Faculty Bibliography

The incidence of congenital heart disease (CHD) has been increasing in the adult patient population in part as a result of better patient survival. Patients with more severe CHD are living longer. Nearly all adults with known CHD require periodic imaging as a means of monitoring their disease process. Furthermore, adult patients with suspected CHD require imaging as a means of definitive diagnosis. As a result, it is important for both the referring clinician and the imager to be aware of the most appropriate imaging modality needed to obtain the data most needed to direct the next steps in patient care. Imaging procedures for the diagnosis of known or suspected CHD in the adult include chest radiography, fluoroscopy, echocardiography, nuclear scintigraphy, cardiac-gated CT, MRI, and cardiac catheterization/angiography. The physician trying to diagnose these often complex conditions needs complete and reliable information that includes details about intracardiac and vascular anatomy, hemodynamics, and function. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

In patients with chronic chest pain in the setting of high probability of coronary artery disease (CAD), imaging has major and diverse roles. First, imaging is valuable in determining and documenting the presence, extent, and severity of myocardial ischemia, hibernation, scarring, and/or the presence, site, and severity of obstructive coronary lesions. Second, imaging findings are important in determining the course of management of patients with suspected chronic myocardial ischemia and better defining those patients best suited for medical therapy, angioplasty/stenting, or surgery. Third, imaging is also necessary to determine the long-term prognosis and likely benefit from various therapeutic options by evaluating ventricular function, diastolic relaxation, and end-systolic volume. Imaging studies are also required to demonstrate other abnormalities, such as congenital/acquired coronary anomalies and severe left ventricular hypertrophy, that can produce angina in the absence of symptomatic coronary obstructive disease due to atherosclerosis. Clinical risk assessment is necessary to determine the pretest probability of CAD. Multiple methods are available to categorize patients as low, medium, or high risk for developing CAD. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

PURPOSE/OBJECTIVE:The aim of this study was to determine if direct in-person communication between an acute care surgical team and radiologists alters surgical decision making. METHODS:Informed consent was waived for this institutional review board-exempt, HIPAA-compliant, prospective quality improvement study. From January 29, 2015 to December 10, 2015, semiweekly rounds lasting approximately 60 min were held between the on-call acute care surgery team (attending surgeon, chief resident, and residents) and one of three expert abdominal radiologists. A comprehensive imaging review was performed of recent and comparison examinations for cases selected by the surgeons in which medical and/or surgical decision making was pending. All reviewed examinations had available finalized reports known to the surgical team. RADPEER interradiologist concordance scores were assigned to all reviewed examinations. The impression and plan of the attending surgeon were recorded before and after each in-person review. RESULTS:One hundred patients were reviewed with 11 attending surgeons. The in-person meetings led to changes in surgeons' diagnostic impressions in 43% (43 of 100) and changes in medical and/or surgical planning in 43% (43 of 100; 20 acute changes, 23 nonacute changes, 19 changes in operative management) of cases. There were major discrepancies (RADPEER score ≥3) between the impression of the reviewing radiologist and the written report in 11% of cases (11 of 100). CONCLUSIONS:Targeted in-person collaboration between radiologists and acute care surgeons is associated with substantial and frequent changes in patient management, even when the original written report contains all necessary data. The primary mechanism seems to be promotion of a shared mental model that facilitates the exchange of complex information.

BACKGROUND:In type I diabetes (T1DM), alterations in LV function may occur due to changes in innervation, metabolism, and efficiency. OBJECTIVES:We evaluated the association between sympathetic nerve function, oxidative metabolism, resting blood flow, LV efficiency and function in healthy diabetics, and assessed gender differences. METHODS:Cross-sectional study of 45 subjects with T1DM, 60% females, age 34 ± 13 years, and 10 age-matched controls. Positron emission tomography (PET) imaging with [(11)C]acetate and [(11)C]meta-hydroxyephedrine was performed, in addition to cardiac magnetic resonance imaging. RESULTS:There were no significant differences in LV function, innervation, or oxidative metabolism between T1DM and controls. Cardiac oxidative metabolism was positively associated with higher levels of sympathetic activation, particularly in women. Diabetic women had significantly lower efficiency compared with diabetic men. Resting flow was significantly higher in diabetic women compared with diabetic men, and tended to be higher in female controls as well. CONCLUSIONS:Measures of myocardial function, metabolism, blood flow, and sympathetic activation were preserved in young, otherwise healthy, T1DM patients. However, T1DM women presented with greater myocardial oxidative metabolism requirements than men. Ongoing studies are evaluating changes over time.

Pre- and postoperative evaluation, serial follow-up studies, and screening examinations of the aorta are performed with noninvasive cross-sectional imaging modalities like CT and MR imaging. MR imaging allows for dedicated comprehensive evaluation without exposure to iodinated contrast or ionizing radiation. The additional advantage of MR imaging is that it can provide not only morphologic but also functional information. The purpose of this article is to advance knowledge and understanding of MR imaging techniques and their application to common aortic pathologies.

PURPOSE/OBJECTIVE:The purpose was to compare first-pass and delayed-phase thoracic computed tomography (CT) venography for the evaluation of suspected central thoracic venous pathology. MATERIAL AND METHODS/METHODS:CT images and medical records of all patients who underwent thoracic CT venography over a 5-year period were retrospectively reviewed. Both first-pass (18s) and delayed-phase (60s) venous images were obtained in all patients. The images were reviewed in random order by three readers using a semiquantitative visual grading scheme for image quality, including artifacts and the uniformity of venous enhancement. In addition, enhancement was quantitatively evaluated. The presence and type of venous pathology, and overall diagnostic confidence were recorded and compared. Reference verification was performed when available. RESULTS:Eighteen patients formed the study group, mean age 49.5years and 28% male. Dual-arm injection was successful in 72% of exams. All readers reported more streak artifacts on first-pass imaging than delayed imaging (72%-94% vs. 27%-44%, respectively; P<.05). First-pass imaging had significantly higher measured enhancement across all central venous segments than delayed imaging (mean HU range 212-906 HU vs. 173-414 HU; P<.05) but also had significantly more heterogeneous enhancement (mean S.D. range 75-1058 HU vs. 67-378 HU; P<.05). For overall diagnosis, reader agreement, accuracy, and confidence levels were higher for delayed-phase images (P<.05). CONCLUSION/CONCLUSIONS:Indirect thoracic CT venography using delayed-phase imaging alone may be sufficient for evaluating clinically suspected central venous abnormality.

Parametric response mapping (PRM) of inspiration and expiration computed tomography (CT) images improves the radiological phenotyping of chronic obstructive pulmonary disease (COPD). PRM classifies individual voxels of lung parenchyma as normal, emphysematous, or nonemphysematous air trapping. In this study, bias and noise characteristics of the PRM methodology to CT and clinical procedures were evaluated to determine best practices for this quantitative technique. Twenty patients of varying COPD status with paired volumetric inspiration and expiration CT scans of the lungs were identified from the baseline COPD-Gene cohort. The impact of CT scanner manufacturer and reconstruction kernels were evaluated as potential sources of variability in PRM measurements along with simulations to quantify the impact of inspiration/expiration lung volume levels, misregistration, and image spacing on PRM measurements. Negligible variation in PRM metrics was observed when CT scanner type and reconstruction were consistent and inspiration/expiration lung volume levels were near target volumes. CT scanner Hounsfield unit drift occurred but remained difficult to ameliorate. Increasing levels of image misregistration and CT slice spacing were found to have a minor effect on PRM measurements. PRM-derived values were found to be most sensitive to lung volume levels and mismatched reconstruction kernels. As with other quantitative imaging techniques, reliable PRM measurements are attainable when consistent clinical and CT protocols are implemented.