Radiology

Forensic Radiology: An Exciting and Developing Field That Needs More Trained Radiologists Publication date: Available online 27 April 2019 Source: Academic Radiology Author(s): Barry Daly

Paired Drainage Catheter Insertion: Feasibility of Placing Two Catheters within the Same Complex Abscess Cavity as a Primary and Salvage Percutaneous Drainage Technique Publication date: Available online 26 April 2019 Source: Academic Radiology Author(s): David H. Ballard, Sarah T. Flanagan, Ryan W. Brown, Romulo Vea, Chaitanya Ahuja, Horacio B. D'Agostino Rationale and Objectives To assess the feasibility of paired catheter drainage for management of complex abdominal abscesses. Materials and Methods This was a single-center retrospective study of 54 patients (35 males; mean age 48.9 years) that underwent paired catheter insertion for complex abdominal fluid collections in an 18-month period. Complex collections were defined as abscesses ≥6 cm in diameter with septations, high viscosity fluid or necrotic debris, or abscesses with an associated fistula. Abscess etiologies included postoperative (n = 28), pancreatitis (n = 12), perforated bowel (n = 7), liver abscess (n = 4), and perihepatic from gallbladder perforation (n = 3). Paired catheter insertion was defined two catheters co-located within one collection through the same skin incision or two closely spaced insertion sites. Paired catheter insertion was used primarily as initial drainage for complex intraabdominal abscesses and for salvage drainage in collections that could not be evacuated by a single catheter. Primary paired catheter insertion was used in 45 patients and as salvage in nine patients. Results Abscess resolution occurred in 51 (94.4%) patients. Patients had a median of three drainage procedures. Median duration of paired catheterization was 22 days. Seven abscesses recurred and all resolved with repeated drainage. Complications included one hemorrhage that was taken for surgical exploration. Overall, 48 patients had good clinical outcome, 3 patients died (multiorgan failure, n = 2; sepsis, n = 1), and 3 patients were lost to follow-up. Conclusion Percutaneous paired catheter drainage is a feasible technique for the treatment of both complex intraabdominal abscesses and abscesses unresponsive to single catheter drainage.

Liver Ultrasound Texture Analysis: The Computer Finds More to Quantify Than Meets the Eye Publication date: Available online 25 April 2019 Source: Academic Radiology Author(s): Andrew Phelps

Reducing Radiation Dose and Improving Image Quality in CT Portal Venography Using 80 kV and Adaptive Statistical Iterative Reconstruction-V in Slender Patients Publication date: Available online 25 April 2019 Source: Academic Radiology Author(s): Zhanli Ren, Xirong Zhang, Zhijun Hu, Dou Li, Zhentang Liu, Donghong Wei, Yongjun Jia, Nan Yu, Yong Yu, Yuxin Lei, Xiaoxia Chen, Changyi Guo, Zhanliang Ren, Taiping He Objective To explore the feasibility of reducing radiation dose and improving image quality in CT portal venography (CTPV) using 80 kV and adaptive statistical iterative reconstruction-V(ASIR-V) in slender patients in comparison with conventional protocol using 120 kV and ASIR. Methods Sixty slender patients for enhanced abdominal CT scanning were randomly divided into group A and group B. Group A used the conventional 120 kV tube voltage, 600 mgI/kg contrast dose and reconstructed with the recommended 40% ASIR. Group B used 80 kV tube voltage, 350 mgI/kg contrast dose and reconstructed with ASIR-V from 40% to 100% with 10% interval. The CT values and standard deviation (SD) values of the main portal vein, left branch, and right branch of portal vein, liver, and erector spinae at the same level were measured to calculate the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). The image quality was subjectively scored by two experienced radiologists blindly using a 5-point criterion. The contrast dose, volumetric CT dose index, and dose length product were recorded in both groups and the effective dose was calculated. Results There was no significant difference in general data between the two groups (p > 0.05), the effective dose and contrast dose in group B were reduced by 63.3% (p < 0.001) and 39.7% (p < 0.001), respectively compared with group A. With the percentage of ASIR-V increased in group B, the CT values showed no significant difference, while the SD values gradually decreased and SNR values and CNR values increased accordingly. Compared with group A, group B demonstrated similar CT values (p > 0.05), while the SD values with 80% ASIR-V to 100% ASIR-V were significantly lower than those of 40% ASIR (p < 0.001), and the SNR values and CNR values with 70% ASIR-V to 100% ASIR-V were significantly higher than those of 40% ASIR (p < 0.001). The subjective image quality scores by the two radiologists had excellent consistency (kappa value>0.75, p < 0.001), and the final subjective image quality scores and the subjective scores in each of the 5 scoring categories with 60% ASIR-V to 100% ASIR-V were all significantly higher than those of 40% ASIR, and 80% ASIR-V obtained the highest subjective score among different reconstructions. Conclusion In CTPV, the application of 80 kV and ASIR-V reconstruction in slender patients can significantly reduce radiation dose (by 63.3%) and contrast agent dose (by 39.7%). Compared with the recommended 40% ASIR using 120 kV, ASIR-V with 80% to 100% percentages can further improve image quality and with 80% ASIR-V being the best reconstruction algorithm. Advances in knowledge CTPV with 80 kV and ASIR-V algorithm in slender patients can significantly reduce radiation dose and contrast agent dose as well as improve image quality, compared with the conventional 120 kV protocol using 40% ASIR.

An Appreciative Approach to Burnout Publication date: Available online 18 April 2019 Source: Academic Radiology Author(s): Richard B Gunderman

Making Learning Fun: Gaming in Radiology Education Publication date: Available online 17 April 2019 Source: Academic Radiology Author(s): Omer Awan, Courtney Dey, Hayden Salts, James Brian, Joseph Fotos, Eric Royston, Maria Braileanu, Emily Ghobadi, Jason Powell, Charlotte Chung, William Auffermann With continued technologic advances, it is not surprising that gaming techniques are increasingly being used in radiology residency programs. This comprehensive review on gaming in radiology education offers insight into the importance of gaming, types of games and principles utilized in gaming, as well as applications that are inherent in artificial intelligence and continued medical education. The advantages and disadvantages of gaming will be considered, as well as barriers to successful adoption of gaming.

Forensic Radiology: A Primer Publication date: Available online 17 April 2019 Source: Academic Radiology Author(s): Summer J. Decker, Maria Braileanu, Courtney Dey, Leon Lenchik, Michael Pickup, Jason Powell, Maria Tucker, Linda Probyn Rationale and objective: Forensic radiology is a relatively unknown subspecialty which is becoming increasingly more important. The field incorporates antemortem and postmortem imaging for the detection and documentation of various pathologies for medicolegal purposes. Postmortem imaging is increasingly used in conjunction with the traditional autopsy in a process called a "virtual" autopsy. Radiography has been a staple of forensic investigations for over a century, first used in 1896. Advanced imaging techniques such as postmortem computed tomography and postmortem magnetic resonance imaging have only recently gained acceptance in the forensic science community. Postmortem computed tomography and postmortem magnetic resonance imaging methods are now widely used in some parts of the world, while other countries including the United States have been slower to adopt these methods into their daily practice. Advanced forensic imaging is increasingly used in the courts where juries have responded positively to such presentation of forensic data. For these reasons, advanced postmortem imaging is becoming a regular part of forensic investigations. The increase in the use of forensic imaging presents a unique opportunity for radiologists to collaborate with pathologists and law enforcement officials. This paper provides an overview of forensic radiology and identifies potential challenges and opportunities.

Discrepancy in Practices Related to the Use of Oral Contrast in Abdominal CT Scan Publication date: Available online 13 April 2019 Source: Academic Radiology Author(s): Shahmeer Khan, Muhammad Awais, Anwar Ahmed

Complicated Cysts: Should Management Depend Upon Age? Publication date: Available online 13 April 2019 Source: Academic Radiology Author(s): Dana Ataya, Bethany L. Niell

Impact of Patient Size and Radiation Dose on Accuracy and Precision of Iodine Quantification and Virtual Noncontrast Values in Dual-layer Detector CT—A Phantom Study Publication date: Available online 12 April 2019 Source: Academic Radiology Author(s): Steven Van Hedent, Curtis Tatsuoka, Sarah Carr, Kai Roman Laukamp, Brendan Eck, Nils Große Hokamp, Rivka Kessner, Pablo Ros, David Jordan Rationale and Objectives Iodine quantification (IQ) and virtual noncontrast (VNC) images produced by dual-energy CT (DECT) can be used for various clinical applications. We investigate the performance of dual-layer DECT (DLDECT) in different phantom sizes and varying radiation doses and tube voltages, including a low-dose pediatric setting. Materials and Methods Three phantom sizes (simulating a 10-year-old child, an average, and a large-sized adult) were scanned with iodine solution inserts with concentrations ranging 0-32 mg/ml, using the DLDECT. Each phantom size was scanned with CTDIvol 2-15 mGy at 120 and 140 kVp. The smallest phantom underwent additional scans with CTDIvol 0.9-1.8 mGy. All scans were repeated 3 times. Each iodine insert was analyzed using VNC and IQ images for accuracy and precision, by comparison to known values. Results For scans from 2 to 15 mGy mean VNC attenuation and IQ error in the iodine inserts in the small, medium, and large phantoms was 1.2 HU ± 3.2, −1.2 HU ± 14.9, 2.6 HU ± 23.6; and +0.1 mg/cc ± 0.4, −0.9 mg/cc ± 0.9, and −1.8 mg/cc ± 1.8, respectively. In this dose range, there were no significant differences (p ≥ 0.05) in mean VNC attenuation or IQ accuracy in each phantom size, while IQ was significantly less precise in the small phantom at 2 mGy and 10 mGy (p < 0.05). Scans with CTDIvol 0.9-1.8 mGy in the small phantom showed a limited, but statistically significantly lower VNC attenuation precision and IQ accuracy (−0.5 HU ± 5.3 and −0.3 mg/cc ± 0.5, respectively) compared to higher dose scans in the same phantom size. Conclusion Performance of iodine quantification and subtraction by VNC images in DLDECT is largely dose independent, with the primary factor being patient size. Low-dose pediatric scan protocols have a significant, but limited impact on IQ and VNC attenuation values.