Multinuclear MR imaging: a technique for combined anatomic and physiologic studies

With the use of specially designed multiple-tuned probes for magnetic resonance (MR) imaging, data collection schemes can be developed for obtaining images of different nuclei simultaneously. Both phantom and in vivo MR images of two nuclei (either hydrogen-1, phosphorus-31, lithium-7, or fluorine-19) were obtained in the time span necessary to collect the image of the less sensitive nuclei. This technique offers a means by which physiologic and anatomic information can be gathered in a highly efficient fashion.     

Breast calcifications: analysis of imaging properties

The imaging characteristics of microcalcifications in both benign and malignant breast conditions were analyzed in 48 digitized film mammograms. Each case included in this analysis had findings considered suggestive of malignancy by the radiologist, with the underlying histologic structure determined by excisional biopsy. Imaging properties of each microcalcification--such as pixel intensity, relative location, distribution, size, and local neighborhood intensities--were recorded. This information was statistically analyzed at the population level according to such selection criteria as histologic type, size of calcification, and cluster size. Distribution ranges were determined for these criteria. Statistical differences between data from benign and malignant cases show the average distance between calcifications in malignant conditions was greater than in benign conditions, and tissue region averages surrounding calcifications associated with malignant conditions were consistently higher than those for benign conditions.     

肉苁蓉类生药中苯乙醇甙类成分的 RP-HPLC 分析

采用反相高效液相色谱法,对4种及1变种肉苁蓉类生药和25份商品药材所含的苯乙醇甙类成分进行了定性和定量分析,结果表明,荒漠肉苁蓉 Cistanche deserticola Ma,盐生肉苁蓉 C.salsa(C.A.Mey) G.Beck,白花盐苁蓉C.salsa var.albiflora P.F.Tu et Z.C.Lou和管花肉苁蓉C.tubulosa (Schenk) Wight 所含成分相似,沙苁蓉 C.sinensis G.Beck区别较大;松果菊甙(echinacoside)和类叶升麻甙(acteoside)的含量以盐生肉苁蓉最高,分别为2.13%和1.51%。采用Altima C₁₈,5μm,250×4.6mm色谱柱;乙腈─1.5%乙酸水溶液,其中乙腈浓度从8%→20%,0～60min线性梯度洗脱,作为定性分析流动相,乙腈浓度从11.5%→20%,0～35min线性梯度洗脱,作为定量分析流动相;流速1.2ml·min^-1,UV335 nm检测。     

Thoracic empyema: management with image-guided catheter drainage

Forty-three patients with thoracic empyema were treated by means of image-guided catheter drainage. In 40 patients, image-guided catheter drainage was the primary treatment method; in three it was used after conventional, surgical chest tube placement failed. Drainage was performed with ultrasound guidance in 30 patients (69.8%), computed tomography in eight (18.6%), and fluoroscopy in five (11.6%). A combination of guidance modalities was used in six patients. Image-guided catheter drainage alone was successful in 31 of 43 patients (72.1%). In three patients (7%), empyemas were initially drained, but a thoracotomy was ultimately required because of a persistent pleural peel. In eight patients (18.6%), the procedure failed, predominantly due to tube clogging, persistent pneumothorax, or progressive development of a pleural peel. In one patient, drainage was successful but he died 10 days later of complications of renal failure. No major complications were encountered. Treatment of these patients requires a thorough understanding of the pathogenesis of pleural space infection, principles of empyema drainage, techniques of abscess drainage under image guidance, and the use of a pleural drainage system.     

CT-guided biopsy: prospective analysis of 1,000 procedures

The authors prospectively analyzed 1,000 biopsies guided with computed tomography (CT) and performed in 955 patients over a 30-month period. All patients were followed up from 3 months to 2 years. The biopsies were performed in an average of 22 minutes (range, 3-85 minutes) by 26 different radiologists; five radiologists performed 547 of the procedures. Of the 1,000 biopsies, 722 were performed in areas in the liver, retroperitoneum, pancreas, pelvis, and adrenal glands. Of 69 errors in diagnosis, 67 were falsely negative and two were falsely positive; 747 true-positive and 184 true-negative diagnoses were made. CT-directed biopsy for accurate diagnosis was 91.8% sensitive and 98.9% specific, with a positive predictive value of 99.7% and a negative predictive value of 73.3%. Of 11 patients with complications, seven had hematomas, three had pneumothorax, and one had hematuria. No deaths occurred, and only one patient required surgery.