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Pseudocapsule of renal cell carcinoma (RCC): Value on evaluating the histologic grade of RCC with MR imaging
tardus waveform. (3) Not all stenoses are Doppler detectable.
9- 5 8 Bladder Pseudotumors on C o n t r a s t - E n h a n c e d Spiral CT" I n c i d e n c e and Clinical I m p l i c a t i o n s
John S. Rhee,MD, Palo Alto Medical Center, Palo Alto, CA, EricW. Olcott, MD, MatildeNino-Murcia, MD P u r p o s e : Abdominal spiral CT scans are acquired so rapidly that renal excretion of intravenous contrast medium often has just begtm at the time the bladder is imaged. We have noted that opacified urine entering the unopacified bladder may simulate the nodularity and wall thickening of bladder neoplasms. We determined the incidence and appearances of these pseudotumors. Methods: Each of 100 consecutive contrast-enhanced abdominal CT scans (91 men, 7 w o m e n ) obtained for various indications was examined and scored by three readers for wall thickening (asymmetry and/ or thickness > 5 mm) and nodules within the bladder. Clear ureteral jets were counted separately. Delayed CT images, ultrasound, urography and/or cystography served as true reference standards. Results: Nodules and/or mural thickening indistinguishable from bladder tumors were identified in 8% of scans in w h i c h delayed CT images, ultrasound, urography or cystography demonstrated no evidence of tumor (2% nodules, 5% mural thickening, 1% both). Clear ureteral jets were visualized in 19% of scans. C o n c l u s i o n : Opacified urine simulates bladder neoplasms in 8% of contrast-enhanced spiral CT scans. Further evaluation is warranted in each patient exhibiting such findings to exclude or confirm the presence of a true bladder neoplasm. Take H o m e Points: Opacified urine simulates bladder neoplasms in the form of nodules and/or mural thickening in 8% of contrast-enhance spiral CT scans. Further evaluation in these patients with delayed CT images, ultrasound, urography or cystography is warranted to exclude or confirm the presence of a true bladder neoplasm.
9- 5 9 P s e u d o c a p s u l e of Renal Cell C a r c i n o m a (RCC): V a l u e on Evaluating t h e Histologic Grade of RCC with MR Imaging
Tao Li, MD, Great Wall Hospital, Beijing, People's Rep of China, Y. G. Gao, MD, Y. A. Gao, MD P u r p o s e : To assess the value of the pseudocapsule on evaluating the histologic grade of RCC with MR imaging. Methods: Thirty-five patients with RCC were imaged at Siemens 1.0 T MR unit with axial SE TlWI(TR/TE=500/15ms) and SE T2WI(TR/ TE=2000/90ms) by use of body coll. The histologic large specimens of the whole t u m o r and adjacent renal tissue were obtained on the corresponding position with MR images. The tlistologic grading of RCC was based on Riches' criterion. Results: At pathologic evaluation, the thicknesses of the pseudocapsule of low and high histologic grade RCCs were 1.26 + 0.31mm and 0.79 + 0.25mm respectively (P<0.05). On MR imaging, T2WI was more sensitive for visualization of the pseudocapsuie (sensitivity, 62.9%) than TIWI was (sensitivity, 8.6%). On T2WI, the pseudocapsule of low histologic grade RCC appeared as continuous thicker rim of low signal with higher appearing incidence (84.4%), but the pseudocapsule of high histologic grade RCC appeared as interrupted thinner rim with lower appearing incidence (44.4%). C o n c l u s i o n s : The pseudocapsuie of low histologic grade RCC is thicker and with higher appearing incidence on MR T2-weighted image than the pseudocapsuie of high histologic grade RCC is.
9- 6 0 Film versus V i d e o Monitor Display for D e t e c t i o n of Small Densities
SpencerB. Gay,MD, University of Virginia HSC, Charlottesville, VA, W. Jung, BS, Hong Liu, PhD
workstations. These two media may have differing degrees of performance for detecting small densities. Methods: The task of detecting small densities was chosen to simulate the clinical problem of detecting renal calculi. We made three exposures of a contrast-detail phantom, recording the data on a Fuji digital p h o s p h o r plate. The data was displayed on film and on a 1K x 1K monitor. Six observers recorded their limit of detectability for small nodular densities on the images of the contrast detail phantom. Results: For each of the digital images and for all observers, film performed better. Smaller densities were visible and those with less attenuation were more often identified. Intra-observer and inter-observer variability were low. Conclusion: Film performed better than did monitor display for detection of small densities likely due to its superior resolving power. When such a clinical problem is considered, the data should be displayed on film for interpretation.
9- 61 Utility of MRI in t h e S y m p t o m a t i c Post C-Section Patient
CatherineMaldjian,MD, Temple University Hospital, Philadelphia, PA, Barton M. Milestone,MD, R. C. Smith, MD, MitchellD. Schnall,MD, PhD, Richard J. Adam, MD P u r p o s e : The purpose of this investigation is to assess the utility of MRi in the symptomatic post-partum population after delivery by C-section. Methods: 53 patients were studied by MRI. The primary indication was persistent low-grade temperatures. We retrospectively reviewed the patients charts and MRI reports. Positive findings included uterine dehiscence and post-operative fluid collections. Results: In 5 cases imaging findings were noted that altered clinical management. These included uterine dehiscence and collections that in conjtmction with clinical findings were presumed to be infected. All of the remaining patients had an unremarkable post-operative course with remittance of fevers on standard antibiotics. Conclusions: MR imaging may facilitate identification of findings requiting intervention, such as uterine dehiscence and abscess, in 10% of the symptomatic post-C-section population.
10- 6 2 Preparation of Radiographic T e a c h i n g C a s e s for t h e World Wide Web
Ernest M. Scalzetti,MD, SUNY Health Science Center, Syracuse, NY P u r p o s e : I will present considerations that bear on the design of a radiographic teaching file for the World Wide Web. Materials a n d Methods: Beginning with assumptions about the client system resources, screen resolution, web-browser software and bandwidth limitations - I use standard Hypertext Mark-Up Language code to display text and navigation controls. I provide navigation controls for each of the case's images. The user can request an image, preselected details views of the image, or an annotated version of the image; the browser spawns a separate w i n d o w to display the requested image. Results: It is possible to use techniques that are generally available, and compatible with essentially all computer platforms, to present a teaching file on the World Wide Web. Navigation aids allow the user to control the presentation. The use of two or more windows allows concurrent viewing of text and images; overlapping windows preserve screen, real-estate and take advantage of the computer's graphical interface. Conclusion: The World Wide Web allows us, as educators, to provide radiologic teaching materials without regard to geography or time of day. The way in which w e present these materials undoubtedly will influence their success. Take H o m e Points: 1. Design for the lowest common denominator, within reason, with respect to client factors including screen resolution, Internet access speed, and browser software. 2. Allow the user to control as much of the presentation as possible.
Purpose: Digital images can be displayed both on film or on digital
851
9- 5 8 Bladder Pseudotumors on C o n t r a s t - E n h a n c e d Spiral CT" I n c i d e n c e and Clinical I m p l i c a t i o n s
John S. Rhee,MD, Palo Alto Medical Center, Palo Alto, CA, EricW. Olcott, MD, MatildeNino-Murcia, MD P u r p o s e : Abdominal spiral CT scans are acquired so rapidly that renal excretion of intravenous contrast medium often has just begtm at the time the bladder is imaged. We have noted that opacified urine entering the unopacified bladder may simulate the nodularity and wall thickening of bladder neoplasms. We determined the incidence and appearances of these pseudotumors. Methods: Each of 100 consecutive contrast-enhanced abdominal CT scans (91 men, 7 w o m e n ) obtained for various indications was examined and scored by three readers for wall thickening (asymmetry and/ or thickness > 5 mm) and nodules within the bladder. Clear ureteral jets were counted separately. Delayed CT images, ultrasound, urography and/or cystography served as true reference standards. Results: Nodules and/or mural thickening indistinguishable from bladder tumors were identified in 8% of scans in w h i c h delayed CT images, ultrasound, urography or cystography demonstrated no evidence of tumor (2% nodules, 5% mural thickening, 1% both). Clear ureteral jets were visualized in 19% of scans. C o n c l u s i o n : Opacified urine simulates bladder neoplasms in 8% of contrast-enhanced spiral CT scans. Further evaluation is warranted in each patient exhibiting such findings to exclude or confirm the presence of a true bladder neoplasm. Take H o m e Points: Opacified urine simulates bladder neoplasms in the form of nodules and/or mural thickening in 8% of contrast-enhance spiral CT scans. Further evaluation in these patients with delayed CT images, ultrasound, urography or cystography is warranted to exclude or confirm the presence of a true bladder neoplasm.
9- 5 9 P s e u d o c a p s u l e of Renal Cell C a r c i n o m a (RCC): V a l u e on Evaluating t h e Histologic Grade of RCC with MR Imaging
Tao Li, MD, Great Wall Hospital, Beijing, People's Rep of China, Y. G. Gao, MD, Y. A. Gao, MD P u r p o s e : To assess the value of the pseudocapsule on evaluating the histologic grade of RCC with MR imaging. Methods: Thirty-five patients with RCC were imaged at Siemens 1.0 T MR unit with axial SE TlWI(TR/TE=500/15ms) and SE T2WI(TR/ TE=2000/90ms) by use of body coll. The histologic large specimens of the whole t u m o r and adjacent renal tissue were obtained on the corresponding position with MR images. The tlistologic grading of RCC was based on Riches' criterion. Results: At pathologic evaluation, the thicknesses of the pseudocapsule of low and high histologic grade RCCs were 1.26 + 0.31mm and 0.79 + 0.25mm respectively (P<0.05). On MR imaging, T2WI was more sensitive for visualization of the pseudocapsuie (sensitivity, 62.9%) than TIWI was (sensitivity, 8.6%). On T2WI, the pseudocapsule of low histologic grade RCC appeared as continuous thicker rim of low signal with higher appearing incidence (84.4%), but the pseudocapsule of high histologic grade RCC appeared as interrupted thinner rim with lower appearing incidence (44.4%). C o n c l u s i o n s : The pseudocapsuie of low histologic grade RCC is thicker and with higher appearing incidence on MR T2-weighted image than the pseudocapsuie of high histologic grade RCC is.
9- 6 0 Film versus V i d e o Monitor Display for D e t e c t i o n of Small Densities
SpencerB. Gay,MD, University of Virginia HSC, Charlottesville, VA, W. Jung, BS, Hong Liu, PhD
workstations. These two media may have differing degrees of performance for detecting small densities. Methods: The task of detecting small densities was chosen to simulate the clinical problem of detecting renal calculi. We made three exposures of a contrast-detail phantom, recording the data on a Fuji digital p h o s p h o r plate. The data was displayed on film and on a 1K x 1K monitor. Six observers recorded their limit of detectability for small nodular densities on the images of the contrast detail phantom. Results: For each of the digital images and for all observers, film performed better. Smaller densities were visible and those with less attenuation were more often identified. Intra-observer and inter-observer variability were low. Conclusion: Film performed better than did monitor display for detection of small densities likely due to its superior resolving power. When such a clinical problem is considered, the data should be displayed on film for interpretation.
9- 61 Utility of MRI in t h e S y m p t o m a t i c Post C-Section Patient
CatherineMaldjian,MD, Temple University Hospital, Philadelphia, PA, Barton M. Milestone,MD, R. C. Smith, MD, MitchellD. Schnall,MD, PhD, Richard J. Adam, MD P u r p o s e : The purpose of this investigation is to assess the utility of MRi in the symptomatic post-partum population after delivery by C-section. Methods: 53 patients were studied by MRI. The primary indication was persistent low-grade temperatures. We retrospectively reviewed the patients charts and MRI reports. Positive findings included uterine dehiscence and post-operative fluid collections. Results: In 5 cases imaging findings were noted that altered clinical management. These included uterine dehiscence and collections that in conjtmction with clinical findings were presumed to be infected. All of the remaining patients had an unremarkable post-operative course with remittance of fevers on standard antibiotics. Conclusions: MR imaging may facilitate identification of findings requiting intervention, such as uterine dehiscence and abscess, in 10% of the symptomatic post-C-section population.
10- 6 2 Preparation of Radiographic T e a c h i n g C a s e s for t h e World Wide Web
Ernest M. Scalzetti,MD, SUNY Health Science Center, Syracuse, NY P u r p o s e : I will present considerations that bear on the design of a radiographic teaching file for the World Wide Web. Materials a n d Methods: Beginning with assumptions about the client system resources, screen resolution, web-browser software and bandwidth limitations - I use standard Hypertext Mark-Up Language code to display text and navigation controls. I provide navigation controls for each of the case's images. The user can request an image, preselected details views of the image, or an annotated version of the image; the browser spawns a separate w i n d o w to display the requested image. Results: It is possible to use techniques that are generally available, and compatible with essentially all computer platforms, to present a teaching file on the World Wide Web. Navigation aids allow the user to control the presentation. The use of two or more windows allows concurrent viewing of text and images; overlapping windows preserve screen, real-estate and take advantage of the computer's graphical interface. Conclusion: The World Wide Web allows us, as educators, to provide radiologic teaching materials without regard to geography or time of day. The way in which w e present these materials undoubtedly will influence their success. Take H o m e Points: 1. Design for the lowest common denominator, within reason, with respect to client factors including screen resolution, Internet access speed, and browser software. 2. Allow the user to control as much of the presentation as possible.
Purpose: Digital images can be displayed both on film or on digital
851