Hard-copy Film Research Articles

Identification of Filling Versus Voiding Reflux as Predictor of Clinical Outcome

In children diagnosed with vesicoureteral reflux (VUR), the identification of reflux is made during either the filling (filling reflux) or voiding (voiding reflux) phase of the voiding cystourethrogram. A retrospective study was performed to determine whether this radiologic distinction has prognostic significance. A retrospective chart review was performed of patients who had undergone voiding cystourethrography from July 1999 to June 2004. Patient age, sex, and reflux grade (unilateral and bilateral) were independently examined in relation to spontaneous resolution, surgical intervention, or observation. These data were subjected to chi-square, analysis of variance with post hoc test, and Kaplan-Meier analysis. The diagnosis of primary VUR was identified in 218 patients, and sufficient chart information and hardcopy films to permit identification of filling versus voiding reflux were available for 201. Of 201 patients, 115 (57%) had filling reflux and 86 (43%) had voiding reflux. Of the 115 with filling reflux, 53 (46%) underwent surgery and 27 (23%) had spontaneous resolution (P <0.001). Of the 86 patients with voiding reflux, 12 (14%) underwent surgery and 57 (66%) had spontaneous resolution (P <0.0001). Advanced age and grade of reflux were independently associated with surgical intervention (P <0.0001 and P <0.04, respectively). Our results have shown that VUR that is first identified during the filling phase of the initial voiding cystourethrogram is more likely to require surgical intervention. In contrast, VUR that is first identified during the voiding phase was independently associated with a greater rate of spontaneous resolution. This radiologic distinction, in addition to reflux grade, might be useful in predicting the clinical outcome for children diagnosed with primary VUR.

COMPARISON OF INTRA- AND INTEROBSERVER RELIABILITY WITH COMPUTED AND CONVENTIONAL RADIOGRAPHY FOR SPINAL DEFORMITY.

Children suffering from scoliosis are routinely monitored with spinal radiographs every 4 to 6 months. This radiation exposure represents a concern in the treatment and observation of children with spinal deformity as increased radiation exposure in childhood is known to correlate with increased incidence of both childhood and adult malignancy. Although the examination of spinal deformity is still studied largely by means of conventional radiography, technologic advances have made computed radiography (CR) and digital radiography (DR) more accessible. It has recently been shown that a significant reduction in radiation exposure can be achieved with both CR and DR compared with conventional radiography in the evaluation of children with scoliosis. Although this reduction in radiation exposure does degrade image quality, the interobserver variability in Cobb-angle measurements is not statistically significant. Our institution uses CR in the outpatient evaluation of scoliosis patients. Shriners Hospital for Children, located in Sacramento, uses conventional plain-film radiography. Per the current protocols, both studies result in an essentially equivalent radiation dose to the patient with similar image quality. Because the primary indication for serial studies in scoliosis patients is to follow curve progression, it may be possible to accept a compromised image quality with CR or DR while lowering the radiation dose and maintaining accurate radiologic measurements. The purpose of our study is to compare the intra- and interobserver reliability of clinical measurements made using CR and conventional radiography in the evaluation of children with idiopathic scoliosis, as well as comparing the radiation exposure of each study. Our study involves 25 patients with idiopathic scoliosis between the ages of 8 and 17 seen at Shriners Hospital. The patients are having conventional films taken at Shriners Hospital, followed by CR scoliosis films taken at UC Davis 4 to 6 months later. Four sets of films will then be examined 2 weeks apart by two orthopedic surgeons and two pediatric radiologists. The four film sets are CR films on PACS, CR hardcopy films, conventional films loaded on PACS, and hardcopy conventional films. A variety of clinical measurements will be made and analyzed. The study is currently ongoing. The objective of the study is to measure the accuracy of measurements made using CR compared with conventional radiography. With this established, it may then be possible to lower radiation exposure while maintaining accurate clinical measurements. Ultimately, this would result in improved care of children with scoliosis.

An observer study: comparison of computed radiography to electronic and film portal imaging

Introduction: Computed radiography (CR) is an imaging facility that does not require the use of hard copy film, digital images are obtained with a photostimulable phosphor plate, which replaces film, in a cassette. As the first UK radiotherapy site to trial CR, we are collecting data to assess the feasibility of using CR in radiotherapy treatment verification.Method: From 30 patients undergoing radical radiotherapy, 10 were consecutively accrued to three sites: pelvis, thorax and head and neck. Treatment verification images were taken using current protocols, but substituting standard imaging for CR images on one fraction. Four independent observers were used: two clinical oncologists and two therapy radiographers. Observers rated CR, electronic portal imaging (EPI) and enhanced contrast (EC) films of the three sites for both landmark visibility and ease of verification decision, using a numerical scoring system.Results: Ratings for visibility of landmarks and for verification decision were similar for CR and film/EPI images for most landmarks. However, CR images rated poorly compared to EC film in the head and neck region with landmarks such as thyroid cartilage and cricoid cartilage rating as ‘not clear’. CR images rated better than EPI images for both visibility and verification decision on the majority of landmarks in the pelvis region.Conclusion: Results gathered from a relatively small sample size have provided the following conclusion. The visibility of landmarks in CR images is comparable to that in film and EPI. Verification of treatment images based on CR is comparable to that of the current imaging media in the department.

Detection of masses and microcalcifications of breast cancer on digital mammograms: comparison among hard-copy film, 3-megapixel liquid crystal display (LCD) monitors and 5-megapixel LCD monitors: an observer performance study

The purpose of the study was to compare observer performance in the detection of masses and microcalcifications of breast cancer among hard-copy reading and soft-copy readings using 3-megapixel (3M) and 5-megapixel (5M) liquid crystal display (LCD) monitors. For the microcalcification detection test, we prepared 100 mammograms: 40 surgically verified cancer cases and 60 normal cases. For the mass detection test, we prepared 100 mammograms: 50 cancer cases and 50 normal cases. After six readers assessed both microcalcifications and masses set for each modality, receiver operating characteristic (ROC) analysis was performed. The average A(z)s for mass detection using a hard copy and 3M and 5M LCD monitors were 0.923, 0.927 and 0.920, respectively; there were no significant differences. The average A(z) for microcalcification detection using hard copy, 3M and 5M LCD monitors was 0.977, 0.954 and 0.972, respectively. There were no significant differences, but the P-values between the hard copy and 3M LCD monitor and that between the 3M and 5M LCD monitor were 0.08 and 0.09, respectively. In conclusion, the observer performances for detecting masses of breast cancers were comparable among the hard copy and two LCD monitors; however, soft-copy reading with a 3M LCD monitor showed slightly lower observer performance for detecting microcalcifications of breast cancers than hard-copy or 5M LCD monitor reading.

Staging performance of carbon‐11 choline positron emission tomography/computed tomography in patients with bone and soft tissue sarcoma: Comparison with conventional imaging

The present study was conducted to compare the diagnostic accuracy between carbon-11 choline (11C-choline) positron emission tomography (PET)/computed tomography (CT) and conventional imaging for the staging of bone and soft tissue sarcomas. Sixteen patients who underwent 11C-choline PET/CT prior to treatment were evaluated retrospectively for staging accuracy. Conventional imaging methods consisted of 99,mTc-hydroxymethylene diphosphonate bone scintigraphy, chest CT and magnetic resonance imaging of the primary site. The images were reviewed and a consensus was reached by two board-certified radiologists who were unaware of any clinical or radiological information using hard-copy films and multimodality computer platform. Tumor stage was confirmed by histological examination and/or by an obvious progression in number and/or size of the lesions on follow-up examinations. Reviewers examining both 11C-choline PET/CT and conventional imaging classified T stage in all patients. Interpretation based on 11C-choline PET/CT, the Node (N) stage was correctly diagnosed in all patients, whereas the accuracy of conventional imaging in N stage was 63%. Tumor Node Metastasis (TNM) stage was assessed correctly with 11C-choline PET/CT in 15 of 16 patients (94%) and with conventional imaging in eight of 16 patients (50%). The overall TNM staging and N staging accuracy of 11C-choline PET/CT were significantly higher than that of conventional imaging (P < 0.05). 11C-choline PET/CT is more accurate than conventional imaging regarding clinical staging of patients with bone and soft tissue sarcomas. A whole body 11C-choline PET/CT might be acceptable for imaging studies of tumor staging prior to treatment.

Relationship between inflammatory lesions and cerebral atrophy in multiple sclerosis

To investigate the temporal relationship between inflammation and cerebral atrophy in a longitudinal study of 19 patients with relapsing-remitting multiple sclerosis (RRMS) using serial monthly contrast enhanced MRI examinations and monthly measurements of brain fractional volume (BFV) for an average of 4 (range 2.4 to 10) years. In this retrospective study, all patients had an active MRI scan at entry with a minimum of two new contrast enhancing lesions (CEL) on baseline MRI examinations. Patients were followed for a minimum of 3 months during a baseline (pretreatment) phase and subsequently followed during treatment with recombinant interferon beta (IFN) and various other immunomodulatory agents. Pre- and post contrast axial images were obtained using 3-mm slice thickness and a gadolinium contrast dose of 0.1 mmol/kg. Monthly CEL were sequentially numbered on hardcopy films and monthly BFV was determined on precontrast T1W images using a semiautomated program. For BFV measurements, all T1W scans were registered to the entry examination, which served as a mask image. Cerebral atrophy was measured as percent brain fractional volume change (PBVC) compared to the entry baseline scan. The results demonstrate that cerebral atrophy paralleled that of contrast enhancing lesion accumulation. The correlation between cumulative CEL and PBVC ranged from R2 = 0.47 to 0.81. Immunomodulatory agents that effectively reduced CEL accumulation also slowed the rate of atrophy. The correlation between contrast enhancing lesions (CEL) and atrophy suggests that patients who are not responding to therapy with a decrease in CEL may also be at risk for developing increased atrophy.

High reproducibility of patellar tendon vascularity assessed by colour Doppler ultrasonography: a reliable measurement tool for quantifying tendon pathology

Background: This study examined whether patellar tendon vascularity could be quantified accurately in the clinical setting using colour Doppler ultrasonography. Methods: A sonographer and two radiologists visually estimated tendon vascularity...

Image Quality Assurance of Soft Copy Display Systems

Image quality assurance has traditionally been a high priority in medical imaging departments. Recently, it has often been neglected with the transition from hard copy (film) to soft copy (computer) display systems, which could potentially result in difficulty in reading images or even misdiagnosis. This transition therefore requires careful management such that comparable image quality is achieved at a minimum. It is particularly difficult to maintain appropriate image quality in the clinical settings outside of medical imaging departments because of the volume of display systems and the financial restraints that prohibit the widespread use of dedicated computers and high-quality monitors. In this study, a protocol to test and calibrate display systems was developed and validated by using an inexpensive calibration tool. Using this protocol, monitors were identified in a hospital in which image quality was found to be inadequate for medical image viewing. It was also found that most monitors could achieve a substantial increase in image quality after calibration. For example, the 0 and 5% luminance difference was discernable on 30% of the piloted display systems before calibration, but it was discernable on 100% post calibration. In addition, about 50% of the piloted display systems did not have the maximum luminance (white level) suitably set, and 35% of them did not have the minimum luminance (dark level) suitably set. The results indicate that medical display systems must be carefully selected and strictly monitored, maintained, and calibrated to ensure adequate image quality.

Coagulation necrosis in malignant mediastinal nodes on endoscopic ultrasound: a new endosonographic sign

Endoscopic ultrasound (EUS) can be used to assess mediastinal lymph nodes, and EUS-guided transoesophageal fine needle aspiration (EUS-FNA) can provide a tissue diagnosis. Previous studies suggest that a uniformly hypoechoic echotexture is a feature of malignant nodes, and echogenic structures within nodes are due to the normal hilum. Ill-defined, non-shadowing echogenic areas within malignant lymph nodes have been termed coagulation necrosis (CN) on neck ultrasound. The purpose of this study is to determine whether CN can be detected on EUS and be used as a predictive sign for malignancy in mediastinal lymph nodes. A total of 36 individuals who underwent EUS-FNA of mediastinal lymph nodes were initially included. A radiologist experienced in neck ultrasound, and blinded to the final diagnosis, reviewed hard-copy films for CN. Comparison was made with the EUS-FNA result and the final diagnosis. Four patients were excluded because their films were deemed inadequate for retrospective diagnosis. The remaining 32 patients were all included, and 11 showed CN. Of the 11 cases, 10 had malignant cytology on EUS-FNA; and in the remaining case follow-up indicated a false-negative EUS-FNA. Of the 21 subjects with no CN, the final diagnosis was malignant in 12 and non-malignant in 9 cases. No participant with a final benign diagnosis had CN. Echogenic structures within mediastinal lymph nodes on EUS are not necessarily due to the normal hilum. Careful analysis of the intranodal echo pattern may reveal CN. CN can be used as a predictive sign of malignancy and EUS-FNA should be targeted towards these nodes.

Phase-inversion tissue harmonic imaging compared to fundamental B-mode ultrasound in the evaluation of the pathology of large and small bowel

Our purpose was to compare phase-inversion harmonic imaging (PIHI) with conventional B-mode ultrasound (US) regarding image quality in the evaluation of bowel pathology. Forty-one patients prospectively underwent intestinal ultrasound scans with US and PIHI in randomly chosen order. Crucial technical parameters were standardized. Bowel morphology as well as perienteric pathology and complications were documented. In 24 cases, the ultrasound results were compared to those of other imaging modalities. Three radiologists evaluated (1) overall image quality, (2) lesion conspicuity and diagnostic confidence, and (3) detection of free fluid on hardcopy films. The ratings for image quality were compared using the two-sample paired t test for means and Bowker's test for symmetry (p=0.05). Compared to US, PIHI provided significantly better overall image quality, lesion conspicuity and diagnostic confidence, as well as better detection of free fluid (p< 0.05). Bowel wall pathology, detected by both modalities, showed good correlation to additional imaging modalities. In 12 patients (29.3%), a gain of crucial diagnostic information was observed with PIHI when compared to US. PIHI significantly enhances sonography of the intestine by offering better overall image quality, better visualization of bowel pathology and associated changes. Additionally, PIHI adds crucial diagnostic information in several patients.

Prevalence of Eye Strain Among Radiologists: Influence of Viewing Variables on Symptoms

To determine the prevalence of and factors contributing to eye strain among radiologists, we examined the influence of the viewing method (PACS vs hard-copy film), age, case volume, technique, work habits, and workstation design on symptoms. An Internet-based survey was sent to 2,700 radiologists randomly selected from the membership database of the Radiological Society of North America. Questions included demographic information, viewing method, work habits, and workstation design. Common eye strain symptoms were evaluated on a 5-point Likert scale. Chi-square analysis, analysis of variance, and step-wise and regression analyses were performed to evaluate codependence of the explanatory variables with eye strain. The adjusted response rate was 14% (380 respondents). The largest age cohort was 36-50 years. The prevalence of eye strain was 36% and was not affected by the viewing method (PACS vs film). Increased symptoms could be independently predicted in radiologists who were women (p <0.001), had longer work days (p=0.009), took fewer breaks (p=0.03), reported screen flicker (p=0.0003), and performed CT screening (p=0.04). Working hours had the strongest influence on eye strain. Eye strain was increased in those who reported studies for longer than 6 hr per day (p=0.01) and decreased in those who took breaks every hour (p=0.04). Symptoms were independent of the length of the break taken and of other workstation and technique factors. Eye strain was common among the radiologists in our study population, with no significant difference between PACS and hard-copy film users. Taking frequent short breaks, eliminating screen flicker, and limiting the number of CT screening studies interpreted may improve symptoms.

Definitive neuroradiological diagnostic features of tuberculous meningitis in children

Although CT scanning is used widely for making the diagnosis and detecting the complications of tuberculous meningitis (TBM) in children, the radiological features are considered non-specific. CT is particularly suggestive of the diagnosis when there is a combination of basal enhancement, hydrocephalus and infarction, and even then the diagnosis may be in doubt. In this paper we introduce a new CT feature for making the diagnosis of TBM, namely, hyperdensity in the basal cisterns on non-contrast scans, and we assess which of the recognized CT features is most sensitive and specific. To determine the sensitivity and specificity of the presence of high-density exudates in the basal cisterns (on non-contrast CT) and basal enhancement (on contrast-enhanced CT) for the diagnosis of TBM in children, and to correlate these with the complications of infarction and hydrocephalus. Retrospective review of CT scans with readers blinded to the diagnosis, which was based on a definitive culture of cerebrospinal fluid (CSF) for TBM or other bacteria. Computer-aided conversion of hard-copy film density to Hounsfield units was employed as well as a density threshold technique for determining abnormally high densities. The most specific feature for TBM is hyperdensity in the basal cisterns prior to IV contrast medium administration (100%). The most sensitive feature of TBM is basal enhancement (89%). A combination of features (hydrocephalus, infarction and basal enhancement) is as specific as pre-contrast hyperdensity, but has a lower sensitivity (41%). There were statistically significant differences in the presence of hydrocephalus (p=0.0016), infarcts (P=0.0014), basal enhancement (P<0.0001) and pre-contrast density (P<0.0001) between the negative and positive TBM patient groups. The presence of granulomas was not statistically significant between the two groups (P=0.44). The presence of high density within the basal cisterns on non-contrast CT scans is a very specific sign for TBM in children. This will enhance diagnostic confidence, allow early institution of therapy and could reduce expenditure on contrast medium, scan time and radiation exposure. With the use of threshold techniques we believe that the pre-contrast hyperdensity may be detectable by a computer program that will facilitate diagnosis, and may also be modified to detect abnormal enhancement. Basal enhancement is a sensitive sign for the diagnosis of TBM and should be sought after contrast medium administration when no hyperdensity is seen in the basal cisterns or when this finding needs to be confirmed. The CT scan feature of hyperdense exudates on pre-contrast scans should be added to the inclusion criteria for the diagnosis of TBM in children.

Evaluation of the display quality of different modalities in digital radiology

To evaluate the display quality of digital radiographies on different monitors in comparison to hard-copy films on view boxes. Radiographs of different statistical phantoms simulating common pathologies of the chest, such as interstitial pneumonia, pneumothorax and pulmonary nodules, were acquired. Under same ambient light condition, the radiographs were rated as to the presence or absence of a simulated pathological finding using a confidence scale. The evaluation was performed on a grey-scale monitor, a color monitor, two LC displays and two different light boxes by four experienced radiologists. Sensitivity and specificity were determined in a ROC analysis for each viewing modality and phantom. The area under the curve (Az) was acquired cumulatively including the results of all investigators. A total of 4200 rating decisions were included. The chi (2)-test was performed for significance analysis using the a and b parameters of two ROC-curves (alpha = 0.05). The rating of the included LC displays (Az = 0.7009 - 0.9608) and color monitors (Az = 0.7993 - 0.9591) showed a significant loss of diagnostic validity in comparison to the grey-scale monitor (Az = 0.8435 - 0.9762) and the view boxes (Az = 0.8228 - 0.9891). LC displays and color monitor included in this study cannot be recommended for diagnostic viewing. The loss of diagnostic validity might be attributable to the viewing-angle-dependent contrast of LC displays. However, no loss in diagnostic validity could be assessed for the tested grey-scale monitor.

Long line positioning in neonates: does computed radiography improve visibility?

Objectives: To assess the use of soft copy reporting of computed radiography (CR) images in determining intravenous long line tip position in neonates and compare visibility rates with hard copy...

Digital Image Processing: A Primer for JVIR Authors and Readers: Part 2: Digital Image Acquisition

This is the second installment of a three-part series on digital image processing intended to prepare authors for online submission of manuscripts. In the first article of the series, we reviewed the fundamentals of digital image architecture. In this article, we describe the ways that an author can import digital images to the computer desktop. We explore the modern imaging network and explain how to import picture archiving and communications systems (PACS) images to the desktop. Options and techniques for producing digital hard copy film are also presented.

A model for a PC-based, universal-format, multimedia digitization system: Moving beyond the scanner 1

Rationale and Objectives. Digitizing images for use in case presentations based on hardcopy films, slides, photographs, negatives, books, and videos can present a challenging task. Scanners and digital cameras have become standard tools of the trade. Unfortunately, use of these devices to digitize multiple images in many different media formats can be a time-consuming and in some cases unachievable process. The authors’ goal was to create a PC-based solution for digitizing multiple media formats in a timely fashion while maintaining adequate image presentation quality. Materials and Methods. The authors’ PC-based solution makes use of off-the-shelf hardware applications to include a digital document camera (DDC), VHS video player, and video-editing kit. With the assistance of five staff radiologists, the authors examined the quality of multiple image types digitized with this equipment. The authors also quantified the speed of digitization of various types of media using the DDC and video-editing kit. Results. With regard to image quality, the five staff radiologists rated the digitized angiography, CT, and MR images as adequate to excellent for use in teaching files and case presentations. With regard to digitized plain films, the average rating was adequate. As for performance, the authors recognized a 68% improvement in the time required to digitize hardcopy films using the DDC instead of a professional quality scanner. Conclusions. The PC-based solution provides a means for digitizing multiple images from many different types of media in a timely fashion while maintaining adequate image presentation quality.

Delivering images to the operating room: a web-based solution.

As radiology departments become filmless, they are discovering that some areas are particularly difficult to deliver images. Many departments have found that the operating room is one such area. There are space constraints and difficulty in manipulating the images by a sterile surgeon. This report describes one method to overcome this obstacle. The author's institution has been using picture archiving and communication system (PACS) for approximately 3 years, and it has been a filmless department for 1 year. The PACS transfers images to a webserver for distribution throughout the hospital. It is accessed by Internet Explorer without any additional software. The authors recently started a pilot program in which they installed dual panel flat screen monitors in 6 operating rooms. The computers are connected to the hospital backbone by ethernet. Graphic cards installed in the computers allow the use of dual monitors. Because the surgeons were experienced in viewing cases on the enterprise web system, they had little difficulty in adapting to the operating room (OR) system. Initial reception of the system is positive. The use of the web system was found to be superior by the surgeons because of the flexibility and manipulation of the images compared with film. Images can be magnified to facilitate viewing from across the room. The ultimate goal of electronic radiology is to replace hardcopy film in all aspects. One area that PACS has difficulty in accomplishing this goal is in the operating room. Most institutions have continued to print film for the OR. The authors have initiated a project that may allow web viewing in the OR. Because of limited space in the OR, an additional computer was undesirable. The CPU tower, keyboard, and mouse were mounted on a frame on the wall. The images were displayed on 2 flat screen monitors, which simulated the viewboxes traditionally used by the surgeons. Interviews with the surgeons have found both positive and negative aspects of the system. Overall impression is good, but the timeliness of the intraoperative films needs to be improved. The author's pilot project of installing a web-based display system in the operating room still is being evaluated. Their initial results have been positive, and if there are no major problems that arise the project will be expanded. These results show that it is possible to provide image delivery to the OR over the intranet that is acceptable to the surgeons.

Method and timing of tumor volume measurement for outcome prediction in cervical cancer using magnetic resonance imaging

Purpose : Recently, imaging-based tumor volume before, during, and after radiation therapy (RT) has been shown to predict tumor response in cervical cancer. However, the effectiveness of different methods and timing of imaging-based tumor size assessment have not been investigated. The purpose of this study was to compare the predictive value for treatment outcome derived from simple diameter-based ellipsoid tumor volume measurement using orthogonal diameters (with ellipsoid computation) with that derived from more complex contour tracing/region-of-interest (ROI) analysis 3D tumor volumetry. Methods and Materials : Serial magnetic resonance imaging (MRI) examinations were prospectively performed in 60 patients with advanced cervical cancer (Stages IB 2-IVB/recurrent) at the start of RT, during early RT (20–25 Gy), mid-RT (45–50 Gy), and at follow-up (1–2 months after RT completion). ROI-based volumetry was derived by tracing the entire tumor region in each MR slice on the computer work station. For the diameter-based surrogate “ellipsoid volume,” the three orthogonal diameters (d 1, d 2, d 3) were measured on film hard copies to calculate volume as an ellipsoid (d 1 × d 2 × d 3 × π/6). Serial tumor volumes and regression rates determined by each method were correlated with local control, disease-free and overall survival, and the results were compared between the two measuring methods. Median post-therapy follow-up was 4.9 years (range, 2.0–8.2 years). Results : The best method and time point of tumor size measurement for the prediction of outcome was the tumor regression rate in the mid-therapy MRI examination (at 45–50 Gy) using 3D ROI volumetry. For the pre-RT measurement both the diameter-based method and ROI volumetry provided similar predictive accuracy, particularly for patients with small (<40 cm 3) and large (≥100 cm 3) pre-RT tumor size. However, the pre-RT tumor size measured by either method had much less predictive value for the intermediate-size (40–99 cm 3) tumors, which accounted for the majority of patients (55%). Tumor regression rate (fast vs. slow) obtained during mid-RT (45–50 Gy), which could only be appreciated by 3D ROI volumetry, had the best outcome prediction rate for local control (84% vs. 22%, p < 0.0001) and disease-free survival (63% vs. 20%, p = 0.0005). Within the difficult to classify intermediate pre-RT size group, slow ROI-based regression rate predicted all treatment failures (local control rate: 0% vs. 91%, p < 0.0001; disease-free survival: 0% vs. 73%, p < 0.0001). Mid-RT regression rate based on simple diameter measurement did not predict outcome. The early-RT and post-RT measurements were least useful with either measuring method. Conclusion : Our preliminary data suggest that for the prediction of treatment outcome in cervical cancer, initial tumor volume can be estimated by simple diameter-based measurement obtained from film hard copies. When initial tumor volume is in the intermediate size range, ROI volumetry and an additional MRI during RT are needed to quantitatively analyze tumor regression rate for the prediction of treatment outcome.

Can electronic medical images replace hard-copy film? Defining and testing the equivalence of diagnostic tests.

Electronic medical images are an efficient and convenient format in which to display, store and transmit radiographic information. Before electronic images can be used routinely to screen and diagnose patients, however, it must be shown that readers have the same diagnostic performance with this new format as traditional hard-copy film. Currently, there exist no suitable definitions of diagnostic equivalence. In this paper we propose two criteria for diagnostic equivalence. The first criterion ('population equivalence') considers the variability between and within readers, as well as the mean reader performance. This criterion is useful for most applications. The second criterion ('individual equivalence') involves a comparison of the test results for individual patients and is necessary when patients are followed radiographically over time. We present methods for testing both individual and population equivalence. The properties of the proposed methods are assessed in a Monte Carlo simulation study. Data from a mammography screening study is used to illustrate the proposed methods and compare them with results from more conventional methods of assessing equivalence and inter-procedure agreement.

The evolution of filmless radiology teaching

The transition from hard-copy film to the picture archiving and communication systems (PACS) arena is often a long and difficult path, but the complete transformation to the digital environment does not end with the successful clinical practice utilizing PACS. The next hurdle for academic institutions is similar changes in the teaching field. The loss of hardcopy films can greatly hinder the radiology teaching file and teaching conference experiences. The next step in our growth is the conversion to digital teaching files and conferences. The original work 10 years ago with utilizing computers linked with laser disks and magneto-optical media, have now evolved into complex networks with expanding and relatively cheap storage media, such as CD-ROM and easily to navigate graphic-user interfaces such as hypertext markup language (HTML) and extensible markup language (XML), for use with multimedia teaching tools. The transition into the digital arena for radiology education and interdepartmental conferences can be accomplished through several different paths. These include direct transfer of images into a presentation program, as well as exportation of images into suitable image file formats for later use. There is also the ability to expand the PACS network to include conference rooms. Similar training and teaching can allow radiologists to transition into the digital environment for future digital teaching file creation as well as correlative radiology interdepartmental conferences.