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Background and purpose:Diffusion-weighted imaging (DWI) is a non-invasive technique of breast magnetic resonance imaging (MRI). DWI is an alternative to dynamic contrast-enhanced (DCE) MRI for differentiating malignant from benign lesions in breast screening or not. This study aimed to evaluate the potential role of DWI in differentiating malignant breast lesions from benign lesions.Methods:Seventy-four patients underwent digital mammography, DCE and DWI (49 patients’b-value of 0, 400, 600 and 800 s/mm2). The detectability, sensitivity and speciifcity of DWI and DCE were compared. Absolute apparent diffusion coefifcient (ADC) was compared with standardized ADC for quantitative analysis.Results:Sixty-four of 74 patients had positive pathologic findings (38 malignant, 26 benign). All of the malignant lesions were detected on DWI and DCE. The sensitivity of DWI was 83.33%, 90.00% and 93.33%, and the specificity was 85.91%, 76.19% and 72.72%, forb-value of 400, 600 and 800 s/mm2, respectively. The sensitivity and speciifcity of DCE were 86.61% and 90.48%. There was no signiifcant difference between absolute and standardized ADC in detecting breast cancer (P>0.05).Conclusion:DWI is an important complemented technique to DCE-MRI for differentiating malignant from benign lesions in breast MRI.
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Objective To compare signal characteristics and image qualities of MR diffusion-weighted imaging (DWI)at 1.5T and 3.0T in patients with the complex adnexal masses.Methods Magnetic resonance imaging including routine MRI and DWI(b=0 s/mm2 ,400 s/mm2 , 600 s/mm2 ,800 s/mm2 ,1 000 s/mm2 )of 1.5T (50 patients with 31 benign and 1 9 malignant lesions )and 3.0T (53 patients with 29 benign and 24 malignant lesions )were performed in 103 patients with histopathologically proved adnexal masses.The optimal b value was analyzed,and the apparent diffusion coefficient (ADC)value and signal intensity (SI)value and contrast to noise ratio (CNR)of solid and cystic components in adnexal masses from both 1.5T and 3.0T MR were respectively compared statistically.Results The 800 s/mm2 was the optimal b value in demonstrating adnexal masses at 1.5T and 3.0T.The CNR of solid and cystic components in adnexal masses were significantly higher at 3.0T than at 1.5T on all b values(all P =0.000).The difference in ADC value of solid lesions between 1.5T and 3.0T on all b values DWI had no statistically significant (all P >0.05),nor did the difference in SI value of solid lesions as well as ADC value of cystic lesions on b800 DWI(P >0.05).Conclusion MR diffusion-weighted imaging at 3.0T compared with 1.5T has quantitative and qualitative advantages of evaluating for adnexal masses,while the 800 s/mm2 is the optimal b value for both of them.
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Objective To study the diagnostic value of calcification in differentiating benign and malignant thyroid lesions. Methods CT images of 318 consecutive patients with pathologically proven thyroid lesions were retrospectively reviewed by two radiologists. The following characteristics of calcification on CT images were evaluated: (1) size (≤2 mm indicating microcalcification and > 2 mm or shelly and irregular shape indicating macrocalcification, and both features indicating mixed calcification), (2) number (single or multiple) and (3)location (internal or edge). χ~2 test was used for statistical analysis. Results Oft he 318 cases, 48 were diagnosed as malignant (papillary carcinoma 26, follicular carcinoma 7, medullary carcinoma 3 and microcarcinoma 12) and 270 were benign (nodular goiter 36, adenoma 170, nodular goiter with adenoma 38 and adenoma with Hashimoto's thyroiditis 26). Calcification was found in 60 cases (18.9%). Among them 21 (papillary carcinoma 12,microcarcinoma 6,follicular carcinoma 2 and medullary carcinoma 1) were malignant(43.8%) and 39(nodular goiter 6, adenoma 13,nodular goiter with adenoma 19 and adenoma with Hashimoto's thyroiditis 1) were benign (14.4%) (P < 0.01). Sensitivity and specificity for diagnosing thyroid carcinoma were 43.8% (21/48) and 85.6% (231/270), respectively. Microcalcification was found in 37 cases (malignant 8, benign 29) and macrocalcification was found in 23 cases(malignant 13, benign 10) (P < 0.01) . Sensitivity and specificity of macrecalcification for diagnosing thyroid carcinoma were 61.9% (13/21) and 74.4% (29/39), respectively. Single calcification was found in 31 cases (malignant 13, benign 18) and multiple calcification was found in 29 cases(malignant 8, benign 21) (P >0.05). Internal calcification was found in 15 cases of malignant lesions(71.4%) and 12 of benign lesions(30.8%); Edge calcification was found in 6 cases of malignant and 27 of benign, (P <0.01). Sensitivity and specificity of internal calcification for diagnosing thyroid carcinoma were 71.4% (15/21) and 69.2% (27/39), respectively. Conclusion Internal calcification or(and) macrocalcification of the thyroid lesions may strongly suspect thyroid carcinoma and fine-needle aspiration or surgery should be further performed.
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Objective To evaluate the diagnosis of of hypoplastic vertebral artery by spiral CT angiography(SCTA).Methods 180patients with clinical diagnosis of vertebrobasilar insufficiency were undergone spiral CT angiography. For SCTA, 80~100 ml contrastmedium (omnipaque 350 mg/100 ml) was injected into the foot vein at the rate of 3 ml/s. The delay time was selected through a time-density curve made by Smart prep. Collimation thickness was 3mm and the table speed was 4.5mm/s. Reconstruction was done with 1.5mm increments. The SCTA images were postprossed with multiplanar volume reconstructions (MPVR) and shaded surface display (SSD). Original axial images were used to measure the diameter of vertebral artery. DSA was performed for those cases with vertebral artery stenosis within one week. Results Seventy eight (21.7%) unilateral vertebral arteries were diagnosed as hypoplastic vertebral artery,the left in 24 and the right in 54,the average diameter was 1.3 mm(1.0~1.5 mm),among them,opposite artery coexisted with local calcifications in13 cases, with twist in 20 and with compression by luschka joint hyperplasia in 11. The results were corresponding to that of DSA.Conclusion Hypoplastic vertebral artery is one of the popular reasons of vertebrobasilar artery insufficiency , it could be diagnosed by SCTA and should be used generally in clinic to substitute the more invasive DSA inspection.
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Objective To evaluate the diagnostic value of MR cholangiopancreatography(MRCP) using three-dimensional fast recovery fast spin-echo(3D FRFSE) in differentiating benign from malignant causes of biliary and pancreatic duct dilatation.Methods 106 cases suspected biliary and pancreatic duct dilatation underwent 3D FRFSE MRCP.The images were prospectively analysed by two skilled radiologists,and the results were compared with that of surgery,biopsy or follow-up.Results MRCP was successful performed at one time in all cases.On MRCP,the visual rate of intra-and extrahepatic bile duct was 100% and that of main pancreatic duct was 93.4%.80 patients had benign lesions: bile duct lithiasis(n=66),papillitis(n=6),descending part of duodenum diverticulitis(n=2),duodenal adenomatoid hyperplasia(n=1) and chronic pancreatitis(n=5).26 patients had malignant lesions: extrahepatic cholangiocarcinoma(n=9),ampullary carcinoma(n=5),gallbladder carcinoma(n=4) and pancreatic head carcinoma(n=8).The sensitivity,specificity and accuracy in differentiating benign from malignant causes of biliary dilatation were 92.3%,96.3% and 95.3%,respectively.Conclusion 3D FRFSE MRCP plays an important role in diagnosis of differentiating diagnosis of the causes of biliary dilatation in clinical practice.