Clinical variables and stone detection in patients with flank pain.

INTRODUCTION: Non-contrast CT (NCT) is commonly used to evaluate flank pain (FP). We sought to evaluate incidence of ureteral calculi on NCT in patients with FP, and to determine if clinical variables are associated with higher detection rates. MATERIALS AND METHODS: Retrospective review identified 613 patients undergoing NCT for FP. Patient clinical data, NCT findings, and intervention were analyzed. Focus was placed on variables commonly associated with urolithiasis (Vstone), comprising hematuria, nausea/vomiting, and prior stone history. Statistical analysis was performed to identify risk of ureteral stones based on number and type of Vstone. RESULTS: No stone disease was identified on NCT in 175 patients (28.5%). NCT demonstrated 214 (35%), 72 (12%), and 152 (25%) patients with stones located in the kidney, ureter, or both, respectively. Only 33 (5%) patients had FP as their sole Vstone, with ureteral calculi identified in 6% of this cohort. The rate of ureteral calculi increased with more Vstone. Patients having all four Vstone were found to have the highest rate of ureteral stones (59%). Statistical analysis demonstrated a statistically significantly increased relative risk of stone formation given three or four Vstone when compared with FP alone. CONCLUSIONS: Whereas isolated FP is associated with a lower rate of ureteral calculus detection, a significant increased relative risk of ureteral calculus is seen in patients with additional clinical variables associated with stone disease. Accordingly, it may be possible to improve detection rates of ureteral stones through the use of additional clinical variables to guide NCT selection.

Application of an interstitial and biodegradable balloon system for prostate-rectum separation during prostate cancer radiotherapy: a prospective multi-center study.

BACKGROUND AND PURPOSE: Rectal toxicity presents a significant limiting factor in prostate radiotherapy regimens. This study evaluated the safety and efficacy of an implantable and biodegradable balloon specifically designed to protect rectal tissue during radiotherapy by increasing the prostate-rectum interspace. PATIENTS AND METHODS: Balloons were transperineally implanted, under transrectal ultrasound guidance, into the prostate-rectum interspace in 27 patients with localized prostate cancer scheduled to undergo radiotherapy. Patients underwent two simulations for radiotherapy planning--the first simulation before implant, and the second simulation seven days post implant. The balloon position, the dimensions of the prostate, and the distance between the prostate and rectum were evaluated by CT/US examinations 1 week after the implant, weekly during the radiotherapy period, and at 3 and 6 months post implant. Dose-volume histograms of pre and post implantation were compared. Adverse events were recorded throughout the study period. RESULTS: Four of 27 patients were excluded from the evaluation. One was excluded due to a technical failure during implant, and three patients were excluded because the balloon prematurely deflated. The balloon status was evaluated for the duration of the radiotherapy period in 23 patients. With the balloon implant, the distance between the prostate and rectum increased 10-fold, from a mean 0.22 ± 0.2 cm to 2.47 ± 0.47 cm. During the radiotherapy period the balloon length changed from 4.25 ± 0.49 cm to 3.81 ± 0.84 cm and the balloon height from 1.86 ± 0.24 cm to 1.67 ± 0.22 cm. But the prostate-rectum interspace distance remained constant from beginning to end of radiotherapy: 2.47 ± 0.47 cm and 2.41 ± 0.43 cm, respectively. A significant mean reduction in calculated rectal radiation exposure was achieved. The implant procedure was well tolerated. The adverse events included mild pain at the perineal skin and in the anus. Three patients experienced acute urinary retention which resolved in a few hours following conservative treatment. No infections or thromboembolic events occurred during the implant procedure or during the radiotherapy period. CONCLUSION: The transperineal implantation of the biodegradable balloon in patients scheduled to receive radiotherapy was safe and achieved a significant and constant gap between the prostate and rectum. This separation resulted in an important reduction in the rectal radiation dose. A prospective study to evaluate the acute and late rectal toxicity is needed.

Paperless protocoling of CT and MRI requests at an outpatient imaging center.

We created our imaging center (IC) to move outpatient imaging from our busy inpatient imaging suite off-site to a location that is more inviting to ambulatory patients. Nevertheless, patients scanned at our IC still represent the depth and breadth of illness complexity seen with our tertiary care population. Thus, we protocol exams on an individualized basis to ensure that the referring clinician's question is fully answered by the exam performed. Previously, paper based protocoling was a laborious process for all those involved where the IC business office would fax the requests to various reading rooms for protocoling by the subspecialist radiologists who are 3 miles away at the main hospital. Once protocoled, reading room coordinators would fax back the protocoled request to the IC technical area in preparation for the next day's scheduled exams. At any breakdown in this process (e.g., lost paperwork), patient exams were delayed and clinicians and patients became upset. To improve this process, we developed a paper free process whereby protocoling is accomplished through scanning of exam requests into our PACS. Using the common worklist functionality found in most PACS, we created "protocoling worklists" that contain these scanned documents. Radiologists protocol these studies in the PACS worklist (with the added benefit of having all imaging and report data available), and subsequently, the technologists can see and act on the protocols they find in PACS. This process has significantly decreased interruptions in our busy reading rooms and decreased rework of IC staff.

Radiologist/Educator knowledge of the audience response system and limitations to its use.

RATIONALE AND OBJECTIVES: Audience response systems (ARS) have been proven to increase residents' retention in the short and long terms. The purpose of this study was to determine what teaching faculty members know about the ARS at one institution, what the obstacles are to its use, and ways to increase its use. MATERIALS AND METHODS: An anonymous and voluntary survey was sent to teaching faculty members. Fifty-two faculty members received the survey request and were included in the study set. The survey included questions regarding the faculty members' prior use of, understanding of, and ideas about ways to improve the ARS, as well as obstacles to its use. RESULTS: Thirty of 52 faculty members (58%) responded. Eight (27%) reported prior use of the ARS. Impediments to using the system more, for infrequent users, included "no need for it again," that it was "a bit tedious to incorporate into lectures," and time limitations. However, most users felt that the system was overall easy to use, and they did so by incorporating it into existing lectures. Perceptions that residents learned more effectively with the ARS motivated faculty members to use it more. They noted that residents seemed to like the ARS lectures more and were more engaged than with other didactic techniques. Faculty members would increase their use of the ARS if more information technology support were available, if training sessions were held, and if they had knowledge that residents preferred this lecture format. CONCLUSIONS: Faculty members at the authors' academic institution used its ARS infrequently but expressed an overall desire to use it more. They suggested methods that would increase their use of the device and were particularly motivated by residents' satisfaction with their lectures. If their suggestions can be implemented, use of the ARS should increase.

An inexpensive distance learning solution for delivering high-quality live broadcasts.

Providing an adequate method of distance learning is a challenge faced by many multicenter residency programs. The delivery of live didactics over the Internet is a convenient means of providing a uniform and equivalent educational experience to residents at distant sites. An application called MedCast has been developed with use of existing technologies, without the need for costly commercial products or equipment. MedCast captures the presenter's computer screen and audio from a microphone source to produce a streaming video that is transmitted online and archived on a local server. Offsite residents can view broadcasts in real time or access archived conference sessions for later viewing. MedCast is available for download at no cost and offers several advantages, including a user-friendly graphical display interface, near-perfect preservation of image quality, and cost efficiency. Future plans include objective assessment of the efficacy of MedCast by comparing postlecture examinations to help evaluate for any differences between on- and offsite residents in terms of knowledge gained. A movie clip to supplement this article is available online at http://radiographics.rsnajnls.org/cgi/content/full/285085701/DC1.

Effect of an audience response system on resident learning and retention of lecture material.

OBJECTIVE: In an era of increasing clinical volume and longer workdays, the time devoted to education may be diminished in many medical centers. The goal of our study was to develop techniques for optimizing educational time. SUBJECTS AND METHODS: Radiology residents in our program were randomized into two groups stratified by level of training. The control group received a standard didactic midday lecture, and the experimental group received the identical lecture material with an audience response system integrated into the lecture delivery. RESULTS: The group who used the interactive audience response software had significantly higher learning (p = 0.02) and long-term retention (p = 0.001) scores on postlecture quizzes administered to both groups of residents on the day of the lecture and 3 months later. CONCLUSION: Use of appropriate interactive teaching techniques facilitates residents' learning and retention of material. In our study, long-term retention was especially improved with use of an interactive lecture style.

Understanding and interpreting MRI of the genitourinary tract.

This article familiarizes the urologist with the most common pulse sequences used in MRI to evaluate the kidneys and adrenal glands. It serves as a basis on which interpretation of genitourinary MRI can be facilitated, and includes specifics on how to perform these studies. MRI analysis of renal masses, cysts, and cystic masses is reviewed thoroughly and the critical factor in determining enhancement in renal lesions is detailed. Adrenal imaging for metastatic disease is reviewed. MR urography is also discussed briefly.

Digitizing and consolidating mammograms and other images for teaching applications.

RATIONALE AND OBJECTIVES: Most mammograms are obtained using screen-film technique and must be digitized for teaching purposes. Digitizing mammograms poses special problems because of high contrast and multiple views. We describe the equipment and process for digitizing and consolidating mammograms for teaching purposes. These techniques can be applied to any type of images where consolidation may be helpful. MATERIALS AND METHODS: Mammograms are digitized using a high optical density scanner. After the window and levels are adjusted, a four-view mammogram may be consolidated into a single image if desired. RESULTS: The high contrast of film screen mammograms is managed by using a high optical density scanner. Consolidation of image sets, such as a four-view mammogram, allows images to be easily inserted into text, slide, or poster documents. CONCLUSIONS: Digitizing mammograms for teaching purposes is facilitated by use of a high optical density scanner and consolidation of image sets into single images. The techniques described are also useful for other areas of radiology in which display of multiple images or modalities is desirable.

Enhanced teaching of screening mammography using an electronic format.

RATIONALE AND OBJECTIVES: Most mammography teaching materials provide only diagnostic images, often with obvious findings due to space constraints. In this work, we describe a method of incorporating full resolution digitized screening mammograms in text teaching file documents to enhance teaching of screening mammography. METHODS: Teaching cases are constructed in a word processing document with images inserted. The four view screening mammogram is presented first and may be opened in an image viewing program using an embedded hyperlink to view at high resolution, similar to using a magnifying glass. The screening study is followed by feedback and presentation of diagnostic images. Feedback is again provided, followed by diagnosis, differential diagnosis, discussion, and references. A six-question survey of residents and fellows using 5-point Likert scales was used to assess performance. RESULTS: Teaching cases in this format mimic clinical practice by separately presenting screening and diagnostic views. Mammograms may be viewed at high resolution, allowing incorporation of subtle findings to build detection skills. Inclusion of diagnostic views builds judgment and management skills. Survey results from 15 residents and 2 fellows found a mean overall rating of the teaching file of 1.6 (1 = excellent, 5 = poor). CONCLUSIONS: Screening mammograms with subtle findings can be incorporated into breast teaching cases by embedding hyperlinks to open images at high resolution in an image-processing program.

Review of technology: planning for the development of telesonography.

Teleradiology allows contemporaneous interpretation of imaging exams performed at some distance from the interpreting radiologist. The transmitted images are usually static. However, there is benefit to real-time review of full-motion ultrasound (US) exams as they are performed. Telesonography is transmission of full-motion sonographic data to a remote site. We hypothesize that US exams, read after having been compressed utilizing Motion Picture Experts Group version 4 (MPEG-4) compression scheme, transmitted over the Internet as streaming multimedia, decompressed, and displayed, are equivalent in diagnostic accuracy to reading the examinations locally. MPEG-4 uses variable compression on each image frame to achieve a constant output bit rate. With less compression, the bit rate rises, and the only way the encoder can contain bit rate within the set bandwidth is by lowering frame rate or reducing image quality. We review the relevant technologies and industry standard components that will enable low-cost telesonography.

Conversion of teaching file cases from film to digital format: a comparison between use of a diagnostic-quality digitizer and use of a flatbed scanner with transparency adapter.

RATIONALE AND OBJECTIVES: The authors' institution had decided to convert its radiology teaching files from film to digital media. This study was performed to determine the simplest method for converting the analog film images to digital images without a subsequent loss in diagnostic accuracy. MATERIALS AND METHODS: Twenty chest radiographs that demonstrated interstitial lung disease were randomly selected from the departmental teaching files and matched with 20 control radiographs from healthy adults. Analog film images were converted with both a diagnostic-quality film image digitizer (digitized) and a flatbed scanner equipped with a transparency adapter (scanned). Three radiology faculty members reviewed a mixed set of corresponding analog film, digitized, and scanned images. Reviewers judged whether each image depicted interstitial lung disease, indicated their level of confidence in the diagnosis, and rated each image for quality. Image quality was assessed by each reviewer subjectively at the time of viewing the individual image, without regard to other images. A one-way analysis of variance was performed to determine whether there was a statistically significant difference in diagnostic accuracy between the three image formats. Agreement in diagnosis between corresponding images in the three different formats was evaluated for each reviewer with the McNemar test. RESULTS: There was no statistically significant difference in diagnostic accuracy between analog film and scanned images, but there was such a difference between these two groups and digitized images. Accuracy was 97% for analog film, 94% for scanned, and 89% for digitized images. Results of the McNemar test showed no statistically significant difference in agreement between the analog film images and the scanned images for any of the reviewers (P > .05). CONCLUSION: A high-end flatbed scanner with transparency adapter provided accurate, simple, and inexpensive conversion of analog film teaching files to digital format, with no loss of the ability to detect or diagnose subtle abnormalities such as interstitial lung disease.