Lumen-apposing covered self-expanding metallic stent for symptomatic pancreatic fluid collections: assessment of outcomes and complications with CT and MRI.

PURPOSE: To assess technical and clinical outcomes following lumen-apposing covered self-expanding metallic stent (LAMS) placement for symptomatic pancreatic fluid collections (PFC) with CT and MRI. METHODS: In this retrospective study, patients with PFC who underwent LAMS placement between March 2015 and June 2018 were included. Primary outcomes included technical success, defined as successful stent placement with resolution of PFC, and clinical success, defined as lack of fluid recurrence after stent removal. Secondary outcomes included time duration from stent placement to removal, complications, and re-intervention need. RESULTS: 28 consecutive patients (20 men, mean age: 53 years ± 17; range 21-75) who underwent endoscopic drainage of symptomatic walled-off necrosis (WON, 21/28, 75%), pseudocyst (PC, 5/28, 18%) or acute necrotic collection (ANC, 2/28, 7%) were included. LAMS were placed successfully in 27/28 (96%) patients. On follow-up imaging after at least one month (n = 24), the volume of the PFC decreased by 99.9% from 425 cm3 [IQR 214 - 636] to 0.6 cm3 [IQR 0-43.9]. After stent removal, 26/27 (96%) patients remained collection free. The median time duration from stent placement to removal was 42 days [IQR 34-71]. Complications (10/28; 36%) included stent occlusion (n = 1), stent migration (n = 3), intraprocedural bleeding (n = 2), postprocedural bleeding (n = 2), and pseudoaneurysm formation (n = 2). Re-intervention was required in 7/27 (26%). CONCLUSION: Following LAMS placement in patients with symptomatic PFC, high technical and clinical success rates of 96% and 96%, respectively, are achieved. Awareness of common complications seen on cross-sectional imaging might help radiologists and gastroenterologist in the patients' management.

MRI characterization of focal liver lesions in non-cirrhotic patients: assessment of added value of gadoxetic acid-enhanced hepatobiliary phase imaging.

BACKGROUND: To evaluate the added value of the hepatobiliary (HPB) phase in gadoxetic acid-enhanced magnetic resonance imaging (MRI) in characterizing newly discovered indeterminate focal liver lesions in non-cirrhotic patients. RESULTS: One-hundred and twenty-five non-cirrhotic patients (median age, 46 years; range, 20-85 years; 100 females) underwent gadoxetic acid-enhanced MRI, including the 20-min delayed HPB phase, for characterization of newly discovered focal liver lesions. Images were independently evaluated by two blinded, board-certified abdominal radiologists (R1 and R2) who characterized liver lesions without and with assessment of the HPB phase images in two separate readout sessions. Confidence in diagnosis was scored on a scale from 0 to 3. Inter-observer agreement was assessed using Cohen κ statistics. Change in diagnosis and confidence in diagnosis were evaluated by Wilcoxon signed rank test. There was no significant change in diagnosis before and after evaluation of the HPB phase for both readers (p = 1.0 for R1; p = 0.34 for R2). Confidence in diagnosis decreased from average 2.8 ± 0.45 to 2.6 ± 0.59 for R1 and increased from 2.6 ± 0.83 to 2.8 ± 0.46 for R2. Change in confidence was only statistically significant for R1 (p = 0.003) but not significant for R2 (p = 0.49). Inter-reader agreement in diagnosis was good without (k = 0.66) and with (k = 0.75) inclusion of the HPB phase images. CONCLUSIONS: The added information obtained from the HPB phase of gadoxetic acid-enhanced MRI does not change the diagnosis or increase confidence in diagnosis when evaluating new indeterminate focal liver lesions in non-cirrhotic patients.

Multimodality imaging and clinicopathologic assessment of abdominal wall endometriosis: knocking down the enigma.

PURPOSE: To review the clinical, multimodality imaging, and pathologic characteristics of abdominal wall endometriosis (AWE), the most common type of extra-pelvic endometriosis. METHODS: 116 women with histopathologically confirmed extragenital endometriosis diagnosed between 2/2014 and 6/2017 were evaluated retrospectively. Of these, 26 (22.4%) were found to have AWE and 18/26 met inclusion criteria for imaging. Available imaging studies were re-reviewed by two expert radiologists. Data regarding clinical features, histopathologic findings, and management were collected through medical record review. RESULTS: 21 pathology-proven AWE deposits were identified by imaging in 18 women [mean age at diagnosis of 38.5 years (range 31-48)]. Prior C-section was present in 15/18 (83.3%) and pelvic endometriosis in 3/18 (16.7%) patients. Patients presented with abdominal pain in 14/18 (77.8%) cases, which was cyclical in 8/14; palpable mass in 12/18 (66.7%); fluid discharge in 2/18 (11.1%); and local skin discoloration in 2/18 (11.1%). Of the 21 lesions, 15 were evaluated with US, 10 with CT, and 5 with MRI. Mean lesion dimensions were 2.5 × 2.2 × 2.6 cm, and deposits were predominantly located at midline or left hemiabdomen [22/30 (73.3%)], were either stellate [15/30 (50%)] or round [15/30 (50%)] in shape, had ill-defined margins [21/30 (70%)], were heterogenous in appearance [27/30 (90%)], and involved both deep and superficial abdominal wall layers [17/30 (56.7%)]. On US, lesions were mainly isoechoic/hyperechoic [7/15 (46.7%)], and scarcely vascular [8/15 (53.3%)] with a peripheral vascular pattern [8/13 (61.5%)]. On CT, AWEs were hypervascular and homogeneous [8/10 (80%)], superiorly located to scar tissue, and on MRI lesions appeared hyperintense [4/5 (80%)] to muscle with T2 cystic and T1 hemorrhagic foci [4/5 (80%)]. In 23/27 (85.1%) original reports, there was at least one known mass prior to imaging; AWE was correctly diagnosed in only 7/23 (30.4%) cases. In those with no prior knowledge of a mass, the lesion was detected in 3/4 (75%), but AWE was only diagnosed in a single case. Median time between onset of symptoms and histopathology was 24.41 moths (IQR 15.18-47.33). CONCLUSIONS: AWE is a challenging clinical entity frequently diagnosed with a significant delay and easily misinterpreted despite multimodality imaging. Familiarity with its radiologic features holds the potential for positively impacting diagnosis.

Imaging guidelines for acute pancreatitis: when and when not to image.

In patients with acute pancreatitis (AP), diagnostic imaging is performed for various reasons, including the detection of the etiology (e.g., biliary obstruction caused by gallstones), diagnosis of pancreatitis in an unclear clinical setting, assessment of the severity of the process, and evaluation of its complications. In spite of the potential benefits of these imaging studies in the setting of AP, especially economic consequences but also medical risks are associated with diagnostic imaging, including increase of the effective radiation dose received by patients with AP and rising health care costs, frequently without impact on management. The rising incidence of acute pancreatitis in the Western world is escalating its financial burden with national health care expenses of over 2.5 billion dollars annually. Despite evidence-based national recommendations on utilization of diagnostic imaging in patients with AP, unnecessary imaging studies are still frequently performed, especially in the early hospital course. The purpose of this article is, therefore, to review the imaging guidelines for acute pancreatitis with regards to when and when not to image, with the aim to minimize inappropriate utilization.

Magnitude and financial implications of inappropriate diagnostic imaging for three common clinical conditions.

OBJECTIVE: To quantify the level of adherence to imaging guidelines for three common clinical indications for a commercially insured population. DESIGN: Retrospective analysis of administrative claims data for commercially insured individuals with diagnostic imaging claims (MRI and X-ray) for either uncomplicated low back pain, non-traumatic knee pain or non-traumatic shoulder pain. SETTING: The State of Massachusetts for 2010 and 2013. PARTICIPANTS: Adults with no chronic conditions and without evidence of prior management in the 12 months preceding to the initial office visit for each of the clinical indications. MAIN OUTCOMES MEASURES: Imaging procedures performed within 30 days of the initial office visit were classified as appropriate or inappropriate according to adherence to imaging guidelines from American College of Radiology. RESULTS: More than 60% of lumbar spine MRI's were deemed inappropriate in 2010 and in 2013. Over 30% of MRI's for shoulder pain and knee pain were inappropriate in 2010 and in 2013. Patients age 18-59 with inappropriate imaging claims had significantly lower rates of surgical procedures within 90 days of imaging than those with appropriate imaging. Inappropriate imaging accounted for over 20% of annual imaging costs for the three clinical indications. CONCLUSIONS: Reducing inappropriate imaging procedures can lead to substantial savings through the elimination of unnecessary and low value procedures. Increased awareness of and adherence to best practice guidelines should be a focus of efforts to cut waste in our healthcare system.

Utilization Trends in Diagnostic Imaging for a Commercially Insured Population: A Study of Massachusetts Residents 2009 to 2013.

PURPOSE: To report utilization trends in diagnostic imaging among commercially insured Massachusetts residents from 2009 to 2013. MATERIALS AND METHODS: Current Procedural Terminology codes were used to identify diagnostic imaging claims in the Massachusetts All-Payer Claims Database for the years 2009 to 2013. We reported utilization and spending annually by imaging modality using total claims, claims per 1,000 individuals, total expenditures, and average per claim payments. RESULTS: The number of diagnostic imaging claims per insured MA resident increased only 0.6% from 2009 to 2013, whereas nonradiology claims increased by 6% annually. Overall diagnostic imaging expenditures, adjusted for inflation, were 27% lower in 2009 than 2013, compared with an 18% increase in nonimaging expenditures. Average payments per claim were lower in 2013 than 2009 for all modalities except nuclear medicine. Imaging procedure claims per 1,000 MA residents increased from 2009 to 2013 by 13% in MRI, from 147 to 166; by 17% in ultrasound, from 453 to 530; and by 12% in radiography (x-ray), from 985 to 1,100. However, CT claims per 1,000 fell by 37%, from 341 to 213, and nuclear medicine declined 57%, from 89 claims per 1,000 to 38. CONCLUSION: Diagnostic imaging utilization exhibited negligible growth over the study period. Diagnostic imaging expenditures declined, largely the result of falling payments per claim in most imaging modalities, in contrast with increased utilization and spending on nonimaging services. Utilization of MRI, ultrasound, and x-ray increased from 2009 to 2013, whereas CT and nuclear medicine use decreased sharply, although CT was heavily impacted by billing code changes.

Prediction of the histopathologic findings of intrahepatic cholangiocarcinoma: qualitative and quantitative assessment of diffusion-weighted imaging.

OBJECTIVE: To correlate qualitative and quantitative diffusion weighted imaging (DWI) characteristics of intrahepatic cholangiocarcinoma (ICC) with histopathologic tumour grade and fibrosis content. METHODS: Fifty-one patients (21M/30F; mean age 61y) with ICC and MRI including DWI were included in this IRB-approved multicentre retrospective study. Qualitative tumour features were assessed. Tumour apparent diffusion coefficient (ADC) mean, minimum, and normalized (nADCliver) values were computed. Tumour grade [well(G1), moderately(G2), or poorly differentiated(G3)] and tumour fibrosis content [minimal(1), moderate(2), or abundant(3)] were categorized pathologically. Imaging findings and ADC values were compared with pathologic measures. Utility of ADC values for predicting tumour grade was assessed using ROC analysis. RESULTS: 51 ICCs (mean size 6.5±1.1 cm) were assessed. 33/51(64%) of ICCs demonstrated diffuse hyperintensity and 15/51(29%) demonstrated target appearance on DWI. Infiltrative morphology (p=0.02) and tumour size (p=0.04) were associated with G3. ADCmean and nADCmean of G3 (1.32±0.47x10-3 mm2/sec and 0.97±0.95) were lower than G1+G2 (1.57±0.39x10-3 mm2/sec and 1.24±0.49; p=0.03 and p=0.04). ADCmean and nADCmean were inversely correlated with tumour grade (p<0.025). No correlation was found between ADC and tumour fibrosis content. AUROC, sensitivity and specificity of nADCmean for G3 versus G1+G2 were 0.71, 89.5% and 55.5%. CONCLUSION: ADC quantification has reasonable accuracy for predicting ICC grade. KEY POINTS: • ADC quantification was useful for predicting ICC tumour grade. • Infiltrative tumour morphology and size were associated with poorly differentiated ICCs. • ADC values depended more on ICC tumour grade than fibrosis content. • Ability to predict ICC tumour grade non-invasively could impact patient management.

Optimizing MRI Logistics: Focused Process Improvements Can Increase Throughput in an Academic Radiology Department.

OBJECTIVE: The purpose of this study was to describe and evaluate the effect of focused process improvements on protocol selection and scheduling in the MRI division of a busy academic medical center, as measured by examination and room times, magnet fill rate, and potential revenue increases and cost savings to the department. MATERIALS AND METHODS: Focused process improvements, led by a multidisciplinary team at a large academic medical center, were directed at streamlining MRI protocols and optimizing matching protocol ordering to scheduling while maintaining or improving image quality. Data were collected before (June 2013) and after (March 2015) implementation of focused process improvements and divided by subspecialty on type of examination, allotted examination time, actual examination time, and MRI parameters. Direct and indirect costs were compiled and analyzed in consultation with the business department. Data were compared with evaluated effects on selected outcome and efficiency measures, as well as revenue and cost considerations. Statistical analysis was performed using a t test. RESULTS: During the month of June 2013, 2145 MRI examinations were performed at our center; 2702 were performed in March 2015. Neuroradiology examinations were the most common (59% in June 2013, 56% in March 2015), followed by body examinations (25% and 27%). All protocols and parameters were analyzed and streamlined for each examination, with slice thickness, TR, and echo train length among the most adjusted parameters. Mean time per examination decreased from 43.4 minutes to 36.7 minutes, and mean room time per patient decreased from 46.3 to 43.6 minutes (p = 0.009). Potential revenue from increased throughput may yield up to $3 million yearly (at $800 net revenue per scan) or produce cost savings if the facility can reduce staffed scanner hours or the number of scanners in its fleet. Actual revenue and expense impacts depend on the facility's fixed and variable cost structure, payer contracts, MRI fleet composition, and unmet MRI demand. CONCLUSION: Focused process improvements in selecting MRI protocols and scheduling examinations significantly increased throughput in the MRI division, thereby increasing capacity and revenue. Shorter scan and department times may also improve patient experience.

A Practical Guide to MR Imaging Safety: What Radiologists Need to Know.

Magnetic resonance (MR) imaging can provide critical diagnostic and anatomic information while avoiding the use of ionizing radiation, but it has a unique set of safety risks associated with its reliance on large static and changing magnetic fields, high-powered radiofrequency coil systems, and exogenous contrast agents. It is crucial for radiologists to understand these risks and how to mitigate them to protect themselves, their colleagues, and their patients from avoidable harm and to comply with safety regulations at MR imaging sites. Basic knowledge of MR imaging physics and hardware is necessary for radiologists to understand the origin of safety regulations and to avoid common misconceptions that could compromise safety. Each of the components of the MR imaging unit can be a factor in injuries to patients and personnel. Safety risks include translational force and torque, projectile injury, excessive specific absorption rate, burns, peripheral neurostimulation, interactions with active implants and devices, and acoustic injury. Standards for MR imaging device safety terminology were first issued in 2005 and are required by the U.S. Food and Drug Administration, with devices labeled as "MR safe," "MR unsafe," or "MR conditional." MR imaging contrast agent safety is also discussed. Additional technical and safety policies relate to pediatric, unconscious, incapacitated, or pregnant patients and pregnant imaging personnel. Division of the MR imaging environment into four distinct, clearly labeled zones--with progressive restriction of entry and increased supervision for higher zones--is a mandatory and key aspect in avoidance of MR imaging-related accidents. All MR imaging facilities should have a documented plan to handle emergencies within zone IV, including cardiac arrest or code, magnet quench, and fires. Policies from the authors' own practice are provided for additional reference. Online supplemental material is available for this article.

Q-elastosonography of solid thyroid nodules: assessment of diagnostic efficacy and interobserver variability in a large patient cohort.

OBJECTIVE: Evaluation of the diagnostic efficacy and interobserver agreement of Q-elastography in the differentiation of benign from malignant thyroid nodules. METHODS: A total of 344 thyroid nodules in 288 patients were examined with grey-scale and colour Doppler ultrasound (CDUS) and Q-elastography by two independent operators. Nodules with hypoechogenicity, poorly defined margins, microcalcifications, and intralesional vascularity were classified as suspicious. Diagnostic performances of CDUS features and Q-elastography for predicting thyroid malignancy were estimated using ROC analysis. Cytology or histopathology was the reference standard. Interobserver agreement in the evaluation of CDUS and Q-elastography was assessed using Cohen's k-statistic. RESULTS: Q-elastography showed excellent diagnostic performance for the prediction of thyroid malignancy, with sensitivity of 93 % and specificity of 92 % for operator 1 (best cutoff at 2.02), and sensitivity of 84 % and specificity of 79 % for operator 2 (best cutoff at 1.86). Performance of Q-elastography was superior to that of CDUS. Reproducibility of the findings was excellent for both Q-elastography and CDUS features as assessed with Cohen's k, which was highest for strain ratio measurements (0.95) and lowest for the echogenicity score (0.83). CONCLUSIONS: Q-elastography showed excellent performance. It is a valid and reproducible diagnostic method as well as a promising tool for identifying suspicious solid thyroid nodules needing cytological assessment and surgery. KEY POINTS: • Elastography is an additional tool for optimal characterisation of malignant thyroid nodules. • The use of semiquantitative elastographic evaluation increases the diagnostic performance, • The interobserver agreement of quantitative elastography can be considered to be good.

Multidetector-row computed tomography enterographic assessment of the ileal-anal pouch: descriptive radiologic analysis with endoscopic and pathologic correlation.

OBJECTIVE: To describe the multidetector-row computed tomography enterographic (MD-CTE) features of the ileal-anal pouch after ileal pouch anal anastomosis (IPAA) surgery and correlate them with pouch endoscopy and histopathologic findings. METHODS: All MD-CTE examinations performed on patients who underwent IPAA from July 1, 2005 to December 1, 2010 (n = 35; 16 [45.7%] men; mean age, 37.7 years; age range, 22-72 years) were retrospectively evaluated in consensus by 2 radiologists. All studies were evaluated for the presence of multiple imaging features. Two radiographic scores were then calculated: a total radiographic score and a radiographic active inflammation score. In patients who underwent MD-CTE, pouch endoscopy, and biopsy within 30 days (n = 13), both scores were correlated with findings on pouch endoscopy and histopathology. RESULTS: Of the 35 patients, 33 (94%) had at least one MD-CTE finding of active or chronic pouch inflammation and 27 patients (77%) had at least one MD-CTE finding of active pouch inflammation. Of the 13 patients who underwent endoscopy and biopsy, the total radiographic score demonstrated a strong positive correlation with endoscopic score (r = 0.81; P = 0.001) and a moderate positive correlation with histopathologic score (r = 0.56; P = 0.047). The radiographic active inflammation score demonstrated a strong positive correlation with endoscopic score (r = 0.83; P = 0.0004), but only a weak nonsignificant positive correlation with histopathologic score (r = 0.492, P = 0.087). CONCLUSIONS: In patients who had IPAA surgery, findings on MD-CTE correlate positively with findings on pouch endoscopy and histopathology and are sensitive measures for pouch inflammation with high positive predictive value. Thus, MD-CTE can be a useful noninvasive test in the early evaluation of symptomatic patients.

Repeat abdominal imaging examinations in a tertiary care hospital.

BACKGROUND: Reducing unnecessary repeat imaging may reduce waste and costs, and improve health care quality. We aimed to quantify repeat imaging rates in patients with abdominal imaging examinations, and identify factors associated with repeat imaging. METHODS: We retrospectively analyzed all diagnostic abdominal computed tomography (CT), magnetic resonance imaging (MRI), ultrasound (US), fluoroscopy, and radiograph reports performed at our institution between January 1, 2000 and December 31, 2009. Primary outcome measure was the rate of repeat abdominal imaging (RAI) examinations, defined as any imaging examination of the abdomen on the same patient within 0-90 days of the first (enrollment) examination. We used natural language processing tools to extract recommendations for follow-up imaging from radiology reports. Univariate and multivariate logistic regressions were fitted to determine the effect of patient age, sex, study modality, care setting, follow-up recommendations, and history of neoplasm on the primary outcome over time. RESULTS: Over 10 years, 245,184 abdominal imaging examinations were performed (43.2% CT, 20.6% US, 16.6% radiograph, 13.9% fluoroscopy, 5.7% MRI). The RAI rate remained unchanged (41.2% to 41.7%); unadjusted RAI volume increased from 6596 to 12,218 (P <.01). Most repeat studies (88.2%) were not preceded by a radiologist's recommendation. Practice setting, study modality, patient age, sex, underlying health condition, and radiologist's recommendations were associated with higher rate of repeat abdominal imaging examinations. CONCLUSIONS: A large proportion of abdominal imaging examinations result in a repeat study. Many factors contribute to repeat imaging, including patient age, sex, underlying disease, initial study modality, practice setting, and radiologist's recommendation.

MDCT assessment of ulcerative colitis: radiologic analysis with clinical, endoscopic, and pathologic correlation.

PURPOSE: Evaluate the utility of multidetector-row computed tomography (MDCT) in assessing the severity of ulcerative colitis (UC) in comparison with clinical assessment, colonoscopy, and histopathology. MATERIALS AND METHODS: Patients with UC evaluated with at least one abdominal contrast-enhanced CT study (CECT) within 7 days of colonoscopy with biopsy were included. CECT of 23 patients (12 male; mean age 40 years; age range, 20-72 years) were retrospectively evaluated in consensus by two radiologists. A total of 138 lower GI tract segments were evaluated by CECT and graded for the presence of bowel wall thickening, mucosal hyperenhancement, mural stratification, mesenteric hyperemia, pericolonic stranding, and lymph nodes. A cumulative CT severity score was calculated and correlated with clinical, colonoscopic, and histopathologic severity grades. RESULTS: The cumulative CT score and individual CECT scores for bowel wall thickening, mucosal hyperenhancement, and mural stratification showed positive correlation with clinical severity (P < 0.05). All individual CECT features as well as the cumulative CT score demonstrated statistically significant correlation with colonoscopic severity (P < 0.0001). Only wall thickening on CECT demonstrated significant correlation with histopathologic severity (P = 0.01). CONCLUSION: Disease severity assessment by MDCT demonstrates positive correlation with severity established by clinical assessment and colonoscopy. Only increasing wall thickness, as graded on MDCT, correlates with histopathologic disease severity.

An assessment of the severity of interstitial pancreatitis.

BACKGROUND & AIMS: There is limited information on the incidence of and factors associated with severe disease among patients with interstitial pancreatitis (IP). We evaluated a large cohort of patients with IP and compared data with those from patients with extrapancreatic necrosis (EXPN). METHODS: We evaluated 149 consecutive patients with IP admitted over a 2.5-year period. Transferred patients were excluded. We collected data on age, Charlson comorbidity score (CCI), measures of severity on admission or within 24 hours (Acute Physiology and Chronic Health Evaluation II, bedside index for severity of acute pancreatitis scores), persistent (>48 h) systemic inflammatory response syndrome, persistent organ failure, need for intensive care unit, length of hospital stay (in days), and mortality. We also analyzed levels of severity among those with IP and EXPN. Statistical analysis was performed using SAS version 9.1 (Cary, NC). RESULTS: Among the patients with IP, the median CCI score was 1, the median Acute Physiology and Chronic Health Evaluation II score was 7, and the median bedside index for severity of acute pancreatitis score was 1. In addition, the median length of hospital stay was only 4 days; only 1% had persistent organ failure and only 1% to 2% required intervention. The mortality rate of IP was 3%; it was associated significantly with comorbidity (the median CCI scores of nonsurvivors and survivors was 4 and 1, respectively, P = .003). Patients with EXPN had greater levels of disease severity, compared with patients with IP. CONCLUSIONS: IP is severe in only 1% to 3% of patients; mortality of IP is associated strongly with comorbidity. EXPN is more frequently severe than IP; EXPN must be distinguished from IP in clinical studies.

Dynamic MR defecography: assessment of the usefulness of the defecation phase.

OBJECTIVE: The purpose of this study was to assess the usefulness of the defecation phase during dynamic MR defecography. MATERIALS AND METHODS: The images from 85 MR defecographic examinations (83 patients; age range, 20-88 years; mean, 52.7) were retrospectively reviewed in consensus by two observers. Images from each of four phases (rest, maximal sphincter contraction and squeezing, maximal straining, and defecation) were evaluated and scored independently with a modified previously published grading system. Features evaluated included the presence and degree of bladder, vaginal, and rectal descent and the presence and size of rectocele, enterocele, and intussusception. Statistical analysis was performed with a variety of tests. RESULTS: Compared with images obtained in the other phases, defecation phase images helped in identification of additional cases of abnormal bladder descent in 43 examinations (50.6%), abnormal vaginal descent in 52 examinations (61.2%), and abnormal rectal descent in 11 examinations (12.9%). Similarly, only defecation phase images depicted previously undetected rectoceles 2 cm or larger in 31 examinations (36.5%), enteroceles in 34 examinations (40%), and intussusceptions in 22 examinations (25.9%). The number of additional cases of abnormalities identified on defecation phase images was significantly greater than the number identified on images obtained in the other phases (p < 0.005). The average total scores for the rest, squeeze, strain, and defecation phases were 1.4, 0.7, 2.3, and 6.6. The average total defecation phase score was significantly greater than the average total score in any of the other phases (p < 0.001). CONCLUSION: During dynamic MR defecography, defecation phase imaging yields important additional information on the presence and degree of pelvic floor abnormalities and is therefore an essential component of MR defecographic examinations.

Acute pancreatitis: imaging utilization practices in an urban teaching hospital--analysis of trends with assessment of independent predictors in correlation with patient outcomes.

PURPOSE: To evaluate imaging utilization trends in patients with acute pancreatitis (AP) and to assess independent predictors of radiology usage in relation to patient outcomes. MATERIALS AND METHODS: Institutional review board approval was obtained for this HIPAA-compliant study; written informed consent was waived. AP-related radiologic studies in 252 patients admitted for AP between June 2005 and December 2007 were collected during and for a 1-year period after hospitalization. Clinical data were collected from patients' medical records, while imaging data were obtained from the radiology information system. Linear regression models were used to investigate predictors and time trends of imaging utilization, after adjustment for confounders. Patient outcomes, measured by using mortality, intensive care unit admission, need for surgical intervention, organ failure, and persistent systemic inflammatory response syndrome, were evaluated by using logistic regression. RESULTS: Mean utilization was 9.9 radiologic studies per patient (95% confidence interval: 7.5, 12.3), with relative value unit (RVU) of 7.8 (95% confidence interval: 6.3, 9.4). Utilization was highest on day 0, declining rapidly by day 4; 53% of imaging occurred during initial hospitalization. Chest radiography (38%) and abdominal computed tomography (CT) (17%) were the most commonly performed studies. Patients with longer hospital stay (P = .001), higher Acute Physiology and Chronic Health Evaluation II score (P = .0012), higher pain levels (P = .003), drug-induced AP (P = .002), and prior episodes of AP (P < .001) underwent significantly more radiologic studies. After adjustment for confounders, a 2.5-fold increase in the use of high-cost (CT and magnetic resonance imaging) examinations and a 1.4-fold increase in RVUs per case-mix-adjusted admissions (P < .05) were observed during the 2.5-year study period. This increased use was not associated with improvement in patient outcomes. CONCLUSION: AP severity explained substantial variation in imaging utilization. After case-mix adjustment for severity and other patient level factors, there was still increasing use over the course of time without notable improvement in patient outcomes.

Low-dose 18F-FDG PET/CT enterography: improving on CT enterography assessment of patients with Crohn disease.

UNLABELLED: The purpose of this study was to evaluate the diagnostic efficacy of low-dose, combined (18)F-FDG PET/CT enterography (PET/CTE), compared with CT enterography (CTE) alone, in the assessment of patients with Crohn disease. METHODS: Thirteen patients with Crohn disease were prospectively enrolled in this pilot study and underwent abdominal-pelvic (18)F-FDG PET/CTE using neutral oral and intravenous contrast medium. The effective dose from PET/CTE was 17.7 mSv for the first 4 patients and 8.31 mSv for the last 9 patients. Six patients underwent surgical resection of the bowel, and 7 patients underwent colonoscopy with biopsies within 27 d (mean, 12 d) of PET/CTE. PET/CTE and CTE images were each visually assessed for Crohn disease involvement in 54 bowel segments with pathology correlation. Extraintestinal findings were recorded. A CTE severity score, maximum standardized uptake value (SUVmax), SUVmax ratio, simplified endoscopic score, and clinical parameters were correlated with pathology inflammation grade, on a per-patient basis and on a per-bowel-segment basis, using Spearman correlation. RESULTS: In 3 (23.1%) of 13 patients, (18)F-FDG uptake using PET/CTE revealed active inflammation in a bowel segment not evident using CTE (n = 2) or revealed an enterocolic fistula missed with CTE (n = 1). Visual interpretation of both PET/CTE and CTE images detected the presence of disease in all bowel segments with more than mild inflammation (sensitivity, 100%; specificity, 89.7%; positive predictive value, 78.9%; and negative predictive value, 100%). Correlation to inflammation grade per patient was the strongest for the SUVmax ratio (0.735, P = 0.004) and SUVmax (0.67, P = 0.013), as compared with the CTE score (0.62, P = 0.024). Correlation with inflammation per bowel segment was higher for the CTE score (0.79, P < 0.0001) than the SUVmax ratio (0.62, P < 0.0001) or SUVmax (0.48, P < 0.0001). SUVmax correlated strongly with serum C-reactive protein (0.82, P = 0.023), but CTE score did not. CONCLUSION: Low-dose (18)F-FDG PET/CTE, compared with CTE, may improve the detection and grading of active inflammation in patients with Crohn disease. PET/CTE also may reveal clinically significant findings, such as enterocolic fistula, not evident on PET or CTE alone.

Incidental extraurinary findings at MDCT urography in patients with hematuria: prevalence and impact on imaging costs.

OBJECTIVE: We determined the prevalence of incidental extraurinary findings at MDCT urography in patients with hematuria and evaluated their impact on subsequent imaging costs. MATERIALS AND METHODS: Three hundred forty-four consecutive patients with hematuria were evaluated with MDCT urography. Incidental extraurinary findings were classified into three categories according to their clinical significance (high, moderate, and low). Medical records were reviewed, and the cost of additional imaging examinations was calculated using 2002 Medicare reimbursements. RESULTS: Extraurinary findings were detected in 259 patients (75.3%). Of these, 62 patients (18.0%) had highly clinically significant findings, including three cancers. Only 20 (32.3%) of the 62 patients with highly clinically significant findings underwent additional imaging for findings of high clinical significance; 10 (16.1%) were followed clinically, and 32 (51.6%) were not evaluated. The most prevalent highly clinically significant findings were pulmonary nodules and lymphadenopathy. Of the 344 patients studied, 116 (33.7%) had findings in which the highest level of clinical significance was moderate; 81 (23.5%) had findings of only low clinical significance. Nine patients (2.6%) underwent additional imaging for findings of moderate or low clinical significance. Overall, 29 patients (8.4%) underwent further imaging at a cost of $14,231 (average of $41.37 per patient). CONCLUSION: Although incidental extraurinary findings were common at MDCT urography, only a small percentage of patients were imaged further. MDCT urography, when used to evaluate patients with hematuria, detects extraurinary disease without a substantial increase in per-patient imaging costs.