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1.
Purpose
CT perfusion has been proposed for pancreatic lesion characterization. However, scan and analysis protocols influence numerical data. To overcome this, the purpose of our study is to evaluate the use of time–density curves obtained from MDCT perfusion of the pancreas for the characterization of normal parenchyma, adenocarcinoma, chronic pancreatitis and endocrine tumors.Methods
31 patients with solid pancreatic lesions and 21 patients with renal cell carcinoma underwent 64-row MDCT perfusion of the pancreas after injection of 50 cc of a 370 mg I/ml solution at 5 cc/s. 63 time–density curves were obtained from normal parenchyma (21 patients), adenocarcinoma (25), endocrine tumors (4) and atrophic parenchyma (13). Two readers independently categorized the 63 time–density curves into 4 different morphologies: normal wash-in and wash-out (A), low wash-in followed by plateau (B), low wash-in followed by faint wash-out (C) and high wash-in and wash-out (D). Interobserver agreement was calculated with kappa statistics. Fisher test was used to calculate sensitivity, specificity, positive (PPV) and negative (NPV) predictive values for each type of curve.Results
Interobserver agreement was very good (Kappa = 0.849). Curve A had 94.4% sensitivity, 91.1% specificity, 80.95% PPV, 97.6% NPV for ‘normal parenchyma’. Curve B had 74.19% sensitivity, 93.75% specificity, 92% PPV, 78.95% NPV in diagnosing ‘adenocarcinoma’. Curve C had 45.45% sensitivity, 84.62% specificity, 38.46% PPV, 88% NPV for ‘chronic pancreatitis’. Curve D had 100% sensitivity, 98.33% specificity, 75% PPV, 100% NPV for ‘endocrine tumor’.Conclusions
The morphology of MDCT perfusion time–density curves appears to be useful in characterizing pancreatic lesions, and might help overcome the differences in scan and postprocessing techniques. 相似文献2.
Objectives
To study the diagnostic performance of computed tomography (CT) quantification of minimal lumen area (MLA) based on multiple factors (image quality, calcification and lesion locations), with reference to intravascular ultrasound (IVUS).Methods
Consecutive clinically ordered patients were prospectively enrolled in our study. CT quantification of MLA was manually measured on cross-sectional view and further compared with IVUS findings. A significant lesion was defined as ≤6 mm2 MLA for the left main (LM) coronary artery and a ≤4 mm2 MLA for other epicardial vessels.Results
Non-calcified lesions had good correlation between CT and IVUS (r = 0.96) and the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 85% (51/60), 93.94% (31/33), 96.23% (51/53) and 77.5% (31/40) respectively. Decreased correlation (r = 0.814) lower specificity (23.81% (5/21)) and positive predictive value (60.98% (25/41)) were observed in calcified subgroup. Artifact-absent lesions demonstrated excellent correlation (r = 0.967) and the sensitivity, specificity, PPV and NPV were 96% (48/50), 93.94% (31/33), 96% (48/50) and 93.94% (31/33) respectively. Impaired correlation (r = 0.584) was noted in artifact-present lesions and the sensitivity, specificity, PPV and NPV were 80% (28/35), 23.81% (5/21), 63.64% (28/44) and 41.67% (5/12) respectively. Excellent correlation between CT and IVUS was noted in proximal epicardial vessels (r = 0.908) and the sensitivity, specificity, PPV and NPV were 92.31% (36/39), 78.13% (25/32), 83.72% (36/43) and 89.29% (25/28) respectively. Middle right coronary artery lesions showed non-significant correlation (r = 0.54, p = 0.055).Conclusions
CT quantification of MLA can only be accurately achieved in non-calcified lesions with absence of artifact. Diagnostic performance is impaired in calcified lesions. 相似文献3.
Glodny B Nasseri P Plaikner M Unterholzner V Rehder P Koppelstätter C Petersen J 《European journal of radiology》2012,81(7):1393-1399
Objective
To establish a method for estimating the probability of renal artery stenosis (RAS) based on the calcium volume score of the aorta (ACS).Materials and Methods
In a retrospective observation study, CT angiographies acquired on a 64-slice MDCT scanner were analyzed for 1351 patients (female: 531; male 826; mean age 60.9 ± 17.7 years). A volumetric scoring method was used, detecting plaques with a density of more than 600 HU.Results
13.8% of the patients showed a stenosis >50%, 4.1% a stenosis >70%. The ACS was 0.61 ± 1.01 ml calcium. The sensitivity for detection of RAS >50% and RAS >80% was 0.9572 and 1.0, respectively. The negative predictive value (NPV) of a lack of calcification for excluding RAS >50% and RAS >80% was 0.9752 and 1, respectively. As ACS increased, the specificity for RAS >50% increased to 0.9390. With an ACS of 0.380 ml, accuracy reached a maximum of 0.6585. ROC analyses yielded an area under the curve of 0.88 (p < 0.0001). Sensitivity, specificity, NPV and PPV are indicated in relation to the degree of RAS, as well as the diagnostic yield of the method, which is valuable in patients older than 50 years.Conclusion
Due to its extremely high sensitivity and NPV, the ACS is a very useful screening method for RAS. The validity of the method, as well as its diagnostic value is equivalent to that of coronary artery calcium scoring. Lack of calcifications of the aorta renders atherosclerotic RAS highly improbable. 相似文献4.
Fiaschetti V Salimbeni C Gaspari E Dembele GK Bolacchi F Cossu E Pistolese CA Perretta T Simonetti G 《European journal of radiology》2012,81(11):3178-3184
Objective
To asses the value of second-look ultrasound (US) for identifying BIRADS 3 (Breast Imaging Reporting Data System) mammary lesions detected by breast Magnetic Resonance imaging (MRI).Materials and methods
From April 2008 to May 2009 330 breast MRI were performed of which 60 patients are classified as BIRADS 3. 84 lesions underwent second-look US and percutaneous vacuum biopsy Vacora system US-guided. Statistical analysis: lesions were stratified into two groups: visible on US (Group 1) and not visible on US (Group 2).The clinical impact of second-look US was studied in terms of negative predictive value (NPV).Results
The positive predictive value (PPV) of category 3 BIRADS MRI was found to be 89%. Second look-US results detected lesions in 51% of the MRI enhancing lesions. The second look-US showed a NPV of 97%. The NPV of second look-US was significantly greater than the NPV of MRI BIRADS 3 (97% vs 89%, p < 0.05). The logistic regression analysis showed a higher number of malignant lesions in group 1 than in group 2 (7vs 2, OR 3.7, p < 0.05).Conclusions
The second-look US permitted the correct management of subcentimetric MRI BIRADS 3 lesions not visible with conventional imaging tecniques. 相似文献5.
Kakigi T Hosono M Shimono T Hiraoka T Nishimura K 《European journal of radiology》2012,81(9):2348-2352
Purpose
To prospectively evaluate the feasibility of using the “iliac wing sign (IWS)” as an indicator of bone and/or soft-tissue injury of the pelvis and hips on magnetic resonance (MR) imaging. IWS means edema of the iliacus muscle attachment entering the iliac wing that is visualized as a linear high signal intensity on fat-suppressed T2-weighted MR images.Methods
Consecutive 106 patients who complained of hip pain were enrolled in this study. We evaluated the correlation between IWS and bone and/or soft-tissue injury of the pelvis and hips using Fisher's exact test. Further, performance parameters of sensitivity, specificity, accuracy, the positive predictive value (PPV), and negative predictive value (NPV) of IWS were calculated.Results
Thirty-eight of the 106 (36%) patients had bone and/or soft-tissue injury. Twenty-seven of these 38 (71%) patients with injury showed a positive IWS, while only 11 of 68 (16%) patients without injury showed a positive IWS (p < .0001). IWS, thus, yielded a sensitivity of 71%, specificity of 84%, accuracy of 79%, positive predictive value (PPV) of 71%, and negative predictive value (NPV) of 84%.Conclusion
In cases with a positive IWS, the careful interpretation of MR images is needed because injury presence is highly likely, as suggested by the relatively high sensitivity and PPV. IWS absence may mean a low probability of injury because of the high specificity and NPV. 相似文献6.
Objectives
To compare the efficiency of contrast-enhanced ultrasonographic micro flow imaging (MFI) with conventional transrectal ultrasound (TRUS) in detecting prostate cancer with serum total prostate-specific antigen (t-PSA) of 4.0–10.0 ng/mL. To evaluate the value of contrast-enhanced ultrasonographic MFI in detecting prostate cancer with t-PSA in diagnostic gray zone.Methods
47 patients with t-PSA 4.0–10.0 ng/mL underwent gray scale, power Doppler TRUS and MFI examinations before ultrasound guided biopsies. Biopsies were performed at twelve sites in the base, the mid-gland and the apex of the prostate in each patient, when there was no abnormal ultrasound finding. When an abnormality was present at MFI, the biopsy specimen from the corresponding site was directed toward the abnormal finding. With histological results of prostate biopsy as reference standards, we assessed the cancer detection of these three methods.Results
564 specimens were collected in this study, in which 101 were prostate cancer confirmed histologically. 152 of 564 specimens were demonstrated abnormal on MFI images, in which 71 were malignant and 81 were benign confirmed histologically. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) for MFI in detecting prostate caner were 70.3%, 82.5%, 80.3%, 46.7% and 92.7%, respectively. The sensitivity and NPV for MFI were significantly better than gray scale (38.6%, 86.9%) and power Doppler (32.7%, 86.0%) (P < 0.001) TRUS.Conclusions
Contrast-enhanced ultrasonographic MFI could significantly improve the detection rate of prostate cancer with t-PSA in diagnostic gray zone (4–10 ng/mL) than conventional ultrasound. 相似文献7.
Hohmann J Skrok J Basilico R Jennett M Müller A Wolf KJ Albrecht T 《European journal of radiology》2012,81(3):e317-e324
Objective
To compare on-site and blinded off-site reading of baseline ultrasound (US) and contrast enhanced ultrasound (CEUS) for classification and characterisation of focal liver lesions.Materials and methods
99 patients (57 women and 42 men, age range 18–89 years, mean age: 59 years) with 53 malignant and 46 benign liver lesions were studied with unenhanced US followed by contrast enhanced US after injection of 2.4 ml SonoVue® (Bracco, Milano, Italy). Image interpretation was performed on-site with clinical information available by consensus of two readers and off-site by two independent blinded readers at two different centers. Comparison of pre and post contrast scans and of the different readers was performed. Reference examinations were histology, intraoperative US, MRI or CT.Results
Sensitivity for malignancy improved from 81/89/66% (on-site/off-site reader 1/2) before to 100/96/96% post contrast administration (p < 0.05, except for reader 1). Specificity improved from 48/48/54% on baseline US to 89/80/76% on CEUS (p < 0.05). Accuracy for specific lesion diagnosis was 62/59/50% pre and 90/77/72% post contrast (p < 0.05). Classification and characterisation post contrast were mildly inferior for off-site reading. Agreement between on-site and off-site readers of unenhanced scans was fair (κ = 0.29–0.39) while it was good for CEUS (κ = 0.63–0.79).Conclusions
CEUS improves classification and characterisation of focal liver lesions and interobserver agreement compared to conventional US. Classification and characterisation post contrast were mildly but statistically significantly better for on-site than for off-site reading. 相似文献8.
Ruder TD Hatch GM Siegenthaler L Ampanozi G Mathier S Thali MJ Weber OM 《European journal of radiology》2012,81(6):1366-1370
Objective
To assess the temperature dependency of tissue contrast on post mortem magnetic resonance (PMMR) images both objectively and subjectively; and to visually demonstrate the changes of image contrast at various temperatures.Materials and methods
The study was approved by the responsible justice department and the ethics committee. The contrast of water, fat, and muscle was measured using regions of interest (ROI) in the orbit of 41 human corpses to assess how body temperature (range 2.1–39.8 °C) relates to image contrast of T1-weighted (T1W) and T2-weighted (T2W) sequences on PMMR. Regressions were calculated using the method of least squares. Three readers judged visible changes of image contrast subjectively by consensus.Results
There was a positive relationship between temperature and contrast on T1-weighted (T1W) images and between temperature and the contrast of fat/muscle on T2-weighted (T2W) images. There was a negative relationship between temperature and the contrast of water/fat and water/muscle on T2W images. Subjectively, the influence of temperature became visible below 20 °C on T2W images, and below 10 °C on T1W images.Conclusion
Image contrast on PMMR depends on the temperature of a corpse. Radiologists involved in post mortem imaging must be aware of temperature-related changes in MR image contrast. To preserve technical quality, scanning corpses below 10 °C should be avoided. 相似文献9.
Objective
To evaluate the contribution of power Doppler ultrasonography (PDUS) to breast imaging reporting and data system ultrasonography (BI-RADS US) categorization of solid breast masses.Materials and methods
Totally 94 solid lesions with histopathological results in 49 patients were included in the study. US features of the lesions were classified according to American College of Radiologists (ACR) BI-RADS US lexicon. Lesions were evaluated qualitatively according to their PDUS properties and quantitatively with spectral analysis. Hypervascularity, penetration of vessels into the mass or branching-disordered course and resistivity index values higher than 0.85 were accepted as probable malignant criteria.Results
Fifty-five of 94 lesions were benign (58.5%), while 39 (41.5%) were malignant histopathologically. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of US and PDUS in the diagnosis of malignant lesions were 100%, 58.2%, 62.9%, 100% and 71.8%, 81.8%, 73.7%, 80.4%, respectively. Criteria used for the distinction of malignant and benign lesions like number of vessels (p < 0.05), distribution of tumoral vessels, morphology of vessels and resistivity index values higher than 0.85 showed statistically significant difference (p < 0.001). When sonographic findings were combined with PDUS and spectral analysis findings, sensitivity, specificity, PPV and NPV were 100%, 52.7%, 60% and 100%, respectively.Conclusion
PDUS and spectral analysis have no contribution to BI-RADS US. For the spectral analysis, when RI value is one or greater, malignancy risk significantly increases. 相似文献10.
Yeh JJ Yu JK Teng WB Chou CH Hsieh SP Lee TL Wu MT 《European journal of radiology》2012,81(1):195-201
Purpose
This study evaluates the use of high-resolution computed tomography (HRCT) to differentiate smear-positive, active pulmonary tuberculosis (PTB) from other pulmonary infections in the emergency room (ER) setting.Methods
One hundred and eighty-three patients diagnosed with pulmonary infections in an ER were divided into an acid fast bacillus (AFB) smear-positive, active PTB group (G1 = 84) and a non-AFB smear-positive, pulmonary infection group (G2 = 99). HRCT images from a 64-Multidetector CT were analyzed, retrospectively, for the morphology, number, and segmental distribution of pulmonary lesions.Results
Utilizing multivariate analysis, five variables were found to be independent risk factors predictive of G1: (1) consolidation involving the apex segment of right upper lobe, posterior segment of the right upper lobe, or apico-posterior segment of the left upper lobe; (2) consolidation involving the superior segment of the right or left lower lobe; (3) presence of a cavitary lesion; (4) presence of clusters of nodules; (5) absence of centrilobular nodules. A G1 prediction score was generated based on these 5 criteria to help differentiate G1 from G2. The area under the receiver operating characteristic (ROC) curve was 0.96 ± 0.012 in our prediction model. With an ideal cut-off point score of 3, the specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV) are 90.9%, 96.4%, 90.0% and 96.8%, respectively.Conclusion
The use of this AFB smear-positive, active PTB prediction model based on 5 key HRCT findings may help ER physicians determine whether or not isolation is required while awaiting serial sputum smear results in high risk patients. 相似文献11.
Langenberger H Friedrich K Plank C Matzek W Wolf F Storto ML Schaefer-Prokop C Herold C 《European journal of radiology》2009,70(3):579-588
Objectives
To compare iomeprol 400 and iodixanol 320 in pulmonary artery MDCTA in subjects with suspected pulmonary embolism.Methods
Eighty randomized subjects received equi-iodine intravenous doses (48 g) of iomeprol 400 (n = 40) or iodixanol 320 (n = 40), via power injector at 4 mL/s. Four-row (35 subjects) and 64-row (45 subjects) scanners were used. Lumen attenuation was determined on-site and by two off-site blinded readers in the main, lobar, segmental and subsegmental pulmonary arteries. Statistical comparison between groups was performed for demographics and lumen attenuation.Results
There were no between-group differences (p > 0.05) in demographics. Pulmonary artery attenuation was significantly (p ≤ 0.03) higher with iomeprol 400 for all readers. Attenuation quality was excellent in more patients after iomeprol 400 than after iodixanol-320 (80% vs. 62.5%; 82.5% vs. 77.5%; off-site readers 1 and 2, respectively). No safety concerns were noted.Conclusion
The greater iodine delivery rate achievable with iomeprol 400 compared to iodixanol-320 at equi-iodine dose and injection rate permits consistently greater attenuation at all levels of the pulmonary arterial tree. 相似文献12.
Objective
To evaluate brachial plexus MRI accuracy with surgical findings and clinical follow-up as reference standard in a large multicentre study.Materials and methods
The research was approved by the Institutional Review Boards, and all patients provided their written informed consent. A multicentre retrospective trial that included three centres was performed between March 2006 and April 2011. A total of 157 patients (men/women: 81/76; age range, 18–84 years) were evaluated: surgical findings and clinical follow-up of at least 12 months were used as the reference standard. MR imaging was performed with different equipment at 1.5 T and 3.0 T. The patient group was divided in five subgroups: mass lesion, traumatic injury, entrapment syndromes, post-treatment evaluation, and other.Sensitivity, specificity with 95% confidence intervals (CIs), positive predictive value (PPV), pre-test-probability (the prevalence), negative predictive value (NPV), pre- and post-test odds (OR), likelihood ratio for positive results (LH+), likelihood ratio for negative results (LH−), accuracy and post-test probability (post-P) were reported on a per-patient basis.Results
The overall sensitivity and specificity with 95% CIs were: 0.810/0.914; (0.697–0.904). Overall PPV, pre-test probability, NPV, LH+, LH−, and accuracy: 0.823, 0.331, 0.905, 9.432, 0.210, 0.878.Conclusions
The overall diagnostic accuracy of brachial plexus MRI calculated on a per-patient base is relatively high. The specificity of brachial plexus MRI in patients suspected of having a space-occupying mass is very high. The sensitivity is also high, but there are false-positive interpretations as well. 相似文献13.
Kawai Y Suzuki K Itoh S Takada A Mori Y Naganawa S 《European journal of radiology》2012,81(11):3055-3060
Purpose
To assess the usefulness of the computed tomography (CT) finding of main pancreatic duct (MPD) wall enhancement, termed the “enhanced duct sign”, for diagnosis of autoimmune pancreatitis (AIP) in comparison with diagnosis of pancreatic carcinoma and chronic pancreatitis.Materials and methods
Two radiologists independently evaluated the presence or absence of the enhanced duct sign on multiphase contrast-enhanced CT in patients with AIP (n = 55), pancreatic carcinoma (n = 50), and chronic pancreatitis (n = 50). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of AIP were calculated. In patients demonstrating the enhanced duct sign, additional findings were evaluated by consensus.Results
The enhanced duct sign was more frequently observed in patients with AIP (37/55, 67%) than in patients with pancreatic carcinoma (5/50, 10%) or chronic pancreatitis (0/50, 0%) (P < 0.05). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the finding were 0.67, 0.95, 0.85, 0.88, and 0.84, respectively. In AIP, the lumen within the enhanced duct was completely or partially invisible in 29 of 37 (78%) patients, and the enhanced duct was observed within the affected pancreatic parenchyma in 35 of 37 (95%) patients. In pancreatic carcinoma, the lumen within the enhanced duct was visible in all patients (5/5, 100%), and the enhanced duct was observed downstream of the tumor (5/5, 100%).Conclusion
The enhanced duct sign is highly specific of AIP. 相似文献14.
Tsiflikas I Biermann C Thomas C Ketelsen D Claussen CD Heuschmid M 《European journal of radiology》2012,81(9):2255-2259
Objectives
The aim of this study was to evaluate time efficiency and diagnostic reproducibility of an advanced vessel analysis software for diagnosis of carotid artery stenosis.Material and methods
40 patients with suspected carotid artery stenosis received head and neck DE-CTA as part of their pre-interventional workup. Acquired data were evaluated by 2 independent radiologists. Stenosis grading was performed by MPR eyeballing with freely adjustable MPRs and with a preliminary prototype of the meanwhile available client-server and advanced visualization software syngo.via CT Vascular (Siemens Healthcare, Erlangen, Germany). Stenoses were graded according to the following 5 categories: I: 0%, II: 1–50%, III: 51–69%, IV: 70–99% and V: total occlusion. Furthermore, time to diagnosis for each carotid artery was recorded.Results
Both readers achieved very good specificity values and good respectively very good sensitivity values without significant differences between both reading methods. Furthermore, there was a very good correlation between both readers for both reading methods without significant differences (kappa value: standard image interpretation k = 0.809; advanced vessel analysis software k = 0.863). Using advanced vessel analysis software resulted in a significant time saving (p < 0.0001) for both readers. Time to diagnosis could be decreased by approximately 55%.Conclusions
Advanced vessel analysis application CT Vascular of the new imaging software syngo.via (Siemens Healthcare, Forchheim, Germany) provides a high rate of reproducibility in assessment of carotid artery stenosis. Furthermore a significant time saving in comparison to standard image interpretation is achievable. 相似文献15.
Manar Hussein Abdelsattar Mohamed Abdelfattah Hassaan Heba Ahmed Kamal 《The Egyptian Journal of Radiology and Nuclear Medicine》2012
Objective
The aim of this study is to assess the diagnostic value of direct MR arthrography compared to conventional MR imaging in the diagnosis of different pathologic entities affecting the triangular fibrocartilage.Subjects and methods
This study included 51 patients complaining of chronic wrist pain. Conventional MRI and MR arthrography (MRA) was done for all cases.Results
A comparison of the sensitivity of conventional MRI versus MRA was done by correlating the final diagnosis of each modality with the results of arthroscopy. MRI revealed a sensitivity (SEN) of 88.5%, specificity (SPE) of 100%, positive predictive value (PPV) of 100%, and a negative predictive value (NPV) of 69.2%, with an overall accuracy (ACC) of 90.9%, while MRA revealed a SEN of 94.2%, SPE of 100%, PPV of 100%, NPV of 81.8%, and ACC of 95.5%.Conclusion
MR arthrography is a potent additional tool facilitating the diagnosis of different pathologic entities affecting the triangular fibrocartilage requiring surgical intervention and help to reduce arthroscopic interventions. 相似文献16.
Objective
Compare apparent diffusion coefficient (ADC) values between benign and malignant mass lesions in a cohort of children referred for imaging of a mediastinal mass.Material and methods
Prospective study including 24 consecutive children (11 boys, 13 girls aged 5 months to 16 years). All underwent echo planar diffusion weighted MR imaging of the mediastinum with b-factors of 0 and 600 s/mm2. Apparent diffusion coefficient (ADC) values were calculated and correlated with the surgical finding or biopsy.Results
The mean ADC value of malignant mediastinal tumors was 0.91 (S.D., 0.17) ×10−3 mm2/s and of benign lesions 1.8 (S.D., 0.33) ×10−3 mm2/s. There was significant different in the ADC value between malignant tumors and benign mediastinal tumors (P < 0.001). Selection of 1.2 × 10−3 mm2/s as a threshold value for differentiating malignant from benign mediastinal masses has an accuracy of 93%, sensitivity of 92%, specificity of 94%, positive predictive value of 94%, negative predictive value of 92% and area under the curve of 0.962.Conclusion
Apparent diffusion coefficient value is a promising non-invasive parameter for assessment of mediastinal mass in children. 相似文献17.
Purpose
To validate the diagnostic performance of quadruple phase low tube voltage liver CT through the comparison with Gd-EOB-DTPA enhanced liver MRI for the detection of HCC.Materials and methods
Non-obese patients (38 men, eight women) with 68 HCCs underwent quadruple-phase CT at 16 MDCT (using low tube voltage, 80 kVp; moderately high tube current, 280 mAs) and Gd-EOB-DTPA-enhanced 3 T MRI. Three observers independently and randomly reviewed the CT and MR images on a tumor-by-tumor basis. The diagnostic accuracy of these techniques for detecting HCC was assessed using alternative free-response receiver operating characteristic analysis. Sensitivity and positive predictive values were evaluated. The mean effective doses for the low dose CT were also evaluated.Results
The areas under the ROC curves were 0.963, 0.959, and 0.941 for low dose CT and 0.981, 0.982, and 0.976 for MRI. Differences in Az of the two techniques for each observer were not statistically significant (P > .05). Differences in sensitivity and positive predictive values between the two techniques for each observer were not also statistically significant: sensitivity (86.8%, 82.4%, 85.3% for CT and 95.6%, 94.1%, 91.2% for MRI) and positive predictive values (92.2%, 90.3%, 89.2% for CT and 92.9%, 92.8%, 92.5% for MRI). Six HCCs (8.8%) in five patients were observed only on hepatobiliary phase of MRI, and all were smaller than 1.5 cm. The mean effective dose for CT was approximately 10.2 mSv.Conclusions
Quadruple-phase low-dose liver CT (80 kVp, 280 mAs) had relatively good diagnostic performance for detecting HCC in non-obese patients. Because no significant difference was observed between low-dose CT and MRI, the use of low-dose liver CT can be justified based on its reduced radiation effects. 相似文献18.
Purpose
To evaluate the diagnostic accuracy of computed tomography (CT) of the parotid gland for Sjögren's syndrome in comparison with conventional X-ray sialography.Methods
CT scans and X-ray sialography were performed in 34 patients with confirmed Sjögren's syndrome and 22 symptomatic controls without the disease. CT data from 57 asymptomatic controls were included for quantitative analysis. The CT findings of heterogeneity, abnormal diffuse fat tissue deposition, diffuse punctate calcification, swelling or atrophy, nodularity or cystic changes of the parotid gland were analyzed by two independent blinded readers. The correlation between CT and X-ray sialography findings was evaluated. Diagnostic performance and receiver operating characteristics curves were calculated.Results
On CT, heterogeneity of the parotid gland was seen in 30/31 (reader 1/reader 2) Sjögren's syndrome patients by the two readers (sensitivity 88.2%/91.2%; specificity 100%/90.9%). Abnormal diffuse fat tissue deposition was seen in 28/28 SS patients by the readers (sensitivity 82.3%/82.3%; specificity 100%/90.9%). Diffuse punctate calcification was seen in 10/12 Sjögren's syndrome patients (sensitivity 29.4%/35.2%; specificity 100%/100%). Stagings of CT findings correlate positively with sialography. The areas under the receiver operating characteristics curves were 0.887 (P = 0.000) and 0.908 (P = 0.000) for the maximum and standard deviation (SD) of the CT value.Conclusions
Parotid CT is accurate and reliable in the diagnosis of Sjögren's syndrome. Heterogeneity, abnormal diffuse fat tissue deposition, and diffuse punctate calcification are specific for Sjögren's syndrome. CT attenuation analysis is helpful in diagnosis. 相似文献19.
Objective
To assess the clinical value of strain ratio in differentiating thyroid solid nodules and explore its distribution characters based on pathological results.Materials and methods
The study was approved by the ethic committee and the informed consents were signed. Ninety nine solid thyroid nodules (67 benign and 32 malignant) from 71 female (mean age 46.3 ± 9.8 years) and 28 male (mean age 54.9 ± 11.7 years) patients were evaluated. Five radiologists evaluated the nodules based on a four-degree elastography score system. Strain ratio was calculated on-line. Diagnostic performances of the two evaluations were compared using Receiver Operating Characteristic (ROC) curves. Values of different pathological nodules were compared by one-way ANOVA.Results
Areas under the ROC curve (AUC) of the five readers were 0.82, 0.81, 0.79, 0.73 and 0.83, respectively. The AUC of strain ratio evaluation was higher (0.88 vs. 0.79, p < 0.001) than that of the ES score evaluation. Best cut-off points of the two evaluations were 3.5 (82% sensitivity, 72% specificity) and 4.225 (81% sensitivity, 83% specificity), respectively. Both the ES score and strain ratio were higher for malignant nodules than that for benign ones (p < 0.001).Conclusions
Strain ratio was a useful index in differential diagnosis of thyroid solid nodules. It can provide quantitative information on thyroid nodule characterization and improve diagnostic confidence. The best cut-off point for benign and malignant nodules was 4.2. 相似文献20.
Pauls S Fischer AC Brambs HJ Fetscher S Höche W Bommer M 《European journal of radiology》2012,81(5):974-978