Natural History, Clinical Significance, and the Role of Vascular Referral in the Management of Penetrating Ulcers of the Abdominal Aorta.

BACKGROUND: Penetrating ulcers of the abdominal aorta (PUAA) are an increasingly common finding on abdominal imaging studies; however, their significance and natural history are not well described. This study's objective was to analyze the demographics, presentation, and outcomes of patients with a radiographic diagnosis of PUAA. MATERIALS AND METHODS: Patients at our tertiary referral center were identified for inclusion based on a search for the term "penetrating ulcer" in abdominal computed tomography and magnetic resonance imaging reports between January 2014 and December 2017. Patients' electronic medical records were retrospectively reviewed to determine baseline medical characteristics, imaging indication, and subsequent clinical course, interventions, and outcomes. Aortic diameters and ulcer depths were measured by a single observer on initial and follow-up imaging to assess for association with concomitant aortic pathology, evolving aortic disease, and ulcer progression, defined as increase in depth of ≥ 1 mm. Statistical analysis was performed using STATA 16 (College Station, TX: StataCorp LLC), and a threshold P-value of <0.05 was set for significance. RESULTS: Ninety-two patients with PUAA were identified; 57 (62%) were male. The mean age at diagnosis was 79.3 years, and comorbidities included hypertension (74%), hyperlipidemia (65%), and malignancy (34%). The most common indication for imaging was chest, back, or abdominal pain (19%). On initial imaging, the mean ulcer depth was 1 cm (range from 0.2 cm to 3.4 cm). Concomitant abdominal aortic dilation ≥ 3 cm was found in 34 (37%) patients. Thirty-six (39%) patients had a vascular surgery consultation immediately after radiographic diagnosis. Follow-up axial imaging was performed on 27 (29%) untreated patients. The overall sample's mean ulcer depth remained essentially unchanged from initial measurement (P = 0.99); however, 14 (52%) patients with follow-up imaging were found to have increased overall aortic diameter. Of the total 92 patients, 9 (10%) underwent an endovascular abdominal aortic intervention during the review period: 2 for symptomatic PUAA and the remainder for progression of concomitant aneurysmal disease. All-cause mortality was 5% during the mean follow-up period of 21.9 months (range 0 to 72.5 months). Of the patients lost to follow-up, 61% did not receive vascular referral after initial diagnosis. CONCLUSIONS: PUAA are typically incidental findings identified in elderly, comorbid patients undergoing imaging for an unrelated indication. Although isolated findings of asymptomatic PUAA rarely require surgical intervention, these patients we argue would benefit from vascular surgery referral for long-term follow-up and interval imaging to assess for disease progression and concomitant aortic degeneration, which may necessitate repair. In addition, we observed that most of those patients lost to follow-up did not receive vascular consultation, suggesting that lack of involvement of vascular specialists at the time of diagnosis is a missed opportunity to secure appropriate follow-up and management.

Downstream Costs Associated With Incidental Pancreatic Cysts Detected at MRI.

OBJECTIVE: The purpose of this study is to assess downstream costs associated with pancreatic cysts incidentally detected at MRI. MATERIALS AND METHODS: Two hundred patients with an incidental pancreatic cyst detected at MRI were identified. Downstream events (imaging, office visits, endoscopic ultrasound-guided fine-needle aspiration, or chemotherapy) were identified from the electronic medical record. Radiologists' recommendations and ordering physician management were classified relative to the American College of Radiology (ACR) incidental findings committee recommendations. Costs for the downstream events were estimated using national Medicare rates and a 3% annual discount rate. Mean costs were computed. RESULTS: Estimated downstream costs averaged $460 per cyst ($872 per cyst with any follow-up testing). Nine patients had a clinically relevant outcome during follow-up (increase in cyst size, development of new cyst, or development of pancreatic cancer). Downstream cost per cyst with a clinically relevant outcome was $1364. Costs were greater when ordering physicians overmanaged ($842) versus when they were adherent ($631) or undermanaged ($252) relative to radiologist recommendation. Although costs were $252 when ordering physicians undermanaged relative to ACR incidental findings committee recommendations, costs were similar when ordering physicians were adherent ($811) or overmanaged ($845) relative to ACR incidental findings committee recommendations. Costs did not vary significantly according to whether radiologists recommended follow-up testing ($317-$491) or whether radiologist recommendations were adherent, undermanaged, or overmanaged relative to ACR incidental findings committee recommendations ($344-$528). CONCLUSION: The findings suggest a role for targeted educational efforts, collaborative partnerships, and other initiatives to foster greater adherence to radiologist recommendations, including critical test results notification systems, automated reminders within electronic health systems, and stronger language within radiology reports when no follow-up testing is recommended.

Informatics Solutions for Driving an Effective and Efficient Radiology Practice.

Radiologists are facing increasing workplace pressures that can lead to decreased job satisfaction and burnout. The increasing complexity and volumes of cases and increasing numbers of noninterpretive tasks, compounded by decreasing reimbursements and visibility in this digital age, have created a critical need to develop innovations that optimize workflow, increase radiologist engagement, and enhance patient care. During their workday, radiologists often must navigate through multiple software programs, including picture archiving and communication systems, electronic health records, and dictation software. Furthermore, additional noninterpretive duties can interrupt image review. Fragmented data and frequent task switching can create frustration and potentially affect patient care. Despite the current successful technological advancements across industries, radiology software systems often remain nonintegrated and not leveraged to their full potential. Each step of the imaging process can be enhanced with use of information technology (IT). Successful implementation of IT innovations requires a collaborative team of radiologists, IT professionals, and software programmers to develop customized solutions. This article includes a discussion of how IT tools are used to improve many steps of the imaging process, including examination protocoling, image interpretation, reporting, communication, and radiologist feedback. ©RSNA, 2018.

Comparison of nonenhanced MR angiographic subtraction techniques for infragenual arteries at 1.5 T: a preliminary study.

PURPOSE: To evaluate diagnostic performance of three nonenhanced methods: variable-refocusing-flip angle (FA) fast spin-echo (SE)-based magnetic resonance (MR) angiography (variable FA MR) and constant-refocusing-FA fast SE-based MR angiography (constant-FA MR) and flow-sensitive dephasing (FSD)-prepared steady-state free precession MR angiography (FSD MR) for calf arteries, with dual-injection three-station contrast material-enhanced MR angiography (gadolinium-enhanced MR) as reference. MATERIALS AND METHODS: This prospective study was institutional review board approved and HIPAA compliant, with informed consent. Twenty-one patients (13 men, eight women; mean age, 62.6 years) underwent calf-station variable-FA MR, constant-FA MR, and FSD MR at 1.5 T, with gadolinium-enhanced MR as reference. Image quality and stenosis severity were assessed in 13 segments per leg by two radiologists blinded to clinical data. Combined constant-FA MR and FSD MR reading was also performed. Methods were compared (logistic regression for correlated data) for diagnostic accuracy. RESULTS: Of 546 arterial segments, 148 (27.1%) had a hemodynamically significant (≥ 50%) stenosis. Image quality was satisfactory for all nonenhanced MR sequences. FSD MR was significantly superior to both other sequences (P < .0001), with 5-cm smaller field of view; 9.6% variable-FA MR, 9.6% constant-FA MR, and 0% FSD MR segmental evaluations had nondiagnostic image quality scores, mainly from high diastolic flow (variable-FA MR) and motion artifact (constant-FA MR). Stenosis sensitivity and specificity were highest for FSD MR (80.3% and 81.7%, respectively), compared with those for constant-FA MR (72.3%, P = .086; and 81.8%, P = .96) and variable-FA MR (75.9%, P = .54; and 75.6%, P = .22). Combined constant-FA MR and FSD MR had superior sensitivity (81.8%) and specificity (88.3%) compared with constant-FA MR (P = .0076), variable-FA MR (P = .0044), and FSD MR (P = .0013). All sequences had an excellent negative predictive value (NPV): 93.2%, constant-FA MR; 94.7%, variable-FA MR; 91.7%, FSD MR; and 92.9%, combined constant-FA MR and FSD MR. CONCLUSION: At 1.5 T, all evaluated nonenhanced MR angiographic methods demonstrated satisfactory image quality and excellent NPV for hemodynamically significant stenosis. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120859/-/DC1.

Intraobserver and interobserver variability of renal volume measurements in polycystic kidney disease using a semiautomated MR segmentation algorithm.

OBJECTIVE: Total renal volume and changes in kidney volume are markers of disease progression in autosomal-dominant polycystic kidney disease (ADPKD) but are not used in clinical practice in part because of the complexity of manual measurements. This study aims to assess the intra- and interobserver reproducibility of a semiautomated renal volumetric algorithm using fluid-sensitive MRI pulse sequences. SUBJECTS AND METHODS: Renal volumes of 17 patients with ADPKD were segmented from high-resolution coronal HASTE and true fast imaging with steady-state precession (FISP) MR acquisitions. Measurements performed independently by four readers were repeated, typically after 7 days. Intraobserver agreement indexes were calculated for total kidney volume for each patient. Interobserver agreement indexes were obtained for the six paired combinations of readers as well as for two readers after rigorous formalized training. Pearson and concordance correlation coefficients, coefficients of variation (CVs), and 95% limits of agreement were determined. RESULTS: The HASTE and true FISP sequences performed similarly with a median intraobserver agreement of greater than 98.1% and a CV of less than 2.4% across all readers. The median interobserver agreement was greater than 95.2% and the CV was less than 7.1%, across all reader pairs. Reader training further lowered interobserver CV. The mean total kidney volume was 1420 mL (range, 331-3782 mL) for HASTE imaging and 1445 mL (range, 301-3714 mL) for true FISP imaging, with mean image processing times per patient of 43 and 28 minutes, respectively. CONCLUSION: This semiautomated MR volumetric algorithm provided excellent intraobserver and very good interobserver reproducibility using fluid-sensitive pulse sequences that emphasize cyst conspicuity.

CT colonography in senior versus nonsenior patients: extracolonic findings, recommendations for additional imaging, and polyp prevalence.

PURPOSE: To retrospectively evaluate the frequency of recommendations for additional imaging (RAIs) for important extracolonic findings and polyp prevalence among a cohort of seniors (age ≥ 65 years) and nonseniors (age < 65 years) undergoing low-dose computed tomographic (CT) colonography. MATERIALS AND METHODS: Institutional review board approval was obtained for this HIPAA-compliant retrospective study. Four hundred fifty-four patients (204 nonseniors: mean age, 52 years; 250 seniors: mean age, 69 years) underwent CT colonography at an outpatient facility. Cases were prospectively reported by one of four abdominal radiologists with expertise in CT colonography. The dictated reports were reviewed to determine the frequency of polyps (≥6 mm), the number of extracolonic findings, and the number of RAIs generated. The Fisher exact test was used to compare the percentage of seniors and nonseniors with at least one reported polyp, with at least one extracolonic finding, as well as the frequency of RAIs. RESULTS: The percentage of patients with at least one reported polyp was 14.2% (29 of 204) for the nonsenior group and 13.2% (33 of 250) for seniors, which was not significantly different (P = .772). The percentage of patients with at least one extracolonic finding was 55.4% (113 of 204) for nonseniors and 74.0% (185 of 250) for seniors (P < .0001). The percentage of patients in which an RAI was suggested was 4.4% (nine of 204) for nonseniors and 6.0% (15 of 250) for seniors, which was not significantly different (P = .450). CONCLUSION: Extracolonic findings were more frequent in seniors than in nonseniors; however, there was no significant difference in the frequency of RAIs between the two groups. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11102144/-/DC1.

Time-resolved lower extremity MRA with temporal interpolation and stochastic spiral trajectories: preliminary clinical experience.

PURPOSE: To assess added value of a new time-resolved technique with temporal interpolation and stochastic spiral trajectory through k-space and parallel imaging (TR-MRA) to conventional bolus chase MRA (BC-MRA) for infragenual peripheral artery evaluation. MATERIALS AND METHODS: An institutional review board-approved retrospective review of peripheral arterial disease patients was performed. Infragenual TR-MRA and BC-MRA were performed in 26 patients over four months. Two readers individually assessed image quality, diagnostic confidence, and stenosis severity and length in 13 defined below knee segments, first with BC-MRA alone, and then with a combined BC-MRA and TR-MRA reading (BC+TR-MRA). Perceived contribution of TR-MRA was rated by each reader. The reference standard was a consensus reading of both sequences. Catheter angiographic (CA) correlation was available in 6 patients. RESULTS: A total of 646 infragenual segments in 51 extremities were evaluated. Image quality and diagnostic confidence were superior for BC+TR-MRA compared with BC-MRA alone (P < 0.001). Adding TR-MRA improved sensitivity (85.7% versus 80.7%; P < 0.05) and diagnostic accuracy (88.1% versus 85.4%; P < 0.05) for hemodynamically significant stenosis. Venous contamination (0% versus 13.1% segments) and motion (0.9% versus 8.0%) were decreased for BC+TR-MRA versus BC-MRA alone, P < 0.01. For BC+TR-MRA, TR-MRA was rated more useful than BC-MRA in 30/51 legs (58.8%). TR-MRA identified retrograde flow in 5 segments. Where available, there was high concordance between CA and BC+TR-MRA (91.6%) for stenosis. CONCLUSION: Adding TR-MRA with temporal interpolation and stochastic spiral trajectories to bolus chase MRA improves image quality, diagnostic confidence and accuracy. It provides hemodynamic information and minimizes venous contamination and patient motion.

Process Improvement for Communication and Follow-up of Incidental Lung Nodules.

OBJECTIVE: Guideline-concordant follow-up of incidental lung nodules (ILNs) is suboptimal. We aimed to improve communication and tracking for follow-up of these common incidental findings detected on imaging examinations. METHODS: We implemented a process improvement program for reporting and tracking ILNs at a large urban academic health care system. A multidisciplinary committee designed, tested, and implemented a multipart tracking system in the electronic health record (EHR) that included Fleischner Society management recommendations for each patient. Plan-do-study-act cycles addressed gaps in the follow-up of ILNs, broken into phases of developing and testing components of the conceived EHR toolkit. RESULTS: The program resulted in standardized text macros with discrete categories and recommendations for ILNs, with ability to track each case in a work list within the EHR. The macros incorporated evidence-based guidelines and also input of collaborating clinical referrers in the respective specialty. The ILN macro was used 3,964 times over the first 2 years, increasing from 104 to over 300 uses per month. Usage spread across all subspecialty divisions, with nonthoracic radiologists currently accounting for 80% (56 of 70) of the radiologists using the system and 31% (1,230 of 3,964) of all captured ILNs. When radiologists indicated ILNs as warranting telephone communication to provider offices, completion was documented in 100% of the cases captured in the EHR-embedded tracking report. CONCLUSION: An EHR-based system for managing incidental nodules enables case tracking with exact recommendations, provider communication, and completion of follow-up testing. Future efforts will target consistent radiologist use of the system and follow-up completion.

Dual-source versus single-source cardiac CT angiography: comparison of diagnostic image quality.

OBJECTIVE: Dual-source CT improves temporal resolution, and theoretically improves the diagnostic image quality of coronary artery examinations without requiring preexamination beta-blockade. The purpose of our study was to show the improved diagnostic image quality of dual-source CT compared with single-source CT despite the absence of preexamination beta-blockade in the dual-source CT group. MATERIALS AND METHODS: We performed a retrospective analysis of consecutive patients who underwent coronary artery evaluation with either single-source CT or dual-source CT at our institution between February 2005 and October 2006. Examination reports were analyzed for the presence of image artifacts, and image quality was graded on a 3-point scale (no, mild, or severe artifact). Type of artifact (motion, calcium, quantum mottle) was also noted. RESULTS: Examinations (339 single-source CT and 126 dual-source CT) of 465 patients were analyzed. Artifact was reported in 39.8% of examinations using single-source CT and in 29.4% of examinations using dual-source CT (p < 0.05). The number of examinations with motion artifact was significantly higher with single-source CT than with dual-source CT (15.9% vs 4.8%; p < 0.001) despite significantly higher heart rates in the dual-source CT group (59.4 +/- 8.4 vs 68.6 +/- 14.6 beats per minute; p < 0.001). No patients in the dual-source CT group received preexamination beta-blockade compared with 81% of patients in the single-source CT group. The presence of severe (nondiagnostic) calcium artifact was also significantly reduced in the dual-source CT group (13.0% vs 3.2%; p < 0.001). CONCLUSION: Dual-source CT provides significantly better diagnostic image quality than single-source CT despite higher heart rates in the dual-source CT group. These findings support the use of dual-source CT for coronary artery imaging without the need for preexamination beta-blockade.

Downstream Costs Associated with Incidental Pulmonary Nodules Detected on CT.

RATIONALE AND OBJECTIVES: To explore downstream costs associated with incidental pulmonary nodules detected on CT. MATERIALS AND METHODS: The cohort comprised 200 patients with an incidental pulmonary nodule on chest CT. Downstream events (chest CT, PET/CT, office visits, percutaneous biopsy, and wedge resection) were identified from the electronic medical record. The 2017 Fleischner Society Guidelines were used to classify radiologists' recommendations and ordering physician management for the nodules. Downstream costs for nodule management were estimated from national Medicare rates, and average costs were determined. RESULTS: Average downstream cost per nodule was $393. Costs were greater when ordering physicians over-managed relative to radiologist recommendations ($940) vs. when adherent ($637) or under-managing ($166) relative to radiologists recommendations. Costs were also greater when ordering physicians over-managed relative to Fleischner Society guidelines ($860) vs. when under-managing ($208) or adherent ($292) to guidelines. Costs did not vary significantly based on whether or not radiologists recommended follow-up imaging ($167-$397), nor whether radiologists were adherent or under- or over-recommended relative to Fleischner Society guidelines ($313-$444). Costs were also higher in older patients, patients with a smoking history, and larger nodules. Five nodules underwent wedge resection and diagnosed as malignancies. No patient demonstrated recurrence or metastasis. Average cost per diagnosed malignancy was $3090. CONCLUSION: Downstream costs for incidental pulmonary nodules are highly variable and particularly high when ordering physicians over-manage relative to radiologist recommendations and Fleischner Society guidelines. To reduce unnecessary utilization and cost from over-management, radiologists may need to assume a greater role in partnering with ordering physicians to ensure appropriate, guideline-adherent, and follow-up testing.

Natural Language Processing for Identification of Incidental Pulmonary Nodules in Radiology Reports.

PURPOSE: To develop natural language processing (NLP) to identify incidental lung nodules (ILNs) in radiology reports for assessment of management recommendations. METHODS AND MATERIALS: We searched the electronic health records for patients who underwent chest CT during 2014 and 2017, before and after implementation of a department-wide dictation macro of the Fleischner Society recommendations. We randomly selected 950 unstructured chest CT reports and reviewed manually for ILNs. An NLP tool was trained and validated against the manually reviewed set, for the task of automated detection of ILNs with exclusion of previously known or definitively benign nodules. For ILNs found in the training and validation sets, we assessed whether reported management recommendations agreed with Fleischner Society guidelines. The guideline concordance of management recommendations was compared between 2014 and 2017. RESULTS: The NLP tool identified ILNs with sensitivity and specificity of 91.1% and 82.2%, respectively, in the validation set. Positive and negative predictive values were 59.7% and 97.0%. In reports of ILNs in the training and validation sets before versus after introduction of a Fleischner reporting macro, there was no difference in the proportion of reports with ILNs (108 of 500 [21.6%] versus 101 of 450 [22.4%]; P = .8), or in the proportion of reports with ILNs containing follow-up recommendations (75 of 108 [69.4%] versus 80 of 101 [79.2%]; P = .2]. Rates of recommendation guideline concordance were not significantly different before and after implementation of the standardized macro (52 of 75 [69.3%] versus 60 of 80 [75.0%]; P = .43). CONCLUSION: NLP reliably automates identification of ILNs in unstructured reports, pertinent to quality improvement efforts for ILN management.

Science to Practice: IT Solutions to Drive Standardized Report Recommendations for Abdominal Aortic Aneurysm Surveillance.

Inadequate imaging surveillance has been identified as the most significant contributor to abdominal aortic aneurysm (AAA) rupture. Radiologists can contribute value to patient care and reduce morbidity and mortality related to AAA by incorporating evidence-based management recommendations from the ACR and Society of Vascular Surgery into their report impression. The challenges lie in achieving 100% radiologist compliance to incorporate the recommendations and ensuring that the patient is notified by their provider, the follow-up examination is scheduled, and the patient returns for an imaging test that may be scheduled 3 to 5 years in the future. To address these barriers, radiology quality and informatics leads have harnessed IT solutions to facilitate integration of content, communication of results, and patient follow-up.

Variation in Downstream Relative Costs Associated With Incidental Ovarian Cysts on Ultrasound.

PURPOSE: To explore variation in downstream relative costs associated with ovarian cysts incidentally detected on ultrasound. METHODS: For 200 consecutive incidental ovarian cysts on ultrasound, ultrasound reports were classified in terms of presence of a radiologist recommendation for additional imaging. All downstream events (imaging, office visits, and surgery) associated with the cysts were identified from the electronic health record. Medical costs associated with these downstream events were estimated using national Medicare rates. Average cost per cyst was stratified by various factors; cost ratios were computed among subgroups. RESULTS: Average costs per cyst were 1.9 times greater in postmenopausal than premenopausal women. Relative to when follow-up imaging was neither recommended nor obtained, costs were 1.1 times greater when follow-up imaging was recommended but not obtained, 5.1 times greater when follow-up imaging was both recommended and obtained, and 8.1 times greater when follow-up imaging was obtained despite not being recommended. Costs were 2.5 times greater when the radiologist underrecommended follow-up compared with Society of Radiologists in Ultrasound (SRU) guidelines for management of ovarian cysts, 3.0 times greater when the ordering physician overmanaged compared with the radiologist's recommendation, as well as 1.7 times and 3.8 times greater when the ordering physician undermanaged and overmanaged compared with SRU guidelines, respectively. Four ovarian neoplasms, although no ovarian malignancy, were diagnosed in the cohort. CONCLUSION: Follow-up costs for incidental ovarian cysts are highly variable based on a range of factors. Radiologist recommendations may contribute to lower costs among patients receiving follow-up imaging. Such recommendations should reflect best practices and support the follow-up that will be of likely greatest value for patient care.

Ventricular diverticula on cardiac CT: more common than previously thought.

OBJECTIVE: We describe the findings of contrast-enhanced gated cardiac CT in 15 patients with 23 incidentally noted cardiac ventricular diverticula. CONCLUSION: Cardiac diverticula most commonly occur in the left ventricle but have been reported to occur in all chambers of the heart. Despite reports of their rare occurrence, cardiac ventricular diverticula are fairly common findings in patients undergoing cardiac MDCT angiography.

A Multidisciplinary Approach to Improving Appropriate Follow-Up Imaging of Ovarian Cysts: A Quality Improvement Initiative.

PURPOSE: Incidental ovarian cysts are frequently detected on imaging. Despite published follow-up consensus statements, there remains variability in radiologist follow-up recommendations and clinician practice patterns. The aim of this study was to evaluate if collaborative ovarian cyst management recommendations and a radiologist decision support tool can improve adherence to follow-up recommendations. METHODS: Gynecologic oncologists and abdominal radiologists convened to develop collaborative institutional recommendations for the management of incidental, asymptomatic simple ovarian cysts detected on ultrasound, CT, and MRI. The recommendations were developed by modifying the published consensus recommendations developed by the Society of Radiologists in Ultrasound on the basis of local practice patterns and the experience of the group members. A less formal process involved the circulation of the published consensus recommendations, followed by suggestions for revisions and subsequent consensus, in similar fashion to the ACR Incidental Findings Committee II. The recommendations were developed by building on the published work of experienced groups to provide the authors' medical community with a set of recommendations that could be endorsed by both the Department of Gynecology and the Department of Radiology to provide supportive guidance to the clinicians who manage incidental ovarian cysts. The recommendations were integrated into a radiologist decision support tool accessible from the dictation software. Nine months after tool launch, institutional review board approval was obtained, and radiology reports mentioning ovarian cysts in the prior 34 months were retrospectively reviewed. For cysts detected on ultrasound, adherence rates to Society of Radiologists in Ultrasound recommendations were calculated for examinations before tool launch and compared with adherence rates to the collaborative institutional recommendations after tool launch. Additionally, electronic medical records were reviewed to determine the follow-up chosen by the clinician. RESULTS: For cysts detected on ultrasound, radiologist adherence to recommendations improved from 50% (98 of 197) to 80% (111 of 139) (P < .05). Overmanagement decreased from 34% (67 of 197) to 10% (14 of 139) (P < .05). A recommendation was considered "overmanaged" if the radiologist recommended follow-up when it was not indicated or if the recommended follow-up time was at a shorter interval than indicated. Clinician adherence to radiologist recommendations showed statistically nonsignificant improvement from 49% (36 of 73) to 57% (27 of 47) (P = .5034). CONCLUSIONS: Management recommendations developed through collaboration with clinicians may help standardize follow-up of ovarian cysts and reduce overutilization.

Comparison of blood pool and extracellular gadolinium chelate for functional MR evaluation of vascular thoracic outlet syndrome.

OBJECTIVE: To compare performance of single-injection blood pool agent (gadofosveset trisodium, BPA) against dual-injection extracellular contrast (gadopentetate dimeglumine, ECA) for MRA/MRV in assessment of suspected vascular TOS. MATERIALS AND METHODS: Thirty-one patients referred for vascular TOS evaluation were assessed with BPA (n=18) or ECA (n=13) MRA/MRV in arm abduction and adduction. Images were retrospectively assessed for: image quality (1=non-diagnostic, 5=excellent), vessel contrast (1=same signal as muscle, 4=much brighter than muscle) and vascular pathology by two independent readers, with a separate experienced reader providing reference assessment of vascular pathology. RESULTS: Median image quality was diagnostic or better (score ≥ 3) for ECA and BPA at all time points, with BPA image quality superior at abduction late (BPA 4.5, ECA 4, p=0.042) and ECA image quality superior at adduction-early (BPA 4.5; ECA 4.0, p=0.018). High qualitative vessel contrast (mean score ≥ 3) was observed at all time points with both BPA and ECA, with superior BPA vessel contrast at abduction-late (BPA 3.97 ± 0.12; ECA 3.73 ± 0.26, p=0.007) and ECA at adduction-early (BPA 3.42 ± 0.52; ECA 3.96 ± 0.14, p<0.001). Readers readily identified arterial and venous pathology with BPA, similar to ECA examinations. CONCLUSION: Single-injection BPA MRA/MRV for TOS evaluation demonstrated diagnostic image quality and high vessel contrast, similar to dual-injection ECA imaging, enabling identification of fixed and functional arterial and venous pathology.

Evaluation of the mitral and aortic valves with cardiac CT angiography.

Cardiac computed tomographic angiography (CTA) using multidetector computed tomographic scanners has proven to be a reliable technique to image the coronary vessels. CTA also provides excellent visualization of the mitral and aortic valves, and yields useful information regarding valve anatomy and function. Accordingly, an assessment of the valves should be performed whenever possible during CTA interpretation. In this paper, we highlight the imaging features of common functional and structural left-sided valvular disorders that can be seen on CTA examinations.

Angiotensin-converting enzyme inhibitor-enhanced MR renography: repeated measures of GFR and RPF in hypertensive patients.

This study aims to assess the feasibility of a protocol to diagnose renovascular disease using dual MR renography acquisitions: before and after administration of angiotensin-converting enzyme inhibitor (ACEi). Results of our simulation study aimed at testing the reproducibility of glomerular filtration rate (GFR) and renal plasma flow demonstrate that for a fixed overall dose of 12 ml gadolinium-based contrast material (500 mmol/l), the second dose should be approximately twice as large as the first dose. A three-compartment model for analyzing the second-injection data was shown to appropriately handle the tracer residue from the first injection. The optimized protocol was applied to 18 hypertensive patients without renovascular disease, showing minimal systematic difference in GFR measurements before and after ACEi of 0.8 +/- 4.4 ml/min or 2.7 +/- 14.9%. For 10 kidneys with significant renal artery stenosis, GFR decreased significantly after ACEi (P < 0.001, T value = 3.79), and the difference in GFR measurements before and after ACEi averaged 8.3 +/- 6.9 ml/min or 26.2 +/- 43.9%. Dual-injection MRI with optimized dose distribution appears promising for ACEi renography by offering measures of GFR changes with clinically acceptable precision and accuracy.

Time-resolved dynamic contrast-enhanced MR urography for the evaluation of ureteral peristalsis: initial experience.

PURPOSE: To determine the feasibility of time-resolved dynamic contrast-enhanced magnetic resonance urography (MRU) for the evaluation of ureteral peristalsis using a data-sharing 3D gradient echo sequence with spiral k-space filling. MATERIALS AND METHODS: Eight patients (M=3, F=5, mean 48.1 years) were referred for MRU for the evaluation for renal mass (n=3), hematuria (n=2), urinary tract tuberculosis (n=1), postoperative bladder cancer (n=1), and postoperative ureteric reimplantation (n=1). Dynamic MRU was performed for 120 seconds at 1.5T after intravenous furosemide and gadolinium administration using an oblique sagittal, time-resolved T1 3D gradient echo sequence with 1 second effective temporal resolution. Study quality was assessed based on artifacts and extent of ureteric visualization. Frequency of peristalsis from the renal pelvis to urinary bladder was evaluated for each subject. RESULTS: A total of 16 ureters were examined. Image quality was good in four ureters, satisfactory in 11 ureters, and poor in one ureter. Mean peristaltic frequency was 3.5 waves per minute (range, 2.5-6.5 waves/minute) in normal ureters (n=11). Five ureters were considered abnormal (one urinary tract tuberculosis and four postsurgical ureters), and all had decreased or no peristalsis (0-1.5 waves per minute). CONCLUSION: MRU using a time-resolved, data-sharing 3D contrast-enhanced technique is able to demonstrate ureteral peristalsis and permits quantification of ureteral peristaltic frequency.