Coil or Plug-Assisted Ethylene Vinyl Alcohol Copolymer (EVOH) Thoracic Duct Embolization in the Treatment of Postoperative Chylothorax.

Eleven patients (5 men, 6 women) with post-operative thoracic duct injuries and high output chylothorax were treated with thoracic duct embolization (TDE). Six patients underwent intraprocedural thoracic duct ligation at the time of original procedure. In all cases, the pleural fluid demonstrated high triglyceride levels (414 mg/dL; interquartile range [IQR], 345 mg/dL). Median daily (IQR) chest tube outputs before and after TDE were 900 mL (1,200 mL) and 325 mL (630 mL), respectively. Coil- or plug-assisted ethylene vinyl alcohol (EVOH) copolymer was used as embolic agent in all patients. Technical and clinical success rates were 100% and 82%, respectively. Nontarget venous embolization of EVOH copolymer was not identified on subsequent imaging.

Minimizing Radiation Dose Outliers Through Systematic Analysis, Computed Tomography Technologist Education, and Standardized System Solutions.

OBJECTIVES: The aims of the study were to systematically analyze causes for radiation dose outliers in emergency department noncontrast head computed tomographies (CTs), to develop and implement standardized system solutions, and audit program success for an extended period of time. METHODS: This study was performed in a large, tertiary academic center between January 2015 and September 2017. Four phases of radiation dose data collection with and without prior interventions were performed. Outliers from 5 categories were evaluated for appropriateness in consensus by 2 radiologists and a senior CT technologist. RESULTS: A total of 275 ± 15 CTs per period were included. Fifty-seven inappropriate scanning parameters were found in 24 (9%) of 254 CTs during the first analysis, 27 in 21 (7%) of 290 CTs during the second, 11 in 10 (4%) of 276 during the third assessment (P = 0.006). After a year without additional intervention, the number remained stable (14 in 11/281 CTs, 4%). CONCLUSIONS: Combining a dose reporting system, individual case analysis, staff education, and implementation of systemic solutions lead to sustained radiation exposure improvement.

Pulmonary cryptococcosis coexisting with central type lung cancer in an immuocompetent patient: a case report and literature review.

BACKGROUND: Pulmonary Cryptococcosis is a common fungal infection mainly caused by Cryptococcus neoformans/C.gattii species in immunocompromised patients. Cases of pulmonary cryptococcosis in patients with normal immune function are increasingly common in China. Clinical and radiographic features of pulmonary cryptococcosis are various and without obvious characteristics, so it is often misdiagnosed as pulmonary metastatic tumor or tuberculosis. When coexisting with malignant lung tumors, it was more difficult to differentiate from metastatic lung cancer, although the coexistence of pulmonary cryptococcosis and central type lung cancer is rare. Reviewing the imaging manifestations and diagnosis of the case and the relevant literature will contribute to recognition of the disease and a decrease in misdiagnoses. CASE PRESENTATION: A 72-year-old immunocompetent Han Chinese man had repeated dry cough for more than half a year. CT examination of chest showed an irregular mass at the left hilum of the lung, and two small nodules in the right lung, which were considered as the left central lung cancer with right lung metastasis. However, the patient was diagnosed with pulmonary cryptococcosis coexisting with central type lung cancer based on the results of laboratory examination, percutaneous lung biopsy, fiberoptic bronchoscopy, and surgical pathology. The patient underwent surgical resection of the left central type lung cancer and was placed on fluconazole treatment after a positive diagnosis was made. Five years after the lung cancer surgery, the patient had a recurrence, but the pulmonary cryptococcus nodule disappeared. CONCLUSION: Our case shows that CT findings of central type lung cancer with multiple pulmonary nodules are not necessarily metastases, but may be coexisting pulmonary cryptococcosis. CT images of cryptococcosis of the lung were diverse and have no obvious characteristics, so it was very difficult to distinguish from metastatic tumors. CT-guided percutaneous lung biopsy was a simple and efficient method for identification.

Adnexal mass staging CT with a disease-specific structured report compared to simple structured report.

OBJECTIVES: To assess a disease-specific structured report (dsSR) for CT staging of ovarian malignancy compared to a simple structured report (sSR). METHODS: This is a HIPAA-compliant, IRB-approved study with waiver of informed consent. An adnexal mass-specific structured reporting CT template was developed in collaboration between gynecologic oncologists and diagnostic radiologists. The study population included 24 consecutive women who had a staging CT prior to undergoing debulking surgery for a primary ovarian malignancy. Objective evaluation by radiologists for the presence of 19 key features and subjective evaluation by gynecologic oncologists were performed to assess the clarity and usefulness for procedural planning of dsSR and sSR. Accuracy, sensitivity, and specificity were assessed using operating room notes and pathology reports as the reference standard. RESULTS: Fewer key features were missing from dsSR than sSR: 0.2 ± 0.8 (range 0-2) vs.10.2 ± 1.7 (range 7-14), respectively (p < 0.0001). Compared to sSR, gynecologic oncologists deemed dsSR more helpful (4.3 ± 0.7 vs. 3.7 ± 0.8, p < 0.0001) and easier to understand (4.3 ± 0.6 vs. 3.9 ± 0.7, p = 0.0057) (on a scale 0-5, 0 not helpful/very difficult to understand; 5 extremely helpful/very clear to understand). Gynecologic oncologists reported a higher rate of potential to modify their surgical approach based on dsSR (33-42%) compared to sSR (13-17%), p = 0.004. CONCLUSIONS: Disease-specific structured reports were more reliable than simple structured reports in describing key features essential for procedural planning. dsSR was described as more helpful and easier to understand and more likely to lead to modification of the surgical approach by gynecologic oncologists compared to sSR. KEY POINTS: • Disease-specific structured report is easier to understand and more helpful for planning gynecological surgery as compared with simple structured report. • Disease-specific structured report for pre-operative evaluation of ovarian cancer provides better documentation of essential features required for surgical planning as compared with simple structured report. • Disease-specific structured report has the potential to modify the surgical approach as assessed by gynecologic oncologists.

Asymptomatic Endometrial Thickening of 8 mm or Greater on Postcontrast Computed Tomography in Postmenopausal Women Is a Predictor of Endometrial Cancer.

OBJECTIVES: The aim of this study was to assess the value of opportunistic endometrial thickness measurement on postcontrast computed tomography (CT) as a predictor of endometrial cancer in asymptomatic postmenopausal women. METHODS: For this Health Insurance Portability and Accountability Act-compliant, institutional review board-approved retrospective study with waiver of informed consent, our institution's tumor board database was searched for postmenopausal patients, diagnosed with endometrial cancer between August 2003 and December 2016 and who had a postcontrast pelvic CT within 12 months prior to the cancer diagnosis (while they were asymptomatic)-"cancer group." Same number of age-matched patients who had postcontrast pelvic CT constituted the noncancer control group. Endometrial thickness was measured on sagittal postcontrast CT images. RESULTS: After applying exclusion criteria, 22 asymptomatic patients who were diagnosed with endometrial cancer within 1 year after the CT comprised the cancer group, and 22 age-matched patients comprised the control group. Average endometrial thickness was 18.7 ± 14.8 mm (range, 2-70 mm) in the cancer group and 3.6 ± 2.5 mm (range, 1.8-10 mm) in the control group (P < 0.0001). Endometrial thickness 8 mm or greater predicted endometrial cancer with 86% sensitivity and 91% specificity in these asymptomatic patients. Area under the receiver operating characteristic curve for endometrial thickness as a predictor of endometrial cancer was 0.92. CONCLUSIONS: Endometrial thickness 8 mm or greater on sagittal postcontrast CT was shown to have high sensitivity in opportunistic detection of endometrial cancer in asymptomatic postmenopausal women.

Ovarian Cancer: Prevalence in Incidental Simple Adnexal Cysts Initially Identified in CT Examinations of the Abdomen and Pelvis.

Purpose To evaluate the rate of malignancy in incidentally detected simple adnexal cysts at computed tomography (CT) to determine if simple-appearing cysts require follow-up. Materials and Methods In this HIPAA-compliant, institutional review board-approved retrospective cohort study, an institutional database was searched for abdominal and pelvic CT studies performed between June 2003 and December 2010 in women reported to have adnexal cysts. Adnexal cyst characterization was determined by prospective report description as well as image review by a research fellow and by a fellowship-trained abdominal radiologist for examinations with disagreement between the original report and the research fellow's assessment. Patients with known ovarian cysts or ovarian cancer at time of the index CT examination were excluded. Clinical outcome was assessed by using follow-up imaging studies, medical records, and the state cancer registry. Benign outcome was determined by benign findings at surgery, a decrease in size or resolution of a simple-appearing cyst at follow-up imaging, or stability of the cyst for at least 1 year. Descriptive statistics and 95% confidence intervals (CIs) were calculated. Results Among 42 111 women who underwent abdominal and pelvic CT examinations in the study period, 2763 (6.6%; 95% CI: 6.3%, 6.8%) (mean age, 48.1 years ± 18.1; range, 15-102 years) had a newly detected finding of ovarian cyst described in the body or impression section of the report. Median cyst size was 3.1 cm (range, 0.8-20.0 cm). Eighteen (0.7%; 95% CI: 0.4%, 1.0%) of 2763 patients were found to have ovarian cancer after an average follow-up of 5.1 years ± 3.8 (range, 0-12.8 years). None (95% CI: 0%, 0.4%) of 1031 women with simple-appearing cysts were given a diagnosis of ovarian cancer. This included none (95% CI: 0%, 0.4%) of 904 women with simple-appearing cysts with an adequate reference standard for benign outcome. Conclusion The prevalence of previously unknown adnexal cysts at CT was 6.6%, with an ovarian cancer rate of 0.7% (95% CI: 0.4%, 1.0%). All simple-appearing cysts were benign (95% CI: 99.6%, 100%). © RSNA, 2017 Online supplemental material is available for this article.

Structured vs narrative reporting of pelvic MRI for fibroids: clarity and impact on treatment planning.

OBJECTIVES: To evaluate clarity and usefulness of MRI reporting of uterine fibroids using a structured disease-specific template vs. narrative reporting for planning of fibroid treatment by gynaecologists and interventional radiologists. METHODS: This is a HIPAA-compliant, IRB-approved study with waiver of informed consent. A structured reporting template for fibroid MRIs was developed in collaboration between gynaecologists, interventional and diagnostic radiologists. The study population included 29 consecutive women who underwent myomectomy for fibroids and pelvic MRI prior to implementation of structured reporting, and 42 consecutive women with MRI after implementation of structured reporting. Subjective evaluation (on a scale of 1-10, 0 not helpful; 10 extremely helpful) and objective evaluation for the presence of 19 key features were performed. RESULTS: More key features were absent in the narrative reports 7.3 ± 2.5 (range 3-12) than in structured reports 1.2 ± 1.5 (range 1-7), (p < 0.0001). Compared to narrative reports, gynaecologists and radiologists deemed structured reports both more helpful for surgical planning (p < 0.0001) (gynaecologists: 8.5 ± 1.2 vs. 5.7 ± 2.2; radiologists: 9.6 ± 0.6 vs. 6.0 ± 2.9) and easier to understand (p < 0.0001) (gynaecologists: 8.9 ± 1.1 vs. 5.8 ± 1.9; radiologists: 9.4 ± 1.3 vs. 6.3 ± 1.8). CONCLUSION: Structured fibroid MRI reports miss fewer key features than narrative reports. Moreover, structured reports were described as more helpful for treatment planning and easier to understand. KEY POINTS: • Structured reports missed only 1.2 ± 1.5 out of 19 key features, as compared to narrative reports that missed 7.3 ± 2.5 key features for planning of fibroid treatment. • Structured reports were more helpful and easier to understand by clinicians. • Structured template can provide essential information for fibroids treatment planning.

Opportunistic Bone Density Measurement on Abdomen and Pelvis Computed Tomography to Predict Fracture Risk in Women Aged 50 to 64 Years Without Osteoporosis Risk Factors.

OBJECTIVE: The aim of this study is to evaluate opportunistic vertebral bone density measurement in abdominal and pelvic computed tomography (CT) to predict future osteoporotic fracture in women aged 50 to 64 years without known osteoporosis risk factors. METHODS: Consecutive female patients 50 to 64 years old without osteoporosis risk factors with 2 CT examinations more than 10 years apart were included. Vertebral height and bone density in each vertebra from T10 to L5 were measured. Vertebral fractures were diagnosed on CT preformed 10 years after the original CT and through online medical records. RESULTS: Thirty (15%) of 199 patients developed osteoporotic fracture. Bone density was lower in patients who developed fractures compared with those who did not (P < 0.05). Development of osteoporotic fracture of any grade was predicted for patients having bone density less than 180 HU at L4 with sensitivity of 90% (95% confidence interval, 74%-97%) and specificity of 43% (95% confidence interval, 34%-50%). CONCLUSIONS: Opportunistic bone density screening can identify women at elevated risk of developing fractures within 10 years.

What Is the Optimal Abdominal Aortic Aneurysm Sac Measurement on CT Images during Follow-up after Endovascular Repair?

Purpose To develop a computed tomographic (CT) angiographic postprocessing protocol with two- and three-dimensional measurements for follow-up of patients who underwent endovascular aortic repair. Materials and Methods This HIPAA-compliant institutional review board-approved retrospective study included 159 patients (129 men, 30 women; mean age ± standard deviation, 74.9 years ± 8.2) who underwent 824 CT examinations (median of five examinations per patient; range, two to 14) with unenhanced and arterial -phase imaging performed between September 2004 and March 2015. The largest diameter on the axial plane; coronal, sagittal, and maximal diameter perpendicular to the reconstructed centerline; volume of the abdominal aortic aneurysm sac; and volume from the lowest renal artery to the aortic bifurcation and to the common iliac artery bifurcation were measured. Endoleaks on contrast material-enhanced images were considered the reference standard, and the predictive value of diameter and volume changes was analyzed. Intraclass correlation was used to compare diameters and volumes. Results All diameters and volumes showed excellent correlation (intraclass coefficient, 0.95 and 0.94, respectively). Average interobserver difference for diameters and volumes was 2%-3% and 4%-12%, respectively. Endoleaks were observed in 80 (50%) of 159 patients (59 [74%] at initial and 21 [26%] at later CT angiography). New endo-leaks were associated with increased aneurysm size measured as the largest diameter on the axial plane (P = .04) and perpendicular to the centerline (P = .01), and volume was measured from the lowest renal artery to the aortic bifurcation (P = .03) and to the common iliac artery bifurcation (P = .01). With a 5% size threshold, sensitivity and specificity for detection of endoleaks was optimal for centerline diameter (64.3% and 81.7%, respectively) and volume from the lowest renal artery to the common iliac artery bifurcation (57.1% and 63.5%). Conclusion The maximal diameter and volume of an abdominal aortic aneurysm sac can be used for temporal monitoring after endovascular aortic repair, with excellent correlation and interobserver agreement. An increase in the centerline diameter and volume from the lowest renal artery to the iliac bifurcation were the most sensitive criteria for detecting endoleaks. © RSNA, 2017 Online supplemental material is available for this article.

Split-Bolus Injection Producing Simultaneous Late Arterial and Portal Venous Phases in CT Enterography: Preliminary Results.

OBJECTIVE: The purpose of this article is to evaluate the image quality and added value of split-bolus contrast agent injection combining late arterial and portal venous phases compared with single-bolus contrast agent injection late arterial phase CT enterography. MATERIALS AND METHODS: Consecutive patients who underwent CT enterography before and after implementation of a single-bolus CT enterography protocol were included. Attenuation and contrast-to-noise ratio (CNR) were assessed by ROI measurements of the bowel wall and arterial and venous structures. Subjective enhancement of the bowel wall (1, arterial; 2, mucosal; 3, transmural; 4, transmural with mucosal hyperenhancement) and bowel abnormalities were assessed by two independent readers. MR enterography examinations, endoscopy reports, and surgery reports within 30 days after CT enterography were used to produce a composite outcome. RESULTS: Sixty-six patients were included in our study: 33 (mean [± SD] age, 46.0 ± 19.8 years) who underwent split-bolus CT enterography and 33 (mean age, 49.9 ± 19.0 years) who underwent single-bolus CT enterography. Bowel wall attenuation and CNR were higher for split-bolus CT enterography than for single-bolus CT enterography at 120 kVp (enhancement, 98.7 ± 23.1 HU vs 85.1 ± 23.3 HU; CNR, 6.4 ± 2.5 vs 4.4 ± 2.3; p < 0.01). Subjective ratings of bowel wall enhancement were higher with the split-bolus CT enterography than the single-bolus CT enterography (2.6 ± 0.8 vs 2.3 ± 0.6; p < 0.001). Split-bolus CT enterography led to a higher detection rate of mucosal hyperenhancement than did single-bolus CT enterography in patients with active inflammatory bowel disease (100.0% [7/7; 95% CI, 59.0-100.0%] vs 33.3% [2/6; 95% CI, 4.3-77.7%]; p = 0.02), whereas both protocols had a specificity of 100.0% (9/9). CONCLUSION: Split-bolus CT enterography led to improved CNR (47%) compared with single-bolus CT enterography and significantly increased the detection rate of mucosal hyperenhancement in patients with active inflammatory bowel disease.

Electronic Kiosks for Patient Satisfaction Survey in Radiology.

OBJECTIVE: The purpose of this article is to analyze patient satisfaction surveys obtained via electronic kiosks in a tertiary-care academic radiology department to detect potential areas of improvement and to identify ways to improve survey response and completion rates. MATERIALS AND METHODS: All patient satisfaction surveys submitted via electronic kiosks and via online surveys between January 2015 and January 2016 were included in this retrospective study. The surveys consisted of questions regarding the patients' overall experience, cleanliness of the department, and interactions with the receptionist, technologist, nurse, and physician. Ratings were assessed using a 5-point scale (where 1 denotes poor and 5 denotes optimal) with an option for free-text comments. The likelihood of recommendation was regarded as an indicator of satisfaction and was our primary evaluation metric. Surveys with less than optimal ratings were analyzed in detail. RESULTS: Of 99,289 patients who visited the department, 6736 (6.8%) initiated surveys, and 4938 (73.3%) of those completed them; 4257 of 4865 (87.5%) patients reported optimal satisfaction. More patients responded via electronic kiosk compared with the online survey (4564/4938 [92.4%] vs 374/4938 [7.6%]; p < 0.001). The frequency of completion rate was lower for kiosks in changing and waiting areas compared with that for kiosks next to elevators (1509/2365 [63.8%] vs 3059/3927 [77.8%]; p < 0.0001). Cleanliness of the department (329/1656 [19.9%]) and courtesy of the receptionist (299/1656 [18.1%]) were the most frequent reasons for the lowest ratings. Wait time (61/278 [21.9%]) and communication (37/278 [13.3%]) were associated with the most frequent free-text complaints. CONCLUSION: Survey kiosks led to a higher response rate than online surveys. The completion rate can be further improved by placing kiosks next to elevators. Cleanliness, wait time, patient-staff communication, and especially courtesy of the receptionist were found to be important factors for patient satisfaction.

Operator radiation exposure during radioembolisation of the liver: transfemoral versus transradial access using real-time dose monitoring.

In this study, operator radiation exposure is compared utilising transradial access (TRA) versus transfemoral access (TFA) during transarterial radioembolisation (TARE) of liver tumors. Patients who underwent Y90 TARE between May 2017 and April 2018 were included. Electronic medical records and interventional data were collected and the following parameters evaluated: technical success, fluoroscopy time, operator radiation exposure and rate of operator radiation exposure per fluoroscopy time. Statistical analysis was performed with the Wilcoxon rank-sum test. A total of 22 patients (12 males, 10 females) underwent 22 procedures. A total of 12 procedures were performed via TFA and 10 via TRA. Technical success was 100% in both groups. Median fluoroscopy time (10 minutes for TRA vs 6.4 minutes for TFA, p = 0.082) was not statistically different. Both operator radiation exposure (49 vs 4.2 µSv, p = 0.00016) and rate of operator exposure (4.9 vs 0.71 µSv per min, p = 0.00021) were significantly higher in the TRA versus TFA groups, respectively.

Performance of a Flexible 12-Channel Head Coil in Comparison to Commercial 16- And 24-Channel Rigid Head Coils.

PURPOSE: To compare the performance of a 12-channel flexible head coil (HFC12) with commercial 16-channel (HRC16) and 24-channel (HRC24) rigid coils. METHODS: The phantom study was performed on a 1.5 T MR scanner with HFC12, HRC16, and HRC24. The SNR and noise correlation matrix of T1WI, T2WI, and diffusion weighted imaging (DWI) were measured. The SNR profiles were created according to the SNR. In addition, 1/g-factors were calculated in different acceleration directions. In the in vivo study, T1WI, T2WI, and DWI were performed in one healthy volunteer with three different coils. The SNR and noise correlation matrix were measured. RESULTS: In the phantom study and in vivo study, the SNR of HFC12 in the transverse, sagittal, and coronal planes was the highest, followed by HRC24, and that of HRC16 was the lowest. The SNR profiles showed that the SNR at the edge of HFC12 was the highest. The mean value of the noise correlation matrix of HFC12 was the highest. The 1/g-factor results showed that HFC12 obtained the best acceleration ability in the head-foot acceleration direction when the reduction factor was set to two. The SNR of HFC12 in most cortices was significantly higher than that of HRC16 and HRC24, except in the occipital cortex. The SNR of HRC24 in the occipital cortex was higher than that of HFC12. CONCLUSION: The SNR of HFC12 in T1WI, T2WI, and DWI was better than that of the HRC24 and HFC16. The SNR of HFC12 in the cortex was significantly higher than that of the commercial rigid head coil, except in the occipital cortex.

Split-bolus pancreas CTA protocol for local staging of pancreatic cancer and detection and characterization of liver lesions.

PURPOSE: To validate the use of a split-bolus pancreas CTA protocol for local staging of pancreatic cancer and to evaluate its ability to detect and characterize liver lesions. METHODS: Consecutive patients with pancreatic cancer who underwent split-bolus pancreas CTA between 12/2015 and 12/2016 were included in this IRB-approved HIPAA-compliant retrospective study. Objective evaluation of the abdominal vessels, the pancreas, the liver, and lesions, if present, was performed with attenuation measurements and tumor conspicuity and contrast-to-noise ratio (CNR) calculations. An abdominal radiologist with 20 years of experience performed subjective evaluation of image quality and blindly detected and characterized liver lesions. Any inconclusive findings or grading scores were evaluated in consensus with another abdominal radiologist with 7 years of experience. Liver findings were validated using a composite reference standard to assess accuracy. RESULTS: There were 82 pancreatic cancer patients with a total of 91 liver findings. Tumor conspicuity and CNR were 60.8 ± 35.1 HU and 8.0 ± 5.8 for the pancreatic lesions and 58 ± 34.7 HU and 9.7 ± 6.3 for the liver lesions, respectively. The accuracy, sensitivity, and specificity of the split-bolus protocol for the hepatic findings were correspondingly 89/91 (97.8%, 95% CI 92.3-99.4), 58/60 (96.7%, 95% CI 88.6-99.1), and 33/33 (100%, 95% CI 89.6-100). The subjective image quality ratings were optimal in more than 89% of the cases for various structures, with no non-diagnostic ratings. CONCLUSION: Split-bolus pancreas CTA protocol allows for detection and staging of pancreatic cancer, both for the primary tumor and detection and characterization of liver lesions.

Radiologists' Experience With Patient Interactions in the Era of Open Access of Patients to Radiology Reports.

PURPOSE: The aim of this study was to evaluate radiologists' experiences with patient interactions in the era of open access of patients to radiology reports. METHODS: This prospective, nonrandom survey of staff and trainee radiologists (n = 128) at a single large academic institution was performed with approval from the institutional review board with a waiver of the requirement to obtain informed consent. A multiple-choice questionnaire with optional free-text comments was constructed with an online secure platform (REDCap) and distributed via departmental e-mail between June 1 and July 31, 2016. Participation in the survey was voluntary and anonymous, and responses were collected and aggregated via REDCap. Statistical analysis of categorical responses was performed with the χ2 test, with statistical significance defined as P < .05. RESULTS: Almost three-quarters of surveys (73.4% [94 of 128]) were completed. Staff radiologists represented 54.3% of survey respondents (51 of 94) and trainees 45.7% (43 of 94). Most respondents (78.7% [74 of 94]) found interactions with patients to be a satisfying experience. More than half of radiologists (54.3% [51 of 94]) desired more opportunities for patient interaction, with no significant difference in the proportion of staff and trainee radiologists who desired more patient interaction (56.9% [29 of 51] versus 51.2% [22 of 43], P = .58). Staff radiologists who specialized in vascular and interventional radiology and mammography were significantly more likely to desire more patient interaction compared with other specialists (77.8% [14 of 18] versus 45.5% [15 of 33], P = .03). Only 4.2% of radiologists (4 of 94) found patient interactions to be detrimental to normal workflow, with 19.1% of radiologists (18 of 94) reporting having to spend more than 15 min per patient interaction. CONCLUSIONS: Most academic staff and trainee radiologists would like to have more opportunities for patient interaction and consider patient interaction rarely detrimental to workflow.

Dual energy CT angiography: pros and cons of dual-energy metal artifact reduction algorithm in patients after endovascular aortic repair.

PURPOSE: To evaluate the value of metal artifact reduction (MAR) post-processing and iodine MD images in fast kV-switching dual-energy computed tomography (DECT) in patients after endovascular aortic repair (EVAR). MATERIALS AND METHODS: Twenty-four consecutive EVAR patients (age 76 ± 9 years, 7/24 (29%) with coils, 9/24 (37.5%) with 10 endoleaks) who underwent DECT angiography were included in this HIPAA-compliant, IRB-approved retrospective study. Monochromatic reconstructions included 55, 60, 65, 70, and 75 keV with and without MAR and iodine MD images. Near field, far field, and vessel artifacts were assessed subjectively (1 = none; 5 = severe) and objectively by measuring noise and contrast-to-noise ratio. Visibility of endoleak was evaluated (1 = optimal; 5 = not visible). RESULTS: MAR objectively decreased artifacts from EVAR stents in the near field (60.7 ± 25.4 HU vs. 70.1 ± 34.2; p = .002) and subjectively increased near field (3.2 ± 0.9 vs. 2.8 ± 0.6; p < .001), far field (2.2 ± 0.6 vs. 1.6 ± 0.6; p < .001), and vessel (3.1 ± 1.1 vs. 2.5 ± 0.9; p < .001) artifacts. Near-field artifacts from coils were reduced by the MAR objectively (72.4 ± 24.8 vs. 182.7 ± 57.3 HU; p < .001) and subjectively (4.5 ± 0.5 vs. 4.9 ± 0.4; p = .02). CNR of standard reconstructions was optimal at 60 keV (38.3 ± 16.8). Reconstructions without MAR and iodine MD images provided improved endoleak visualization in 6/10 (60%) of cases (median 1 for both) compared to MAR (median 3) (p < 0.001). However, MAR improved visualization in 1/10 (10%) cases due to endoleak location adjacent to a coil. CONCLUSION: DECT with MAR reduced artifacts from coils and improved endoleak visualization in 1/10 (10%) cases due to location adjacent to a coil. However, MAR impaired endoleak visualization in 6/10 (60%) cases and should be reviewed combined with 60 keV standard reconstructions and iodine MD images.

Metal implants on CT: comparison of iterative reconstruction algorithms for reduction of metal artifacts with single energy and spectral CT scanning in a phantom model.

PURPOSE: To assess single energy metal artifact reduction (SEMAR) and spectral energy metal artifact reduction (MARS) algorithms in reducing artifacts generated by different metal implants. MATERIALS AND METHOD: Phantom was scanned with and without SEMAR (Aquilion One, Toshiba) and MARS (Discovery CT750 HD, GE), with various metal implants. Images were evaluated objectively by measuring standard deviation in regions of interests and subjectively by two independent reviewers grading on a scale of 0 (no artifact) to 4 (severe artifact). Reviewers also graded new artifacts introduced by metal artifact reduction algorithms. RESULTS: SEMAR and MARS significantly decreased variability of the density measurement adjacent to the metal implant, with median SD (standard deviation of density measurement) of 52.1 HU without SEMAR, vs. 12.3 HU with SEMAR, p < 0.001. Median SD without MARS of 63.1 HU decreased to 25.9 HU with MARS, p < 0.001. Median SD with SEMAR is significantly lower than median SD with MARS (p = 0.0011). SEMAR improved subjective image quality with reduction in overall artifacts grading from 3.2 ± 0.7 to 1.4 ± 0.9, p < 0.001. Improvement of overall image quality by MARS has not reached statistical significance (3.2 ± 0.6 to 2.6 ± 0.8, p = 0.088). There was a significant introduction of artifacts introduced by metal artifact reduction algorithm for MARS with 2.4 ± 1.0, but minimal with SEMAR 0.4 ± 0.7, p < 0.001. CONCLUSION: CT iterative reconstruction algorithms with single and spectral energy are both effective in reduction of metal artifacts. Single energy-based algorithm provides better overall image quality than spectral CT-based algorithm. Spectral metal artifact reduction algorithm introduces mild to moderate artifacts in the far field.

Thirty-day emergency room visits and hospital admissions after outpatient non-vascular image-guided procedures.

PURPOSE: To evaluate the rate of post-procedure emergency department (ED) visits and hospital admissions following outpatient non-vascular image-guided interventions performed under moderate sedation and to identify common and preventable causes of emergency department visits and hospital admissions. MATERIALS AND METHODS: Institutional review board approval was acquired for this HIPAA-compliant retrospective study with waiver of informed consent. 1426 consecutive patients undergoing 1512 outpatient image-guided procedures under moderate sedation from November 2012 to August 2014 were included. The average patient age was 57.2 ± 15.2 years, and 602 (42%) patients were women. Major procedure categories included ultrasound-guided liver biopsies, ultrasound-guided kidney biopsies, and CT-guided lung biopsies/fiducial placement. Procedure details and medical follow-up within and after 30 days of the procedure were analyzed. RESULTS: A total of 168 (11.8%) patients were admitted to the hospital within 30 days of the procedure, with 29 of the admissions (17.3% of total admissions and 1.9% of total procedures) being procedure related. The most common procedure-related complication that required admission was hemorrhage (10/29, 34.5% of procedure-related admissions, 6.0% of total admissions, and 0.7% of total procedures), followed by pneumothorax (9/29, 31%, 5.4%, 0.6%), infection (4/29, 13.8%, 2.4%, 0.3%), and pain (3/29, 10.3%, 1.8%, 0.2%). Eighteen (62.1%) procedure-related admissions were immediately indicated. Thirty patients visited the ED and were subsequently discharged without admission with eight of the visits being procedure related (8/1512, 0.5%). All the procedure-related ED visits were due to pain. There were two deaths (2/1512, 0.1%) related to procedures, one from a thromboembolic event and another from post-biopsy hemorrhage. CONCLUSION: Outpatient non-vascular image-guided procedures result in a 30-day 1.9% hospital admission, 30-day 0.5% emergency room visit, and 30-day 0.1% mortality rate.

Array-optimized composite pulse for excellent whole-brain homogeneity in high-field MRI.

A number of methods to improve excitation homogeneity in high-field MRI have been proposed, and some of these methods rely on separate control of radiofrequency (RF) coils in a transmit array. In this work we combine accurate RF field calculations and the Bloch equation to demonstrate that by using a sequence of pulses with individually optimized current distributions (i.e., an array-optimized composite pulse), one can achieve remarkably homogeneous distributions of available signal intensity over the entire brain volume. This homogeneity is greater than that achievable using the same transmit array to produce either a single optimized (or RF shimmed) pulse or a single RF shimmed field distribution in a standard 90x-90y composite pulse arrangement. Simulations indicate that with a very simple array-optimized composite pulse, excellent whole-brain excitation homogeneity can be achieved at up to 600 MHz.