Journal of Magnetic Resonance Imaging
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Potential of <sup>1</sup>H MR spectroscopic imaging to segregate patients who are likely to show malignancy of the peripheral zone of the prostate on biopsy Abstract Purpose To evaluate the potential of MR spectroscopic imaging (MRSI) to segregate patients who, upon prostate biopsy, are more likely to show a malignancy in the peripheral zone (PZ) of the prostate gland. Materials and Methods Before biopsy, MRSI was carried in 123 men with elevated prostate specific antigen level or an abnormal digital rectal examination. After the MRSI investigation, all patients underwent systematic transrectal ultrasound guided biopsy and were categorized using standard random number tables into the following two groups: (i) Group I, a 62 member training set; and (ii) Group II, a 61‐member test set. The cutoff value for the [citrate/(choline+creatine)] ratio for patients in the training set was obtained using the receiver operating characteristic (ROC) curve method. This value was then applied to the test set of patients as well. Results The ROC method gave a cutoff value of 1.2 for the [Citrate/(Choline+Creatine)] ratio. When applied as a malignancy‐predictor to the test group of patients (Group II), the ROC method generated the following results: sensitivity, 77%; specificity, 83%; negative predictive value, 93%; positive predictive value, 55% and accuracy, 82%. Conclusion The results indicate that patients who are deemed as malignancy‐positive in the PZ by MRSI using the ROC cutoff may be subjected to prostate biopsy to confirm the diagnosis of cancer. J. Magn. Reson. Imaging 2009. © 2009 Wiley‐Liss, Inc.
Journal of Magnetic Resonance Imaging - Tập 30 Số 4 - Trang 842-848 - 2009
Detection and localization of prostate cancer with the targeted biopsy strategy based on ADC Map: A prospective large‐scale cohort study Abstract Purpose: To investigate the usefulness of targeted biopsy strategy based on apparent diffusion coefficient (ADC) maps in the detection and localization of prostate cancer. Materials and Methods: Institutional review board approval and informed consent from all participants were obtained. This study included 1448 consecutive patients suspected of having prostate cancer based on PSA level, who were divided into two groups: Group A included 890 patients with low‐ADC lesions who underwent targeted and systematic biopsies; Group B included 558 patients with no low‐ADC lesions who underwent only systematic biopsies. The cancer detection rates (CDR) of each group, positive predictive value (PPV), and negative predictive value (NPV) of ADC maps were calculated. Results: The CDR was 70.1% for Group A, higher than those for overall patients (48.1%) and for Group B (13.1%) with significant difference (P < 0.001). In the serum, PSA range from 4 to 20 ng/mL, the CDR was higher for the Group A than for the Group B and overall patients with significant differences. PPV and NPV of MR findings were 70.1% and 86.9%, respectively. Especially, the PPV of the MR findings for the anterior portion was as high as 90.1%. Among the false negatives of MR findings, Gleason score proved 6 or smaller in 79.5%, and positive core number was merely one or two in 80.8%. Conclusion: The targeted biopsy strategy based on ADC maps can be useful in the detection and localization of prostate cancer with high PPV. J. Magn. Reson. Imaging 2012;35:1414–1421. © 2012 Wiley Periodicals, Inc.
Journal of Magnetic Resonance Imaging - Tập 35 Số 6 - Trang 1414-1421 - 2012
Multiparametric MRI for prostate cancer detection: Performance in patients with prostate-specific antigen values between 2.5 and 10 ng/mL
Journal of Magnetic Resonance Imaging - Tập 39 Số 5 - Trang 1206-1212 - 2014
Prostate cancer detection with 3 T MRI: Comparison of diffusion‐weighted imaging and dynamic contrast‐enhanced MRI in combination with T2‐weighted imaging Abstract Purpose: To evaluate the diagnostic ability of diffusion‐weighted imaging (DWI) and dynamic contrast‐enhanced imaging (DCEI) in combination with T2‐weighted imaging (T2WI) for the detection of prostate cancer using 3 T magnetic resonance imaging (MRI) with a phased‐array body coil. Materials and Methods: Fifty‐three patients with elevated serum levels of prostate‐specific antigen (PSA) were evaluated by T2WI, DWI, and DCEI prior to needle biopsy. The obtained data from T2WI alone (protocol A), a combination of T2WI and DWI (protocol B), a combination T2WI and DCEI (protocol C), and a combination of T2WI plus DWI and DCEI (protocol D) were subjected to receiver operating characteristic (ROC) curve analysis. Results: The sensitivity, specificity, accuracy, and area under the ROC curve (Az) for region‐based analysis were: 61%, 91%, 84%, and 0.8415, respectively, in protocol A; 76%, 94%, 90%, and 0.8931, respectively, in protocol B; 77%, 93%, 89%, and 0.8655, respectively, in protocol C; and 81%, 96%, 92%, and 0.8968, respectively in protocol D. ROC analysis revealed significant differences between protocols A and B (P = 0.0008) and between protocols A and D (P = 0.0004). Conclusion: In patients with elevated PSA levels the combination of T2WI, DWI, DCEI using 3 T MRI may be a reasonable approach for the detection of prostate cancer. J. Magn. Reson. Imaging 2010;31:625–631. © 2010 Wiley‐Liss, Inc.
Journal of Magnetic Resonance Imaging - Tập 31 Số 3 - Trang 625-631 - 2010
Voxel‐based analysis of R2* maps in the healthy human brain Abstract Purpose To develop a voxel‐based analysis of an R2* map of healthy human brain that is automatic, reproducible, and realizable in a single examination on a 3T MR imager. Such a tool could be useful to measure iron accumulation in neurodegenerative diseases. Materials and Methods In all, 18 healthy subjects underwent MR imaging at a field strength of 3T: 1) six consecutive T2*‐weighted gradient‐echo volumes were acquired using a segmented echo‐planar imaging sequence and 2) a conventional dual‐echo turbo spin echo sequence was also applied to acquire T2‐weighted images. Images were realigned and spatial correction was performed using a template brain dataset with SPM2. For each subject we performed a voxel‐by‐voxel nonlinear least‐squares fitting of the data acquired at the six echo times to obtain a monoexponential signal decay curve. The reproducibility and sensitivity to age variation were assessed by voxel‐based analysis. Results The reproducibility tests in whole brain analysis showed little R2* variation. Furthermore, the statistical analysis, performed on each brain voxel, revealed a significant positive correlation between age and MR values located in regions where a slow and constant age‐related iron deposition is known. Conclusion Our method, combining data acquisition and data processing, demonstrates the feasibility of voxel‐based analysis on an R2* map and affords a high degree of sensitivity and good reproducibility while maintaining high spatial resolution. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Journal of Magnetic Resonance Imaging - Tập 26 Số 6 - Trang 1413-1420 - 2007
In vivo measurements of T1 relaxation times in mouse brain associated with different modes of systemic administration of manganese chloride Abstract Purpose To measure regional T1 and T2 values for normal C57Bl/6 mouse brain and changes in T1 after systemic administration of manganese chloride (MnCl2 ) at 9.4 T. Materials and Methods C57Bl/6 mice were anesthetized and baseline T1 and T2 measurements obtained prior to measurement of T1 after administration of MnCl2 at 9.4 T. MnCl2 was administered systemically either by the intravenous (IV), intraperitoneal (IP), or subcutaneous (SC) routes. T1 and T2 maps for each MRI transverse slice were generated using commercial software, and T1 and T2 values of white matter (WM), gray matter (GM), pituitary gland, and lateral ventricle were obtained. Results When compared with baseline values at low‐field, significant lengthening of the T1 values was shown at 9.4 T, while no significant change was seen for T2 values. Significant T1 shortening of the normal mouse brain was observed following IV, IP, and SC administration of MnCl2 , with IV and IP showing similar acute effects. Significant decreases in T1 values were seen for the pituitary gland and the ventricles 15 minutes after either IV or IP injection. GM showed greater uptake of the contrast agent than WM at 15 and 45 minutes after either IV or IP injections. Although both structures are within the blood‐brain barrier (BBB), GM and WM revealed a steady decrease in T1 values at 24 and 72 hours after MnCl2 injection regardless of the route of administration. Conclusion Systemic administration of MnCl2 by IV and IP routes induced similar time‐course of T1 changes in different regions of the mouse brain. Acute effects of MnCl2 administration were mainly influenced by either the presence or absence of BBB. SC injection also provided significant T1 change at subacute stage after MnCl2 administration. J. Magn. Reson. Imaging 2005;21:334–339. © 2005 Wiley‐Liss, Inc.
Journal of Magnetic Resonance Imaging - Tập 21 Số 4 - Trang 334-339 - 2005
Rectal cancer: Assessment of response to neoadjuvant chemoradiation by dynamic contrast-enhanced MRI
Journal of Magnetic Resonance Imaging - Tập 38 Số 1 - Trang 119-126 - 2013
Quantitative intravoxel incoherent motion parameters derived from whole‐tumor volume for assessing pathological complete response to neoadjuvant chemotherapy in locally advanced rectal cancer Background Many locally advanced rectal cancer (LARC) patients can benefit from neoadjuvant chemotherapy (NACT), with some achieving a pathological complete response (pCR). However, there is limited research reporting on the value of intravoxel incoherent motion (IVIM) in monitoring pCR in patients with LARC. Purpose To identify whether IVIM parameters derived from whole‐tumor volume (WTV) before and after NACT could accurately assess pCR in patients with LARC. Study Type Prospective patient control study. Population Fifty‐one patients with LARC before and after NACT, prior to surgery. Field Strength/Sequence IVIM‐diffusion imaging at 3T. Assessment Apparent diffusion coefficient (ADC), slow diffusion coefficient (D), fast diffusion coefficient (D*), and perfusion‐related diffusion fraction (f ) values were obtained on diffusion‐weighted magnetic resonance images (DW‐MRI) using WTV methods and calculated using a biexponential model before and after NACT. Statistical Tests DWI‐derived ADC and IVIM‐derived parameters and their percentage changes (ΔADC%, ΔD%, ΔD*%, and Δf %) were compared using independent‐samples t ‐test and Mann–Whitney U ‐test between the pCR and non‐pCR groups. The diagnostic performance of IVIM parameters and their percentage changes were evaluated using receiver operating characteristic curves. Results Compared with the non‐pCR group, the pCR group exhibited significantly lower pre‐ADCmean (P = 0.003) and pre‐D values (P = 0.024), and significantly higher post‐f (P = 0.002), ΔADCmean % (P = 0.002), ΔD% (P = 0.001), and Δf % values (P = 0.017). Receiver operating characteristic curves showed that the pre‐D value had the best specificity (95.12%) and accuracy (86.27%) in predicting the pCR status, and ΔD% had the highest area under the curve (0.832) in assessing the pCR response to NACT. Data Conclusions The IVIM‐derived D value is a promising tool in predicting the pCR status before therapy. The percentage changes in D values after therapy may help assess the pCR status prior to surgery. Level of Evidence: 2Technical Efficacy: Stage 2J. Magn. Reson. Imaging 2017.
Journal of Magnetic Resonance Imaging - Tập 48 Số 1 - Trang 248-258 - 2018
Diagnostic accuracy of quantitative diffusion parameters in the pathological grading of hepatocellular carcinoma: A meta‐analysis Background Accurate preoperative assessment of the pathological grade of hepatocellular carcinoma (HCC) could greatly benefit prognostic predictions. Purpose To assess and compare the diagnostic accuracy of the apparent diffusion coefficient (ADC) and tissue diffusivity (D ) for the noninvasive pathological grading of HCC. Study Type Meta‐analysis. Data Sources PubMed/Medline, EMBASE, the Web of Science, and the Cochrane Library were searched to find related original articles published up to May 30, 2019. Field Strength/Sequence Diffusion‐weighted imaging (DWI) and/or intravoxel incoherent motion (IVIM) were performed with a 1.5T or 3.0T scanner. Assessment The Quality Assessment of Diagnostic Accuracy Studies 2 tool was used to assess the methodologic quality. Statistical Tests The bivariate random‐effects model was used to obtain the pooled sensitivity and specificity, and the area under summary receiver operating characteristic curve (AUROC) was obtained. Subgroup analyses were performed. Results A total of 16 original articles (1428 HCCs) were included. Most studies had a low to unclear risk of bias and minimal concerns regarding applicability. For the discrimination of well‐differentiated HCCs, the pooled sensitivity and specificity of the ADC value were 85% and 92%, respectively. For the discrimination of poorly differentiated HCCs, the pooled sensitivity and specificity of the ADC value and D were 84% and 80%, and 92% and 77%, respectively. The summary AUROC of D (0.94) was significantly higher than that of ADC (0.89) (z = –2.718, P = 0.007). The subgroup analyses identified three covariates including size, number of included lesions in the studies, and blindness to the reference standard as possible sources of heterogeneity. Data Conclusion This meta‐analysis showed that the ADC and D values had a high to excellent accuracy for the noninvasive pathological grading of HCCs and that the D value was superior to the ADC value for discriminating poorly differentiated HCCs. Level of Evidence: 3Technical Efficacy Stage: 2J. Magn. Reson. Imaging 2020;51:1581–1593.
Journal of Magnetic Resonance Imaging - Tập 51 Số 5 - Trang 1581-1593 - 2020
Dynamic contrast-enhanced MRI to evaluate the therapeutic response to neoadjuvant chemoradiation therapy in locally advanced rectal cancer
Journal of Magnetic Resonance Imaging - Tập 40 Số 3 - Trang 730-737 - 2014
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