Purpose: To determine breast carcinoma detection rate of a new mammographic computer-aided system (CAD) in order to assess its clinical usefulness. Methods: 467 cases of breast carcinoma proved by surgery and pathology were retrospectively analyzed. All the mammograms of the cases were reviewed by two radiologists working as a team and then analyzed by the CAD-system. The sensitivity for breast carcinoma detection (masses or calcification) was calculated respectively, and the results compared. Results: The sensitivity for breast carcinoma detection by the same radiologists without and with the CAD-system were 80. 94% , 88. 01% , respectively (P

Objective To study the values of HMRS and DTI technology for detecting brain damage in heroin-dependent patients.Methods The routine MRI,HMRS and DTI were performed in 7 heroin abuser8 and 8 healthy volunteers without the history of drug abuse.The regions of interest(ROI) were selected in the gray matter and white matter of prefrontal lobe in HMRS exam,and the ratio of NAA/ Cr、Cho/Cr and Cho/NAA were measured respectively.For the DTI,six ROIs were selected,and the values of fractional anisotropy(FA)and ADC were calculated respectively.The independent samples t test was used for the statistics.Results No abnormality was found in the routine MRI.The ratio of NAA/Cr decreased in the prefrontal lobe.the values were 1.40±0.16 in gray matter and 1.72±0.41 in white matter 0f the drug group.1.57±0.09 and 2.08±0.21 in the control group on HMRS examiation.The differenee between the two groups had statistical significance(t=2.183,2.190,P<0.05)On DTI examination,the values of FA decreased in GCC,SCC and AIC,each was 0.70±0.04,0.76±0.41,0.55±0.03 in drug group,and 0.76±0.03,0.82±0.03,0.64±0.03 in controlgroup.The difference betweenthetwo groups had statistical significance(t=3.830,3.713,5.555,P<0.05).The value8 of ADC increased in SCC,PIC and EC in drug group,each Was(8.18±0.48)×10-4,(7.54±0.22)×10-4,(7.72±0.30)× 10-4and(7.50±0.26)×10-4,(7.154-0.20)×10-4,(7.19±0.39)×10-4mm2/s in control group respectively.The difference between tlle two groups had statistical significance(t=3.477,3.507,2.895, P<0.05).Conclusion The early abnormalities of the brain in heroin-induced patients can be found combining HMRS and DRI.

Objective To evaluate MRI in diagnosing brachial plexus preganglionic injury.Methods Twenty cases with brachial plexus preganglionic injury underwent M R scanning before operation.MR imaging was obtained by GE Signa EXCITE 1.5 T scanner.The scanning sequences included SE T1 WI,FSE T2 WI,T2 WI STIR and 3D Fast imaging employing steady state with phase cycled(3D-FIESTA-c).All the patients had exploration of the supraclavicular plexus and electrophysiology examination. And the accuracy, sensitivity and specificity of MRI in diagnosing preganglionic brachial plexus iniury were calculated with the standards of surgical and EMG results.Results Among the 73 pairs of i,jured roots.MR imaging detected the abnormalities in 63 pairs.The accuracy, sensitivity and specificity of MRI in diagnosing preganglionic brachial plexus injury were 86.5/(83/96),86.3/(63/73).87.0/(20/23),respectively.The direct signs of brachial plexus preganglionic injury included (1) lack or mutilation of netwe root in 54 pairs (85.7/),(2)coarsening,bending,stiff course and unable to be traced to the intervertebral foramen continuously in 9 pairs (14.3/).The indirect signs included (1)cystic cerebrospinal fluid gathering in the vertebral canal,posttraumatic spinal meningocele in 46 pairs (73.0/),(2)abnormal shape of nerve sleeve in 13 pairs(20.6/),(3)displacement and deformity of spinal cord in 50 pairs(79.4/),(4)abnormal signal of paravertebral muscles in 1 9 patients.Conclusion MRI can distinctly show the nerve rootlets within the vertebral canal,so it is helpful in making a correct diagnosis of brachial plexus preganglionic injuries.

Objective To evaluate the MRI application in the common non-traumatic brachial plexopathies.Methods Twenty-seven patients with non-traumatic brachial plexopathies were retrospectively analyzed,which consisted of 10 males and 17 females with age range from 22 to 70 years old.Among the patients,2 were neurofibromatosis,8 were schwannoma,3 were metastases,2 were radiation plexopathy,1 was multifocal motor neuropathy (MMN),and 11 were typical thoracic outlet syndrome (TOS).Before treatment,all patients underwent MRI of brachial plexus,in which 8 patients underwent Gd-DTPA enhanced MRI.Results In 2 cases of neurofibromatosis,the tumors appeared as fusiform,bead-like masses,growing along the course of brachial plexus with involvement of rootlets in vertebral canal,and iso-to little hypointensity on T1WI,inhomogeneous hyperintensity on T2WI and inhomogeneously enhanced.Schwannoma of 8 cases displayed as fusiform mass,eccentric to the original nerve with sharply defined edge,and hypointensity or inhomogeneous hyperintensity on T1WI,inhomogeneous hyperintensity on T2WI with cystic necrosis in 3 cases which was inhomogeneously enhanced.Two of the 3 cases of metastases manifested as multiple masses besides brachial plexus,the other one appeared as widespread lesion infiltrating brachial plexus and surrounding structures.Two cases of radiation plexopathy displayed as diffused thickened nerves,with increased signal intensity on short time inversion recovery (STIR),clear structure and no mass surrounding the plexus.One case of MMN showed thickened nerves with increased signal intensity on STIR.Eleven cases of typical TOS manifested as arched elevation of C8,T1 and inferior trunk,with thickened nerves and increased signal intensity on STIR.Elevated subclavian artery could be seen in 8 cases.And in one case of TOS,a mass in the end of cervical rib compressed the local brachial plexus.Conclusions MRI can clearly show the location,involved scope and the relationship with adjacent structures.So MRI can provide reliable information for clinical diagnosis and treatment.

Total 52 patients with breast lesions underwent dynamic contrast-enhanced breast MRI; and the breast vascularization was scored on the MRI vascular maps with a range of 0 to 3. The mean number of vessels per ipsilateral breast in malignant cases was higher than that of benign cases (3.8±2.0 vs. 1.3± 1.0; P=0.000). When the breast vascularity score 0-1 was defined as benign and 2-3 was defined as malignant, the sensitivity and specificity was 79% and 83%, respectively. Results indicate that dynamic contrast-enhanced breast MRI is of value in diagnosis of malignant breast lesions.

Objective (1) To determine the relationship between the MR signal intensity and the actual flow velocity under steady flow condition (2) to analyze the influence produced by the angle (?) between the flow direction and the velocity encoded gradient direction, and flip angle as well as section thickness on the velocity measurement under oblique flow condition (3) to develop a suitable protocol for using this method to measure volumetric flow rate in the transverse sinus system Methods Flow phantom, which simulated blood flow conditions in the transverse sinus system, consisted of a fluid filled cylinder and a bent tube with a 3 4 mm internal diameter A 1 5 T superconductive MR imager and VIGRE sequence were used for these studies A suitable protocol was based on consideration of the effects of (1) the accuracy of velocity and transverse area measurement of flow, and (2) signal to noise ratio (SNR) Results (1) Signal intensity (y) determined by MR and the actual flow velocity (x) showed straight line correlation, y=68 914x+357 206, R 2=0 998 (2) As the angle (?) increased, the transverse area of the signal determined by MR also increased, but the value of flow velocity decreased (3) As the flip angle increased, the SNR varied from 5 7 to 11 2 The maximum SNR was obtained with 30?flip angle (4) As the section thickness increased, the SNR and the transverse area of the signal determined by MR slightly increased Conclusions Phase contrast MR imaging is a practical method for measuring volumetric flow rates The angle (?) influenced the accuracy of flow velocity and the measurement of transverse area of flow whereas the flip angle and the section thickness substantially influenced the signal to noise ratio and the transverse area of flow

Objective To assess the accuracy of two-dimensional phase contrast (2D-PC) MR method for blood flow measurement within transverse sinusesby comparing this method with cine phase contrast (cine-PC) MR and Doppler in volunteers and patients. Methods (1) A total of 12 transverse sinuses were examined in 8 healthy volunteers. 2D-PC MR and cine-PC MR were used respectively to measure the transverse area of flow, the flow velocities, and the volumetric flow rates in the same position in every transverse sinus. Paired t-test was used for comparison between the results determined by 2D-PC MR and that determined by cine-PC MR. (2) A total of 6 transverse sinuses were examined in 5 patients who needed operation. 2D-PC MR was used to determine the blood flow velocity of transverse sinus before operation, and Doppler was used to determine the blood flow velocity of the same transverse sinus during operation. The linear regression analysis was used for statistical analysis. Results (1) Statistical analysis indicated that there were no significant difference among the transverse area of flow (t=-1.106, P=0.293), the flow velocities (t=0.262, P=0.798), and the volumetric flow rates (t=0.439, P=0.669) measured by using 2D-PC MR and cine PC MR, respectively. (2) The correlation between flow velocities determined by 2D-PC MR imaging before operation and that determined by Doppler during operation was in excellent agreement (=1.303x+0.62,r 2=0.88). Conclusion 2D-PC MR may be a practical convenient method for blood flow measurement within transverse sinuses system.

Objective To analyses the CT misdiagnostic causes of gallbladder carcinoma, in order to improve the diagnostic rate.Methods Fourty-three patients with the gallbladder carcinoma proved histologically were examined by computed tomography (CT), twenty-three of them were misdiagnosed.The misdiagnostic causes were analysed and compared CT images with operation.Results In the cases of misdiagnosis they were diagnosed as acute or chronic cholecystitis in 5; polyp in 1; bile duct carcinoma in porta hepatis in 2; cholangiocarcinoma in 1; neoplasm of distal part of common bile duct or ampulla in 3; carcinoma of head of pancreas in 5;cholangitis in 1; jaundice of obstruction in 2;tumefaction of gallbladder in 2;carcinoma of colon in 1. Conclusion To be aware of CT characters of gallbladder carcinoma and the way of metastasis is useful to avoid misdiagnosis of the gallbladder carcinoma and to improve the diagnostic rate.

Objectives To examine the clinical usefulness of magnetic resonance spectroscopy (MRS) on assessment of vascular dementia (VD) in patients with stroke; the relationships between metabolic changes of brain and clinical symptom improvements after giving rivastigmine in these patients.Methods 20 stroke patients without VD, male 17, female 3, with a mean age of (71.7?4.7) years old; 23 stroke patients with VD, male 20, female 3, a mean age of (72.9?5.1) years old; 20 normal volunteers were studied, a mean age of (70.9?4.8) years old. MRS was performed in all these patients. The patients with VD were prescribed rivastigmine hydrogen tartrate ("Exelon", Norvatis), and given MRS assessment half a year later.Results The patients with VD had a significantly lower N-acetyl aspartate/Creatine (NAA/Cr) ratio (mean?SD: left: 0.57?0.30; right: 0.66?0.29) and higher Choline/Creatine (Cho/Cr) ratio (mean?SD: left: 1.79?0.52; right: 1.97?0.44) in bilateral temporal hippocampus area, compared to those without VD (mean?SD: NAA/Cr: left, 0.91?0.31; right, 0.87?0.27, P

Objective To study the imaging features of the ventricular meningioma, in order to improve the understanding knowledge. Methods Compared with operative and pathological findings,the CT and MRI features of ventricular meningioma were analyzed in 22 patients (8 males and 14 females,range from 17~72 years old with average age 45 years).21 cases were examined by MRI(17 with enhanced scan),11 cases by CT(4 with enhanced scan).Results The ventricular meningioma were mostly fibrous type. Mostly, the locations were in the trigone of the lateral ventricle with regular shape. On imaging, the most were parenchymatous with markedly enhancement. Calcification may be found, but cystic changes and hemorrhage were very rare.Conclusion The ventricular meningiomas have characteristic imaging features. CT and MRI are valuable in diagnosis, especially MRI.