A systematic approach for analysis, interpretation, and reporting of coronary CTA studies

Coronary computed tomography angiography to guide percutaneous coronary intervention: Expert opinion from a SCAI/SCCT roundtable

Coronary computed tomography angiography (CCTA) has emerged as an important tool for planning percutaneous coronary intervention (PCI). While it has traditionally been employed for diagnostic purposes, increasing evidence and real-world experience suggest that CCTA can be used for the pre-procedural planning of PCI and inform patient triage, shared decision-making, case complexity, and resource use. This approach mirrors how computed tomography angiography is routinely used to plan structural interventions. To address these emerging opportunities, the Society for Cardiovascular Angiography & Interventions (SCAI) and the Society of Cardiovascular Computed Tomography (SCCT) organized a multidisciplinary, expert scientific roundtable on the use of CCTA for guiding PCI. The goal of this document is to provide a state-of-the-art overview of CCTA-guided PCI, focused on practical applications and key coronary lesion subsets, define unmet needs and barriers, and outline future directions.

Assessment of bystander coronary artery disease in transcatheter aortic valve replacement (TAVR) patients using noncoronary-dedicated planning computed tomography angiography (CTA): diagnostic accuracy in a retrospective real-world cohort

AIM

To assess the diagnostic potential of a noncoronary-dedicated pre-TAVR CT angiography (CTA) conducted as a prospective ECG-gated scan without premedication and standard cardiac reconstructions in evaluating bystander coronary artery disease (CAD) against invasive coronary angiography (ICA) as the gold standard.

MATERIALS AND METHODS

This retrospective study included 232 patients who underwent both CTA and ICA as part of their pre-TAVR evaluation. Exclusion criteria included prior stent, pacemaker, coronary artery bypass, or valve surgery. Coronary arteries were analysed solely through thin-slice axial reconstructions, with observers blinded to ICA results. Stenosis was categorised as mild (< 50%), moderate (50%-69%), or severe (≥70%). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated for 50% and 70% diameter stenosis (DS) thresholds.

RESULTS

At the 50% DS threshold, CTA demonstrated 71% sensitivity, 74% specificity, 92% NPV, and 38% PPV. At the 70% DS threshold, results included 46% sensitivity, 91% specificity, 93% NPV, and 41% PPV. The highest vessel-specific NPV at 50% DS was for the left main (98%) and left anterior descending (LAD) (91%); at 70% DS, left main (LM) (98%) and left circumflex (LCX) (94%) showed the highest NPV. Image quality impacted NPV, with excellent or very good image quality linked to higher diagnostic performance.

CONCLUSION

Noncoronary-dedicated pre-TAVR CTA shows promise for ruling out significant CAD effectively and may act as a gatekeeper for ICA, aligning with typical coronary CT angiography (CCTA) outcomes.

Perivascular fat attenuation index value and plaque volume increased in non-target lesions of coronary arteries after stenting

BACKGROUND

Progression of non-target lesions (NTLs) after stenting has been reported and is associated with the triggering of an inflammatory response. The perivascular fat attenuation index (FAI) may be used as a novel imaging biomarker for the direct quantification of coronary inflammation.

OBJECTIVES

To investigate whether FAI values can help identify changes in inflammation status in patients undergoing stent implantation, especially in NTLs.

METHODS

Patients who underwent pre- and post-stenting coronary computed tomography angiography (CCTA) examination between January 2015 and February 2021 were consecutively enrolled. The pre- and post-stenting FAIs of the full coronary arteries were compared in both the non- and stent-implanted coronary arteries. Moreover, local FAI values were measured and compared between the NTLs and target lesions in the stent implantations. We also compared changes in plaque type and volume in NTLs before and after stenting.

RESULTS

A total of 89 patients (mean age 61 years; male 59) were enrolled. The perivascular FAI values in the full coronary arteries decreased after stenting in both the non- and stent-implanted coronary arteries, similar to those in the target lesions. Conversely, the perivascular FAI values in the NTLs increased after stenting (p < 0.05). In addition, the plaque volumes significantly increased in the NTLs after stenting, regardless of whether they were non-calcified, mixed, or calcified (p < 0.05).

CONCLUSION

Perivascular FAI values and plaque volumes increased in the NTLs after stenting. Perivascular FAI can be a promising imaging biomarker for monitoring coronary inflammation after stenting and facilitate long-term monitoring in clinical settings.

CLINICAL RELEVANCE STATEMENT

Perivascular fat attenuation index, a non-invasive imaging biomarker, may help identify coronary arteries with high inflammation in non-target lesions and facilitate long-term monitoring, potentially providing an opportunity for more targeted treatment.

KEY POINTS

• Perivascular fat attenuation index (FAI) values and plaque volumes increased in the non-target lesions (NTLs) after stenting, suggesting potential focal inflammation progression after stenting. However, stenting along with anti-inflammatory treatment ameliorated inflammation in the full coronary arteries. • Perivascular FAI, a non-invasive imaging biomarker, may help identify coronary arteries with high inflammation in NTLs and facilitate long-term monitoring, potentially providing an opportunity for more targeted treatment.

Communicating difficult news in pediatric radiology

Effective communication is an important aspect of providing quality healthcare. Radiology staff may be called upon to communicate results, even when it is difficult. Simple, efficient communication models can be learned to reduce clinician distress and support patients and families through stressful times. These practical tips ensure essential communication elements are met, including assessing patient and family perspectives, clearly delivering medical information, responding with empathy, and collaborating around next steps. Models such as "Ask-Tell-Ask," "SPIKES," and "NURSE" can be used to disclose results, communicate serious news, and respond to emotion. Lastly, clinicians can also utilize "I wish… I worry… I wonder" statements to align with a patient's hopes and acknowledge a family's concerns, ultimately allowing healthcare professionals to support and guide families through challenging situations.

Automated Identification of Coronary Arteries in Assisting Inexperienced Readers: Comparison between Two Commercial Vendors

Background: to assess the performance and speed of two commercially available advanced cardiac software packages in the automated identification of coronary vessels as an aiding tool for inexperienced readers. Methods: Hundred and sixty patients undergoing coronary CT angiography (CCTA) were prospectively enrolled from February until September 2021 and randomized in two groups, each one composed by 80 patients. Patients in group 1 were scanned on Revolution EVO CT Scanner (GE Healthcare), while patients in group 2 had the CCTA performed on Brilliance iCT (Philips Healthcare); each examination was evaluated on the respective vendor proprietary advanced cardiac software (software 1 and 2, respectively). Two inexperienced readers in cardiac imaging verified the software performance in the automated identification of the three major coronary vessels: (RCA, LCx, and LAD) and in the number of identified coronary segments. Time of analysis was also recorded. Results: software 1 correctly and automatically nominated 202/240 (84.2%) of the three main coronary vessels, while software 2 correctly identified 191/240 (79.6%) (p = 0.191). Software 1 achieved greater performances in recognizing the LCx (81.2% versus 67.5%; p = 0.048), while no differences have been reported in detecting the RCA (p = 0.679), and the LAD (p = 0.618). On a per-segment analysis, software 1 outperformed software 2, automatically detecting 942/1062 (88.7%) coronary segments, while software 2 detected 797/1078 (73.9%) (p < 0.001). Average reconstruction and detection time was of 13.8 s for software 1 and 21.9 s for software 2 (p < 0.001). Conclusions: automated cardiac software packages are a reliable and time-saving tool for inexperienced reader. Software 1 outperforms software 2 and might therefore better assist inexperienced CCTA readers in automated identification of the three main vessels and coronaries segments, with a consistent time saving of the reading session.

Cardiovascular Imaging and Intervention Through the Lens of Artificial Intelligence

Artificial Intelligence (AI) is the simulation of human intelligence in machines so they can perform various actions and execute decision-making. Machine learning (ML), a branch of AI, can analyse information from data and discover novel patterns. AI and ML are rapidly gaining prominence in healthcare as data become increasingly complex. These algorithms can enhance the role of cardiovascular imaging by automating many tasks or calculations, find new patterns or phenotypes in data and provide alternative diagnoses. In interventional cardiology, AI can assist in intraprocedural guidance, intravascular imaging and provide additional information to the operator. AI is slowly expanding its boundaries into interventional cardiology and can fundamentally alter the field. In this review, the authors discuss how AI can enhance the role of cardiovascular imaging and imaging in interventional cardiology.

Coronary Computer Tomography Angiography in 2021-Acquisition Protocols, Tips and Tricks and Heading beyond the Possible

Recent technological advances, together with an increasing body of evidence from randomized trials, have placed coronary computer tomography angiography (CCTA) in the center of the diagnostic workup of patients with coronary artery disease. The method was proven reliable in the diagnosis of relevant coronary artery stenosis. Furthermore, it can identify different stages of the atherosclerotic process, including early atherosclerotic changes of the coronary vessel wall, a quality not met by other non-invasive tests. In addition, newer computational software can measure the hemodynamic relevance (fractional flow reserve) of a certain stenosis. In addition, if required, information related to cardiac and valvular function can be provided with specific protocols. Importantly, recent trials have highlighted the prognostic relevance of CCTA in patients with coronary artery disease, which helped establishing CCTA as the first-line method for the diagnostic work-up of such patients in current guidelines. All this can be gathered in one relatively fast examination with minimal discomfort for the patient and, with newer machines, with very low radiation exposure. Herein, we provide an overview of the current technical aspects, indications, pitfalls, and new horizons with CCTA, providing examples from our own clinical practice.

Accuracy of High Resolution Multidetector Computed Tomography in the Local Staging of Rectal Cancer

Background Magnetic resonance imaging (MRI) is the gold standard for local staging of rectal cancer. Advanced computed tomography (CT) machines are now capable of high-resolution images of rectal cancer and utilized for CT perfusion. The possibility of local staging of rectal cancer by CT needs to be explored.

Purpose The aim of the study is to evaluate accuracy of high-resolution CT for local rectal cancer staging.

Methods A high-resolution CT was performed for local staging of rectal cancer in our study group of 93 patients, where 64 underwent primary surgery and 29 underwent surgery post neoadjuvant chemoradiotherapy (NACRT).

Results In differentiating stages T2-and-less than T2 from T3–T4 rectal cancer, accuracy, sensitivity, specificity, and kappa score in overall patients were 91%, 87%, 94%, and 0.8; in primary surgery group were 89%, 76%, 94%, and 0.7; in NACRT group were 97%, 100%, 94%, and 0.9; in low rectal group were 94%, 89%, 97%, and 0.82, respectively.

Conclusion High resolution CT is an accurate tool for local staging of rectal cancer.

Hinge point-based annular plane with abnormal aortic cusps in transcatheter aortic valve replacement

A virtual aortic annular plane that is built using the three hinge points, known as the hinge point-based annular plane (HPAP), is routinely used during transcatheter aortic valve replacement (TAVR). Abnormal aortic cusps (AAC) with unequal length and size influence the relationship of the HPAP to the aortic root axis significantly and pose challenges to valve deployment, leading to paravalvular leak and valve embolisation. Obtaining a centreline-based aortic annular plane in addition may help to understand valve deployment behaviour in AAC better.

Dual-source computed tomography coronary artery imaging in children

Computed tomography (CT) has a well-established diagnostic role in the assessment of coronary arteries in adults. However, its application in a pediatric setting is still limited and often impaired by several technical issues, such as high heart rates, poor patient cooperation, and radiation dose exposure. Nonetheless, CT is becoming crucial in the noninvasive approach of children affected by coronary abnormalities and congenital heart disease. In some circumstances, CT might be preferred to other noninvasive techniques such as echocardiography and MRI for its lack of acoustic window influence, shorter acquisition time, and high spatial resolution. The introduction of dual-source CT has expanded the role of CT in the evaluation of pediatric cardiovascular anatomy and pathology. Furthermore, technical advances in the optimization of low-dose protocols represent an attractive innovation. Dual-source CT can play a key role in several clinical settings in children, namely in the evaluation of children with suspected congenital coronary artery anomalies, both isolated and in association with congenital heart disease. Moreover, it can be used to assess acquired coronary artery abnormalities, as in children with Kawasaki disease and after surgical manipulation, especially in case of transposition of the great arteries treated with arterial switch operation and in case of coronary re-implantation.

Concordance between preoperative computed tomography angiographic mapping and intraoperative perforator selection for deep inferior epigastric artery perforator flap breast reconstructions

Background

Preoperative imaging for perforator identification prior to a deep inferior epigastric artery perforator (DIEP) flap elevation for breast reconstruction has many advantages. Currently, computed tomography (CT) angiography provides good visualization of the perforators and their course, and is thus the imaging technique of choice. The primary aim of this study was to determine the concordance between the perforators identified preoperatively and the perforators ultimately selected intraoperatively, with a standardized protocol, in a single institution. Secondly, we wanted to compare our results with those of other, similar studies and, thirdly, to identify those factors that may lead to a higher concordance.

Methods

A retrospective review was undertaken of a case series of 49 consecutive patients undergoing unilateral autologous breast reconstruction with a DIEP flap at the Gelre Hospital, in the Netherlands, over a 4-year period from 2013 to 2017. The preoperative identification and selection of perforator number and location with the aid of CT angiography scanning were compared to the intraoperative findings and preference.

Results

Our study revealed a concordance of 67.3% between one or more perforators advised preoperatively by the radiologist and chosen intraoperatively by the surgeon. We identified significant differences in our protocol compared to others.

Conclusions

The study confirmed the benefit to both the patient and the surgeon when preoperative CT angiography is used. Scanning protocols may vary considerably and should thus be carefully scrutinized before future comparisons are made. Based on this study, the scanning range, method of selecting perforators and timing of image acquisition may have to be optimized for future prospective clinical trials.

Cinematic rendering - an alternative to volume rendering for 3D computed tomography imaging

Abstract

Volume rendering (VR) represents today’s standard three-dimensional (3-D) image post-processing technique, and often is used to visualize complex anatomical information. Recently, a novel 3-D technique for post-processing of computed tomography (CT) image data has been introduced, which is called cinematic rendering (CR). The objective of this review is to illustrate the image appearance and potential value of CR in comparison with conventional VR in a number of various applications and different anatomical regions. Similar to VR, CR best visualizes high density and high contrast structures such as bones and contrast-enhanced vessels, but at the same time provides a more natural and photo-realistic illumination of the rendered data. Further research will be necessary for determining possible advantages of CR over conventional VR and over two-dimensional (2-D) image post-processing for CT image data.

Teaching Points

• Cinematic rendering is a novel post-processing technique for 3D visualization of CT image data.

• Compared to volume rendering, CR results in a more photo-realistic representation of anatomy.

• Similar to volume rendering, CR provides best image quality of high density structures.

Cardiac multidetector computed tomography in infective endocarditis: a pictorial essay

Objectives

The goals of this pictorial essay are: (1) to set out a multislice computed tomography (MSCT) imaging protocol to assess infective endocarditis (IE); (2) to give an MSCT overview of valvular and peri-valvular involvement during IE; (3) to give a CT overview of septic embolism and infectious pseudoaneurysms during IE.

Methods

MSCT acquisition protocols to assess IE are performed in two different phases: the first acquisition, under electrocardiography (ECG) gating, covers the cardiac structures during first-pass iodine injection; the second acquisition covers the thorax, abdomen, pelvic and cerebral regions.

Results

Valvular and peri-valvular lesions during IE are: vegetation—a hypodense, homogeneous, irregular mass on a valve or endocardial structure; perforation—a defect in the leaflet; valvular aneurysm—loss of the homogenous curvature of the leaflet; valvular thickening; peri-valvular abscess; pseudoaneurysm; fistula and disinsertion of a prosthetic valve. Extra-cardiac location could involve all organs.

Conclusions

MSCT can be considered as a useful complement in visualising the cardiac lesions of IE if echocardiography is inconclusive. MSCT is the only imaging modality that provides assessment of valvular and peri-valvular involvement, extra-cardiac lesions, and non-invasive evaluation of the coronary artery anatomy, simultaneously.

Main Messages

• MSCT provides assessment of coronary anatomy, cardiac and extra-cardiac lesions.

• MSCT represents an alternative to echocardiography during IE.

• Surgical valve replacement is usually required if vegetation is >10 mm.

• Peri-valvular extension (abscesses, pseudoaneurysm and fistulae) required surgical treatment.