Reference ranges ("normal values") for cardiovascular magnetic resonance (CMR) in adults and children: 2020 update.

Cardiovascular magnetic resonance (CMR) enables assessment and quantification of morphological and functional parameters of the heart, including chamber size and function, diameters of the aorta and pulmonary arteries, flow and myocardial relaxation times. Knowledge of reference ranges ("normal values") for quantitative CMR is crucial to interpretation of results and to distinguish normal from disease. Compared to the previous version of this review published in 2015, we present updated and expanded reference values for morphological and functional CMR parameters of the cardiovascular system based on the peer-reviewed literature and current CMR techniques. Further, databases and references for deep learning methods are included.

A Practice Quality Improvement Project: Reducing Dose of Routine Chest CT Imaging in a Busy Clinical Practice.

The purpose of this report is to describe our experience with the implementation of a practice quality improvement (PQI) project in thoracic imaging as part of the American Board of Radiology Maintenance of Certification process. The goal of this PQI project was to reduce the effective radiation dose of routine chest CT imaging in a busy clinical practice by employing the iDose(4) (Philips Healthcare) iterative reconstruction technique. The dose reduction strategy was implemented in a stepwise process on a single 64-slice CT scanner with a volume of 1141 chest CT scans during the year. In the first annual quarter, a baseline effective dose was established using the standard filtered back projection (FBP) algorithm protocol and standard parameters such as kVp and mAs. The iDose(4) technique was then applied in the second and third annual quarters while keeping all other parameters unchanged. In the fourth quarter, a reduction in kVp was also implemented. Throughout the process, the images were continually evaluated to assure that the image quality was comparable to the standard protocol from multiple other scanners. Utilizing a stepwise approach, the effective radiation dose was reduced by 23.62 and 43.63 % in quarters two and four, respectively, compared to our initial standard protocol with no perceived difference in diagnostic quality. This practice quality improvement project demonstrated a significant reduction in the effective radiation dose of thoracic CT scans in a busy clinical practice.

Two-in-one aortic valve sizing and valvuloplasty conductance balloon catheter.

BACKGROUND: Inaccurate aortic valve sizing and selection is linked to paravalvular leakage in transcatheter aortic valve replacement (TAVR). Here, a novel sizing valvuloplasty conductance balloon (SVCB) catheter is shown to be accurate, reproducible, unbiased, and provides real-time tool for aortic valve sizing that fits within the standard valvuloplasty procedure. METHODS AND RESULTS: The SVCB catheter is a valvuloplasty device that uses real-time electrical conductance measurements based on Ohm's Law to size the balloon opposed against the aortic valve at any given inflation pressure. Accuracy and repeatability of the SVCB catheter was performed on the bench in phantoms of known dimension and ex vivo in three domestic swine aortic annuli with comparison to computed tomography (CT) and dilator measurements. Procedural workflow and safety was demonstrated in vivo in three additional domestic swine. SVCB catheter measurements had negligible bias or error for bench accuracy considered as the gold standard (Bias: -0.11 ± 0.26 mm; Error: 1.2%), but greater disagreement in ex vivo versus dilators (Bias: -0.3 ± 1.1 mm; Error: 4.5%), and ex vivo versus CT (Bias: -1.0 ± 1.6 mm; Error: 8.7%). The dilator versus CT accuracy showed similar agreement (Bias: -0.9 ± 1.5 mm; Error: 7.3%). Repeatability was excellent on the bench (Bias: 0.02 ± 0.12 mm; Error: 0.5%) and ex vivo (Bias: -0.4 ± 0.9 mm; Error: 4.6%). In animal studies, the device fit well within the procedural workflow with no adverse events or complications. CONCLUSIONS: Due to the clinical relevance of this accurate, repeatable, unbiased, and real-time sizing measurement, the SVCB catheter may provide a useful tool prior to TAVR. These findings merit a future human study.

Deep Learning-based Fibrosis Extent on Computed Tomography Predicts Outcome of Fibrosing Interstitial Lung Disease Independent of Visually Assessed Computed Tomography Pattern.

Rationale: Radiologic pattern has been shown to predict survival in patients with fibrosing interstitial lung disease. The additional prognostic value of fibrosis extent by quantitative computed tomography (CT) is unknown. Objectives: We hypothesized that fibrosis extent provides information beyond visually assessed CT pattern that is useful for outcome prediction. Methods: We performed a retrospective analysis of chest CT, demographics, longitudinal pulmonary function, and transplantation-free survival among participants in the Pulmonary Fibrosis Foundation Patient Registry. CT pattern was classified visually according to the 2018 usual interstitial pneumonia criteria. Extent of fibrosis was objectively quantified using data-driven textural analysis. We used Kaplan-Meier plots and Cox proportional hazards and linear mixed-effects models to evaluate the relationships between CT-derived metrics and outcomes. Results: Visual assessment and quantitative analysis were performed on 979 enrollment CT scans. Linear mixed-effect modeling showed that greater baseline fibrosis extent was significantly associated with the annual rate of decline in forced vital capacity. In multivariable models that included CT pattern and fibrosis extent, quantitative fibrosis extent was strongly associated with transplantation-free survival independent of CT pattern (hazard ratio, 1.04; 95% confidence interval, 1.04-1.05; P < 0.001; C statistic = 0.73). Conclusions: The extent of lung fibrosis by quantitative CT is a strong predictor of physiologic progression and survival, independent of visually assessed CT pattern.

CT-based diagnosis of diffuse coronary artery disease on the basis of scaling power laws.

PURPOSE: To provide proof of concept for a diagnostic method to assess diffuse coronary artery disease (CAD) on the basis of coronary computed tomography (CT) angiography. MATERIALS AND METHODS: The study was approved by the Cleveland Clinic Institutional Review Board, and all subjects gave informed consent. Morphometric data from the epicardial coronary artery tree, determined with CT angiography in 120 subjects (89 patients with metabolic syndrome and 31 age- and sex-matched control subjects) were analyzed on the basis of the scaling power law. Results obtained in patients with metabolic syndrome and control subjects were compared statistically. RESULTS: The mean lumen cross-sectional area (ie, lumen cross-sectional area averaged over each vessel of an epicardial coronary artery tree) and sum of intravascular volume in patients with metabolic syndrome (0.039 cm(2) ± 0.015 [standard deviation] and 2.71 cm(3) ± 1.75, respectively) were significantly less than those in control subjects (0.054 cm(2)± 0.015 and 3.29 cm(3)± 1.77, respectively; P < .05). The length-volume power law showed coefficients of 27.0 cm(-4/3) ± 9.0 (R(2) = 0.91 ± 0.08) for patients with metabolic syndrome and 19.9 cm(-4/3) ± 4.3 (R(2) = 0.92 ± 0.07) for control subjects (P < .05). The probability frequency shows that more than 65% of patients with metabolic syndrome had a coefficient of 23 or more for the length-volume scaling power law, whereas approximately 90% of the control subjects had a coefficient of less than 23. CONCLUSION: The retrospective scaling analysis provides a quantitative rationale for diagnosis of diffuse CAD.

Imaging of the coronary sinus: normal anatomy and congenital abnormalities.

Knowledge of the anatomy of the coronary sinus (CS) and cardiac venous drainage is important because of its relevance in electrophysiologic procedures and cardiac surgeries. Several procedures make use of the CS, such as left ventricular pacing, mapping and ablation of arrhythmias, retrograde cardioplegia, targeted drug delivery, and stem cell therapy. As a result, it is more important for physicians interpreting the results of computed tomographic (CT) examinations dedicated to the heart or including the heart to be able to identify normal variants and congenital anomalies and to understand their clinical importance. Abnormalities of the CS range from anatomic morphologic variations to hemodynamically significant anomalies such as an unroofed CS, anomalous pulmonary venous connection to the CS, and coronary artery-CS fistula. It can be important to identify some anatomic variations, even though they are clinically occult, to ensure appropriate preprocedural planning. Both CT and magnetic resonance imaging provide excellent noninvasive depiction of the anatomy and anomalies of the CS. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.324105220/-/DC1.

Lung nodule computer-aided detection as a second reader: influence on radiology residents.

OBJECTIVE: The purpose of this study was to evaluate the use of a computed tomographic lung nodule computer-aided detection (CAD) software as a second reader for radiology residents. METHODS: The study involved 110 cases from 4 sites. Three expert radiologists identified nodules that were 4 to 30 mm in maximum diameter to form the ground truth. These cases were then interpreted by 6 board-certified radiologists and 6 radiology residents. The residents read each case without and then with a CAD software (Lung Nodule Assesment, Extended Brilliance Workspace; Philips Healthcare, Highlands Heights, OH) to identify nodules that were 4 to 30 mm in maximum diameter. RESULTS: The experts identified 91 nodules as the ground truth for the study. The mean sensitivity of the 6 board-certified radiologists was 89%. The mean sensitivity of the residents was 85% without the CAD and 90% (P < 0.05) with the CAD as a second reader. CONCLUSIONS: The CAD software can help improve the sensitivity of residents in the detection of pulmonary nodules on computed tomography, making them comparable with board-certified radiologists.

Reconstruction of myocardial tissue motion and strain fields from displacement-encoded MR imaging.

A quantitative analysis of myocardial mechanics is fundamental to understanding cardiac function, diagnosis of heart disease, and assessment of therapeutic intervention. Displacement encoding with stimulated-echo (DENSE) magnetic resonance imaging (MRI) technique was developed to track the three-dimensional (3D) displacement vector of discrete material grid points in the myocardial tissue. Despite the wealth of information gained from DENSE images, the current software only provides two-dimensional in-plane deformation. The objective of this study is to introduce a postprocessing method to reconstruct and visualize continuous dynamic 3D displacement and strain fields in the ventricular wall from DENSE data. An anatomically accurate hexagonal finite-element model of the left ventricle (LV) is reconstructed by fitting a prolate spheroidal primitive to contour points of the epi- and endocardial surfaces. The continuous displacement field in the model is described mathematically based on the discrete DENSE vectors using a minimization method with smoothness regularization. Based on the displacement, heart motion and myocardial stretch (or strain) are analyzed. Illustratory computations were conducted with DENSE data of three infarcted and one normal sheep ventricles. The full 3D results show stronger overall axial shortening, wall thickening, and twisting of the normal LV compared with the infarcted hearts. Local myocardial stretches show a dyskinetic LV in the apical region, dilation of apex in systole, and a compensatory increase in strain in the healthy basal region as a compensatory mechanism. We conclude that the proposed postprocessing method significantly extends the utility of DENSE MRI, which may provide a patient-specific 3D model of cardiac mechanics.

64-slice multidetector computed tomography (MDCT) for detection of aortic regurgitation and quantification of severity.

BACKGROUND: Recent advances in 64-slice multidetector computed tomography (MDCT) provide an opportunity to assess coronary artery disease, left ventricular function and, potentially, valvular heart disease. OBJECTIVE: To determine the ability of 64-MDCT to both detect and to quantify the severity of aortic regurgitation (AR), as compared with transthoracic echocardiography (TTE). METHODS: We evaluated a total of 64 patients (43 males, mean age 63+/-11 years), 30 with varying severities of AR as assessed by TTE and 34 matched controls. The severity of AR by TTE was determined using the vena contracta, the ratio of jet to left ventricular outflow tract (LVOT) height, and the ratio of the jet to LVOT cross-sectional area. AR by MDCT was defined as a lack of coaptation of the aortic valve leaflets in diastole and, if detected, the maximum anatomic aortic regurgitant orifice was determined. RESULTS: All 34 control patients without AR were correctly identified by MDCT. There were 14 patients with mild AR, 10 with moderate AR, and 6 with severe AR by TTE. Of these patients, MDCT correctly identified 21 patients with AR (sensitivity 70%, specificity 100%, positive predictive value [PPV] 100%, and negative predictive value [NPV] 79%). Anatomic regurgitant orifice area measured by MDCT correlated well with the TTE-derived vena contracta (r=0.79, P<0.001), ratio of jet to LVOT height (r=0.79, P<0.001), and ratio of jet to LVOT cross-sectional area (r=0.75, P<0.001). CONCLUSIONS: Direct planimetric measurement of the aortic valve anatomic regurgitant orifice area on 64-MDCT provides an accurate, noninvasive technique for detecting and quantifying AR.

Prevalence of left atrial abnormalities in atrial fibrillation versus normal sinus patients.

BACKGROUND: Atrial fibrillation (AF) may be the cause or sequela of left atrial abnormalities and variants. PURPOSE: To determine the prevalence of left atrial (LA) abnormalities in AF patients compared to normal sinus rhythm (NSR) patients. MATERIAL AND METHODS: We retrospectively reviewed 281 cardiac CT examinations from 2010 to 2012, excluding patients with prior pulmonary vein ablation, known coronary artery disease, prior coronary stent placement, or coronary artery bypass grafts. The first group consisted of 159 AF patients undergoing cardiac CT prior to pulmonary vein ablation and the second group consisted of 122 NSR patients evaluated with coronary CT angiography. Demographic data were collected. LA abnormalities were analyzed. Left atrial diameter was measured on an axial view. RESULTS: A total of 281 patients were included. The male gender has significantly higher prevalence of AF than female gender, P value <0.001. Patients with AF were significantly older (mean age, 57.4 years; standard deviation [SD], 11.8 years) than NSR patients (mean age, 53.4 years; SD, 13.6 years), P value, 0.01. The left atrial diameter was greater in the AF patients (mean diameter, 4.3 cm; SD, 0.82 cm) versus the NSR patients (3.4 cm; SD, 0.58 cm), P value, <0.0001. LA diverticulum was the most prevalent variant, occurring in 28.4% of the entire patient population followed by LA pouch, occurring in 24%. There was no significant between group differences in the prevalence of these or the remainder of the LA variants. CONCLUSION: AF patients differed significantly from NSR patients in LA size, gender, and mean age. There was no statistical significance between the two groups with regard to the LA morphologic abnormalities other than size.

Radiology of community-acquired pneumonia.

This article reviews the radiographic appearance of common community-acquired pneumonia. Included are the common bacterial pneumonias, tuberculosis, fungal pneumonia, pneumocystis pneumonia, and viral pneumonias. The various radiographic appearances and the clues for differentiating the pneumonias are discussed. Images enhance the discussion.

Revised curriculum on cardiothoracic radiology for diagnostic radiology residency with goals and objectives related to general competencies.

This document is a revision of a previously published cardiothoracic curriculum for diagnostic radiology residency, and reflects interval changes in the clinical practice of cardiothoracic radiology and changes in the Accreditation Council for Graduate Medical Education (ACGME) requirements for diagnostic radiology training programs. The revised ACGME Program Requirements for Residency Education in Diagnostic Radiology went into effect December 2003.

Metastatic meningioma to the lungs.

Meningioma with extracranial metastases is a rare occurrence. However, the lungs are the most common site of extracranial metastases. We describe a case of a patient with recurrent intracranial meningioma and intrapulmonary metastases.

MR imaging evaluation of pericardial constriction.

Abnormal thickening or rigidity of the pericardium may compromise normal cardiac function. This condition is known as pericardial constriction, or constrictive pericarditis. Several imaging modalities are used to evaluate the pericardium, including MR, computed tomography, and echocardiography, which can all play a complementary role aiding diagnosis. This article focuses on MR imaging and its role in the detection and evaluation of pericardial constriction. MR imaging has many advantages compared with other modalities including precise delineation of the pericardial thickness, evaluation of ventricular function, detection of wall motion abnormalities, and provision of information about common (and potentially harmful) sequelae of pericardial constriction.

Compensatory Enlargement of Ossabaw Miniature Swine Coronary Arteries in Diffuse Atherosclerosis.

Studies in human and non-human primates have confirmed the compensatory enlargement or positive remodeling (Glagov phenomenon) of coronary vessels in the presence of focal stenosis. To our knowledge, this is the first study to document arterial enlargement in a metabolic syndrome animal model with diffuse coronary artery disease (DCAD) in the absence of severe focal stenosis. Two different groups of Ossabaw miniature pigs were fed a high fat atherogenic diet for 4 months (Group I) and 12 months (Group II), respectively. Group I (6 pigs) underwent contrast enhanced computed tomographic angiography (CCTA) and intravascular ultrasound (IVUS) at baseline and after 4 months of high fat diet, whereas Group II (7 pigs) underwent only IVUS at 12 months of high fat diet. IVUS measurements of the left anterior descending (LAD), left circumflex (LCX) and right coronary (RCA) arteries in Group I showed an average increase in their lumen cross-sectional areas (CSA) of 25.8%, 11.4%, and 43.4%, respectively, as compared to baseline. The lumen CSA values of LAD in Group II were found to be between the baseline and 4 months values in Group I. IVUS and CCTA measurements showed a similar trend and positive correlation. Fractional flow reserve (FFR) was 0.91±0.07 at baseline and 0.93±0.05 at 4 months with only 2.2%, 1.6% and 1% stenosis in the LAD, LCX and RCA, respectively. The relation between percent stenosis and lumen CSA shows a classical Glagov phenomenon in this animal model of DCAD.

Fundamentals of multichannel CT.

Multichannel CT has become a very valuable tool in diagnostic imaging. It provides a combination of fast and long coverage in conjunction with thin slices. The fast scanning allows for single-breathhold scanning, fewer motion artifacts, and better use of intravenous contrast media. The brains of the MCCT scanners are the sophisticated detector arrays packed with electronics to handle the flow of image information. The submillimeter detectors rows offer isotropic properties to the image voxels, thereby creating viewing in any plane and better three-dimensional renderings.