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91.
PURPOSE: To investigate if the extraction flow product (EFP), as determined on dynamic contrast material-enhanced magnetic resonance (MR) images, could be a potential marker of tumor response to neoadjuvant chemotherapy in patients with locally advanced breast cancer. MATERIALS AND METHODS: Fourteen women with proven breast cancer underwent MR imaging prior to and following neoadjuvant chemotherapy. Dynamic gradient-echo and echo-planar MR images were acquired before and after injection of gadopentetate dimeglumine. Precontrast T1s were measured before EFP maps were calculated by using a multicompartmental model. Mean EFP (EFPmean) and distribution analysis of EFP (EFPcount) were measured in tumors before and after neoadjuvant chemotherapy and were compared with tumor response at MR imaging. The significance of the difference in EFP values between the responders and nonresponders was calculated with a two-tailed Student t test. RESULTS: EFPmean after neoadjuvant chemotherapy in partial responders and nonresponders was 33 mL x 100 g-1 x min-1 +/- 9.8 and 54.2 mL x 100 g-1 x min-1 +/- 10.3, respectively (P <.005). EFPmean decreased after neoadjuvant chemotherapy in the responders and nonresponders by 37% +/- 30 and -5% +/- 35, respectively (P >.05). An increase in EFPmean values was observed only in nonresponders who received taxanes. For regimens without taxanes, EFPmean decreased regardless of the morphologic response. EFPcount decreased for all the responders by 77% +/- 33 and increased for all the nonresponders by 45% +/- 68 (P <.02). CONCLUSION: EFPcount appears to provide functional information regarding changes in tumor angiogenesis due to neoadjuvant chemotherapy. Functional MR imaging of the breast may be useful in monitoring tumor response to neoadjuvant chemotherapy.  相似文献   
92.
BACKGROUND: Specific anatomic variations of the ankle mortise may predispose people to ankle sprains. HYPOTHESIS: There is a correlation between a higher malleolar index (posteriorly positioned fibula) and incidence of ankle sprain. STUDY DESIGN: Prospective case control study. METHODS: We compared the malleolar index (transverse plane of the talus) on computerized axial tomographic images of 61 patients with ankle sprain with that of 101 normal controls. A positive number for the malleolar index meant that the lateral malleolus was posterior to the plane of the medial malleolus. A negative number meant that the lateral malleolus was actually anterior to the plane of the medial malleolus. RESULTS: The average malleolar index of the patients with ankle sprain was +11.5 degrees with a standard deviation of 7 degrees. Malleolar relationships varied from -6 degrees to +39 degrees, a range of 45 degrees. The average malleolar index in the control group was +5.85 degrees with a standard deviation of 4.9 degrees, which varied from -8 degrees to +16 degrees. However, there was no correlation between recurrence of sprains and malleolar index values. CONCLUSION: Patients with an ankle sprain were more likely to have a posteriorly positioned fibula, possibly predisposing them to ankle sprain.  相似文献   
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94.
PURPOSE: To assess three-dimensional measurement accuracy of articular cartilage (AC) and subchondral bone (SB) thickness from MRI. MATERIALS AND METHODS: A computer program was used to calculate AC and SB thickness from MRI (three-dimensional spoiled gradient echo (SPGR),.31-mm resolution, 1-mm slice thickness) of six adult femoral heads. Specimens were imaged in five anatomical planes ranging between +30 degrees to -30 degrees from neutral and cut into 2-mm thick sections along the five anatomical planes. Faxitron x-ray was used to produce microradiographic (.05-mm resolution) images of the sections. RESULTS: In-plane measurement accuracy was.165 +/-.108 mm for AC thickness and.387 +/-.174 mm for SB thickness. Taking into account chemical-shift misregistration in SB thickness, accuracy of measurements improved to.213 +/- 128 mm. Out-of-plane (three-dimensional) thickness accuracy of the model, assessed by numerical simulation, was.015 mm. However, three-dimensional thickness errors in specimens were.319 +/-.256 mm for AC and.253 +/-.183 mm for SB thickness. CONCLUSION: Errors in three-dimensional AC thickness were attributed to volume-averaging effects caused by oblique intersection of the image plane with the joint surface. Errors in three-dimensional SB thickness were attributed to chemical-shift artifact. We conclude that accuracy of AC thickness is within clinically acceptable standards but that more sophisticated pulse sequences are needed to improve the measurement of SB thickness.  相似文献   
95.
Secretory meningiomas   总被引:4,自引:0,他引:4  
Secretory meningiomas are a rare meningioma subtype. Among meningiomas, the frequency of secretory meningiomas is 1.6%. Unlike other meningioma types, most of the patients were female (ratio 3:1). No recurrence was reported during the 24–180 months follow-up period of our secretory meningiomas in which, a low level of 0.3% Ki-67 proliferative index was reported. In this meningioma subtype, the percentage of cases with positive progesterone receptor is 33%. With carcinoembryonic antigen, cytokeratin and epithelial membrane antigen, in all the cases positivity was observed in both, the inclusions and the cells surrounding them. With human milk fat globulin 2, a high ratio (92%) of positivity was observed. Majority of the cases were negative with CA125, only three of the cases had suspicious positivity. Distribution of inclusions was irregular and their positive reactions showed varying staining features. Positivity with alpha-1-antitripsin was seen not only in the inclusions but also in some meningothelial cells as well. Ubiquitin was positive in inclusions of the 83% of cases. Staining features of the inclusions pointed out the possibility of them being in a varying age and/or content. Secretory meningiomas are a different type compared to other meningiomas, not only with their histological features but also with their clinical features as well.  相似文献   
96.
BACKGROUND: There has been great debate regarding the importance of ductal carcinoma in situ (DCIS) in the breast. Autopsy results that demonstrate a much greater number of these lesions compared with the number of invasive carcinomas, and the numbers of deaths from breast carcinoma each year have been cited as evidence that DCIS rarely leads to invasion and death. These analyses have overlooked the fact that, to sustain a rate of detection each year, there would have to be a reservoir of undetected breast carcinomas growing in the population. The authors developed a simple model that makes this clear. In addition, complex phenomena have been suggested to explain why invasive breast disease may grow more rapidly among very young women and more slowly among the very old. A simple model provides some insight that may simplify the explanation of these observations. METHODS: The simple model of breast carcinoma growth assumes that there are three types of breast carcinoma that begin each year in a cohort of women. It assumes that all breast carcinomas begin as DCIS and take 9 years to go from a single cell to an invasive lesion for the slowest growing lesions, 6 years for intermediate growing DCIS lesions, and 3 years for fast-growing DCIS lesions. Furthermore, once an invasive clone forms, the model assumes that it will double in 60 days for fast-growing lesions, 120 days for intermediate growing lesions, and 180 days for slow-growing lesions. Three new tumors begin to grow in each successive year (one of each type). The model uses simple vectors that are defined by the size of the tumors and the time since tumor initiation, and it assumes that all tumors are detected when they reach 2 cm in greatest dimension. The model can be used to show graphically how many undetected tumors (DCIS as well as invasive carcinomas) there may be in the population to sustain the detection of three invasive tumors each year. RESULTS: Using the assumptions described above, the model showed that, by the time the first slow-growing breast carcinoma reaches 2 cm in greatest dimension, there will be 29 other slow-growing tumors that have not reached that size (9 DCIS and 20 smaller invasive carcinomas), 19 moderately growing tumors (6 DCIS and 13 smaller invasive carcinomas), and 9 fast-growing tumors (3 DCIS and 6 smaller invasive carcinomas). This means that, for every three breast tumors that reach 2 cm, the model predicted that there would be another 57 tumors (39 smaller invasive carcinomas and 18 DCIS) that would be undetected "below the surface". The model showed clearly that faster growing tumors would be expected to predominate among the youngest women, because they are the first to "reach the surface"; and, if the number of newly initiated tumors decreases with age, then there will be more of the slowest growing tumors that are left to reach the surface among the oldest women in the population. CONCLUSIONS: Even if the authors' assumptions are incorrect, their model made it clear that, to diagnose several breast carcinomas per 1000 women each year means that there have to be many more undetected carcinomas in the population to sustain the rate of detection. Although the model did not prove that DCIS may become potentially invasive and lethal, it did demonstrate that, even if all of these in situ lesions become invasive and lethal, many more DCIS lesions would have to be expected in the population than the number of invasive carcinomas detected each year and the number of deaths from breast carcinoma each year. Furthermore, the model provided a simple, purely mechanical illustration that may explain the preponderance of faster growing breast carcinomas among very young women and the preponderance of slower growing tumors among elderly women.  相似文献   
97.
The study was performed on 11 female and 9 male dogs to investigate the effect of hypertonic NaCl in severe hypotension and shock caused by acute pulmonary artery obstruction. The investigation was performed in Dicle University Healt Research Center (DUHRC). The youngest subject was six months old and the oldest was two years old. Their mean body weight was found as 19 kg. All the subjects were operated under general anesthesia. Invasive measurements of arterial pressure were performed through the right femoral artery by monitorization. All subjects were performed left thoracotomy, entrance to thorax was through 5th intercostal space, and first left then right pulmonary artery were circumferenced loosely with tape. After this, mean pulmonary artery pressures are recorded with the help of monitor by inserting canulla into the pulmonary artery. Pulmonary artery pressures at 3rd, 5th, 10th, 13th, 15th, 18th and 21st minutes after ligation of right main pulmonary artery and left lower lobe pulmonary artery, and mean artery pressures are recorded. Sodium nitroprusside is given to half of the subjects and nitroglycerine is given to the other half in order to lower pulmonary hypertension. Pulmonary arterial pressure measurements following administration of these drugs are recorded. 7.5% of NaCl infusion to subjects is performed in case of hypotension and shock. Isotonic NaCl solution is used in the control group. Mean arterial pressures in group receiving sodium nitroprusside + 7.5% NaCl solution are found significantly higher statistically when compared to group receiving sodium nitroprusside + 0.9% NaCl isotonic solution. Difference in mean arterial pressures were not found statistically significant in the group receiving nitroglycerin + 7.5% NaCl when compared to group receiving nitroglycerin + 0.9% NaCl solution.  相似文献   
98.
99.
We retrospectively reviewed the 4.5 year (range, 21-88 months) follow-up results of arthroscopic partial meniscectomies performed in 11 knees between 1994 and 2000 to treat a symptomatic discoid lateral meniscus. The average age at surgery was 11.5 years (range, 5-17 years). All except one of the discoid menisci were of a complete type, and all except three were torn menisci. At the latest follow-up examination, the result was excellent for nine knees, and good for two; no degenerative changes were evident on the roentgenograms. Arthroscopic partial meniscectomy should be the treatment of choice for the complete type symptomatic lateral discoid meniscus, even if it is intact. Preoperative lack of the knee extension requires a gentle rehabilitation program postoperatively.  相似文献   
100.
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