Optimisation in daily practice - it's more than just radiation dose.

On this editorial, the importance of optimisation of diagnostic imaging and radiation therapy in terms of diagnostic and therapeutic tests and treatments, education and service provision are discussed.

Daily Caffeine Consumption Is Associated with Decreased Incidence of Symptoms and Hemodynamic Changes During Pharmacologic Stress with Regadenoson.

Regadenoson is an adenosine A2A receptor agonist widely used as a pharmacologic stress agent for myocardial perfusion imaging. Approximately 3.4 million regadenoson pharmacologic stress tests were performed annually as of 2011. Caffeine is a competitive antagonist of all adenosine receptor subtypes; thus, caffeine is typically withheld 12-24 h before stress with regadenoson. However, the effects of daily caffeine intake on regadenoson stress are unknown. This study assessed the effects of daily caffeine intake on symptoms and hemodynamic changes during stress testing with regadenoson. Methods: Patients presenting for regadenoson stress myocardial perfusion imaging were asked their amounts of daily caffeine intake. Chart review was used to collect data on demographics, comorbidities, and use of ß-blockers. Data collected from the regadenoson stress test included symptoms, administration of aminophylline, heart rate, blood pressure, and arrhythmias. χ2 testing and ANOVA were used to analyze data divided into 3 categories of caffeine intake (<200, 200-400, and >400 mg daily). χ2 testing was used for nominal data, and unpaired t testing was used for continuous data. Results: In total, 101 patients were enrolled: 53% men and 47% women. Of the 101 patients, 89% reported caffeine intake, with 13% reporting heavy caffeine intake (>400 mg daily). The last intake of caffeine was at least 12 h before the test. During the test, 63% of patients reported symptoms, but the test was completed successfully in all patients. Compared with those who do not use caffeine, intake for caffeine users was associated with less chest pain (P = 0.0013), less aminophylline administration (P = 0.0371), lower resting and peak heart rate (P = 0.0497 and 0.0314, respectively), and lower diastolic blood pressure response (P = 0.0468). No associations were found between caffeine intake and arrhythmia or systolic blood pressure response. Conclusion: The use of regadenoson stress for myocardial perfusion imaging in caffeine consumers is very common, safe, and associated with a lower incidence of certain symptoms than in non-caffeine consumers. Specifically, caffeine intake was associated with less aminophylline use and chest pain.

Invention and Early History of Telepathology (1985-2000).

This narrative-based paper provides a first-person account of the early history of telepathology (1985-2000) by the field's inventor, Ronald S. Weinstein, M. D. During the 1980s, Dr. Weinstein, a Massachusetts General Hospital-trained pathologist, was director of the Central Pathology Laboratory (CPL) for the National Cancer Institute-funded National Bladder Cancer Project, located at Rush Medical College in Chicago, IL. The CPL did post therapy revalidations of surgical pathology and cytopathology diagnoses before outcomes of the completed clinical trials were published. The CPL reported that interobserver variability was invalidating inclusion of dozens of treated bladder cancer patients in published reports on treatment outcomes. This problem seemed ripe for a technology-assisted solution. In an effort to solve the interobserver variability problem, Dr. Weinstein devised a novel solution, dynamic-robotic telepathology, that would potentially enable CPL uropathologists to consult on distant uropathology cases in real-time before their assignment to urinary bladder cancer, tumor stage, and grade-specific clinical trials. During the same period, universities were ramping up their support for faculty entrepreneurism and creating in-house technology transfer organizations. Dr. Weinstein recognized telepathology as a potential growth industry. He and his sister, Beth Newburger, were a successful brother-sister entrepreneur team. Their PC-based education software business, OWLCAT™, had just been acquired by Digital Research Inc., a leading software company, located in California. With funding from the COMSAT Corporation, a publically traded satellite communications company, the Weinstein-Newburger team brought the earliest dynamic-robotic telepathology systems to market. Dynamic-robotic telepathology became a dominant telepathology technology in the late 1990s. Dr. Weinstein, a serial entrepreneur, continued to innovate and, with a team of optical scientists at The University of Arizona's College of Optical Sciences, developed the first sub-1-min whole-slide imaging system, the DMetrix DX-40 scanner, in the early 2000s.

Diffusion Tensor Imaging of the Ankle as a Possible Predictor of Chemotherapy Induced Peripheral Neuropathy: Pilot Study.

PURPOSE: Chemotherapy induced peripheral neuropathy (CIPN) is seen in up to 75% of treated cancer patients and can drastically limit their medical management and affect quality of life. Clinical and electrodiagnostic testing for CIPN have many pitfalls. Magnetic resonance neurography (MRN) is being increasingly used in the evaluation of peripheral nerves. Diffusion tensor imaging (DTI) shows promise in the workup of peripheral nerves. In this prospective pilot study, we investigated a possible relationship between DTI and peripheral neuropathy of the ankle and foot in cancer patients treated with chemotherapy. METHODS: Nine cancer patients with and without CIPN were clinically evaluated using vibratory perception threshold (VPT) testing. VPT score of >25Volts defined presence of CIPN. The posterior tibial nerve and branches in both feet were imaged using MRN and DTI. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were measured at the posterior tibial, medial plantar, and lateral plantar nerves. Measurements for the CIPN group were compared to without CIPN by VPT cutoff. Correlations and possible relationships between DTI parameters and CIPN were analyzed. RESULTS: A total of 16feet of 9 enrolled patients were imaged (9feet with CIPN and 7feet without CIPN). Average age was 60.6 ± 13.4 years (range: 33-74). Posterior tibial nerve ADC values were significantly lower than the medial plantar nerve ADC values in all feet (F = 3.50, P = 0.04). We found a correlation with FA and ADC values at specific nerve locations with CIPN, with the left medial plantar nerve FA value and left lateral plantar nerve ADC value demonstrating the strongest positive correlations (0.73 and 0.62, respectively). CONCLUSIONS: The use of DTI for assessing CIPN is challenging but promising. This pilot study provides preliminary data showing correlations between FA and ADC measurements with CIPN and potential utility of DTI as a predictive marker of onset and severity of CIPN in the ankle and foot, which could aid in preventive strategies. Larger, prospective DTI studies are needed to draw definitive conclusions. CLINICAL RELEVANCE: MRN with DTI shows promising results as a potential predictive marker of CIPN in the ankle and foot.

Patient Knowledge Regarding Colorectal Cancer Risk, Opinion of Screening, and Preferences for a Screening Test.

AIMS: To assess patient knowledge about colorectal cancer incidence and prognosis as well as willingness to undergo screening with various tests (eg, optical colonoscopy, stool-based tests, computed tomographic colonography (CTC)). MATERIALS AND METHODS: A survey was administered to consecutive patients of a general academic-based internal medicine clinic. RESULTS: Survey response rate was 86.3%. A majority of respondents (55%) reported being aware of general information about colorectal cancer, and 99% indicated a belief that colorectal cancer screening was a good idea. A majority of respondents (73%) were willing to undergo optical colonoscopy, and some were willing to undergo stool-based tests (48%), or CT colonography CTC (40%). A majority reported being more willing to undergo a colorectal cancer screening test if the test did not involve radiation (86%), did not involve insertion of a tube or device into the rectum (78%), did not involve a pre-proceduralpreprocedural bowel cleansing regimen (73%), or did not involve sedation (60%). CONCLUSION: Improved patient education about the negligible radiation risk associated with CTC or development of a non-invasive imaging test that did not involve a preprocedural bowel cleansing regimen may increase rates of colorectal cancer screening.

The Veil of Obscuration: Additional Radiographic Sign of Posterior Shoulder Dislocation.

OBJECTIVE: To describe a new radiographic sign, "veil of obscuration", associated with posterior glenohumeral joint (shoulder) dislocations and determine its incidence and validity compared to other known classic radiographic signs. METHODS: Four-year retrospective study identified 30 acute posterior shoulder dislocation patients. Radiographs reviewed in consensus by 2 musculoskeletal radiologists for the "veil of obscuration", seen on AP shoulder radiographs and representing a comminuted fracture of the lesser tuberosity projecting over the humeral head or glenohumeral joint. Incidence of this radiographic sign of posterior glenohumeral joint dislocation in addition to other previously described classic radiographic signs, and association with other fractures, surgery, and mechanism of injury were evaluated. Continuous data was analyzed with student t-test and categorical data with Chi-Square test. RESULTS: There were 20 right and 10 left posterior shoulder dislocations. Majority of injuries resulted from vehicle crash (44%). In most cases, reverse Hill-Sachs lesion (83%) and fixed internal rotation of the humeral head (76%) were present, followed by trough line (43%) and "veil of obscuration" (40%). Trough line was seen in significantly more major trauma and vehicle crashes (78% and 46%; P=0.015), while "veil of obscuration" was seen in more seizures (86%; P=0.037) and in all surgical patients. No significant difference in presence of other classic radiographic signs in regards to surgery. CONCLUSION: The newly described radiographic sign of posterior shoulder dislocations named the "veil of obscuration" has comparable incidence as other classic radiographic signs and may be useful in the recognition and diagnosis of these injuries.

A New Software Platform to Improve Multidisciplinary Tumor Board Workflows and User Satisfaction: A Pilot Study.

BACKGROUND: Workflow and preparation for holding multidisciplinary cancer case reviews (i.e., Tumor Boards) is time-consuming and cumbersome. Use of a software platform might improve this process. This pilot study assessed the impact of a new software platform on tumor board preparation workflow and user satisfaction compared to current methods. MATERIALS AND METHODS: Using current methods and the NAVIFY Tumor Board Solution, this study assessed the number of tasks and time to prepare tumor board cases. Participants completed online surveys assessing ease of use and satisfaction with current and new platforms. RESULTS: A total of 41 sessions included two surgeons, two oncologists, two pathologists, and two radiologists preparing tumor board cases with 734 tasks were recorded. Overall, there was no difference in the number of tasks using either preparation method (341 current, 393 NAVIFY Tumor Board solution). There was a significant difference in overall preparation time as a function of specialty (F = 71.74, P < 0.0001), with oncologists, radiologists, and surgeons having reduced times with NAVIFY Tumor Board solution compared to the current platform and pathologists having equivalent times. There was a significant difference (F = 38.98, P < 0.0001) for times as a function of task category. Review of clinical course data and other preparation tasks decreased significantly, but pathology and radiology review did not differ significantly. The new platform received higher ratings than the current methods on all survey questions regarding the ease of use and satisfaction. CONCLUSIONS: The study supported the hypothesis that the new software platform can improve Tumor Board preparation. Further study is needed to assess the impact of this platform in different hospitals, different data storage systems, with different observers, and different types of Tumor board cases as well as its impact on the quality of the tumor board discussion.

Increasing display luminance as a means to enhance interpretation accuracy and efficiency when reducing full-field digital mammography dose.

Reducing dose increases noise impacting image quality but can be offset by increasing display luminance. Two contrast detail mammography images were obtained at 26 kV and the same distance between detectors, at 45 and 50 mAs resulting in entrance surface doses of 7.09 and 7.88 mGy, respectively. They were processed to make average gray level of the background independent of the dose level while maintaining original SNR. Eight radiologists viewed the images at 420, 1000 cd/m2 , and SpotView™ a tool that resulted in an average display luminance of 3138.8 cd/m2 . Percent correct (PC) for all three luminances was higher for high versus low dose. Performance was always higher with high dose no matter what the luminance. For low dose, PC was highest with SpotView™, and SpotView™ and 1000 cd/m2 were significantly higher than 420 cd/m2 . At high dose, SpotView™ PC was significantly higher than both lower luminances. Average time per image was lower in high dose, and, at both doses, time decreased as luminance increased, with SpotView™ having significantly shorter times. Increasing luminance from 420 to 1000 cd/m2 significantly increases target detection by ∼3.0% and with SpotView™ by ∼6.2% . Increasing display luminance with SpotView™ significantly decreases reading time by 16.0%.

Addressing Racial Disparity in Colorectal Cancer Screening With CT Colonography: Experience in an African-American Cohort.

BACKGROUND: Incidence and mortality from colorectal cancer (CRC) are higher among African Americans where CRC screening rates lag behind non-Hispanic whites. The purpose of this investigation was to evaluate CT colonography (CTC) performance and outcome measures in an African-American cohort. MATERIALS AND METHODS: This study is an institutional review board-approved and Health Insurance Portability and Accountability Act-compliant study. Retrospective evaluation of the African-American cohort from the Atlanta VA Medical Center (Decatur, Georgia) CTC screening program. Colonoscopy referral rates and histologic diagnoses were evaluated. RESULTS: CTC studies (n = 2490; mean age, 59.5 years [range, 50-80 years]; 85.5% male; all African American) were performed between 2007 and 2016. The per-patient CTC positive rate was 9.8% for polyps from 6 to 9 mm, 5.4% for polyps from 10 to 29 mm, and 1.3% for masses ≥ 30 mm. Based on CTC findings and patient preference, 13.9% of patients were referred to optical colonoscopy and 2.9% were referred to CTC follow-up. Of patients recommended to undergo colonoscopy, 80.6% completed the procedure and colonic pathology was confirmed in 83.2% thereof. Histologic diagnoses were 221 tubular adenomas (161 6-9 mm; 60 ≥ 10 mm), 59 tubulovillous adenomas/villous adenomas (14 6-9 mm; 45 ≥ 10 mm), 34 hyperplastic-serrated polyps (27 6-9 mm; 7 ≥ 10 mm), 18 adenocarcinomas (all ≥ 10 mm), and 11 adenomas with high-grade dysplasia (all ≥ 10 mm). The per-patient positivity rate for patients who had optical colonoscopy (n = 279) was 71.3% for adenoma, 9.7% for hyperplastic polyp, and 6.1% for adenocarcinoma. CONCLUSIONS: CTC is an effective screening modality for African-American adults and could potentially improve rates of colorectal screening in this underserved population.

Structured Protocol for Benign Biliary Anastomotic Strictures: Impact on Long-Term Clinical Effectiveness.

OBJECTIVE: The purpose of this study is to compare long-term clinical effectiveness before and after implementation of a structured protocol for percutaneous drainage of benign anastomotic biliary strictures. MATERIALS AND METHODS: Three hundred five adult patients undergoing percutaneous biliary drainage for biliary anastomotic strictures between 1994 and 2015 were identified using Current Procedural Terminology billing codes, with 234 undergoing intervention before implementation of a structured protocol and 71 undergoing intervention after implementation of the protocol. The frequency of surgical anastomotic revision was compared between patients treated before and after the implementation of the structured protocol. Patient characteristics and treatment variables were also analyzed with respect to the frequency of surgical revision. A Kaplan-Meier analysis was performed to determine the long-term probabilities of avoiding surgical revision and patency rates. RESULTS: Overall, 72.8% of patients avoided surgical revision, with 71.1% before and 81.7% after the protocol was implemented (p = 0.1052). A larger maximum drain size was significantly associated with a lower frequency of surgical revision (p = 0.0006). The rates of surgical avoidance 5 years after treatment before and after protocol implementation were 69.1% and 80.8%, respectively. Patency rates 5 years after treatment before and after protocol implementation were 73.8% and 76.8%, respectively. CONCLUSION: Percutaneous drainage and management of benign biliary anastomotic strictures is an effective treatment regardless of the presence of a structured protocol. Although there was no significant benefit in terms of avoidance of surgical revision, the time until surgical revision and patency rates were increased with the protocol. In addition, a larger maximum drain size was associated with a better outcome.

"Partially Matched" US Senior Diagnostic Radiology Applicants: Scope of the Problem and Implications for Applicants, Residency Training Programs, and the Academic Diagnostic Radiology Community.

RATIONALE AND OBJECTIVES: Anecdotal reports have recently surfaced of an increase in the number of US senior diagnostic radiology (DR)-bound residency applicants who did not secure a preliminary year position through the Main Resident Match (the Match) of the National Resident Matching Program (NRMP), so-called "partial matches." This study sought to determine the scope of this phenomenon and address potential causes and solutions. MATERIALS AND METHODS: Publicly available and proprietary data from the National Resident Matching Program were analyzed from 2005-2016 to determine the number of partially matched US senior applicants, selectivity of DR residency training, availability of preliminary year positions, number of unique preliminary year applicants, distribution of preliminary year matches by successfully matched applicants in relevant specialties (DR, anesthesiology, dermatology, neurology, physical medicine and rehabilitation, and radiation oncology), and percentage of categorical training programs participating in the Match. RESULTS: Since 2012, there has been a trend toward an increase in the number of partially matched US senior DR applicants, with a transitory recovery in the 2015 Match. Although possible explanations for this increase are proposed, a definitive etiology remains elusive. Strategies to offset this phenomenon include advising perceived at-risk applicants to apply more broadly to preliminary year positions, creating more categorical training positions, abolishing the preliminary year requirement, and drawing high-caliber medical students to the field. CONCLUSIONS: Although a definitive explanation for a recent increase in partial matches remains elusive, strategies exist for DR applicants, residency programs, and the DR academic community to minimize this risk.

Patient Compliance in the Setting of BI-RADS Category 3: What Factors Impact Compliance With Short-Term Follow-Up Recommendations?

The study aims to define how imaging findings, patient demographics, patient-provider interactions, and health care practices may affect a woman's decision to follow-up in the setting of a BI-RADS Category 3. A total of 398 women from the University of Arizona Breast Imaging Center with a BI-RADS Category 3 assessment for mammography and/or ultrasound findings were evaluated between February 2012 and June 2014. Demographic information was analyzed for all patients, regardless of follow-up. Women who returned for follow-up within the recommended time period were given one survey at the time of their follow-up appointment, and women who returned for follow-up, but later than recommended, were given a separate survey to complete. Age, palpability of a lesion, and menopause status were related to follow-up. Self-rated general health was the only factor found to be associated with the decision to follow-up on time. The majority of patients who followed up on time reported that mailed reminder cards were the primary practice that prompted follow-up. Of patients who followed up later than recommended, the major reason was "no time." The findings suggest that additional counseling regarding the benefits of short-interval imaging follow-up might be advantageous for patients.

Ultrasound Evaluation of Morton Neuroma Before and After Laser Therapy.

OBJECTIVE: The objective of our study was to retrospectively assess for differences in imaging appearances of Morton neuromas before and after laser therapy using diagnostic ultrasound (US). MATERIALS AND METHODS: A retrospective review was performed to identify patients who underwent US imaging to evaluate for Morton neuroma during the study period (June 1, 2013-July 1, 2014); of the 42 patients identified, 21 underwent US evaluations before and after laser therapy. US reports and images were reviewed and correlated with clinical history. The final study group consisted of 21 patients who had a total of 31 Morton neuromas evaluated using US after treatment. A retrospective review was then performed to characterize the appearances of these lesions before and after therapy followed by an analysis of variables. RESULTS: Retrospective US review of 31 pretreatment Morton neuromas showed fusiform, heterogeneously hypoechoic masses with well-defined borders in most cases and that pain was reported when transducer pressure was applied in 97% (30/31) of cases. After treatment, lesions showed ill-defined borders (23/31), and pain with application of transducer pressure was either significantly decreased or absent (29/31); these findings were concordant with the clinical findings. Both of these characteristics were statistically significant (p < 0.0001). In addition, more Morton neuromas occurred in the second intermetatarsal space than in the third intermetatarsal space (p < 0.0001). CONCLUSION: US may be used to identify posttreatment changes after laser therapy of Morton neuromas. Posttreatment changes include ill-defined borders and less pain or the absence of pain with the application of transducer pressure. These criteria may be applied in future clinical studies evaluating the efficacy of laser therapy for Morton neuroma.

Diagnostic Accuracy and Visual Search Efficiency: Single 8 MP vs. Dual 5 MP Displays.

This study compared a single 8 MP vs. dual 5 MP displays for diagnostic accuracy, reading time, number of times the readers zoomed/panned images, and visual search. Six radiologists viewed 60 mammographic cases, once on each display. A sub-set of 15 cases was viewed in a secondary study using eye-tracking. For viewing time, there was significant difference (F = 13.901, p = 0.0002), with 8 MP taking less time (62.04 vs. 68.99 s). There was no significant difference (F = 0.254, p = 0.6145) in zoom/pan use (1.94 vs. 1.89). Total number of fixations was significantly (F = 4.073, p = 0.0466) lower with 8 MP (134.47 vs. 154.29). Number of times readers scanned between images was significantly fewer (F = 10.305, p = 0.0018) with 8 MP (6.83 vs. 8.22). Time to first fixate lesion did not differ (F = 0.126, p = 0.7240). It did not take any longer to detect the lesion as a function of the display configuration. Total time spent on lesion did not differ (F = 0.097, p = 0.7567) (8.59 vs. 8.39). Overall, the single 8 MP display yielded the same diagnostic accuracy as the dual 5 MP displays. The lower resolution did not appear to influence the readers' ability to detect and view the lesion details, as the eye-position study showed no differences in time to first fixate or total time on the lesions. Nor did the lower resolution result in significant differences in the amount of zooming and panning that the readers did while viewing the cases.

Impact of Patient Photographs on Radiologists' Visual Search of Chest Radiographs.

RATIONALE AND OBJECTIVES: To increase detection of mislabeled medical imaging studies, evidence shows it may be useful to include patient photographs during interpretation. This study examined how inclusion of photographs impacts visual search. MATERIALS AND METHODS: Ten radiologists participated. Average age was 43.00 years and average years Board-certified was 9.70, with 2 residents, 1 general, 2 abdominal, 4 cardiothoracic, and 1 pediatric radiologist. They viewed 21 portable chest radiographs with and without a simultaneously acquired photograph of the patient while visual search was recorded. Their task was to note placement of lines and tubes. RESULTS: Presence of the photograph reduced the number of fixations (chest radiograph only mean 98.68; chest with photograph present 80.81; photograph 10.59; p < 0.0001) and total dwell (chest radiograph only mean 30.84 seconds; chest radiograph with photograph present 25.68; photograph 3.93; p < 0.0001) on the chest radiograph as a result of periodically looking at the photograph. Overall viewing time did not increase with addition of the photograph because time not spent on the radiograph was spent on the photograph. On average, readers scanned from the radiograph to the photographs about four times during search. Men and non-cardiothoracic radiologists spent significantly more time scanning all the images, including the photographs. Average preference for having photographs was 6.10 on a 0-10 scale, and neck and chest were preferred as areas to include in the photograph. CONCLUSION: Photographs may help with certain image interpretation tasks and may help personalize the reading experience for radiologists without increasing interpretation time.

Communicating Uncertainty in Surgical Pathology Reports: A Survey of Staff Physicians and Residents at an Academic Medical Center.

In order to document perceptions of text comments appearing in surgical pathology reports, questionnaires were distributed to 4 groups of caregivers: university staff pathologists, resident pathologists, faculty clinicians (other than pathologists), and resident clinicians at a teaching hospital. Results of this pilot study showed a wide degree of variability existed within each group of surgical pathology report users, with respect to percent confidence assigned to various phrases, commonly used to express diagnostic uncertainty, appearing often as free-text comments in surgical pathology reports. The unavailability of immunohistochemistry tests, or ambiguous immunohistochemistry test results, was especially problematic. With respect to modes of communication between the surgical pathology laboratory and its service users, clinicians indicated they preferred to use tumor boards/interdisciplinary conferences, face-to-face meetings, and phone calls to clarify their interpretations of a pathologist's diagnoses, as compared with simply reading free-text comments. On the other hand, surgical pathologists rely heavily on their use of the comment portion of a surgical pathology report to clarify, modify, or expand on the diagnoses they render. The majority of clinicians stated that they "always" read the free-text comment portion of a surgical pathology report, whereas some acknowledged they do not always read it. Pathology residents had significantly less confidence in the ability of a free-text comment on a surgical pathology report to clarify a diagnosis (χ2 = 46.36, P < .0001). Pathology departments should consider standardizing definitions and weighting the words and phrases they use in their free-text comment sections of surgical pathology reports.

Accuracy of High-Resolution Ultrasonography in the Detection of Extensor Tendon Lacerations.

BACKGROUND: Lacerations to the extensor mechanism are usually diagnosed clinically. Ultrasound (US) has been a growing diagnostic tool for tendon injuries since the 1990s. To date, there has been no publication establishing the accuracy and reliability of US in the evaluation of extensor mechanism lacerations in the hand. The purpose of this study is to determine the accuracy of US to detect extensor tendon injuries in the hand. METHODS: Sixteen fingers and 4 thumbs in 4 fresh-frozen and thawed cadaveric hands were used. Sixty-eight 0.5-cm transverse skin lacerations were created. Twenty-seven extensor tendons were sharply transected. The remaining skin lacerations were used as sham dissection controls. One US technologist and one fellowship-trained musculoskeletal radiologist performed real-time dynamic US studies in and out of water bath. A second fellowship trained musculoskeletal radiologist subsequently reviewed the static US images. Dynamic and static US interpretation accuracy was assessed using dissection as "truth." RESULTS: All 27 extensor tendon lacerations and controls were identified correctly with dynamic imaging as either injury models that had a transected extensor tendon or sham controls with intact extensor tendons (sensitivity = 100%, specificity = 100%, positive predictive value = 1.0; all significantly greater than chance). Static imaging had a sensitivity of 85%, specificity of 89%, and accuracy of 88% (all significantly greater than chance). The results of the dynamic real time versus static US imaging were clearly different but did not reach statistical significance. CONCLUSIONS: Diagnostic US is a very accurate noninvasive study that can identify extensor mechanism injuries. Clinically suspected cases of acute extensor tendon injury scanned by high-frequency US can aid and/or confirm the diagnosis, with dynamic imaging providing added value compared to static. Ultrasonography, to aid in the diagnosis of extensor mechanism lacerations, can be successfully used in a reliable and accurate manner.

Pigeons (Columba livia) as Trainable Observers of Pathology and Radiology Breast Cancer Images.

Pathologists and radiologists spend years acquiring and refining their medically essential visual skills, so it is of considerable interest to understand how this process actually unfolds and what image features and properties are critical for accurate diagnostic performance. Key insights into human behavioral tasks can often be obtained by using appropriate animal models. We report here that pigeons (Columba livia)-which share many visual system properties with humans-can serve as promising surrogate observers of medical images, a capability not previously documented. The birds proved to have a remarkable ability to distinguish benign from malignant human breast histopathology after training with differential food reinforcement; even more importantly, the pigeons were able to generalize what they had learned when confronted with novel image sets. The birds' histological accuracy, like that of humans, was modestly affected by the presence or absence of color as well as by degrees of image compression, but these impacts could be ameliorated with further training. Turning to radiology, the birds proved to be similarly capable of detecting cancer-relevant microcalcifications on mammogram images. However, when given a different (and for humans quite difficult) task-namely, classification of suspicious mammographic densities (masses)-the pigeons proved to be capable only of image memorization and were unable to successfully generalize when shown novel examples. The birds' successes and difficulties suggest that pigeons are well-suited to help us better understand human medical image perception, and may also prove useful in performance assessment and development of medical imaging hardware, image processing, and image analysis tools.

Retrospective review of the drop in observer detection performance over time in lesion-enriched experimental studies.

The vigilance decrement describes a decrease in sensitivity or increase in specificity with time on task. It has been observed in a variety of repetitive visual tasks, but little is known about these patterns in radiologists. We investigated whether there is systematic variation in performance over the course of a radiology reading session. We re-analyzed data from six previous lesion-enriched radiology studies. Studies featured 8-22 participants assessing 27-100 cases (including mammograms, chest CT, chest x-ray, and bone x-ray) in a reading session. Changes in performance and speed as the reading session progressed were analyzed using mixed effects models. Time taken per case decreased 9-23% as the reading session progressed (p < 0.005 for every study). There was a sensitivity decrease or specificity increase over the course of reading 100 chest x-rays (p = 0.005), 60 bone fracture x-rays (p = 0.03), and 100 chest CT scans (p < 0.0001). This effect was not found in the shorter mammography sessions with 27 or 50 cases. We found evidence supporting the hypothesis that behavior and performance may change over the course of reading an enriched test set. Further research is required to ascertain whether this effect is present in radiological practice.