Eric J. Keller

Physicians’ professional identities: a roadmap to understanding “value” in cardiovascular imaging

BackgroundQuality improvement efforts in cardiovascular imaging have been challenged by limited adoption of initiatives and policies. In order to better understand this limitation and inform future efforts, the range clinical values related to cardiovascular imaging at a large academic hospital was characterized.Materials and methods15 Northwestern Medicine physicians from internal medicine, cardiology, emergency medicine, cardiac/vascular surgery, and radiology were interviewed about their use of cardiovascular imaging and imaging guidelines. Interview transcripts were systemically analyzed according to constructivist grounded theory and combined with 56 previous interviews with interventional radiologists, interventional cardiologists, gynecologists, and vascular surgeons to develop a model describing specialty-specific values. This model was applied to the 15 pilot interviews focused on cardiovascular imaging, highlighting specialty specific differences in values and practice patterns. Transcripts were also reviewed independently by a cardiologist and 2 radiologists followed by a group discussion to assess reproducibility and achieve a consensus regarding the results.ResultsDifferences in perceived value of cardiovascular imaging and use of guidelines among physicians were well explained by three value-associated identity categories (managers, diagnosticians, and fixers) that were further differentiated along three axes (broad v. focused-thinkers, complex v. definitive-answer-seekers, and public visibility).ConclusionsQuality improvement in cardiovascular imaging may be limited by a lack of understanding and incorporation of the complexity of medical culture into ongoing initiatives. Both individually and during policy development, it is important to first understand the complexity of stakeholders’ diverse perceptions of “value,” “quality,” and “appropriateness.”

Philosophy in Medical Education: A Means of Protecting Mental Health

ObjectiveThis study sought to identify and examine less commonly discussed challenges to positive mental health faced by medical students, residents, and physicians with hopes of improving current efforts to protect the mental health of these groups. Additionally, this work aimed to suggest an innovative means of preventing poor mental health during medical education.MethodsLiterature on medical student, resident, and physician mental health was carefully reviewed and a number of psychiatrists who treat physician-patients were interviewed.ResultsThe culture of medicine, medical training, common physician psychology and identity, and conflicting professional expectations all seem to contribute to poor mental health among medical students, residents, and physicians. Many current efforts may be more successful by better addressing the negative effects of these characteristics of modern medicine.ConclusionsPrograms aimed at promoting healthy mental lifestyles during medical education should continue to be developed and supported to mitigate the deleterious effects of the challenging environment of modern medicine. To improve these efforts, educators may consider incorporating philosophical discussions on meaning and fulfillment in life between medical students and faculty. Through medical school faculty members sharing and living out their own healthy outlooks on life, students may emulate these habits and the culture of medicine may become less challenging for positive mental health.

Fostering better policy adoption and inter-disciplinary communication in healthcare: A qualitative analysis of practicing physicians’ common interests

Purpose In response to limited physician adoption of various healthcare initiatives, we sought to propose and assess a novel approach to policy development where one first characterizes diverse physician groups’ common interests, using a medical student and constructivist grounded theory. Methods In 6 months, a medical student completed 36 semi-structured interviews with interventional radiologists, gynecologists, and vascular surgeons that were systematically analyzed according to constructivist grounded theory to identifying common themes. Common drivers of clinical decision making and professional values across 3 distinct specialty groups were derived from physicians’ descriptions of their clinical decision making, stories, and concerns. Results Common drivers of clinical decision making included patient preference/benefit, experience, reimbursement, busyness/volume, and referral networks. Common values included honesty, trustworthiness, loyalty, humble service, compassion and perseverance, and practical wisdom. Although personal gains were perceived as important interests, such values were easily sacrificed for the good of patients or other non-financial interests. This balance was largely dependent on the incentives and security provided by physicians’ environments. Conclusions Using a medical student interviewer and constructivist grounded theory is a feasible means of collecting rich qualitative data to guide policy development. Healthcare administrators and medical educators should consider incorporating this methodology early in policy development to anticipate how value differences between physician groups will influence their acceptance of policies and other broad healthcare initiatives.

JOURNAL CLUB: Four-Dimensional Flow MRI–Based Splenic Flow Index for Predicting Cirrhosis-Associated Hypersplenism

OBJECTIVE The objective of this study is to evaluate the ability of spleen volume, blood flow, and an index incorporating multiple measures to predict cirrhosis-associated hypersplenism. MATERIALS AND METHODS A total of 39 patients (14 women and 25 men; mean [± SD] age, 52 ± 10 years) with cirrhosis and sequelae of portal hypertension underwent 4D flow MRI and anatomic 3-T MRI performed before and after contrast administration. Unenhanced 4D flow MRI was used to assess abdominal hemodynamics, and splenic volumes were measured on T1-weighted gradient-recalled echo MRI. Relationships among demographic characteristics, blood component counts, splenic volume, arterial flow, venous flow, and the percentage of shunted portal flow were assessed in 29 consecutive patients (i.e., the derivation group), to develop a splenic flow index. This index was assessed along with splenic volume and blood flow alone in 10 additional consecutive patients (i.e., the validation group) via ROC curve analysis, to identify platelet counts of less than 50 × 103 cells/μL, leukocyte counts of less than 3.0 × 103 cells/μL, or both. RESULTS In the derivation cohort (platelet count, 129 ± 76 × 103 cells/μL), splenic volume, arterial flow, venous flow, and the percentage of shunted portal flow were inversely correlated with platelet counts (ρ = -0.68, -0.68, -0.56, and -0.36, respectively; p < 0.05). Adding splenic volume to arterial flow and the product of venous flow and the percentage of shunted portal flow indexed to the body surface area yielded superior correlations with platelet counts, leukocyte counts, and the degree of severity of hypersplenism (ρ = -0.75, -0.48, and -0.75, respectively; p ≤ 0.001) and predicted severe hypersplenism (sensitivity, 100%; specificity, 100%) in the validation cohort (platelet count, 93 ± 71 × 103 cells/μL). CONCLUSION A splenic flow index that incorporates both splenic volume and blood flow is a better indicator of hypersplenism than is splenic volume alone.

Restoration of physiologic hemodynamics in the ascending aorta following aortic valve Rreplacement: a 4D flow MR study

Background Previous work has illustrated that blood flow patterns following aortic valve and/or aortic root replacement (AVR/ ARR) are dependent on the valve and procedure type. Compared to healthy volunteers, ARR with bioprosthetic and mechanical valves demonstrated increased blood velocities and helicity/vorticity in the ascending aorta, with none restoring physiologic hemodynamics. On-X mechanical valves have unique design features, such as flared inlets and larger length-to-diameter ratios more analogous to the natural left ventricular outflow tract. Thus, we sought to examine the impact of this alternative design on ascending aortic hemodynamics.

Reinforcing the Importance and Feasibility of Implementing a Low-dose Protocol for CT-guided Biopsies

RATIONALE AND OBJECTIVES This study sought to more definitely illustrate the impact and feasibility of implementing a low-dose protocol for computed tomography (CT)-guided biopsies using size-specific dose estimates and multivariate analyses. MATERIALS AND METHODS Fifty consecutive CT-guided lung and extrapulmonary biopsies were reviewed before and after implementation of a low-dose protocol (200 patients total, mean age 61 ± 15 years, 128 women). Analyses of variance with Bonferroni correction were used to compare standard and low-dose protocols in terms of patient demographics, physician experience, target lesion size, total dose-length product, total acquisitions, size-specific dose estimate, signal-to-noise ratio, contrast-to-noise ratio, and lesion conspicuity ratings. All procedures were performed on the same 16-slice CT scanner. RESULTS Voluntary protocol adherence was 100% (lung) and 89% (extrapulmonary). The low-dose protocol achieved significantly lower total average dose-length product [(lung) 735.6 ± 599.4 mGy × cm to 252.1 ± 101.9 mGy × cm, P < .001; (extrapulmonary) 724.7 ± 545.0 mGy × cm to 392.9 ± 239.5 mGy × cm, P < .001] and size-specific dose estimate [(lung) 5.2 ± 0.8 mGy × cm to 4.3 ± 1.5 mGy, P < .001; (extrapulmonary) 10.1 ± 6.7 mGy to 6.5 ± 2.7 mGy, P < .001]. Only the change in protocol was independently associated with lower size-specific dose estimates when controlling for the other variables (P < .0001). This was achieved with no significant differences in signal-to-noise ratio, contrast-to-noise ratio, or lesion conspicuity. CONCLUSIONS Implementation of a low-dose protocol for CT-guided biopsies resulted in 21% and 36% of size-specific dose estimate reduction for lung and extrapulmonary biopsies, respectively, with excellent adherence. Interventional and body radiologists should implement low dose CT-guidance protocols aiming to improve patient safety.

Superior Abdominal 4D Flow MRI Data Consistency with Adjusted Preprocessing Workflow and Noncontrast Acquisitions

RATIONALE AND OBJECTIVES To assess the impact of an alternative preprocessing workflow on noncontrast- and contrast-enhanced abdominal four-dimensional flow magnetic resonance imaging (4D flow MRI) data consistency. MATERIALS AND METHODS Twenty patients with cirrhosis and portal hypertension (5 women; 53 ± 10 years old) underwent 4D flow MRI at 3.0T before and after administration of 0.03 mmol/kg of gadofosveset trisodium with velocity sensitivities of 100 and 50 cm/s for arterial and venous flow quantifications, respectively. 4D flow MRI data were preprocessed using the conventional workflow (workflow 1), applying noise filters prior to eddy current correction, and an alternative workflow (workflow 2), first correcting for eddy currents and using noise filtering only if needed for anti-aliasing. Vessel segmentation quality was ranked by independent reviewers and compared via Wilcoxon signed-rank tests. Flow quantification and conservation of mass at two portal and one arterial branch points were compared via paired t tests. RESULTS Segmentation quality was significantly higher for workflow 2 (P < 0.05) with excellent interobserver agreement (κ = 0.92). Workflow 2 resulted in larger flow values (P < 0.05) with improved conservation of mass (7.3 ± 6.1% vs. 27.7 ± 25.0%, P < 0.001 [portal]; 10.7 ± 9.0% vs. 21.7 ± 21.6%, P = 0.02 [arterial]). Peak velocities and abdominal aortic flow were similar (P > 0.05). Noncontrast acquisitions yielded significantly smaller portal flow values (P < 0.05) with improved conservation of mass (5.8 ± 4.7% vs. 8.7 ± 6.9%, P = 0.05 [portal]; 6.2 ± 4.5% vs. 13.7 ± 10.2%, P = 0.03 [arterial]). CONCLUSIONS Superior abdominal 4D flow MRI data consistency was obtained by applying eddy current correction before any other data manipulation, using noise masking and velocity anti-aliasing cautiously, and using noncontrast acquisitions.

Spatio-temporal visualization of regional myocardial velocities

Cardiovascular disease is the leading cause of death worldwide according to the World Health Organization (WHO). Nearly half of all heart failures occur due to the decline in the performance of the left ventricle (LV). Therefore, early detection, monitoring, and accurate diagnosis of LV pathologies are of critical importance. Usually, global cardiac function parameters are used to assess the cardiac structure and function, although regional abnormalities are important biomarkers of several cardiac diseases. Regional motion of the myocardium, the muscular wall of the LV, can be captured in a non-invasive manner using the velocity-encoded magnetic resonance (MR) imaging method known as Tissue Phase Mapping (TPM). To analyze the complex motion pattern, one typically visualizes for each time step the radial, longitudinal, and circumferential velocities separately according to the American Heart Association (AHA) model, which makes the comprehension of the spatio-temporal pattern an extremely challenging cognitive task. We propose novel spatio-temporal visualization methods for LV myocardial motion analysis with less cognitive load. Our approach uses coordinated views for navigating through the data space. One view visualizes individual time steps, which can be scrolled or animated, while a second view visualizes the temporal evolution using the radial layout of a polar plot for the time dimension. Different designs for visual encoding were considered in both views and evaluated with medical experts to demonstrate and compare their effectiveness and intuitiveness for detecting and analyzing regional abnormalities.

The Role of Four-Dimensional Flow MR Imaging in the Diagnosis and Treatment of a Splenic Arteriovenous Fistula

Editor: We recently used abdominal four-dimensional (4D) flow magnetic resonance (MR) imaging to guide the treatment of a splenic arteriovenous fistula (SAVF) in the presence of multiple splenic artery aneurysms (SAAs). Institutional review board exemption was obtained for this case presentation. The patient was a 34-year-old man with combined variable immunodeficiency and portal hypertension who underwent orthotopic liver transplantation for suspected decompensated cirrhosis. He initially recovered but had multiple hospital admissions during the next 5 months for abdominal pain, pancytopenia, infections, and wor-

Comparison of derived strain values of myocardial regions, levels, and segments by field strength and temporal resolution via cine bSSFP MR imaging

Background Non-invasive assessment of myocardial strain has many promising implications in the early detection and management of cardiac disease. Preliminary work at our institution has shown deformation field analysis of balanced steady state free precision (bSSFP) cine MR images to compare favorably with speckle-tracking echocardiography. We have also illustrated that global strain values obtained by this MR-based technique demonstrate good agreement across field strengths and temporal resolutions in healthy volunteers. To further delineate the potential of this technique, we assessed strain values across field strengths and temporal resolutions for myocardial regions (endo-, meso-, and epicardium), levels (base, mid, and apex), and smaller divisions (segments) within each region and level.