across the body. Physician physical exams had a sensitivity of 59% and a specificity of 90% compared with CT detection. A higher calcium score correlated with higher Physician Global Damage, Calcinosis Severity scores, and disease duration. CONCLUSION: Whole-body CT scans and the Agatston scoring metric define distinct calcinosis patterns and provide novel insights relating to calcinosis in DM and JDM patients. Physicians' physical examinations underrepresented the presence of calcium. Calcium scoring of CT scans correlated with clinical measures, which suggests that this method may be used to assess calcinosis and follow its progression.

Heart rate sensitivity of virtual non-contrast calcium scores derived from photon counting detector CT data: a phantom study.

PURPOSE: To assess the reliability of virtual non-contrast (VNC) derived coronary artery calcium quantities in relation to heart rate and the VNC algorithm used compared to reference true non-contrast (TNC), considering several clinically established acquisition modes. MATERIAL AND METHODS: An ad hoc built coronary phantom containing four calcified lesions and an iodinated lumen was scanned using three cardiac acquisition modes three times within an anthropomorphic cardiac motion phantom simulating different heart rates (0, 60, 80, 100 bpm) and reconstructed with a conventional (VNCconv) and a calcium-sensitive (VNCpc) VNC algorithm. TNC reference was scanned at 0 bpm with non-iodinated lumen. Calcium scores were assessed in terms of number of lesions detected, Agatston and volume scores and global noise was measured. Paired t-test and Wilcoxon test were performed to test measurements for significant difference. RESULTS: For both VNC algorithms used, calcium levels or noise were not significantly affected by heart rate. Measurements on VNCpc reconstructions best reproduced TNC results, but with increased variability (Agatston scores at 0 bpm for TNC, VNCconv, and VNCpc were 47.1 ± 1.1, 6.7 ± 2.8 (p < 0.001), and 45.3 ± 7.6 (p > 0.05), respectively). VNC reconstructions showed lower noise levels compared to TNC, especially for VNCpc (noiseheart on TNC, VNCconv and VNCpc at 0 bpm was 5.0 ± 0.4, 4.5 ± 0.2, 4.2 ± 0.2). CONCLUSION: No significant heart rate dependence of VNC-based calcium scores was observed in an intra-reconstruction comparison. VNCpc reproduces TNC scores better than VNCconv without significant differences and decreased noise, however, with an increasing average deviation with rising heart rates. VNC-based CACS should be used with caution as the measures show higher variability compared to reference TNC and therefore hold the potential of incorrect risk categorization.

Incorporating coronary artery calcium scoring in the prediction of obstructive coronary artery disease with myocardial ischemia: a study with sequential use of coronary computed tomography angiography and positron emission tomography imaging.

BACKGROUND: Additional strategies are needed to refine the referral for diagnostic testing of symptomatic patients with suspected coronary artery disease (CAD). We aimed to compare various models to predict hemodynamically obstructive CAD. METHODS AND RESULTS: Symptomatic patients with suspected CAD who underwent coronary artery calcium scoring (CACS) and sequential coronary computed tomography angiography (CCTA) and [15O]H2O positron emission tomography (PET) myocardial perfusion imaging were analyzed. Obstructive CAD was defined as a suspected coronary artery stenosis on CCTA with myocardial ischemia on PET (absolute stress myocardial perfusion ≤ 2.4 mL/g/min in ≥ 1 segment). Three models were developed to predict obstructive CAD-induced myocardial ischemia using logistic regression analysis: (1) basic model: including age, sex and cardiac symptoms, (2) risk factor model: adding number of risk factors to the basic model, and (3) CACS model: adding CACS to the risk factor model. Model performance was evaluated using discriminatory ability with area under the receiver-operating characteristic curves (AUC). A total of 647 patients (mean age 62 ± 9 years, 45% men) underwent CACS and sequential CCTA and PET myocardial perfusion imaging. Obstructive CAD with myocardial ischemia on PET was present in 151 (23%) patients. CACS was independently associated with myocardial ischemia (P < .001). AUC for the discrimination of ischemia for the CACS model was superior over the basic model and risk factor model (P < .001). CONCLUSIONS: Adding CACS to the model including age, sex, cardiac symptoms and number of risk factors increases the accuracy to predict obstructive CAD with myocardial ischemia on PET in symptomatic patients with suspected CAD.

The incremental value of coronary artery calcium score in predicting long-term prognosis and defining the warranty period of normal adenosine stress-only myocardial perfusion imaging using CZT SPECT.

BACKGROUND: Normal stress-only (SO) myocardial perfusion imaging (MPI) using SPECT reduces imaging time and radiation dose with a good prognosis. However, the long-term prognostic value of combining coronary artery calcium score (CACS) with SO MPI to determine the warranty period remains unknown. Hence, we assessed the incremental prognostic value of CACS and its impact on the warranty period of normal SO MPI using SPECT. METHODS: We retrospectively included 1375 symptomatic patients without a history of coronary artery disease (CAD) and a normal SO MPI using adenosine who underwent simultaneous CAC scoring. Annual major adverse cardiac events (MACE) rates were calculated for CACS categories: 0, 1-399, 400-999, and ≥1000. RESULTS: The mean age was 60.0 ± 11.8 years (66.9% female) with a median follow-up of 10.3 [IQR 9.6-10.9] years. The warranty period for annual MACE rate for normal SO SPECT extended the total follow-up time in years. MACE rate categorized by CAC categories demonstrated an increase in MACE rates with increasing CACS; CACS 0 and CACS 1-399 were associated with a 10-year warranty period, CACS 400-999 had a warranty period of 4 years and no warranty period could be given for CACS≥1000 (5.9 % at 1 year). CONCLUSIONS: CACS as an adjunct to normal pharmacological SO MPI provides additional prognostic information and aids in determining a warranty period.

Risk Assessment and Coronary Artery Calcium Scoring in Transgender and Gender-Diverse Individuals Receiving Gender-Affirming Hormone Therapy.

OBJECTIVE: To evaluate cardiovascular risk factors and prevalent coronary artery disease (CAD) using Coronary Artery Calcium (CAC) scoring in transgender and gender-diverse (TGD) individuals receiving gender-affirming hormone therapy (GAHT) and compare the CAC scores of TGD individuals with those of the general population. METHODS: TGD individuals aged ≥30 years, without known risk factors for cardiovascular disease (CVD), other than tobacco use and family history of CVD, on GAHT were recruited, and baseline information, including metabolic parameters, was collected. CAC scores were obtained and compared with those of a cisgender age-matched population. RESULTS: Of 25 transwomen recruited, 24 underwent CAC scans. Of them, 2 (8.3%) had a CAC score of >0 to 99 and 1 (4.1%) had a CAC score of ≥100. Of 22 transmen recruited, 16 underwent CAC scans. Of them, 26 (12.5%) had a CAC score of >0 to 99 and none had a CAC score of ≥100. Framingham Risk Scores were not correlated with the presence of CAC. CONCLUSION: The presence of CAC in this small cohort of TGD individuals on GAHT was similar to that in the cisgender age-matched population. CAC scoring is a means to assess the prevalence of CAD in TGD individuals and identify those in whom aggressive risk reduction is indicated.

Atherosclerosis of the iliac arteries for the prediction of erectile dysfunction and epistaxis in men undergoing abdominal CT scan.

BACKGROUND: To investigate the association between erectile dysfunction (ED) as well as epistaxis (ES) in relation to the extent of iliac atherosclerosis. METHODS: In this retrospective cross-sectional study, all consecutive male patients treated at our institution from 01/2016 to 12/2020 undergoing abdominal CT scan were evaluated. Patients (n = 1272) were invited by mail to participate in the study in returning two questionnaires for the evaluation of ED (IIEF-5) and ES. Patients who returned filled-in questionnaires within a 3-month deadline were included in the study. The extent of atherosclerosis in the common iliac artery (CIA) and the internal iliac artery (IIA) was assessed by calcium scoring on unenhanced CT. Stratification of results was performed according to reported IIEF-5 scores and consequential ED groups. RESULTS: In total, 437 patients (34.4% of contacted) met the inclusion criteria. Forty-two patients did not fulfill predefined age requirements (< 75 years) and 120 patients had to be excluded as calcium scoring on nonenhanced CT was not feasible. Finally, 275 patients were included in the analysis and stratified into groups of "no-mild" (n = 146) and "moderate-severe" (n = 129) ED. The calcium score (r=-0.28, p < 0.001) and the number of atherosclerotic lesions (r=-0.32, p < 0.001) in the CIA + IIA showed a significant negative correlation to the IIEF-5 score, respectively. Patients differed significantly in CIA + IIA calcium score (difference: 167.4, p < 0.001) and number of atherosclerotic lesions (difference: 5.00, p < 0.001) when belonging to the "no-mild" vs. "moderate-severe" ED group, respectively. A multivariable regression model, after adjusting for relevant baseline characteristics, showed that the number of atherosclerotic CIA + IIA lesions was an independent predictor of ED (OR = 1.05, p = 0.036), whereas CIA + IIA calcium score was not (OR = 1.00031, p = 0.20). No relevant correlation was found between ES episodes and IIEF-5 scores (r=-0.069, p = 0.25), CIA + IIA calcium score (r=-0.10, p = 0.87) or number of atherosclerotic CIA + IIA lesions (r=-0.032, p = 0.60), respectively. CONCLUSIONS: The number of atherosclerotic lesions in the iliac arteries on nonenhanced abdominal CT scans is associated with the severity of ED. This may be used to identify subclinical cardiovascular disease and to quantify the risk for cardiovascular hazards in the future. TRIAL REGISTRATION: BASEC-Nr. 2020 - 01637.

Coronary artery calcium quantification: comparison between filtered-back projection, hybrid iterative reconstruction, and deep learning reconstruction techniques.

BACKGROUND: The reference protocol for the quantification of coronary artery calcium (CAC) should be updated to meet the standards of modern imaging techniques. PURPOSE: To assess the influence of filtered-back projection (FBP), hybrid iterative reconstruction (IR), and three levels of deep learning reconstruction (DLR) on CAC quantification on both in vitro and in vivo studies. MATERIAL AND METHODS: In vitro study was performed with a multipurpose anthropomorphic chest phantom and small pieces of bones. The real volume of each piece was measured using the water displacement method. In the in vivo study, 100 patients (84 men; mean age = 71.2 ± 8.7 years) underwent CAC scoring with a tube voltage of 120 kVp and image thickness of 3 mm. The image reconstruction was done with FBP, hybrid IR, and three levels of DLR including mild (DLRmild), standard (DLRstd), and strong (DLRstr). RESULTS: In the in vitro study, the calcium volume was equivalent (P = 0.949) among FBP, hybrid IR, DLRmild, DLRstd, and DLRstr. In the in vivo study, the image noise was significantly lower in images that used DLRstr-based reconstruction, when compared images other reconstructions (P < 0.001). There were no significant differences in the calcium volume (P = 0.987) and Agatston score (P = 0.991) among FBP, hybrid IR, DLRmild, DLRstd, and DLRstr. The highest overall agreement of Agatston scores was found in the DLR groups (98%) and hybrid IR (95%) when compared to standard FBP reconstruction. CONCLUSION: The DLRstr presented the lowest bias of agreement in the Agatston scores and is recommended for the accurate quantification of CAC.

[Morphological and functional diagnostics of coronary artery disease by computed tomography]. / Morphologische und funktionelle Diagnostik der koronaren Herzkrankheit mittels Computertomographie.

Computed tomography coronary angiography (cCTA) is a safe option for the noninvasive exclusion of significant coronary stenoses in patients with a low or moderate pretest probability for coronary artery disease (CAD). Furthermore, it also allows functional and morphological assessment of coronary stenoses. The European Society of Cardiology (ESC) guidelines on the diagnosis and management of chronic coronary syndrome published in 2019 have strengthened the importance of cCTA in this context and for this reason it has experienced a considerable upgrade. The determination of the Agatston score is a clinically established method for quantifying coronary calcification and influences the initiation of drug treatment. With technologies, such as the introduction of electrocardiography (ECG)-controlled dose modulation and iterative image reconstruction, cCTA can be performed with high image quality and low radiation exposure. Anatomic imaging of coronary stenoses alone is currently being augmented by innovative techniques, such as myocardial CT perfusion imaging or CT-fractional flow reserve (FFR) but the clinical value of these methods merits further investigation. The cCTA could therefore develop into a gatekeeper with respect to the indications for invasive coronary diagnostics and interventions.

Current and Future Applications of Artificial Intelligence in Cardiac CT.

PURPOSE OF REVIEW: In this review, we aim to summarize state-of-the-art artificial intelligence (AI) approaches applied to cardiovascular CT and their future implications. RECENT FINDINGS: Recent studies have shown that deep learning networks can be applied for rapid automated segmentation of coronary plaque from coronary CT angiography, with AI-enabled measurement of total plaque volume predicting future heart attack. AI has also been applied to automate assessment of coronary artery calcium on cardiac and ungated chest CT and to automate the measurement of epicardial fat. Additionally, AI-based prediction models integrating clinical and imaging parameters have been shown to improve prediction of cardiac events compared to traditional risk scores. Artificial intelligence applications have been applied in all aspects of cardiovascular CT - in image acquisition, reconstruction and denoising, segmentation and quantitative analysis, diagnosis and decision assistance and to integrate prognostic risk from clinical data and images. Further incorporation of artificial intelligence in cardiovascular imaging holds important promise to enhance cardiovascular CT as a precision medicine tool.

Prediction of cardiovascular events in patients with chronic myeloid leukaemia using baseline risk factors and coronary artery calcium scoring.

A standardised method for cardiovascular risk stratification in chronic myeloid leukaemia patients treated with tyrosine kinase inhibitors is lacking. We report an algorithm for risk stratification applicable to all patients commencing tyrosine kinase inhibitor therapy based on age, prior cardiovascular disease and Framingham Risk Score, incorporating coronary artery calcium scoring in patients at intermediate Framingham Risk Score risk. Of 88 patients retrospectively studied, major adverse cardiovascular event rates in our study-defined low-, intermediate- and high-risk categories were 0%, 10% and 19% respectively. Of nine patients down-classified from intermediate to low risk on the basis of coronary artery calcium scoring, none went on to experience a major adverse cardiovascular event.

Surgical management of misdeployed transcatheter aortic valve due to eccentric leaflet calcification.

A serious complication of transcatheter valves is the mechanistic failure of the deployment system and prosthesis migration. We report the case of a transcatheter aortic valve implantation which failed during implantation resulting in dislodgement of the prosthesis. Emergency surgery to retrieve the deployment system and surgically replace the native valve was the only option to salvage the patient.

Conventional Computed Tomographic Calcium Scoring vs full chest CTCS for lung cancer screening: a cost-effectiveness analysis.

BACKGROUND: Conventional CTCS images the mid/lower chest for coronary artery disease (CAD). Because many CAD patients are also at risk for lung malignancy, CTCS often discovers incidental pulmonary nodules (IPN). CTCS excludes the upper chest, where malignancy is common. Full-chest CTCS (FCT) may be a cost-effective screening tool for IPN. METHODS: A decision tree was created to compare a FCT to CTCS in a hypothetical patient cohort with suspected CAD. (Figure) The design compares the effects of missed cancers on CTCS with the cost of working up non-malignant nodules on FCT. The model was informed by results of the National Lung Screening Trial and literature review, including the rate of malignancy among patients receiving CTCS and the rate of malignancy in upper vs lower portions of the lung. The analysis outcomes are Quality-Adjusted Life Year (QALY) and incremental cost-effectiveness ratio (ICER), which is generally considered beneficial when <$50,000/QALY. RESULTS: Literature review suggests that rate of IPNs in the upper portion of the lung varied from 47 to 76%. Our model assumed that IPNs occur in upper and lower portions of the lung with equal frequency. The model also assumes an equal malignancy potential in upper lung IPNs despite data that malignancy occurs 61-66% in upper lung fields. In the base case analysis, a FCT will lead to an increase of 0.03 QALYs comparing to conventional CTCS (14.54 vs 14.51 QALY, respectively), which translates into an QALY increase of 16 days. The associated incremental cost for FCT is $278 ($1027 vs $748, FCT vs CTCS respectively. The incremental cost-effectiveness ratio (ICER) is $10,289/QALY, suggesting significant benefit. Sensitivity analysis shows this benefit increases proportional to the rate of malignancy in upper lung fields. CONCLUSION: Conventional CTCS may be a missed opportunity to screen for upper lung field cancers in high risk patients. The ICER of FCT is better than screening for breast cancer screening (mammograms $80 k/QALY) and colon cancer (colonoscopy $6 k/QALY). Prospective studies are appropriate to define protocols for FCT.

[Meaningful diagnostics: imaging]. / Sinnvolle Diagnostik: Bildgebung.

Imaging of subclinical atherosclerosis is an integrated component of a preventive medicine algorithm; i.e. on the basis of a cardiovascular risk stratification patients with a low and intermediate risk qualify for further imaging (cave: Bayes' theorem). Imaging procedures for subclinical atherosclerosis have one thing in common: atherosclerosis is detected and localized directly, for which cardiac multidetector computed tomography (MDCT; coronary calcium scoring, CACS) and vascular ultrasound (carotid and/or femoral arteries) are used to measure the plaque burden. The result is viewed as a risk modifier. The risk assessment is not related to symptoms. In addition to the detection and localization of atherosclerosis this also enables assessment of the "risk age" according to the tables of the European Society of Cardiology (ESC) and even the biological age, which can be estimated based on nomograms. This knowledge can be used to promote patient compliance and adherence to medication.

Machine Learning and Coronary Artery Calcium Scoring.

PURPOSE OF REVIEW: To summarize current artificial intelligence (AI)-based applications for coronary artery calcium scoring (CACS) and their potential clinical impact. RECENT FINDINGS: Recent evolution of AI-based technologies in medical imaging has accelerated progress in CACS performed in diverse types of CT examinations, providing promising results for future clinical application in this field. CACS plays a key role in risk stratification of coronary artery disease (CAD) and patient management. Recent emergence of AI algorithms, particularly deep learning (DL)-based applications, have provided considerable progress in CACS. Many investigations have focused on the clinical role of DL models in CACS and showed excellent agreement between those algorithms and manual scoring, not only in dedicated coronary calcium CT but also in coronary CT angiography (CCTA), low-dose chest CT, and standard chest CT. Therefore, the potential of AI-based CACS may become more influential in the future.

Standardized approach to result analysis and interpretation of initial experience of coronary computed tomography angiography in a tertiary care hospital.

OBJECTIVE: To have a systematic standardized approach to performing and interpretation of coronary CT Angiography (CTA) in order to maintain and enhance the diagnostic accuracy of the imaging modality. METHODS: This retrospective observational study was performed in Radiology Department, Lady Reading Hospital, Medical Teaching Institute, Peshawar, Pakistan from August 2018 to September 2019. Patients referred for coronary CT angiography were screened and prepared in radiology department. The examination was performed on Toshiba-160 slice CT Scanner (Prime Aquilion) utilizing standardized protocols tailored towards optimum image acquisition. Interpretation of the images were based on the guidelines provided by the Society of Cardiovascular Computed Tomography (SCCT). RESULTS: Total 95 CTCA procedures were performed in the department, out of which 85 were included in study showing 49(57%) as normal and 36(42%) were positive for coronary disease. Of the abnormal cases 16(18.8%) had mild disease, nine (10.6%) patients had moderate disease, while severe disease was noted in 11 (12.9%) cases. Coronary quantitative stenosis revealed five cases (5.9%) with LAD involvement only and five (5.9%) with severe triple vessel disease. The remaining varied in degree of stenosis and number of segments involved. Post CABG were 14 cases (16%) and native arteries showed triple vessel disease. CTA for percutaneous stent patency were three (3.5%) cases with 100% stent patency. CONCLUSION: Patient selection with tailored protocols are the mainstay for achieving optimal images. This form the basis for accurate interpretation, based on a standardized and systematic approach, utilizing various post processing tools, in order to maintain the high diagnostic accuracy of this semi-invasive, safe imaging modality in a variety of patients suspected of coronary artery disease, coronary artery bypass grafts and stent patency.

Coronary artery CT calcium score assessed by direct calcium quantification using atomic absorption spectroscopy and compared to macroscopic and histological assessments.

The Agatston score (AS) is the gold standard CT calcium scoring method in clinical practice. However, the AS is an indirect method of determining calcium amount, whereas atomic absorption spectroscopy (AAS) can directly measure the calcium amount. Our primary aim was to investigate the association between the AS and the coronary calcium amount measured by AAS. Furthermore, we compared our outcome to the macroscopic and histological coronary calcification and stenosis assessment, thus allowing us to infer a clinical coronary artery status based on post-mortem findings. Deceased individuals were examined with a 64-slice multidetector CT scanner, and the AS was determined. At autopsy, the degree of CAC and stenosis was determined, and the coronary arteries were excised and weighed. The coronary arteries were decalcified in a solution that was examined using AAS to measure the calcium amount. The degree of CAC and stenosis was also assessed by a histological examination. One hundred thirty-two coronary arteries were examined, and AS was highly correlated to the coronary calcium amount, measured by AAS, (r2 = 0.72, Pearson 0.85, p < 0.0001). In cases with AS 0, AAS measurements showed zero or very low calcium amounts. AS was also correlated to macroscopic and histological calcification assessments (Spearman's rho 0.68, p < 0.0001, Spearman's rho 0.82, p < 0.0001). Furthermore, an underestimation of subclinical atherosclerosis was seen and AS 0 could not rule out stenosis.

Coronary calcium score influences referral for invasive coronary angiography after normal myocardial perfusion SPECT.

BACKGROUND: In patients with normal SPECT but persistent complaints, invasive angiography may exclude obstructive coronary disease. We assessed whether high coronary artery calcium (CAC) scores are associated with increased referral for invasive angiography following normal SPECT. METHODS AND RESULTS: 2286 consecutive patients (mean age 60 ± 12, 39% male) with normal SPECT were assessed. All patients underwent simultaneous CAC scoring. Patients were categorized into four groups based on their CAC score: CAC = 0 (n = 694), CAC 1 to 100 (n = 891), CAC 101 to 400 (n = 368), and CAC >400 (n = 333). The decision to perform angiography was left to the discretion of treating physician. Follow-up angiography was confined to the first 60 days after SPECT. Occurrence of MACE (late revascularization, myocardial infarction or death) was recorded. Overall, 100 patients (4.4%) underwent early angiography with increasing rates in higher CAC score groups (1.0%, 2.6%, 8.4%, and 11.7%), respectively, P < .001). A CAC score >400 (OR 3.56, 95% CI 2.19 to 5.77, P < .001) was independently associated with referral to angiography. Similarly, CAC score >400 was an independent predictor for MACE (HR 9.26, 95% CI 5.06 to 16.93). Early angiography did not influence prognosis (HR 1.57, 95% CI 0.91 to 2.73). CONCLUSIONS: CAC scoring impacts clinical decision-making and increases referral rates for invasive angiography after normal SPECT.

Cardiac CT: why, when, and how : Update 2019.

PURPOSE: The aim of this study was to review established and emerging techniques of cardiac computed tomography (CT) and their clinical applications with a special emphasis on new techniques, recent trials, and guidelines. TECHNOLOGICAL INNOVATIONS: Cardiac CT has made great strides in recent years to become an ever more robust and safe imaging technique. The improvements in spatial and temporal resolution are equally important as the substantial reduction in radiation exposure, which has been achieved through prospective ECG-triggering, low tube voltage scanning, tube current modulation, and iterative reconstruction techniques. CT-derived fractional flow reserve and CT myocardial perfusion imaging are novel, investigational techniques to assess the hemodynamic significance of coronary stenosis. ESTABLISHED AND EMERGING INDICATIONS: In asymptomatic patients at risk for coronary artery disease, CT coronary artery calcium scoring is useful to assess cardiovascular risk and guide the intensity of risk factor modification. Coronary CT angiography is an excellent noninvasive test to rule out obstructive coronary artery disease in patients with stable chest pain. In acute chest pain with normal ECG and normal cardiac enzymes, cardiac CT can safely rule out acute coronary syndrome although its benefit and role in this indication remains controversial. Cardiac CT is the established standard for planning transcatheter aortic valve implantation and-increasingly-minimally invasive mitral valve procedures. PRACTICAL RECOMMENDATIONS: Our review makes practical recommendations on when and how to perform cardiac CT and provides templates for structured reporting of cardiac CT examinations.

Automatic determination of cardiovascular risk by CT attenuation correction maps in Rb-82 PET/CT.

BACKGROUND: We investigated fully automatic coronary artery calcium (CAC) scoring and cardiovascular disease (CVD) risk categorization from CT attenuation correction (CTAC) acquired at rest and stress during cardiac PET/CT and compared it with manual annotations in CTAC and with dedicated calcium scoring CT (CSCT). METHODS AND RESULTS: We included 133 consecutive patients undergoing myocardial perfusion 82Rb PET/CT with the acquisition of low-dose CTAC at rest and stress. Additionally, a dedicated CSCT was performed for all patients. Manual CAC annotations in CTAC and CSCT provided the reference standard. In CTAC, CAC was scored automatically using a previously developed machine learning algorithm. Patients were assigned to a CVD risk category based on their Agatston score (0, 1-10, 11-100, 101-400, >400). Agreement in CVD risk categorization between manual and automatic scoring in CTAC at rest and stress resulted in Cohen's linearly weighted κ of 0.85 and 0.89, respectively. The agreement between CSCT and CTAC at rest resulted in κ of 0.82 and 0.74, using manual and automatic scoring, respectively. For CTAC at stress, these were 0.79 and 0.70, respectively. CONCLUSION: Automatic CAC scoring from CTAC PET/CT may allow routine CVD risk assessment from the CTAC component of PET/CT without any additional radiation dose or scan time.

[Value of cardiac CT in the diagnostic work-up of coronary artery disease : Update 2017]. / Stellenwert der Herz-CT in der Diagnostik der koronaren Herzerkrankung : Update 2017.

The quantification of coronary calcifications using noncontrast-enhanced computed tomography (CT) as well as coronary CT angiography (cCTA) have rapidly evolved in the recent years. Nowadays, both techniques are increasingly clinically accepted regarding risk stratification and accurate exclusion of significant coronary artery disease (CAD). The higher acceptance of cCTA is mainly based on the higher robustness, lower radiation exposure through continuous technical innovations as well as by the growing scientific evidence. The poor predictive value of cCTA for predicting the hemodynamic significance of detected coronary artery stenosis may be improved by continuous technical developments in the area of functional imaging. The aim of this educational article is to summarize the current clinical status of calcium scoring and morphological cCTA and to provide an overview on novel functional CT techniques.