Can Radiologists Learn From Airport Baggage Screening?: A Survey About Using Fictional Patients for Quality Assurance.

RATIONALE AND OBJECTIVES: For both airport baggage screeners and radiologists, low target prevalence is associated with low detection rate, a phenomenon known as "prevalence effect." In airport baggage screening, the target prevalence is artificially increased with fictional weapons that are digitally superimposed on real baggage. This strategy improves the detection rate of real weapons and also allows airport supervisors to monitor screener performance. A similar strategy using fictional patients could be applied in radiology. The purpose of this study was twofold: (1) to review the psychophysics literature regarding low target prevalence and (2) to survey radiologists' attitudes toward using fictional patients as a quality assurance tool. MATERIALS AND METHODS: We reviewed the psychophysics literature on low target prevalence and airport x-ray baggage screeners. An online survey was e-mailed to all members of the Association of University Radiologists to determine their attitudes toward using fictional patients in radiology. RESULTS: Of the 1503 Association of University Radiologists member recipients, there were 153 respondents (10% response rate). When asked whether the use of fictional patients was a good idea, the responses were as follows: disagree (44%), neutral (25%), and agree (31%). The most frequent concern was the time taken away from doing clinical work (89% of the respondents). CONCLUSIONS: The psychophysics literature supports the use of fictional targets to mitigate the prevalence effect. However, the use of fictional patients is not a popular idea among academic radiologists.

How Much Does Lead Shielding during Fluoroscopy Reduce Radiation Dose to Out-of-Field Body Parts?

BACKGROUND: Fluoroscopy technologists routinely place a lead shield between the x-ray table and the patient's gonads, even if the gonads are not directly in the x-ray field. Internal scatter radiation is the greatest source of radiation to out-of-field body parts, but a shield placed between the patient and the x-ray source will not block internal scatter. Prior nonfluoroscopy research has shown that there is a small reduction in radiation dose when shielding the leakage radiation that penetrates through the collimator shutters. The goal of this in vitro study was to determine if there was any radiation dose reduction when shielding leakage radiation during fluoroscopy. METHODS: This was an in vitro comparison study of radiation doses using different collimation and shielding strategies during fluoroscopy. Ionization chamber measurements were obtained during fluoroscopy of an acrylic block with and without collimation and shielding. Ionization chamber readings were taken in-field at 0 cm and out-of-field at 7.5, 10, and 12.5 cm from beam center. RESULTS: Collimation reduced 87% of the out-of-field radiation dose, and the remaining measurable dose was because of internal scatter. The radiation dose contribution from leakage radiation was negligible, as there was not any measurable radiation dose difference when shielding leakage radiation, with P value of .48. CONCLUSION: These results call into question the clinical utility of routinely shielding out-of-field body parts during fluoroscopy.

Congenital midline cervical cleft.

Congenital midline cervical cleft is a rare anomaly that typically presents in the neonatal period as a thin suprasternal vertical band of erythematous skin with a nipple-like projection superiorly, which may exude fluid. We present the clinical and pathophysiologic features and the imaging findings of this uncommon, and rarely described entity in a newborn girl.

Pairwise comparison versus Likert scale for biomedical image assessment.

OBJECTIVE: Biomedical imaging research relies heavily on the subjective and semi-quantitative reader analysis of images. Current methods are limited by interreader variability and fixed upper and lower limits. The purpose of this study was to compare the performance of two assessment methods, pairwise comparison and Likert scale, for improved analysis of biomedical images. MATERIALS AND METHODS: A set of 10 images with varying degrees of image sharpness was created by digitally blurring a normal clinical chest radiograph. Readers assessed the degree of image sharpness using two different methods: pairwise comparison and a 10-point Likert scale. Reader agreement with actual chest radiograph sharpness was calculated for each method by use of the Lin concordance correlation coefficient (CCC). RESULTS: Reader accuracy was highest for pairwise comparison (CCC, 1.0) and ranked Likert (CCC, 0.99) scores and lowest for nonranked Likert scores (CCC, 0.83). Accuracy improved slightly when readers repeated their assessments (CCC, 0.87) or had reference images available (CCC, 0.91). CONCLUSION: Pairwise comparison and ranked Likert scores yield more accurate reader assessments than nonranked Likert scores.

Journal Club: Structured radiology reports are more complete and more effective than unstructured reports.

OBJECTIVE: The radiology report serves as the primary method of communication about imaging findings. Traditional free-text (i.e., unstructured) radiology reporting entails dictating in a stream-of-consciousness manner. Structured reporting aims to standardize the format and lexicon used in reports. This standardization may improve the communication of findings, allowing ease of reading and comprehension. A structured reporting template may also be used as a checklist while reviewing a case, which may facilitate focused attention and analysis. The goal of this study was to compare unstructured and structured reports in terms of their completeness and effectiveness. MATERIALS AND METHODS: Radiology trainees were given an educational lecture on the background of reporting and were provided with a structured reporting template for dictating chest radiographs. Twelve trainees completed the study. Sixty reports from before and 60 reports from after the intervention were each independently scored by four blinded physician raters for completeness and effectiveness. RESULTS: Structured reports were found to be statistically significantly more complete and more effective than unstructured reports (mean completeness score, 4.42 vs 3.99, p<0.001; mean effectiveness score, 4.11 vs 3.85, p<0.001). A combined score was calculated for each report and was higher for the structured reports (mean combined score, 8.54 vs 7.83, p<0.001). CONCLUSION: Structured chest radiograph reports were more complete and more effective than unstructured chest radiograph reports. Although additional studies are needed for validation, this study suggests that structured reporting may represent an improved reporting method for radiologists.

Computed tomography depiction of small pediatric vessels with model-based iterative reconstruction.

BACKGROUND: Computed tomography (CT) is extremely important in characterizing blood vessel anatomy and vascular lesions in children. Recent advances in CT reconstruction technology hold promise for improved image quality and also reductions in radiation dose. This report evaluates potential improvements in image quality for the depiction of small pediatric vessels with model-based iterative reconstruction (Veo™), a technique developed to improve image quality and reduce noise. OBJECTIVE: To evaluate Veo™ as an improved method when compared to adaptive statistical iterative reconstruction (ASIR™) for the depiction of small vessels on pediatric CT. MATERIALS AND METHODS: Seventeen patients (mean age: 3.4 years, range: 2 days to 10.0 years; 6 girls, 11 boys) underwent contrast-enhanced CT examinations of the chest and abdomen in this HIPAA compliant and institutional review board approved study. Raw data were reconstructed into separate image datasets using Veo™ and ASIR™ algorithms (GE Medical Systems, Milwaukee, WI). Four blinded radiologists subjectively evaluated image quality. The pulmonary, hepatic, splenic and renal arteries were evaluated for the length and number of branches depicted. Datasets were compared with parametric and non-parametric statistical tests. RESULTS: Readers stated a preference for Veo™ over ASIR™ images when subjectively evaluating image quality criteria for vessel definition, image noise and resolution of small anatomical structures. The mean image noise in the aorta and fat was significantly less for Veo™ vs. ASIR™ reconstructed images. Quantitative measurements of mean vessel lengths and number of branches vessels delineated were significantly different for Veo™ and ASIR™ images. Veo™ consistently showed more of the vessel anatomy: longer vessel length and more branching vessels. CONCLUSION: When compared to the more established adaptive statistical iterative reconstruction algorithm, model-based iterative reconstruction appears to produce superior images for depiction of small pediatric vessels on computed tomography.

Digitization of medicine: how radiology can take advantage of the digital revolution.

In the era of medical cost containment, radiologists must continually maintain their actual and perceived value to patients, payers, and referring providers. Exploitation of current and future digital technologies may be the key to defining and promoting radiology's "brand" and assure our continued relevance in providing predictive, preventive, personalized, and participatory medicine. The Association of University of Radiologists Radiology Research Alliance Digitization of Medicine Task Force was formed to explore the opportunities and challenges of the digitization of medicine that are relevant to radiologists, which include the reporting paradigm, computational biology, and imaging informatics. In addition to discussing these opportunities and challenges, we consider how change occurs in medicine, and how change may be effected in medical imaging community. This review article is a summary of the research of the task force and hopefully can be used as a stimulus for further discussions and development of action plans by radiology leaders.

Intuition versus rational thinking: psychological challenges in radiology and a potential solution.

Humans think overwhelmingly intuitively rather than rationally. We perceive what is apparent to us and attribute differences in perception to the fault of others. Many cognitive biases are unconscious, and we assume they affect others more than ourselves. Radiologists should understand these limitations and seek methods to address them. A potential method is the checklist, which has been used to improve consistency and quality both outside and within medicine. Structured reporting can serve as a checklist and, although promising, has yet to widely demonstrate benefits.

Embedding 3D radiology models in portable document format.

OBJECTIVE: The purpose of this article is to discuss how to convert cross-sectional images into a 3D model and embed them in a Portable Document Format (PDF) file. Four programs are used: OsiriX, MeshLab, Microsoft PowerPoint, and Adobe Acrobat. Step-by-step instructions are provided. CONCLUSION: Embedding 3D radiology models into PDF files is a powerful tool that may be used for clinical, educational, and research purposes.

MRI for the evaluation of pectus excavatum.

Pectus excavatum, the most common congenital deformity of the anterior chest wall, is both a cosmetic and functional abnormality. The degree of abnormal chest wall deformity determines its functional effect, particularly its cardiac and pulmonary impact. Although CT scanning is the most widely used cross-sectional imaging technique used to measure the Haller index, the radiation exposure is reason to seek other alternatives. At our institution, we have introduced a rapid MRI technique for this purpose, which utilizes a single-axial 2-D FIESTA acquisition.

Osteochondromas and growth retardation secondary to externally or internally administered radiation in childhood.

For over five decades, osteochondromas (exostoses) and associated growth retardation have been known to be caused by radiation damage to the growing skeleton. Patients can be divided into three exposure groups. Group I received external beam radiation therapy primarily for the treatment of childhood cancers (typical dose 3,500 cGy), and 6-20% developed osteochondromas and growth retardation within the radiation portal. Group II consists of recently described patients who received total body irradiation in preparation for bone marrow transplant (typical dose: 800-1,200 cGy), and about 20% developed osteochondromas and growth retardation. Group III consists of 206 German children who in the 1940s and early 1950s received intravenous radioactive Peteosthor (Ra-224) to treat bone tuberculosis (estimated typical dose: 1,000-2,000 cGy), and 14% developed osteochondromas and growth retardation, among other benign and malignant sequelae. Combining these three exposure groups, osteochondromas and growth retardation develop in at least 6-20% of children who receive therapeutic radiation to their growing skeletons.