Coronary vasomotor dysfunction in cancer survivors treated with thoracic irradiation.

BACKGROUND: We sought to test the hypothesis that thoracic radiation therapy (RT) is associated with impaired myocardial flow reserve (MFR), a measure of coronary vasomotor dysfunction. METHODS: We retrospectively studied thirty-five consecutive patients (71% female, mean ± standard deviation (SD) age: 66 ± 11 years) referred clinically for positron emission tomography/computed tomography (PET/CT) myocardial perfusion imaging at a median (interquartile range, IQR) interval of 4.3 (2.1, 9.7) years following RT for a variety of malignancies. Radiation dose-volume histograms were generated for the heart and coronary arteries for each patient. RESULTS: The median (IQR) of mean cardiac radiation doses was 12.0 (1.2, 24.2) Gray. There were significant inverse correlations between mean radiation dose and global MFR (MFRGlobal) and MFR in the left anterior descending artery territory (MFRLAD): Pearson's correlation coefficient = - .37 (P = .03) and - .38 (P = .03), respectively. For every one Gray increase in mean cardiac radiation dose, there was a mean ± standard error decrease of .02 ± .01 in MFRGlobal (P = .04) and MFRLAD (P = .03) after adjustment. CONCLUSIONS: In patients with a history of RT clinically referred for cardiac stress PET, we found an inverse correlation between mean cardiac radiation dose and coronary vasomotor function.

Prostate MRI using an external phased array wearable pelvic coil at 3T: comparison with an endorectal coil.

PURPOSE: To evaluate T2w and DWI image quality using a wearable pelvic coil (WPC) compared with an endorectal coil (ERC). METHODS: Twenty men consecutively presenting to our prostate cancer MRI clinic were prospectively consented to be scanned using a wearable pelvic coil then an endorectal coil and pelvic phased array coil at 3T. Eighteen patients were suitable for inclusion. Axial T2w images were obtained using the WPC and ERC, and DWI images were obtained using the WPC, ERC, and PPA. Analysis was performed in consensus by two readers with experience in prostate MRI. The readers scored the T2w images using six qualitative criteria and the DWI images using five criteria. Signal-to-noise ratio (SNR) was also measured. RESULTS: T2w artifact severity was greater for an ERC than a WPC (p = 0.003). There was no significant difference in T2w qualititatve image quality by other measures. The distinction of zonal anatomy on DWI was superior for an ERC compared with both a WPC and a PPA (p = 0.018 and p < 0.001 respectively), and there was no significant difference in DWI image quality by other measures. SNR was significantly higher for ERC imaging for both T2w and DWI. CONCLUSION: WPC imaging provides comparable image quality to that of an ERC, potentially reducing the need for an ERC. WPC imaging shows reduced T2w artifact severity and inferior DWI zonal anatomy distinction compared with an ERC. Imaging with a WPC produces a lower SNR than an ERC.

Interreader Agreement of Prostate Imaging Reporting and Data System Version 2 Using an In-Bore MRI-Guided Prostate Biopsy Cohort: A Single Institution's Initial Experience.

OBJECTIVE: The purpose of this study is to determine the interobserver agreement of the Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) for diagnosing prostate cancer using in-bore MRI-guided prostate biopsy as the reference standard. MATERIALS AND METHODS: Fifty-nine patients underwent in-bore MRI-guided prostate biopsy between January 21, 2010, and August 21, 2013, and underwent diagnostic multiparametric MRI 6 months or less before biopsy. A single index lesion per patient was selected after retrospective review of MR images. Three fellowship-trained abdominal radiologists (with 1-11 years' experience) blinded to clinical information interpreted all studies according to PI-RADSv2. Interobserver agreement was assessed using Cohen kappa statistics. RESULTS: Thirty-eight lesions were in the peripheral zone and 21 were in the transition zone. Cancer was diagnosed in 26 patients (44%). Overall PI-RADS scores were higher for all biopsy-positive lesions (mean ± SD, 3.9 ± 1.1) than for biopsy-negative lesions (3.1 ± 1.0; p < 0.0001) and for clinically significant lesions (4.2 ± 1.0) than for clinically insignificant lesions (3.1 ± 1.0; p < 0.0001). Overall suspicion score interobserver agreement was moderate (κ = 0.45). There was moderate interobserver agreement among overall PI-RADS scores in the peripheral zone (κ = 0.46) and fair agreement in the transition zone (κ = 0.36). CONCLUSION: PI-RADSv2 scores were higher in the biopsy-positive group. PI-RADSv2 showed moderate interobserver agreement among abdominal radiologists with no prior experience using the scoring system.

Clinical Applications of a CT Window Blending Algorithm: RADIO (Relative Attenuation-Dependent Image Overlay).

A methodology is described using Adobe Photoshop and Adobe Extendscript to process DICOM images with a Relative Attenuation-Dependent Image Overlay (RADIO) algorithm to visualize the full dynamic range of CT in one view, without requiring a change in window and level settings. The potential clinical uses for such an algorithm are described in a pictorial overview, including applications in emergency radiology, oncologic imaging, and nuclear medicine and molecular imaging.

Prostate imaging reporting and data system version 2 (PI-RADS v2): a pictorial review.

The most recent edition of the prostate imaging reporting and data system (PI-RADS version 2) was developed based on expert consensus of the international working group on prostate cancer. It provides the minimum acceptable technical standards for MR image acquisition and suggests a structured method for multiparametric prostate MRI (mpMRI) reporting. T1-weighted, T2-weighted (T2W), diffusion-weighted (DWI), and dynamic contrast-enhanced (DCE) imaging are the suggested sequences to include in mpMRI. The PI-RADS version 2 scoring system enables the reader to assess and rate all focal lesions detected at mpMRI to determine the likelihood of a clinically significant cancer. According to PI-RADS v2, a lesion with a Gleason score ≥7, volume >0.5 cc, or extraprostatic extension is considered clinically significant. PI-RADS v2 uses the concept of a dominant MR sequence based on zonal location of the lesion rather than summing each component score, as was the case in version 1. The dominant sequence in the peripheral zone is DWI and the corresponding apparent diffusion coefficient (ADC) map, with a secondary role for DCE in equivocal cases (PI-RADS score 3). For lesions in the transition zone, T2W images are the dominant sequence with DWI/ADC images playing a supporting role in the case of an equivocal lesion.

Frequency and Severity of Pulmonary Hemorrhage in Patients Undergoing Percutaneous CT-guided Transthoracic Lung Biopsy: Single-Institution Experience of 1175 Cases.

PURPOSE: To evaluate the frequency and severity of pulmonary hemorrhage after transthoracic needle lung biopsy (TTLB) and assess possible factors associated with pulmonary hemorrhage. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board. The requirement to obtain informed consent was waived. Records from 1113 patients who underwent 1175 TTLBs between January 2008 and April 2013 were retrospectively reviewed. Primary outcomes were pulmonary hemorrhage, documented hemoptysis, and bleeding complications necessitating intervention. Pulmonary hemorrhage was graded as follows: 0, none; 1, less than or equal to 2 cm around the needle; 2, more than 2 cm and sublobar; 3, at least lobar; and 4, hemothorax. Patient, technique, and lesion-related variables were evaluated as predictors of pulmonary hemorrhage. Patient-related variables included main pulmonary artery diameter (mPAD) at computed tomography (CT), pulmonary artery pressures at echocardiography and right-sided heart catheterization, medications, chronic lung disease, bleeding diathesis, and immunodeficiency. Technique- and lesion-related variables included needle gauge, number of passes, pleura-needle angle, lesion size and morphologic characteristics, and distance to pleura. Univariate analysis was performed with χ(2), Fisher exact, and Student t tests. RESULTS: Pulmonary hemorrhage occurred in 483 of the 1175 TTLBs (41.1%); hemoptysis was documented in 21 of the 1175 TTLBs (1.8%). Higher-grade hemorrhage (grade 2 or higher) occurred in 201 of the 1175 TTLBs (17.1%); five of the 1175 TTLBs (0.4%) necessitated hemorrhage-related admission. Higher-grade hemorrhage was more likely to occur with female sex (P = .001), older age (P = .003), emphysema (P = .004), coaxial technique (P = .025), nonsubpleural location (P < .001), lesion size of 3 cm or smaller (P < .001), and subsolid lesions (P = .028). Enlarged mPAD at CT (≥2.95 cm) was not significantly associated with higher-grade hemorrhage (P = .430). CONCLUSION: Pulmonary hemorrhage after TTLB is common but rarely requires intervention. An enlarged mPAD at CT may not be a risk factor for higher-grade hemorrhage.

Evidence-based Practice of Radiology.

Current health care reform in the United States is producing a shift in radiology practice from the traditional volume-based role of performing and interpreting a large number of examinations to providing a more affordable and higher-quality service centered on patient outcomes, which is described as a value-based approach to the provision of health care services. In the 1990 s, evidence-based medicine was defined as the integration of current best evidence with clinical expertise and patient values. When these methods are applied outside internal medicine, the process is called evidence-based practice (EBP). EBP facilitates understanding, interpretation, and application of the best current evidence into radiology practice, which optimizes patient care. It has been incorporated into "Practice-based Learning and Improvement" and "Systems-based Practice," which are two of the six core resident competencies of the Accreditation Council for Graduate Medical Education and two of the 12 American Board of Radiology milestones for diagnostic radiology. Noninterpretive skills, such as systems-based practice, are also formally assessed in the "Quality and Safety" section of the American Board of Radiology Core and Certifying examinations. This article describes (a) the EBP framework, with particular focus on its relevance to the American Board of Radiology certification and maintenance of certification curricula; (b) how EBP can be integrated into a residency program; and (c) the current value and likely place of EBP in the radiology information technology infrastructure. Online supplemental material is available for this article.

Association Between Confidence Level of Acute Pulmonary Embolism Diagnosis on CTPA images and Clinical Outcomes.

RATIONALE AND OBJECTIVES: The purpose was to evaluate clinical characteristics associated with low confidence in diagnosis of acute pulmonary embolism (PE) as expressed in computed tomography pulmonary angiography (CTPA) reports and to evaluate the effect of confidence level in PE diagnosis on patient clinical outcomes. MATERIALS AND METHODS: This study included radiology reports from 1664 consecutive CTPA considered positive for acute PE (8/2003-5/2010). All reports were retrospectively assessed for the level of confidence in diagnosis. Baseline characteristics and outcomes (therapies related to PE and short-term mortality) were compared between high and low confidence groups. Multivariable logistic and Cox regression analyses were used to analyze the relationship between the confidence level and outcomes. RESULTS: One-hundred sixty of 1664 (9.6%) reports had language that reflected a low confidence in PE diagnosis. The low confidence group had smaller (segmental and subsegmental) suspected emboli (prevalence, 72.5% vs. 50.7%; P < .001) and more comorbidities. The low confidence group had a lower likelihood of receiving PE-related therapies (adjusted odds ratio [OR], 0.18; 95% confidence interval, 0.10-031, P < .001), but there was no change in the all-cause and PE-related 30-day and/or 90-day mortality (OR of death for low confidence, 0.81-1.13, P values > .5). CONCLUSIONS: Roughly 10% of positive CTPA reports had uncertainty in PE findings, and patients with reports categorized as low confidence had smaller emboli and more comorbidities. Although the low confidence group was less likely to receive PE-related therapies, patients in this group were not associated with higher probability of short-term mortality.

Effects of Performance Feedback Reports on Adherence to Evidence-Based Guidelines in Use of CT for Evaluation of Pulmonary Embolism in the Emergency Department: A Randomized Trial.

OBJECTIVE: The purpose of this study was to assess whether implementing emergency department (ED) physician performance feedback reports improves adherence to evidence-based guidelines for use of CT for evaluation of pulmonary embolism (PE) beyond that achieved with clinical decision support (CDS) alone. SUBJECTS AND METHODS: This prospective randomized controlled trial was conducted from January 1, 2012, to December 31, 2013, at an urban level 1 adult trauma center ED. Attending physicians were stratified into quartiles by use of CT for evaluation of PE in 2012 and were randomized to receive quarterly feedback reporting or not, beginning January 2013. Reports consisted of individual and anonymized group data on guideline adherence (using the Wells criteria), use of CT for PE (number of CT examinations for PE per 1000 patients), and yield (percentage of CT examinations for PE with positive findings). We compared guideline adherence (primary outcome) and use and yield (secondary outcomes) of CT for PE between the control and intervention groups in 2013 and with historical imaging data from 2012. RESULTS: Of 109,793 ED patients during the control and intervention periods, 2167 (2.0%) underwent CT for evaluation of PE. In the control group, guideline adherence remained unchanged between 2012 (78.8% [476/604]) and 2013 (77.2% [421/545]) (p = 0.5); in the intervention group, guideline adherence increased 8.8% after feedback report implementation, from 78.3% (426/544) to 85.2% (404/474) (p < 0.05). Use and yield were unchanged in both groups. CONCLUSION: Implementation of quarterly feedback reporting resulted in a modest but significant increase in adherence to evidence-based guidelines for use of CT for evaluation of PE in ED patients, enhancing the impact of CDS alone. These results suggest potentially synergistic effects of traditional performance improvement tools with CDS to improve guideline adherence.

Effect of Evidence-based Clinical Decision Support on the Use and Yield of CT Pulmonary Angiographic Imaging in Hospitalized Patients.

PURPOSE: To determine the effect of clinical decision support (CDS) on the use and yield of inpatient computed tomographic (CT) pulmonary angiography for acute pulmonary embolism (PE). MATERIALS AND METHODS: This HIPAA-compliant, institutional review board-approved study with waiver of informed consent included all adults admitted to a 793-bed teaching hospital from April 1, 2007, to June 30, 2012. The CDS intervention, implemented after a baseline observation period, informed providers who placed an order for CT pulmonary angiographic imaging about the pretest probability of the study based on a validated decision rule. Use of CT pulmonary angiographic and admission data from administrative databases was obtained for this study. By using a validated natural language processing algorithm on radiology reports, each CT pulmonary angiographic examination was classified as positive or negative for acute PE. Primary outcome measure was monthly use of CT pulmonary angiography per 1000 admissions. Secondary outcome was CT pulmonary angiography yield (percentage of CT pulmonary angiographic examinations that were positive for acute PE). Linear trend analysis was used to assess for effect and trend differences in use and yield of CT pulmonary angiographic imaging before and after CDS. RESULTS: In 272 374 admissions over the study period, 5287 patients underwent 5892 CT pulmonary angiographic examinations. A 12.3% decrease in monthly use of CT pulmonary angiography (26.0 to 22.8 CT pulmonary angiographic examinations per 1000 admissions before and after CDS, respectively; P = .008) observed 1 month after CDS implementation was sustained over the ensuing 32-month period. There was a nonsignificant 16.3% increase in monthly yield of CT pulmonary angiography or percentage of CT pulmonary angiographic examinations positive for acute PE after CDS (P = .65). CONCLUSION: Implementation of evidence-based CDS for inpatients was associated with a 12.3% immediate and sustained decrease in use of CT pulmonary angiographic examinations in the evaluation of inpatients for acute PE. for this article.

Classification of CT pulmonary angiography reports by presence, chronicity, and location of pulmonary embolism with natural language processing.

In this paper we describe an efficient tool based on natural language processing for classifying the detail state of pulmonary embolism (PE) recorded in CT pulmonary angiography reports. The classification tasks include: PE present vs. absent, acute PE vs. others, central PE vs. others, and subsegmental PE vs. others. Statistical learning algorithms were trained with features extracted using the NLP tool and gold standard labels obtained via chart review from two radiologists. The areas under the receiver operating characteristic curves (AUC) for the four tasks were 0.998, 0.945, 0.987, and 0.986, respectively. We compared our classifiers with bag-of-words Naive Bayes classifiers, a standard text mining technology, which gave AUC 0.942, 0.765, 0.766, and 0.712, respectively.

Percutaneous cryoablation of hepatic tumors adjacent to the gallbladder: assessment of safety and effectiveness.

PURPOSE: To assess safety and effectiveness of percutaneous image-guided cryoablation of hepatic tumors adjacent to the gallbladder. MATERIALS AND METHODS: Twenty-one cryoablation procedures were performed to treat 19 hepatic tumors (mean size, 2.7 cm; range, 1.0-5.0 cm) adjacent to the gallbladder in 17 patients (11 male; mean age, 59.2 y; range, 40-82 y) under computed tomography (n = 15) or magnetic resonance imaging (n = 6) guidance in a retrospective study. All tumors (mean size, 2.67 cm; range, 1.0-5.0 cm) were within 1 cm (mean, 0.4 cm) of the gallbladder; seven (33%) were contiguous with the gallbladder. Primary outcomes included complication rate and severity and postprocedure gallbladder imaging findings. Secondary outcomes included technical success and technique effectiveness at 6 months. RESULTS: Complications occurred in six of 21 procedures (29%); one (5%) was severe. Ice balls extended into the gallbladder lumen in 20 of 21 procedures (95%); no gallbladder-related complications occurred. The most common gallbladder imaging finding was mild, asymptomatic focal wall thickening after nine of 21 procedures (42%), which resolved on follow-up. Technical success was achieved in 19 of 21 sessions (90%). Six-month follow-up was available for 16 tumors; of these, all but two (87%) had no imaging evidence of local tumor progression. CONCLUSIONS: Percutaneous cryoablation of hepatic tumors adjacent to the gallbladder can be performed safely and successfully. Although postprocedural gallbladder changes are common, they are self-limited and clinically inconsequential, even when the ice ball extends into the gallbladder lumen.

Percutaneous treatment of hepatocellular carcinoma in patients with cirrhosis: a comparison of the safety of cryoablation and radiofrequency ablation.

PURPOSE: To compare the safety of image-guided percutaneous cryoablation and radiofrequency ablation in the treatment of hepatocellular carcinoma in patients with cirrhosis. MATERIALS AND METHODS: This retrospective HIPAA-compliant study received institutional review board approval. Forty-two adult patients with cirrhosis underwent image-guided percutaneous ablation of hepatocellular carcinoma from 2003 to 2011. Twenty-five patients underwent 33 cryoablation procedures to treat 39 tumors, and 22 underwent 30 radiofrequency ablation procedures to treat 39 tumors. Five patients underwent both cryoablation and radiofrequency ablation procedures. Complication rates and severity per procedure were compared between the ablation groups. Potential confounding patient, procedure, and tumor-related variables were also compared. Statistical analyses included Kruskal-Wallis, Wilcoxon rank sum, and Fisher's exact tests. Two-sided P-values <0.05 were considered significant. RESULTS: The overall complication rates, 13 (39.4%) of 33 cryoablation procedures versus eight (26.7%) of 30 radiofrequency ablation procedures and severe/fatal complication rates, two (6.1%) of 33 cryoablation procedures versus one (3.3%) of 30 radiofrequency ablation procedures, were not significantly different between the ablation groups (both P=0.26). Severe complications included pneumothoraces requiring chest tube insertion during two cryoablation procedures. One death occurred within 90 days of a radiofrequency ablation procedure; all other complications were managed successfully. CONCLUSION: No significant difference was seen in the overall safety of image-guided percutaneous cryoablation and radiofrequency ablation in the treatment of hepatocellular carcinoma in patients with cirrhosis.

Computed tomography and echocardiography in patients with acute pulmonary embolism: part 2: prognostic value.

PURPOSE: The aim of the study was to compare the prognostic value of right ventricular (RV) dysfunction detected on computed tomography pulmonary angiography (CTPA) and transthoracic echocardiography (TTE) in patients with acute pulmonary embolism (PE). MATERIALS AND METHODS: From all consecutive CTPAs performed between August 2003 and May 2010 that were positive for acute PE (n=1744), those with TTE performed within 48 hours of CTPA (n=785) were selected as the study cohort. Multivariate logistic regression analysis was performed to assess the association of CTPA RV/left ventricular (LV) diameter ratio and TTE RV strain with PE-related 30-day mortality, including other associated factors as covariates. The predictive ability (area under the curve) was compared between the model including the CT RV/LV diameter ratio and that including TTE RV strain. Test characteristics of the 2 modalities were calculated. RESULTS: Both CT RV/LV diameter ratio and TTE RV strain were independently associated with PE-related 30-day mortality (adjusted odds ratio=1.14, P=0.023 for 0.1 increment of the CT RV/LV diameter ratio; and odds ratio=2.13, P=0.041 for TTE RV strain). History of congestive heart failure and malignancy were independent predictors of PE-related mortality, while there was significantly lower mortality associated with anticoagulation use. The model including TTE RV strain and that including CT RV/LV had similar predictive ability (area under the curve=0.80 vs. 0.81, P=0.50). The sensitivity, specificity, and positive and negative predictive values of TTE RV strain and CT RV/LV diameter ratio at a cutoff of ≥1.0 were similar for PE-related 30-day mortality. CONCLUSIONS: Both RV strain on TTE and an increased CT RV/LV diameter ratio are predictors of PE-related 30-day mortality with similar prognostic significance.