Magnetic resonance urography and X-ray urography findings of congenital megaureter.

OBJECTIVE: To observe the imaging findings of congenital megaureter in order to enhance the understanding of this disease. METHODS: Image data of 5 patients with congenital megaureter and 2 misdiagnosed patients were analyzed, and image findings of congenital megaureter were summarized.Elscint Prestig 2.0T superconductive magnetic resonance urography (MRU) with conventional sequence (spin-echo, T1WI560 ms/16 ms; fast spin-echo, T2WI 9600 ms/96 ms ) was performed. Raw data were acquired with fastspin-echo sequence from heavy T2-weighted image (9600 ms/120 ms). Post-processing method of MRU was the maximum intensity projection with three-dimensional reconstruction in the workstation. Intravenous pyelography (IVP) was conducted, in which X-rayfilms were taken 7 minutes, 15 minutes, and 30 minutes after injecting contrast agent, exceptthat in 2 patients the films were taken delayed at 60 and 90 minutes .X-ray retrograde pyelography was performed on 2 patients, successful in one butfailed in the other. RESULTS: The dilated ureter showed hypointensity on T1-weighted images and hyperintensity on T2-weighted images in conventional MRI. The mass wall was intact, uniform in thickness, and showing hypointensity on T1-weighted and T2-weighted images. The MRU images showed a retroperitoneal mass appearing as an elongated tubular cystic structure spreading from kidney to bladder. MRU also revealed dilated calices and renal pelvis, pelviureteric obstruction, and renal duplication. The main signs of congenital megaureter in X-urography was significant dilatation of ureter, or normal renal pelvis with ureter dilatation, hydronephrosis, deformity, and displacement. CONCLUSIONS: MRU with X-urography could visualizethe characteristics of congenital megaureter, including the dilation of renal pelvis and ureter, calculi, urinary tract duplication, and stenosis location. The two techniques can complement each other in disease diagnosis and provide more detailed information for preoperative treatment.

[Preparation of magnetic resonance molecular probe for breast cancer detection in vitro].

OBJECTIVE: To prepare magnetic resonance (MR) molecular probe for somatostain receptor expressed on breast cancer cell membranes and investigate its physico-chemical properties and imaging features in vitro. METHODS: Molecular probe was prepared through superparamagnetic iron oxide (SPIO) conjugated to somatostatin analog-octreotide (OCT) using chemical method. Its features at different Fe(2+) concentrations were tested by MTT assay and Prussian blue staining respectively. Molecular probes at different Fe(2+) concentration and various numbers of cells labeled with the probe at Fe(2+) concentrations of 20 mg/L were scanned with 1.5 Tesla MR. Resovist was used in control group when labeling cells. RESULTS: Various blue-staining particles were found in the cytoplasms of labeled cells with the molecular probes at different concentrations after Prussion blue staining and there were more particles with the increase of Fe(2+) concentration. The label rate of the probe was 96.15% which was higher than that in control group (80.00%). The bioactivity had no difference between labeled and non-labeled cells (P>0.05). There was remarkable low signal intensity on T(2)-weighed imaging and no evident artifacts for molecular probe when the concentration of Fe(2+) was 20 mg/L. The least number of labeled cells detected by MR in vitro was 6 x 10(6) when the concentration of Fe(2+) was 20 mg/L. CONCLUSION: Molecular probe, SPIO-OCT, can effectively label breast cells which express SSTR. The reasonable Fe(2+) concentration of labeled cells and imaging was 20 mg/L. There is a correlation between MR signal intensity in vitro and the number of labeled cells.

[Relationship between the data from MR-diffusion tensor imaging and the clinical cognitive evaluation in Alzheimer's disease].

OBJECTIVE: To determine the relationship between the extent of the damage and clinical data in Alzheimer's disease (AD). METHODS: Twenty-two patients with AD and twenty-two controls received MR-diffusion tensor scanning. The fractional anisotropy (FA) values of white matter in AD patients were measured respectively in parietal lobe and the genu of corpus callosum. Independent-samples t-test for non-paired data was used to test differences between AD and controls for FA values. Correlation analysis was applied to reveal the correlations between FA values in each region and the MMSE, FOM, RVR, BD and DS scores. RESULTS: Positive correlations were found between FA values in left parietal lobe and FOM/DS, and between FA values in genu of corpus callosum and MMSE scores. CONCLUSIONS: In AD, the MR-DTI can reflect the relationship between the degree of white matter abnormalities and the cognitive impairment.

[Clinical investigation of outbreak of nosocomial severe acute respiratory syndrome].

OBJECTIVE: To summarize and analyze the clinical manifestation, diagnosis and therapeutic strategy of severe acute respiratory syndrome (SARS), and its characteristics of outbreak in hospital via infection transmission cluster associated with SARS patients. METHODS: (1) Two hospitalized community acquired SARS cases with their clinical data and epidemiologically linked transmission clusters in our hospital were analyzed; (2) The clinical data from 41 SARS cases were summarized. RESULTS: (1) The contagiousness of SARS virus in SARS patients was extremely strong, especially in their acute stage. (2) The majority of clinical manifestations were fever (100% cases), and there were no obvious respiratory symptoms in more than half of the patients (53.7%) at early SARS stage (day 1 to day 3), accompanied by leucopenia(52.6%) and lymphopenia (68.4%). (3) Timely administration of Ribavirin, Methylprednisolone, immunoenhancer (such as interferon alpha-2b, thymosin-alpha1) to SARS patients was efficacious to certain extent in controlling the development of the disease. CONCLUSION: It is very important for clinicians to pay great attention to protect themselves from infection of SARS. Early discovery of SARS, early isolation of SARS patients, and early treatment are very helpful to improving patient's prognosis and controlling SARS overspread.

Combination of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography and magnetic resonance imaging is an optimal way to evaluate rheumatoid arthritisin rats dynamically.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic, systemic autoimmune inflammatory disorder. Many methods have been used to observe the progress of RA. The purpose of this study was to observe the progress of RA in rats with 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT), magnetic resonance (MR) imaging and arthritis score, and analyze the relationships among different methods in evaluation of RA. METHODS: Sixteen healthy Sprague Dawley (SD) rats about 8-week old were randomly assigned to a RA group and a control group. Bovine type II emulsified incomplete Freud's adjuvant was used to induce arthritis in the RA group. Arthritis score of the rats in two groups were recorded, and (18)F-FDG PET/CT, MR imaging were performed both on the corresponding rats every 3 days. All the rats were sacrificed at week 5, and histopathological examination was performed on rat knees stained with haematoxylin and eosin. RESULTS: The arthritis score and the standard uptake value (SUV) of knee joints in RA rats increased with the progression of arthritis gradually. Both peaks of arthritis score and SUV appeared at 21 days after the first immune injection, then the arthritis score and SUV of knee joints decreased slowly. The arthritis scores of knee joints in RA rats were positively correlated with their SUV changes. The MR images were confirmed by the histopathological studies. CONCLUSION: PET/CT can detect the earliest molecular metabolism changes of RA, and MR imaging can follow up the dynamical anatomical changes of RA, all of which indicated that PET/CT and MR imaging may be applied as useful tools to monitor the progress of RA.

Quantitative T2 mapping evaluation for articular cartilage lesions in a rabbit model of anterior cruciate ligament transection osteoarthritis.

BACKGROUND: Quantitative T2 mapping has been a widely used method for the evaluation of pathological cartilage properties, and the histological assessment system of osteoarthritis in the rabbit has been published recently. The aim of the study was to investigate the effectiveness of quantitative T2 mapping evaluation for articular cartilage lesions of a rabbit model of anterior cruciate ligament transection (ACLT) osteoarthritis. METHODS: Twenty New Zealand White (NZW) rabbits were divided into ACLT surgical group and sham operated group equally. The anterior cruciate ligaments of the rabbits in ACLT group were transected, while the joints were closed intactly in sham operated group. Magnetic resonance (MR) examinations were performed on 3.0T MR unit at week 0, week 6, and week 12. T2 values were computed on GE ADW4.3 workstation. All rabbits were killed at week 13, and left knees were stained with Haematoxylin and Eosin. Semiquantitative histological grading was obtained according to the osteoarthritis cartilage histopathology assessment system. Computerized image analysis was performed to quantitate the immunostained collagen type II. RESULTS: The average MR T2 value of whole left knee cartilage in ACLT surgical group ((29.05±12.01) ms) was significantly higher than that in sham operated group ((24.52±7.97) ms) (P=0.024) at week 6. The average T2 value increased to (32.18±12.79) ms in ACLT group at week 12, but remained near the baseline level ((27.66±8.08) ms) in the sham operated group (P=0.03). The cartilage lesion level of left knee in ACLT group was significantly increased at week 6 (P=0.005) and week 12 (P<0.001). T2 values had positive correlation with histological grading scores, but inverse correlation with optical densities (OD) of type II collagen. CONCLUSION: This study demonstrated the reliability and practicability of quantitative T2 mapping for the cartilage injury of rabbit ACLT osteoarthritis model.