Matthew P. Lungren

White Paper Report of the RAD-AID Conference on International Radiology for Developing Countries: Identifying Challenges, Opportunities, and Strategies for Imaging Services in the Developing World

The RAD-AID Conference on International Radiology for Developing Countries was an assembly of individuals and organizations interested in improving access to medical imaging services in developing countries where the availability of radiology has been inadequate for both patient care and public health programs. The purpose of the meeting was to discuss data, experiences, and models pertaining to radiology in the developing world and to evaluate potential opportunities for future collaboration. Conference participants included radiologists, technologists, faculty members of academic medical institutions, and leadership of nongovernmental organizations involved in international health care and social entrepreneurship. Four main themes from the conference are presented in this white paper as important factors for the implementation and optimization of radiology in the developing world: (1) ensuring the economic sustainability of radiologic services through financial and administrative training support of health care personnel; (2) designing, testing, and deploying clinical strategies adapted for regions with limited resources; (3) structuring and improving the role of American radiology residents interested in global health service projects; and (4) implementing information technology models to support digital imaging in the developing world.

Tunneled Peritoneal Drainage Catheter Placement for Refractory Ascites: Single-center Experience in 188 Patients

PURPOSE To assess the success and safety of tunneled peritoneal drainage catheters for the management of ascites refractory to medical management. MATERIALS AND METHODS A total of 188 consecutive patients (83 male, 105 female; average age 59 y) with refractory ascites were treated with tunneled peritoneal drainage catheters from January 1, 2006, to August 10, 2012. A combination of fluoroscopic and ultrasound guidance was used to insert all catheters. Patient history, procedural records, and clinical follow-up documents were retrospectively reviewed. Clinical data (malignancy, renal disease, chemotherapy, neutropenia, albumin levels) were compared with respect to patency and complication rates with the use of odds ratios. Catheter survival curves were generated with the Kaplan-Meier method and life-table analysis for the cumulative and infection-free survival of primary and secondary catheters. RESULTS A total of 193 catheter placements or interventions were performed in 188 patients with refractory ascites: 170 catheters (93%) were placed for malignant etiologies and 13 (7%) for nonmalignant etiologies. The most common malignancies were ovarian (22%), pancreatic (12%), and breast (11%). The most common nonmalignant etiologies were end-stage liver disease (n = 7) and heart failure (n = 6). There was a 100% technical success rate for catheter insertion; no procedure-related deaths or major placement complications were identified. Catheter survival ranged from 0 to 796 days (mean, 60 d), with a total of 11,936 cumulative catheter-days. Fourteen postplacement complications were identified: five patients experienced catheter malfunction, four had leakage of ascites at the incisional site requiring suture placement, three had cellulitis of the tunnel tract, and two developed peritonitis. The annual complication event rate was 0.43 events per year (ie, 0.12 events per 100 catheter-days). Pancreatic malignancy was associated with a significantly increased rate of catheter malfunction (ie, occlusion). CONCLUSIONS Radiologic insertion of tunneled peritoneal drainage catheters demonstrated a 100% technical success rate for insertion and an acceptable complication rate for the management of refractory ascites.

Radiation Dose Estimations to the Thorax Using Organ-Based Dose Modulation

OBJECTIVE The purpose of this study was to assess the radiation dose distribution and image quality for organ-based dose modulation during adult thoracic MDCT. MATERIALS AND METHODS Organ doses were measured using an anthropomorphic adult female phantom containing 30 metal oxide semiconductor field-effect transistor detectors on a dual-source MDCT scanner with two protocols: standard tube current modulation thoracic CT and organ-based dose modulation using a 120° radial arc. Radiochromic film measured the relative axial dose. Noise was measured to evaluate image quality. Breast tissue location across the anterior aspect of the thorax was retrospectively assessed in 100 consecutive thoracic MDCT examinations. RESULTS There was a 17-47% decrease (p = < 0.05) in anterior thoracic organ dose and a maximum 52% increase (p = < 0.05) in posterior thoracic organ dose using organ-based dose modulation compared with tube current modulation. Effective dose (SD) for tube current modulation and organ-based dose modulation were 5.25 ± 0.36 mSv and 4.42 ± 0.30 mSv, respectively. Radiochromic film analysis showed a 30% relative midline anterior-posterior gradient. There was no statistically significant difference in image noise. Adult female breast tissue was located within an average anterior angle of 155° (123-187°). CONCLUSION Organ-based dose modulation CT using an anterior 120° arc can reduce the organ dose in the anterior aspect of the thorax with a compensatory organ dose increase posteriorly without impairment of image quality. Laterally located breast tissue will have higher organ doses than medially located breast tissue when using organ-based dose modulation. The benefit of this dose reduction must be clinically determined on the basis of the relationship of the irradiated organs to the location of the prescribed radial arc used in organ-based dose modulation.

Physician Self-Referral of Lumbar Spine MRI With Comparative Analysis of Negative Study Rates as a Marker of Utilization Appropriateness

OBJECTIVE Financial interest in imaging equipment may affect the imaging referral patterns of ordering physicians. The purpose of this article is to determine whether ownership of MRI equipment by ordering physicians predicts the likelihood and prevalence of positive findings on lumbar spine MRI as a metric for comparison of utilization. MATERIALS AND METHODS A retrospective review was performed of 500 consecutive diagnostic lumbar spine MRI examinations in one radiology practice ordered by two separate referring physician groups serving the same geographic community: one with financial interest in the MRI equipment used (financial-interest group) and one without financial interest in the MRI equipment used (no-financial-interest group). Negative examinations and total number of lesions per positive study were recorded for each group. RESULTS Five hundred scans met inclusion criteria during the study period (250 in the financial-interest group and 250 in the no-financial-interest group). The negative scan frequency was 86% higher in the financial-interest group (p < 0.0001). Among positive scans, there was no significant difference in the average total number of positive lesions per scan (3.93 for the financial-interest group and 4.31 for the no-financial-interest group; p = 0.132). The average age of patients imaged by the financial-interest group was 49.8 years, versus 56.9 years for the no-financial-interest group (p < 0.0001). CONCLUSION Lumbar spine MRI examinations referred by the financial-interest group were significantly more likely to be negative than those referred by the no-financial-interest group. Lesion frequency among positive scans suggests similar severity of disease between the two patient populations. Patients imaged by the financial-interest group were significantly younger than those imaged by the no-financial-interest group.

White Paper Report of the 2010 RAD-AID Conference on International Radiology for Developing Countries: Identifying Sustainable Strategies for Imaging Services in the Developing World

The 2010 RAD-AID Conference on International Radiology for Developing Countries was a multidisciplinary meeting to discuss data, experiences, and models pertaining to radiology in the developing world, where widespread shortages of imaging services reduce health care quality. The theme of this years conference was sustainability, with a focus on establishing and maintaining imaging services in resource-limited regions. Conference presenters and participants identified 4 important components of sustainability: (1) sustainable financing models for radiology development, (2) integration of radiology and public health, (3) sustainable clinical models and technology solutions for resource-limited regions, and (4) education and training of both developing and developed world health care personnel.

Global Health Training in Radiology Residency Programs

RATIONALE AND OBJECTIVES To measure perceptions of radiology residents regarding the imaging needs of the developing world and the potential role of an organized global health imaging curriculum during residency training. MATERIALS AND METHODS An electronic survey was created and then distributed to residents in accredited US radiology residency. RESULTS Two hundred ninety-four residents responded to the survey. A majority (61%) planned to pursue future international medical aid work, even though a similar proportion (59%) believed that they would be ill-prepared with their current training to pursue this career goal. The vast majority (91%) of respondents stated that their residency program offers no opportunities to participate in global health imaging experiences. Most surveyed residents felt that an organized global health imaging curriculum would improve understanding of basic disease processes (87%) and cost-conscious care (82%), prepare residents for lifelong involvement in global health (80%), and increase interpretative skills in basic radiology modalities (73%). If such a curriculum were available, most (62%) of surveyed residents stated that they would be likely or very likely to participate. Many (58%) believed the availability of such a program would have influenced their choice of residency program; a similar proportion of residents (75%) believed that the availability of a global health imaging curriculum would increase recruitment to the field of radiology. CONCLUSION Many radiology residents are motivated to acquire global health imaging experience, with most survey respondents planning to participate in global health initiatives. These data demonstrate an imbalance between the level of resident interest and the availability of global health imaging opportunities, and support the need for discussion on how to implement global health imaging training within radiology residency programs.

Isolated Intracranial Rosai-Dorfman Disease in a Child

Sinus histiocytosis with massive lymphadenopathy (SHML), described by Rosai and Dorfman, is a rare histoproliferative disease that classically presents with painless bilateral cervical lymphadenopathy in 83% of patients.[1][1] Extranodal disease is rare whereas isolated central nervous system

Performance of a Deep-Learning Neural Network Model in Assessing Skeletal Maturity on Pediatric Hand Radiographs

Purpose To compare the performance of a deep-learning bone age assessment model based on hand radiographs with that of expert radiologists and that of existing automated models. Materials and Methods The institutional review board approved the study. A total of 14 036 clinical hand radiographs and corresponding reports were obtained from two childrens hospitals to train and validate the model. For the first test set, composed of 200 examinations, the mean of bone age estimates from the clinical report and three additional human reviewers was used as the reference standard. Overall model performance was assessed by comparing the root mean square (RMS) and mean absolute difference (MAD) between the model estimates and the reference standard bone ages. Ninety-five percent limits of agreement were calculated in a pairwise fashion for all reviewers and the model. The RMS of a second test set composed of 913 examinations from the publicly available Digital Hand Atlas was compared with published reports of an existing automated model. Results The mean difference between bone age estimates of the model and of the reviewers was 0 years, with a mean RMS and MAD of 0.63 and 0.50 years, respectively. The estimates of the model, the clinical report, and the three reviewers were within the 95% limits of agreement. RMS for the Digital Hand Atlas data set was 0.73 years, compared with 0.61 years of a previously reported model. Conclusion A deep-learning convolutional neural network model can estimate skeletal maturity with accuracy similar to that of an expert radiologist and to that of existing automated models.

Transjugular Intrahepatic Portosystemic Shunt Complications: Prevention and Management

Transjugular intrahepatic portosystemic shunt (TIPS) insertion has been well established as an effective treatment in the management of sequelae of portal hypertension. There are a wide variety of complications that can be encountered, such as hemorrhage, encephalopathy, TIPS dysfunction, and liver failure. This review article summarizes various approaches to preventing and managing these complications.

Bacteriophage K for reduction of Staphylococcus aureusbiofilm on central venous catheter material

The purpose of this project was to determine whether bacteriophage can reduce bacterial colonization and biofilm formation on central venous catheter material. Twenty silicone discs were inoculated for 24 h with broth culture of Methicillin sensitive staphylococcus aureus (0.5 McFarland standard). The inoculate was aspirated and discs placed into two equal groups for 24 h: (1) untreated controls; (2) bacteriophage treatment (staphylococcal bacteriophage K, propagated titer > 108). At the completion of the experiment discs were processed for quantitative culture. Statistical testing was performed using the rank sum test. Mean colony forming units (CFU) were significantly decreased in experimental compared with controls (control 6.3 × 105 CFU, experimental 6.7 × 101, P ≤ 0.0001). Application of bacteriophage to biofilm infected central venous catheter material significantly reduced bacterial colonization and biofilm presence. Our data suggests that bacteriophage treatment may be a feasible strategy for addressing central venous catheter staph aureus biofilm infections.