Frequency of recommendations for additional imaging in diagnostic ultrasound examinations: Evaluation of radiologist, technologist, and other examination-related factors.

OBJECTIVE: Our aim in this study was to evaluate the effect of the radiologist, technologist, and other examination-related factors on the frequency of recommendations for additional imaging (RAI) during sonographic (US) interpretation. METHODS: We retrospectively reviewed 719 US reports from a single academic medical center for the presence of RAI. All studies had been interpreted by one of three abdominal radiologists. Examinations were performed at an outpatient radiology facility with no onsite radiologist (n = 299) or at an inpatient emergency department or hospital-based outpatient setting that had an onsite radiologist (n = 420). Possible associations between the frequency of RAI and the presence of an onsite radiologist, location of the examination, body part or region imaged, patient age, technologist performing the exam, and radiologist reading the exam were evaluated. RESULTS: There were significant differences between each pair of radiologists in terms of overall frequency of RAI (p < 0.001) (radiologist 1: 12.0% [22/184]; radiologist 2: 21.6% [78/361]; and radiologist 3: 45.5% [79/174]). In addition, there were statistically significant differences in the frequency of RAI among studies scanned by the 10 different US technologists (13.6%-40.0%, p = 0.03). However, other factors such as patient age, patient sex, US unit, patient location, and radiologist location were not associated with the frequency of RAI (p = 0.15-0.93). CONCLUSIONS: The individual radiologist and technologist influenced the frequency of RAI for US examinations, whereas other examination-related factors did not. The observed substantial variability in RAI between radiologists and technologists warrants further study, with consideration of strategies to optimize RAI within US reports.

Pancreatic ductal adenocarcinoma radiology reporting template: consensus statement of the Society of Abdominal Radiology and the American Pancreatic Association.

Pancreatic ductal adenocarcinoma is an aggressive malignancy with a high mortality rate. Proper determination of the extent of disease on imaging studies at the time of staging is one of the most important steps in optimal patient management. Given the variability in expertise and definition of disease extent among different practitioners as well as frequent lack of complete reporting of pertinent imaging findings at radiologic examinations, adoption of a standardized template for radiology reporting, using universally accepted and agreed on terminology for solid pancreatic neoplasms, is needed. A consensus statement describing a standardized reporting template authored by a multi-institutional group of experts in pancreatic ductal adenocarcinoma that included radiologists, gastroenterologists, and hepatopancreatobiliary surgeons was developed under the joint sponsorship of the Society of Abdominal Radiologists and the American Pancreatic Association. Adoption of this standardized imaging reporting template should improve the decision-making process for the management of patients with pancreatic ductal adenocarcinoma by providing a complete, pertinent, and accurate reporting of disease staging to optimize treatment recommendations that can be offered to the patient. Standardization can also help to facilitate research and clinical trial design by using appropriate and consistent staging by means of resectability status, thus allowing for comparison of results among different institutions.

Pancreatic ductal adenocarcinoma radiology reporting template: consensus statement of the society of abdominal radiology and the american pancreatic association.

Pancreatic ductal adenocarcinoma is an aggressive malignancy with a high mortality rate. Proper determination of the extent of disease on imaging studies at the time of staging is one of the most important steps in optimal patient management. Given the variability in expertise and definition of disease extent among different practitioners as well as frequent lack of complete reporting of pertinent imaging findings at radiologic examinations, adoption of a standardized template for radiology reporting, using universally accepted and agreed on terminology for solid pancreatic neoplasms, is needed. A consensus statement describing a standardized reporting template authored by a multi-institutional group of experts in pancreatic ductal adenocarcinoma that included radiologists, gastroenterologists, and hepatopancreatobiliary surgeons was developed under the joint sponsorship of the Society of Abdominal Radiologists and the American Pancreatic Association. Adoption of this standardized imaging reporting template should improve the decision-making process for the management of patients with pancreatic ductal adenocarcinoma by providing a complete, pertinent, and accurate reporting of disease staging to optimize treatment recommendations that can be offered to the patient. Standardization can also help to facilitate research and clinical trial design by using appropriate and consistent staging by means of resectability status, thus allowing for comparison of results among different institutions.

Managing incidental findings on abdominal and pelvic CT and MRI, Part 2: white paper of the ACR Incidental Findings Committee II on vascular findings.

This white paper describes vascular incidental findings found on CT and MRI of the abdomen and pelvis. Recommendations for management are included. This represents the second of 4 such papers from the ACR Incidental Findings Committee II, which used a consensus method based on repeated reviews and revisions and a collective review and interpretation of relevant literature. Topics include definitions and recommended management for abdominal aortic, iliac, splenic, renal, and visceral artery aneurysms. Other incidentally discovered aortic conditions, systemic venous anomalies, compression syndromes, abdominal venous thrombosis, and gonadal and pelvic venous conditions are also discussed. A table is provided for reference.

Diagnosis and management of cystic pancreatic lesions.

OBJECTIVE: The purpose of this review is to outline the management guidelines for the care of patients with cystic pancreatic lesions. CONCLUSION: The guidelines are as follows: Annual imaging surveillance is generally sufficient for benign serous cystadenomas smaller than 4 cm and for asymptomatic lesions. Asymptomatic thin-walled unilocular cystic lesions smaller than 3 cm or side-branch intraductal papillary mucinous neoplasms should be followed up with CT or MRI at 6 and 12 months interval after detection. Cystic lesions with more complex features or with growth rates greater than 1 cm/year should be followed more closely or recommended for resection if the patient's condition allows surgery. Symptomatic cystic lesions, neoplasms with high malignant potential, and lesions larger than 3 cm should be referred for surgical evaluation. Endoscopic ultrasound with fine-needle aspiration (FNA) biopsy can be used preoperatively to assess the risk of malignancy.

Impacting key performance indicators in an academic MR imaging department through process improvement.

PURPOSE: The aim of this study was to evaluate all aspects of workflow in a large academic MRI department to determine whether process improvement (PI) efforts could improve key performance indicators (KPIs). METHODS: KPI metrics in the investigators' MR imaging department include daily inpatient backlogs, on-time performance for outpatient examinations, examination volumes, appointment backlogs for pediatric anesthesia cases, and scan duration relative to time allotted for an examination. Over a 3-week period in April 2011, key members of the MR imaging department (including technologists, nurses, schedulers, physicians, and administrators) tracked all aspects of patient flow through the department, from scheduling to examination interpretation. Data were analyzed by the group to determine where PI could improve KPIs. Changes to MRI workflow were subsequently implemented, and KPIs were compared before (January 1, 2011, to April 30, 2011) and after (August 1, 2011, to December 31, 2011) using Mann-Whitney and Fisher's exact tests. RESULTS: The data analysis done during this PI led to multiple changes in the daily workflow of the MR department. In addition, a new sense of teamwork and empowerment was established within the MR staff. All of the measured KPIs showed statistically significant changes after the reengineering project. CONCLUSIONS: Intradepartmental PI efforts can significantly affect KPI metrics within an MR imaging department, making the process more patient centered. In addition, the process allowed significant growth without the need for additional equipment or personnel.

Well-differentiated pancreatic neuroendocrine carcinoma in tuberous sclerosis--case report and review of the literature.

Neuroendocrine tumors of the pancreas are rare in children. They usually occur in the setting of genetic syndromes such as multiple endocrine neoplasia type 1, von Hippel-Lindau disease, and neurofibromatosis 1. These tumors have also been reported in the tuberous sclerosis complex (TSC), but the incidence is low in comparison with other syndromes. Only 9 cases have been described to date, and it is not yet well understood if any connection exists between TSC and pancreatic endocrine tumors. TSC is characterized by mutations in TSC1 and TSC2 genes, which activate the AKT-mTOR oncogenic cascade. Recent molecular studies in pancreatic endocrine tumors showed activation of the same pathway, which points toward a common molecular pathway between these two entities. We present a case of well-differentiated neuroendocrine carcinoma of the pancreas in a child with TSC and discuss the genetic aspects of this disease.

Dual-energy computed tomography applications in uroradiology.

The introduction of dual-energy computed tomography systems (ie, scanners that can simultaneously acquire images at different energies) has significant and unique applications for urologists. Imaging data from these scanners can be used to evaluate composition of urinary calculi and, by "removing" iodine from an image, significantly decrease radiation dose to patients referred for hematuria. Further, the ability to create a virtual noncontrast image obviates the need for repeated scanning in patients with incidentally detected renal and adrenal masses. Finally, the ability to quantify the regional concentration of iodine in a renal neoplasm may provide a method to monitor effectiveness of therapy before size changes become apparent.

Computer-aided detection of colorectal polyps in CT colonography with and without fecal tagging: a stand-alone evaluation.

PURPOSE: To evaluate the stand-alone performance of a computer-aided detection (CAD) algorithm for colorectal polyps in a large heterogeneous CT colonography (CTC) database that included both tagged and untagged datasets. METHODS: Written, informed consent was waived for this institutional review board-approved, HIPAA-compliant retrospective study. CTC datasets from 2063 patients were assigned to training (n = 374) and testing (n = 1689). The test set consisted of 836 untagged and 853 tagged examinations not used for CAD training. Examinations were performed at 15 sites in the United States, Asia, and Europe, using 4- to 64-multidetector-row computed tomography and various acquisition parameters. CAD sensitivities were calculated on a per-patient and per-polyp basis for polyps measuring ≥6 mm. The reference standard was colonoscopy in 1588 (94%) and consensus interpretation by expert radiologists in 101 (6%) patients. Statistical testing employed χ, logistic regression, and Mann-Whitney U tests. RESULTS: In 383 of 1689 individuals, 564 polyps measuring ≥6 mm were identified by the reference standard (347 polyps: 6-9 mm and 217 polyps: ≥10 mm). Overall, CAD per-patient sensitivity was 89.6% (343/383), with 89.0% (187/210) for untagged and 90.2% (156/173) for tagged datasets (P = 0.72). Overall, per-polyp sensitivity was 86.9% (490/564), with 84.4% (270/320) for untagged and 90.2% (220/244) for tagged examinations (P = 068). The mean false-positive rate per patient was 5.14 (median, 4) in untagged and 4.67 (median, 4) in tagged patient datasets (P = 0.353). CONCLUSION: Stand-alone CAD can be applied to both tagged and untagged CTC studies without significant performance differences. Detection rates are comparable to human readers at a relatively low false-positive rate, making CAD a useful tool in clinical practice.

Delayed presentation of splenic rupture following colonoscopy: clinical and CT findings.

The purpose of this study is to investigate the clinical and CT findings in patients with symptomatic colonoscopy-induced splenic rupture, and to assess for common features among this cohort. Multi-center search yielded 11 adults with symptomatic splenic injury related to colonoscopy. Workup included abdominal CT in 10 (91%) cases and abdominal radiography in two patients (one patient had both). Colonoscopy findings, post-procedural course, and CT findings were systematically reviewed. Mean patient age was 62.2 years (range, 51-84 years); 8 (73%) of 11 were female. The majority (64%) of colonoscopies were for screening. No immediate complications were reported at optical colonoscopy; tortuosity/redundancy was noted in five cases. Except for a small (8 mm) polyp in one case and a large (10 mm) polyp in another, the remaining nine patients had either diminutive or no polyps. Only one patient presented with hemodynamic instability during post-colonoscopy recovery; the other ten had a delayed presentation ranging from 8 h to 8 days (mean, 2.1 days). All 11 patients presented with abdominal pain. CT was diagnostic for splenic injury with subcaspular and/or perisplenic hematoma in all ten CT cases. Hemoperitoneum was present in eight, visible splenic laceration in three cases, and splenic artery pseudoaneurysm in one case. Five patients underwent splenectomy (four emergent) and six patients were treated conservatively. Average hospital stay was 5.5 days (range, 3-10 days). Colonoscopy-induced splenic rupture characteristically presents as a delayed and often serious complication. In cases of apparent non-traumatic splenic hematoma or rupture at CT, eliciting a history of recent colonoscopy may identify the etiology.

Iodine quantification with dual-energy CT: phantom study and preliminary experience with renal masses.

OBJECTIVE: The purpose of this study was to validate the utility of dual-source dual-energy MDCT in quantifying iodine concentration in a phantom and in renal masses. MATERIALS AND METHODS: A series of tubes containing solutions of varying iodine concentration were imaged with dual-source dual-energy MDCT. Iodine concentration was calculated and compared with known iodine concentration. Single-phase contrast-enhanced dual-source dual-energy MDCT data on 15 patients with renal lesions then were assessed independently by two readers. Dual-energy postprocessing was used to generate iodine-only images. Regions of interest were placed on the iodine image over the lesion and, as a reference, over the aorta, for recording of iodine concentration in the lesion and in the aorta. Another radiologist determined lesion enhancement by comparing truly unenhanced with contrast-enhanced images. Mixed-model analysis of variance based on ranks was used to compare lesion types (simple cyst, hemorrhagic cyst, enhancing mass) in terms of lesion iodine concentration and lesion-to-aorta iodine ratio. RESULTS: In the phantom study, there was excellent correlation between calculated and true iodine concentration (R(2) = 0.998, p < 0.0001). In the patient study, 13 nonenhancing (10 simple and three hyperdense cysts) and eight enhancing renal masses were evaluated in 15 patients. The lesion iodine concentration and lesion-to-aorta iodine ratio in enhancing masses were significantly higher than in hyperdense and simple cysts (p < 0.0001). CONCLUSION: Iodine quantification with dual-source dual-energy MDCT is accurate in a phantom and can be used to determine the presence and concentration of iodine in a renal lesion. Characterization of renal masses may be possible with a single dual-source dual-energy MDCT acquisition without unenhanced images or reliance on a change in attenuation measurements.

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.

Dual-energy computed tomography imaging of the aorta after endovascular repair of abdominal aortic aneurysm.

Endovascular repair is increasingly considered a less-invasive alternative to open repair of abdominal aortic aneurysm. However, there are still many potential complications of endovascular repair, including endoleaks, graft migration, thrombosis, and fistula formation. Endoleak is the most common complication for which these patients undergo long-term imaging surveillance. Most centers acquire computed tomographic (CT) data before contrast administration and during an arterial and delayed phase of aortic enhancement after the administration of intravenous contrast material to optimize detection of endoleaks. Although this technique works well, the downside is significant patient radiation exposure. Although the carcinogenic risk of ionizing radiation because of CT exposure is low, it has been linked to an increase in the lifelong risk of developing fatal cancers. Furthermore, this risk is cumulative and increases with multiple radiation exposure, as is true in surveillance after endovascular repair. As a result, considerable research is being performed to optimize CT protocols in an effort to decrease radiation dose. One such approach is to image these patients with recently introduced dual source dual-energy CT system. Using this technique, virtual noncontrast data may be generated from a postcontrast acquisition which may obviate the routine acquisition of noncontrast acquisition, thus decreasing radiation dose. In this article, we discuss the role of dual energy CT imaging in evaluation of patients after endovascular repair of abdominal aortic aneurysm.

Dual source dual energy MDCT: comparison of 80 kVp and weighted average 120 kVp data for conspicuity of hypo-vascular liver metastases.

PURPOSE: To determine whether liver metastases conspicuity is improved at 80 kVp when compared with weighted average (WA) simulated 120 kVp data using dual source dual energy CT. METHODS: A total of 11 patients with 44 hypo-vascular liver metastases underwent contrast enhanced Dual Energy CT (DECT). In all cases the subject's abdominal diameter measured

Single-phase dual-energy CT allows for characterization of renal masses as benign or malignant.

PURPOSE: To evaluate the diagnostic accuracy of dual-energy CT (DECT) in renal mass characterization using a single-phase acquisition. MATERIALS AND METHODS: A total of 202 patients (148 males, 54 females; 63 +/- 13 years) with ultrasound-based suspicion of a renal mass underwent unenhanced single energy and nephrographic phase DECT on a dual source scanner (Siemens Somatom Definition Dual Source, n = 174; Somatom Definition Flash, n = 28). Scan parameters for DECT were: tube potential, 80/100 and 100/Sn140 kVp; exposure, 404/300 and 96/232 effective mAs; collimation, 14 x 1.2/32 x 0.6 mm. Two abdominal radiologists assessed DECT and SECT image quality and noise on a 5-point visual analogue scale. Using solely the DE acquisition including virtual nonenhanced (VNE) and color coded iodine images that enable direct visualization of iodine, masses were characterized as benign or malignant. In a second reading session after 34 to 72 (average: 55) days, the same assessment was again performed using both the true nonenhanced (TNE) and nephrographic phase scans thereby simulating conventional single-energy CT. Sensitivities, specificities, diagnostic accuracies, and interpretation times and were recorded for both reading paradigms. Dose reduction of a single-phase over a dual-phase protocol was calculated. Results were tested for statistical significance using the paired Wilcoxon signed rank test and student t test. Differences in sensitivities were tested for significance using the McNemar test. RESULTS: Of the 202 patients, 115 (56.9%) underwent surgical resection of renal masses. Histopathology showed malignancy in 99 and benign tumors in 18 patients, in 48 patients (23.7%), follow-up imaging showed size stability of lesions diagnosed as benign, and 37 patients (18.3%) had no mass. Based on DECT only, 95/99 (96.0%) patients with malignancy and 96/103 (93.2%) patients without malignancy were correctly identified, for an overall accuracy of 94.6%. The dual-phase approach identified 96/99 (97.0%) and 98/103 (95.1%), accuracy 96.0%, P > 0.05 for both. Mean interpretation time was 2.2 +/- 0.8 minutes for DECT, and 3.5 +/- 1.0 minutes for the dual-phase protocol, P < 0.001. Mean VNE/TNE image quality was 1.68 +/- 0.65/1.30 +/- 0.59, noise was 2.03 +/- 0.57/1.18 +/- 0.29, P < 0.001 for both. Omission of the true unenhanced phase lead to a 48.9 +/- 7.0% dose reduction. CONCLUSION: DECT allows for fast and accurate characterization of renal masses in a single-phase acquisition. Interpretation of color coded images significantly reduces interpretation time. Omission of a nonenhanced acquisition can reduce radiation exposure by almost 50%.

Frequency of intraductal papillary mucinous neoplasm in patients with and without pancreas cancer.

PURPOSE: To determine the frequency of intraductal papillary mucinous neoplasm (IPMN) in patients with and without invasive ductal adenocarcinoma (IDAC). METHODS: 82 patients underwent pancreatectomy for pancreas adenocarcinoma. 68/82 subjects underwent at least one preoperative imaging study including CT (n = 43), MRI (n = 25), or both (n = 12). Imaging studies were retrospectively evaluated to determine if IPMN was present in the gland at a location distant from IDAC. In 183 different adult patients undergoing MRI for renal mass, images were evaluated to determine the frequency of IPMN. Fisher's exact test was used to test whether the prevalence of IPMN was greater among patients with pancreas cancer than those without. RESULTS: Five of 68 (7.3%) patients who underwent pancreatic resection for IDAC had IPMN at a site distant from the cancer. Two of 182 (1.1%) patients undergoing MRI for renal cancer had imaging evidence of IPMN. There was a significant difference (p = 0.017) in the prevalence of IPMN between patients with and without IDAC. The odds ratio for IPMN as a predictor of pancreas cancer was estimated as 7.18. CONCLUSION: IPMN occurs with increased frequency in patients with pancreas cancer as opposed to those without pancreas cancer. and IAP.

Dual-source dual-energy MDCT of pancreatic adenocarcinoma: initial observations with data generated at 80 kVp and at simulated weighted-average 120 kVp.

OBJECTIVE: The purpose of this study was to determine whether the conspicuity of malignant tumors of the pancreas at dual-source dual-energy CT is better with 80-kVp acquisition than with 120-kVp acquisition simulated with a weighted average. MATERIALS AND METHODS: Fifteen patients with pancreatic adenocarcinoma underwent contrast-enhanced dual-source dual-energy CT. The abdominal diameter of all patients was 35 cm or less. Data were reconstructed as a weighted average of the 140- and 80-kVp acquisitions, simulating 120 kVp, and as a pure 80-kVp data set. A region-of-interest cursor was placed within the tumor and the adjacent normal parenchyma, and attenuation differences and contrast-to-noise ratios were calculated for pancreatic tumors at 80 kVp and with the weighted-average acquisition. The 80-kVp and weighted-average images were subjectively compared in terms of lesion conspicuity, image quality, and duct visualization. An exact Wilcoxon's matched pairs signed rank test was used to test whether differences in attenuation, contrast-to-noise ratio, and subjective assessment were greater at 80 kVp. RESULTS: The mean difference in attenuation for each pancreatic tumor and adjacent portion of normal pancreas was 83.27+/-29.56 (SD) HU at 80 kVp and 49.40+/-23.00 HU at weighted-average 120 kVp. Adenocarcinoma attenuation differences were significantly greater at 80 kVp than at 120 kVp (p=0.00006). Contrast-to-noise ratio was significantly higher at 80 kVp than at 120 kVp (p=0.00147). Subjective analysis showed lesion conspicuity (p=0.001) and duct visualization (p=0.0156) were significantly better on the 80-kVp images. CONCLUSION: At portal venous phase dual-source dual-energy CT, the conspicuity of malignant tumors of the pancreas is greater at 80 kVp than with weighted-average acquisition.

ACR Colon Cancer Committee white paper: status of CT colonography 2009.

PURPOSE: To review the current status and rationale of the updated ACR practice guidelines for CT colonography (CTC). METHODS: Clinical validation trials in both the United States and Europe are reviewed. Key technical aspects of the CTC examination are emphasized, including low-dose protocols, proper insufflation, and bowel preparation. Important issues of implementation are discussed, including training and certification, definition of the target lesion, reporting of colonic and extracolonic findings, quality metrics, reimbursement, and cost-effectiveness. RESULTS: Successful validation trials in screening cohorts both in the United States with ACRIN and in Germany demonstrated sensitivity > or = 90% for patients with polyps >10 mm. Proper technique is critical, including low-dose techniques in screening cohorts, with an upper limit of the CT dose index by volume of 12.5 mGy per examination. Training new readers includes the requirement of interactive workstation training with 2-D and 3-D image display techniques. The target lesion is defined as a polyp > or = 6 mm, consistent with the American Cancer Society joint guidelines. Five quality metrics have been defined for CTC, with pilot data entered. Although the CMS national noncoverage decision in May 2009 was a disappointment, multiple third-party payers are reimbursing for screening CTC. Cost-effective modeling has shown CTC to be a dominant strategy, including in a Medicare cohort. CONCLUSION: Supported by third-party payer reimbursement for screening, CTC will continue to further transition into community practice and can provide an important adjunctive examination for colorectal screening.