Ischemic heart disease and its sequelae are one of the major contributors to morbidity and mortality worldwide. Over the last decades, technological developments have strengthened the role of noninvasive imaging for detection, risk stratification, and management of patients with ischemic heart disease. Cardiac magnetic resonance (CMR) imaging incorporates both functional and morphological characterization of the heart to determine presence, acuteness, and severity of ischemic heart disease by evaluating myocardial wall motion and function, the presence and extent of myocardial edema, ischemia, and scarring. Currently established clinical protocols have already demonstrated their diagnostic and prognostic value. Nevertheless, there are emerging imaging technologies that provide additional information based on advanced quantification of imaging biomarkers and improved diagnostic accuracy, therefore potentially allowing reduction or avoidance of contrast and/or stressor agents. The aim of this review is to summarize the current state of the art of CMR imaging for ischemic heart disease and to provide insights into promising future developments.

PurposeThe aim of this study was to evaluate strategies to reduce contrast media volumes for coronary computed tomography (CT) angiography on a clinical first-generation dual-source photon-counting detector (PCD)-CT system using a dynamic circulation phantom.Materials and MethodsCoronary CT angiograph is an established method for the assessment of coronary artery disease that relies on the administration of iodinated contrast media. Reduction of contrast media volumes while maintaining diagnostic image quality is desirable. In this study, a dynamic phantom containing a 3-dimensional-printed model of the thoracic aorta and coronary arteries was evaluated using a clinical contrast injection protocol with stepwise reduced contrast agent concentrations (100%, 75%, 50%, 40%, 30%, and 20% contrast media content of the same 50 mL bolus, resulting in iodine delivery rates of 1.5, 1.1, 0.7, 0.6, 0.4 and 0.3 gl/s) on a first-generation, dual-source PCD-CT. Polychromatic images (T3D) and virtual monoenergetic images were reconstructed in the range of 40 to 70 keV in 5-keV steps. Attenuation and noise were measured in the coronary arteries and background material and the contrast-to-noise ratio (CNR) were calculated. Attenuation of 350 HU and a CNR of the reference protocol at 70 keV were regarded as sufficient for simulation of diagnostic purposes. Vessel sharpness and noise power spectra were analyzed for the aforementioned reconstructions.ResultsThe standard clinical contrast protocol (bolus with 100% contrast) yielded diagnostic coronary artery attenuation for all tested reconstructions (>398 HU). A 50% reduction in contrast media concentration demonstrated sufficient attenuation of the coronary arteries at 40 to 55 keV (>366 HU). Virtual monoenergetic image reconstructions of 40 to 45 and 40 keV allowed satisfactory attenuation of the coronary arteries for contrast concentrations of 40% and 30% of the original protocol. A reduction of contrast agent concentration to 20% of the initial concentration provided insufficient attenuation in the target vessels for all reconstructions. The highest CNR was found for virtual monoenergetic reconstructions at 40 keV for all contrast media injection protocols, yielding a sufficient CNR at a 50% reduction of contrast agent concentration.ConclusionsUsing virtual monoenergetic image reconstructions at 40 keV on a dual-source PCD-CT system, contrast media concentration could be reduced by 50% to obtain diagnostic attenuation and objective image quality for coronary CT angiography in a dynamic vessel phantom. These initial feasibility study results have to be validated in clinical studies.

Purpose: Photon-counting detector computed tomography (PCD-CT) has the potential to significantly improve CT imaging in many ways including, but not limited to, low-dose high-resolution CT (HRCT) of the lung. The aim of this study was to perform an intrapatient comparison of the radiation dose and image quality of PCD-CT compared with conventional energy-integrating detector CT (EID-CT). Methods: A total of 32 consecutive patients with available PCD-CT and EID-CT HRCT scans were included in the final analysis. The CT dose index (CTDIvol) was extracted from patient dose reports. Qualitative image analysis comprised the lung parenchyma and mediastinal structures and was assessed by 3 readers using a 5-point Likert scale. Quantitative image analysis included assessment of noise and signal-to-noise ratio in the lung parenchyma, trachea, aorta, muscle, and background. Results: The mean CTDIvol was 2.0 times higher in the conventional EID-CT scans (1.8±0.5 mGy) compared with PCD-CT (0.9±0.5 mGy, P<0.001). The overall image quality was rated significantly better by all 3 raters (P<0.001) in the PCD-CT relative to the EID-CT. Quantitative analysis showed no significant differences in noise and signal-to-noise ratio in the lung parenchyma between PCD-CT and EID-CT. Conclusion: Compared with conventional EID-CT scans, PCD-CT demonstrated similar or better objective and subjective image quality at significantly reduced dose levels in an intrapatient comparison. These results and their effect on clinical decision-making should be further investigated in prospective studies.

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Background Left‐to‐right (L‐R) shunts are characterized by a pathological connection between high‐ and low‐pressure systems, leading to a mixing of oxygen‐rich blood with low oxygenated blood. They are typically diagnosed by phase‐contrast cardiac magnetic resonance imaging (MRI) which requires extensive planning. T2 is sensitive to blood oxygenation and may be able to detect oxygenation differences between the left (LV) and right ventricles (RV) caused by L‐R shunts. Purpose To test the feasibility of routine T2 mapping to detect L‐R shunts. Study Type Retrospective. Population Patients with known L‐R shunts (N = 27), patients with RV disease without L‐R shunts (N = 21), and healthy volunteers (HV; N = 52). Field Strength/Sequence 1.5 and 3 T/balanced steady‐state free‐precession (bSSFP) sequence (cine imaging), T2‐prepared bSSFP sequence (T2 mapping), and velocity sensitized gradient echo sequence (phase‐contrast MRI). Assessment Aortic (Qs) and pulmonary (Qp) flow was measured by phase‐contrast imaging, and the Qp/Qs ratio was calculated as a measure of shunt severity. T2 maps were used to measure T2 in the RV and LV and the RV/LV T2 ratio was calculated. Cine imaging was used to calculate RV end‐diastolic volume index (RV‐EDVi). Statistical Tests Wilcoxon test, paired t‐tests, Spearmen correlation coefficient, receiver operating curve (ROC) analysis. Significance level P < 0.05. Results The Qp/Qs and T2 ratios in L‐R shunt patients (1.84 ± 0.84 and 0.89 ± 0.07) were significantly higher compared to those in patients with RV disease (1.01 ± 0.03 and 0.72 ± 0.10) and in HV (1.04 ± 0.04 and 0.71 ± 0.09). A T2 ratio of >0.78 showed a sensitivity, specificity, and negative predictive value of 100%, 73.9%, and 100%, respectively, for the detection of L‐R shunts. The T2 ratio was strongly correlated with the severity of the shunt (r = 0.83). Data Conclusion RV/LV T2 ratio is an imaging biomarker that may be able to detect or rule‐out L‐R shunts. Such a diagnostic tool may prevent unnecessary phase‐contrast acquisitions in cases with RV dilatation of unknown etiology. Level of Evidence 3 Technical Efficacy Stage 2

Background To evaluate the implementation process of structured reporting (SR) in a tertiary care institution over a period of 7 years. Methods We analysed the content of our image database from January 2016 to December 2022 and compared the numbers of structured reports and free-text reports. For the ten most common SR templates, usage proportions were calculated on a quarterly basis. Annual modality-specific SR usage was calculated for ultrasound, CT, and MRI. During the implementation process, we surveyed radiologists and clinical referring physicians concerning their views on reporting in radiology. Results As of December 2022, our reporting platform contained more than 22,000 structured reports. Use of the ten most common SR templates increased markedly since their implementation, leading to a mean SR usage of 77% in Q4 2022. The highest percentages of SR usage were shown for trauma CT, focussed assessment with ultrasound for trauma (FAST), and prostate MRI: 97%, 95%, and 92%, respectively, in 2022. Overall modality-specific SR usage was 17% for ultrasound, 13% for CT, and 6% for MRI in 2022. Both radiologists and referring physicians were more satisfied with structured reports and rated SR better than free-text reporting (FTR) on various attributes. Conclusions The increasing SR usage during the period under review and the positive attitude towards SR among both radiologists and clinical referrers show that SR can be successfully implemented. We therefore encourage others to take this step in order to benefit from the advantages of SR. Key points Structured reporting usage increased markedly since its implementation at our institution in 2016. Mean usage for the ten most popular structured reporting templates was 77% in 2022. Both radiologists and referring physicians preferred structured reports over free-text reports. Our data shows that structured reporting can be successfully implemented. We strongly encourage others to implement structured reporting at their institutions.

BackgroundFour‐dimensional (4D) flow MRI allows for the quantification of complex flow patterns; however, its clinical use is limited by its inherently long acquisition time. Compressed sensing (CS) is an acceleration technique that provides substantial reduction in acquisition time.PurposeTo compare intracardiac flow measurements between conventional and CS‐based highly accelerated 4D flow acquisitions.Study TypeProspective.SubjectsFifty healthy volunteers (28.0 ± 7.1 years, 24 males).Field Strength/SequenceWhole heart time‐resolved 3D gradient echo with three‐directional velocity encoding (4D flow) with conventional parallel imaging (factor 3) as well as CS (factor 7.7) acceleration at 3 T.Assessment4D flow MRI data were postprocessed by applying a valve tracking algorithm. Acquisition times, flow volumes (mL/cycle) and diastolic function parameters (ratio of early to late diastolic left ventricular peak velocities [E/A] and ratio of early mitral inflow velocity to mitral annular early diastolic velocity [E/e′]) were quantified by two readers.Statistical TestsPaired‐samples t‐test and Wilcoxon rank sum test to compare measurements. Pearson correlation coefficient (r), Bland–Altman‐analysis (BA) and intraclass correlation coefficient (ICC) to evaluate agreement between techniques and readers. A P value < 0.05 was considered statistically significant.ResultsA significant improvement in acquisition time was observed using CS vs. conventional accelerated acquisition (6.7 ± 1.3 vs. 12.0 ± 1.3 min). Net forward flow measurements for all valves showed good correlation (r > 0.81) and agreement (ICCs > 0.89) between conventional and CS acceleration, with 3.3%–8.3% underestimation by the CS technique. Evaluation of diastolic function showed 3.2%–17.6% error: E/A 2.2 [1.9–2.4] (conventional) vs. 2.3 [2.0–2.6] (CS), BA bias 0.08 [−0.81–0.96], ICC 0.82; and E/e′ 4.6 [3.9–5.4] (conventional) vs. 3.8 [3.4–4.3] (CS), BA bias −0.90 [−2.31–0.50], ICC 0.89.Data ConclusionAnalysis of intracardiac flow patterns and evaluation of diastolic function using a highly accelerated 4D flow sequence prototype is feasible, but it shows underestimation of flow measurements by approximately 10%.Evidence Level2Technical EfficacyStage 1

Aims The purpose of this retrospective single-centre study was to evaluate the non-invasive detection of endomyocardial biopsy (EMB)-established chronic myocardial inflammation in patients with heart failure with reduced ejection fraction (HFrEF) using T1 and T2 mapping. Methods and results The study population consisted of 52 retrospectively identified HFrEF patients who underwent EMB and cardiac magnetic resonance imaging at 3 Tesla. EMB was defined according to the position statement of the European Society of Cardiology and served as reference to identify inflammation in all patients. A control group of healthy volunteers with prior cardiac magnetic resonance imaging studies (n = 58) was also identified. Global and segmental T1 and T2 values as well as septal measurements and tissue heterogeneity parameters were calculated. Out of the 52 patients with HFrEF, 33 patients had myocardial inflammation detected by EMB, while 19 patients were EMB negative for inflammation. Mean left ventricular ejection fraction was 31% in both groups (P = 0.97). Global T1 and T2 values in HFrEF patients were significantly higher compared with healthy controls (T1 1275 ± 69 ms vs. 1,175 ± 44 ms, P < 0.001; T2 40.0 ± 3.4 ms vs. 37.9 ± 1.6 ms, P < 0.001). The distribution of T1 and T2 values between patients with and without EMB-proven chronic myocardial inflammation was not statistically different when regarding global (T1 1292 ± 71 ms vs.