Radiology

Sommer, G; Corrigan, G; Fredrickson, J; Sawyer-Glover, A; Liao, J R; Myers, B; Pelc, N

doi: N/Apmid: 9722853

PURPOSE: To assess the ability of three cine phase-contrast magnetic resonance (MR) imaging techniques to measure normal human renal blood flow (RBF) in vivo. MATERIALS AND METHODS: Eighteen healthy volunteers were studied with three cine phase-contrast MR imaging techniques: breath-hold, segmented k-space, two-dimensional, Fourier transform technique (ie, time-resolved imaging with automatic data segmentation, or TRIADS); a breath-hold rapid spiral acquisition; and a non-breath-hold rapid spiral acquisition that allowed resolution of both cardiac and respiratory cycles. In each case, total arterial RBF and blood flow per unit of renal volume were calculated. For each subject, RBF was measured with a standard technique of p-aminohippuric acid (PAH)-clearance hematocrit on the same day as the MR imaging examination was performed. RESULTS: The range of agreement (2 standard deviations, or 95% confidence interval) between RBF measurements obtained with the PAH-clearance hematocrit technique and the various cine phase-contrast techniques varied from +/- 17.6% to +/- 26.5%. The best agreement was obtained with non-breath-hold rapid spiral data, by using data from the end-expiratory phase of respiration. CONCLUSION: Findings with cine phase-contrast MR imaging employing rapid spiral acquisition are in good agreement with measurements made with PAH-clearance hematocrit and give the promise of clinical measurements of RBF.

Hertzberg, B S; Kliewer, M A; Bowie, J D; McNally, P J

doi: N/Apmid: 9722862

PURPOSE: To test the strength of the association of cholecystomegaly with aneuploidy and biliary abnormality and to assess the prognostic importance of the detection of an enlarged fetal gallbladder at antenatal ultrasonography (US). MATERIALS AND METHODS: Gallbladder size was prospectively evaluated during 842 consecutive second-and third-trimester US examinations in 775 fetuses. The area of the gallbladder was calculated on the image that depicted the maximal gallbladder size, and the actual gallbladder areas was compared with the gallbladder area expected on the basis of the gestational age. Fetuses with an enlarged gallbladder were followed up. RESULTS: Forty-three fetuses had an enlarged gallbladder (area more than 2 SDs above the mean for gestational age). Outcome was normal in 38 of the 39 fetuses who could be followed up. With the exception of a single baby with an isolated ventricular septal defect, which closed spontaneously, none of the babies with an enlarged fetal gallbladder had structural anatomic defects or evidence of aneuploidy or a biliary tract abnormality. CONCLUSION: Identification of an enlarged gallbladder at antenatal US does not appear to be associated with a substantially increased risk of chromosomal aneuploidy or biliary tract malformation.

Roubidoux, M A; Wilson, T E; Orange, R J; Fitzgerald, J T; Helvie, M A; Packer, S A

doi: N/Apmid: 9722852

PURPOSE: To compare the breast cancer stages and detection methods in screened women who receive hormone replacement therapy (HRT) with those in screened women who do not receive HRT to determine whether HRT affects the stage or mammographic detection of malignancy. MATERIALS AND METHODS: One hundred fifteen cases of breast cancer in women (age range, 55-65 years) in whom at least one screening mammogram had been obtained at least 24 months before diagnosis and in whom the history regarding HRT could be determined were reviewed retrospectively. Statistical analysis was performed with CHI-2 analysis and the Fischer exact test. RESULTS: The cancer stages in the 58 women who received HRT were stage 0 in 15 (26%), stage I in 28 (48%), stage II in 13 (22%), and stage III in two (3%) women. The stages in the 57 women who did not receive HRT were stage 0 in 19 (33%), stage I in 24 (42%), stage II in 11 (19%), stage III in two (4%), and stage IV in one (2%) woman. Cancers in 38 (67%) of the women who did not receive HRT and in 38 (66%) of those who did receive HRT were detected with mammography alone; false-negative mammograms were obtained in five (9%) women in the non-HRT group and in four (7%) women in the HRT group (P = .89). CONCLUSION: Among screened women who developed breast cancer, there were no significant differences in cancer stages or in the number of mammographically detected cancers or false-negative mammograms between the HRT group and the non-HRT group.

Evans, G F; Haller, R G; Wyrick, P S; Parkey, R W; Fleckenstein, J L

doi: N/Apmid: 9722865

PURPOSE: To assess correlations between muscle edema on magnetic resonance (MR) images and clinical indexes of muscle injury in delayed-onset muscle soreness (DOMS) produced by submaximal exercise protocols. MATERIALS AND METHODS: Sixteen subjects performed 36 elbow flexions ("biceps curls") at one of two submaximal workloads that emphasized eccentric contractions. Changes in MR imaging findings, plasma levels of creatine kinase, and pain scores were correlated. RESULTS: Both exercise protocols produced DOMS in all subjects. The best correlation was between change in creatine kinase level and volume of muscle edema on MR images, regardless of the workload. Correlations tended to be better with the easier exercise protocol. CONCLUSION: Whereas many previous studies of DOMS focused on intense exercise protocols to ensure positive results, the present investigation showed that submaximal workloads are adequate to produce DOMS and that correlations between conventionally measured indexes of injury may be enhanced at lighter exercise intensities. NASA Discipline Cardiopulmonary Non-NASA Center

Song, H Y; Lee, D H; Ahn, H; Kim, J H; Kang, S G; Yoon, H K; Sung, K B

doi: N/Apmid: 9722847

PURPOSE: To describe the short- and long-term outcomes of the removal of occluded stents. MATERIALS AND METHODS: With fluoroscopic guidance, 571 lacrimal polyurethane stents were placed in 502 patients with epiphora due to obstruction of the lacrimal system. Of the 571 stents, 142 were removed 2 weeks to 42 months (mean, 7 months) after placement because of recurrent epiphora, and the lacrimal system was irrigated with saline solution through the lacrimal point. RESULTS: Stent removal was well tolerated. Mild epistaxis occurred in one patient and was controlled with a nasal pack. Recurrent epiphora was due to obstruction of the stent with mucoid material in 49 (35%) of 142 systems and granulation tissue in 93 (65%) systems. After stent removal, 73 (51%) of the 142 lacrimal systems showed improvement of epiphora, with a patent lacrimal system at 7-day follow-up dacryocystography. During the follow-up of 2 weeks to 49 months (mean, 22 months) after stent removal, patency was maintained in 24 (33%) of the 73 lacrimal systems. CONCLUSION: Removal of an occluded lacrimal plastic stent was easy and safe. Recurrent epiphora after placement of lacrimal plastic stents can be treated with removal of the occluded stents an irrigation with saline solution through the lacrimal point, which resulted in a patent lacrimal system in 33% of cases in this study.

Wacker, F K; Cholewa, D; Roggan, A; Schilling, A; Waldschmidt, J; Wolf, K J

doi: N/Apmid: 9722861

PURPOSE: To investigate the use of magnetic resonance (MR) imaging to guide interstitial laser therapy of deep hemangiomas and vascular malformations in children. MATERIALS AND METHODS: Sixteen children aged 3 months to 16 years with symptomatic vascular lesions underwent percutaneous laser treatment. MR imaging guidance of the laser applicator and online thermomonitoring with MR imaging were performed with a 0.2-T open MR system. Follow-up studies were performed 2 days and 6 weeks after thermotherapy. RESULTS: Interactive positioning of the laser applicator was possible in all patients. Online thermomonitoring was possible in 122 of 137 therapy spots (89%). There was a good correlation between volumes of coagulated tissue on intraprocedural T1-weighted images and volumes of coagulated tissue on follow-up T2-weighted images. At 6-week follow-up, MR imaging demonstrated a reduction in lesion size in 10 patients (mean reduction, 72%) and an increase in lesion size in two patients (mean increase, 134%). Clinical symptoms improved in 14 of 16 patients (88%). CONCLUSION: MR imaging-guided laser therapy appears to be a safe and potentially effective minimally invasive treatment for selected children with vascular lesions.

Liberman, L; Feng, T L; Dershaw, D D; Morris, E A; Abramson, A F

doi: N/Apmid: 9722851

PURPOSE: To determine the frequency with which ultrasonographically (US) guided core biopsy obviated diagnostic surgical biopsy of nonpalpable breast masses, to calculate the cost savings of diagnosis attributable to US-guided core biopsy, and to compare the costs of US-guided versus stereotactically guided core biopsy. MATERIALS AND METHODS: US-guided core biopsy was performed in 151 consecutive solitary, nonpalpable breast masses in 151 women (age range, 23-80 years) by using a 14-gauge automated gun and needle. Clinical follow-up data were obtained. Cost savings were assessed by using national Medicare reimbursement costs of +385 for US-guided core biopsy, +610 for stereotactic core biopsy, and +1,332 for needle localization and surgical biopsy. RESULTS: US-guided core biopsy obviated a surgical procedure in 128 (85%) of 151 women. The mean adjusted direct cost saving per US-guided core biopsy was +744 per case. Use of US-guided biopsy decreased the cost of diagnosis by 56% (+744/+1,332) over the cost of surgical biopsy. If biopsy had been performed with stereotactic rather than with US guidance, the mean adjusted direct cost saving would have been +519 per case, a 39% (+519/1,332) decrease in the cost of diagnosis compared with the cost of surgical biopsy. CONCLUSION: Percutaneous biopsy of a nonpalpable breast mass with either US or stereotactic guidance is less expensive than surgery, but cost savings are greater with US-guided biopsy.

Callister, T Q; Cooil, B; Raya, S P; Lippolis, N J; Russo, D J; Raggi, P

doi: N/Apmid: 9722864

PURPOSE: To assess the variability and reproducibility of a volumetric calcium score calculated with electron-bean computed tomographic (CT) scans of coronary arteries. MATERIALS AND METHODS: Two sets of electron-beam CT scans were obtained in patients with coronary calcification (group A) or known risk factors for coronary arterial disease (group B). The second set or scans was obtained after a brief interval (group A, n = 52) or after 1 year with no risk modification (group B, n = 27). Traditional (plaque area and attenuation) and volumetric calcium scores were calculated for each patient and lesion. RESULTS: The median percentage change for individual lesions in group A was 13% for the volumetric and 19% for the traditional score. The overall reduction in error with the volumetric score was 40% (P < .001). The median percentage change for group A patient totals was 9% for the volumetric and 15% for the traditional score (P < .001). In group B patients, the median volumetric score increased by 44% after 1 year. CONCLUSION: The volumetric score showed better reproducibility than the traditional score, and its variability was considerably less than the score increase in untreated patients after 1 year. The reproducibility of the volumetric method makes it useful for assessing the progression of coronary arterial disease on serial electron-beam CT studies.

Bosch, J L; Tetteroo, E; Mali, W P; Hunink, M G

doi: N/Apmid: 9722840

PURPOSE: To evaluate the relative benefits and cost-effectiveness of treating iliac arterial occlusive disease with various interventions. MATERIALS AND METHODS: Cost-effectiveness was analyzed in a hypothetical cohort of patients with intermittent claudication caused by an iliac arterial stenosis. Primary stent placement, percutaneous transluminal angioplasty (PTA), and PTA with selective stent placement were analyzed. Reduction in the risk of failure after primary stent placement versus that after PTA with selective stent placement, quality of life, and cost data were derived from results of a randomized, controlled trail. Complication rates, patency results, and the reduction in risk of failure were derived from a published meta-analysis. RESULTS: PTA with selective stent placement yielded equivalent complication rates, patency results, and quality-of-life outcomes compared with those of primary stent placement, and the latter cost +957 less (95% confidence interval = +726, +1,188). PTA with selective stent placement was more expensive than PTA alone but yielded higher patency results (relative risk of long-term failure, 0.61; 95% confidence interval = 0.49, 0.75) and quality-adjusted life expectancy (0.2 quality-adjusted life year QALY gained) and had an incremental cost-effectiveness ratio of less than +20,000 per QALY gained. CONCLUSION: PTA with selective stent placement is a cost-effective treatment strategy compared with primary stent placement or PTA alone in the treatment of intermittent claudication caused by an iliac arterial stenosis.

Hasegawa, S; Semelka, R C; Noone, T C; Woosley, J T; Marcos, H B; Kenney, P J; Siegelman, E S

doi: N/Apmid: 9722833

PURPOSE: To define the appearance of gastric stromal sarcomas at magnetic resonance (MR) imaging. MATERIALS AND METHODS: Nine patients with gastric stromal sarcoma underwent MR imaging with the following sequences: nonenhanced and gadolinium-enhanced breath-hold, T1-weighted, spoiled gradient-recalled echo (n = 9); fat-suppressed, T2-weighted, fast spin echo (n = 9); and breathing-independent, half-Fourier rapid acquisition with relaxation enhancement (n = 6). Lesion morphology, signal intensity features, and relationships to the gastric wall and surrounding organs were retrospectively evaluated. The diagnosis of gastric stromal sarcoma was histologically proved in all patients. RESULTS: The nine tumors were solitary, multilobulated, shaped irregularly, predominantly exophytic, and large (diameter range, 7-28 cm mean, 15.8 cm). The epicenters of all lesions were extrinsic to the stomach, and all lesions arose from the gastric cardia or body. Regions of necrosis and hemorrhage were detected in all cases. Marginal definition on MR images corresponded to histologic grade: High-grade neoplasms possessed ill-defined margins, and low-grade neoplasms demonstrated more well-defined margins. Relationships to surrounding organs depicted at MR imaging corresponded well with histopathologic findings. CONCLUSION: Gastric stromal sarcomas demonstrate characteristic MR imaging features, which correspond well with histopathologic findings. The direct multiplanar capability of MR imaging facilitates delineation of relationships of the tumors to the stomach and surrounding organs.