Prostate cancer detection with 3 T MRI: Comparison of diffusion‐weighted imaging and dynamic contrast‐enhanced MRI in combination with T2‐weighted imaging

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.     

Added value of diffusion-weighted MR imaging to T2-weighted and dynamic contrast-enhanced MR imaging in T staging of gastric cancer

ObjectiveTo assess the utilization of diffusion-weighted (DW) magnetic resonance (MR) imaging in T staging of gastric cancer prospectively.MethodsFifty-one patients underwent T2-weighted (T2W), contrast-enhanced (CE) and DW MR imaging. Two radiologists independently interpreted the images for T staging of the tumors.ResultsThe overall accuracy of T staging in pT1-4 gastric cancers by T2W+CE+DW (88.2%) was significantly higher than that by T2W+CE and T2W+DW (both 76.5%, P= .031).ConclusionDW adds useful information to T2W and CE MR imaging in T staging of gastric cancer.     

The value of diffusion-weighted imaging in combination with T2-weighted imaging for rectal cancer detection

OBJECTIVE: To evaluate the clinical value of diffusion-weighted imaging (DWI) in combination with T(2)-weighted imaging (T(2)WI) for the detection of rectal cancer as compared with T(2)WI alone. MATERIALS AND METHODS: Forty-five patients with rectal cancer and 20 without rectal cancer underwent DWI with parallel imaging and T(2)WI on a 1.5 T scanner. Images were independently reviewed by two readers blinded to the results to determine the detectability of rectal cancer. The detectability of T(2)W imaging without and with DW imaging was assessed by means of receiver operating characteristic analysis. The interobserver agreement between the two readers was calculated with kappa statistics. RESULTS: The ROC analysis showed that each of two readers achieved more accurate results with T(2)W imaging combined with DW imaging than with T(2)W imaging alone significantly. The A(z) values for the two readers for each T(2)WI and T(2)WI combined with DWI were 0.918 versus 0.991 (p=0.0494), 0.934 versus 0.997 (p=0.0475), respectively. The values of kappa were 0.934 for T(2)WI and 0.948 for T(2)WI combined with DWI between the two readers. CONCLUSION: The addition of DW imaging to conventional T(2)W imaging provides better detection of rectal cancer.     

MR spectroscopic imaging and diffusion-weighted imaging of prostate cancer with Gleason scores

Purpose:

To investigate functional changes in prostate cancer patients with three pathologically proven different Gleason scores (GS) (3+3, 3+4, and 4+3) using magnetic resonance spectroscopic imaging (MRSI) and diffusion‐weighted imaging (DWI).

Materials and Methods:

In this study MRSI and DWI data were acquired in 41 prostate cancer patients using a 1.5T MRI scanner with a body matrix combined with an endorectal coil. The metabolite ratios of (Cho+Cr)/Cit were calculated from the peak integrals of total choline (Cho), creatine (Cr), and citrate (Cit) in MRSI. Apparent diffusion coefficient (ADC) values were derived from DWI for three groups of Gleason scores. The sensitivity and specificity of MRSI and DWI in patients were calculated using receiver operating characteristic curve (ROC) analysis.

Results:

The mean and standard deviation of (Cho+Cr)/Cit ratios of GS 3+3, GS 3+4, and GS 4+3 were: 0.44 ± 0.02, 0.56 ± 0.06, and 0.88 ± 0.11, respectively. For the DWI, the mean and standard deviation of ADC values in GS 3+3, GS 3+4, and GS 4+3 were: 1.13 ± 0.11, 0.97 ± 0.10, and 0.83 ± 0.08 mm²/sec, respectively. Statistical significances were observed between the GS and metabolite ratio as well as ADC values and GS.

Conclusion:

Combined MRSI and DWI helps identify the presence and the proportion of aggressive cancer (ie, Gleason grade 4) that might not be apparent on biopsy sampling. This information can guide subsequent rebiopsy management, especially for active surveillance programs. J. Magn. Reson. Imaging 2012;36:697–703. © 2012 Wiley Periodicals, Inc.     

Prostate cancer detection with 3-T MRI: comparison of diffusion-weighted and T2-weighted imaging

OBJECTIVE: To compare the clinical value of diffusion-weighted (DW) and T2-weighted (T2W) imaging in detecting prostate cancer using a 3-Tesla (3T) magnetic resonance (MR) system. MATERIALS AND METHODS: Thirty-seven patients with suspected prostate cancer underwent T2W and DW imaging at 3T using an 8-channel phased-array coil. These images and apparent diffusion coefficient (ADC) maps were read retrospectively and blindly. The results were compared with histopathologic findings, and receiver operating characteristic (ROC) analysis was used to compare the cancer detection performance of T2W and DW imaging. RESULTS: The areas under the ROC curves for DW imaging and T2W imaging were 0.89 and 0.82, respectively. The performance of DW imaging in prostate cancer detection was significantly better than that of T2W imaging (P=0.0371). CONCLUSION: With a 3T MR system, the performance of DW imaging in detecting prostate cancer was better than that of T2W imaging. DW imaging appears to be a robust and reliable method to examine the whole prostate within an acceptable scan time in clinical settings.     

DWI、T2加权像及综合应用对前列腺癌诊断价值的研究

目的:通过对分别应用T2WI及DWI两种成像方法及其综合应用对前列腺癌进行定性诊断的比较,探讨两种方法各自及综合应用对前列腺癌的诊断价值。方法:应用1.5T MR成像仪对42例前列腺疾病患者进行前列腺磁共振高分辨成像,其中前列腺癌15例,良性病变包括良性前列腺增生及慢性前列腺炎症等27例。在MRI常规成像基础上行DWI扫描,扩散敏感系数(b)值分别为0、1000s/mm2。采用盲法阅片,按照前列腺6分区法将两种MR技术分别所得图像数据分区评估测量并采用5分制评分,根据两种技术的5分制评分进行T2加权像综合DWI方法评分,将所得结果与病理结果对照。利用SPSS 11.5分别做ROC曲线分析比较,计算各组方法诊断的敏感度、特异度及准确度等。结果:各组诊断方法的敏感度、特异度及ROC曲线下面积(Az)如下:T2WI:88.2%,67.2%和0.848±0.030,最佳诊断界值为3;ADC诊断:82.4%,81.6%和0.860±0.033,最佳界值为4;ADC结合T2WI诊断:78.4%,92.5%和0.922±0.021,最佳界值为4.结论:通过独立评估T2WI及DWI两种方法均可以有效诊断前列腺癌;两种成像方法综合应用诊断前列腺癌的准确度显著高于两种成像技术独立诊断,其诊断结果与病理分析一致性较好。     

Prostate cancer: utility of fusion of T2-weighted and high b-value diffusion-weighted images for peripheral zone tumor detection and localization

Purpose:

To retrospectively assess the utility of fusion of T2‐weighted images (T2WI) and high b‐value diffusion‐weighted images (DWI) for prostate cancer detection and localization.

Materials and Methods:

In this IRB‐approved HIPAA‐compliant study, 42 patients with prostate cancer underwent MRI including multiplanar T2WI and axial DWI before prostatectomy. Two independent radiologists first assessed multiplanar T2WI and axial DWI_b‐1000 images and recorded whether tumor was present in each sextant. Axial T2WI was then fused with axial DWI_b‐1000 images, and the radiologists re‐evaluated each sextant for tumor. Accuracy was compared using generalized estimating equations based on a binary logistic regression model.

Results:

The accuracy, sensitivity, specificity, PPV, and NPV for tumor detection on a sextant‐basis using separate and fused image sets was 65.1%, 50.8%, 78.0%, 67.8%, and 63.6% and 71.0%, 60.8%, 80.3%, 73.7%, and 69.3%, respectively, for reader 1, and 54.0%, 42.5%, 64.4%, 52.0%, and 55.2%, and 61.1%, 56.7%, 65.2%, 59.6%, and 62.3%, respectively, for reader 2. The improvements in accuracy, sensitivity, and NPV using fused images were statistically significant for both readers, as was the improvement in PPV for reader 2 (P ranging from <0.0001 to 0.041). With either separate or fused images, there was greater sensitivity for tumors of higher grade or larger size (P ranging from <0.001 to 0.099).

Conclusion:

Fusion of T2WI and high b‐value DWI resulted in significant improvements in sensitivity and accuracy for tumor detection on a sextant‐basis, with similar specificity. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.     

Combined diffusion-weighted and dynamic contrast-enhanced MRI for prostate cancer diagnosis--correlation with biopsy and histopathology

PURPOSE: To determine whether the combination of diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI provides higher diagnostic sensitivity for prostate cancer than each technique alone. MATERIALS AND METHODS: Fourteen patients with a clinical suspicion of prostate cancer underwent endorectal MRI on a 1.5T scanner prior to transrectal ultrasound (TRUS)-guided biopsies. The average values of the apparent diffusion coefficient (ADC, calculated from b-values of 0 and 600), K(trans), v(e), maximum gadolinium (Gd) concentration, onset time, mean gradient, and maximum enhancement were determined. Correlation with histology was based on biopsy (six patients) and prostatectomy specimen (eight patients) results. The Tukey-Kramer test was used for statistical analysis. RESULTS: The average values of all MRI parameters, except v(e) and maximum Gd concentration, showed significant differences between tumor and normal prostate. The sensitivity and specificity values were respectively 54% (35-72%) and 100% (95-100%) for the ADC data, and 59% (39-77%) and 74% (63-83%) for the DCE data. When both ADC and DCE results were combined, the sensitivity increased to 87% (68-95%) and specificity decreased to 74% (62-83%). CONCLUSION: All but two DW- and DCE-MRI parameters showed significant differences between tumor and normal prostate. Combining both techniques provides better sensitivity, with a small decrease in specificity.     

Added diagnostic value of T2-weighted MR imaging to gadolinium-enhanced three-dimensional dynamic MR imaging for the detection of small hepatocellular carcinomas

Purpose

To assess the added value of T2-weighted MRI to gadolinium-enhanced dynamic MRI for detection of HCCs.

Materials and methods

Two readers retrospectively analyzed MRIs of 115 patients with 131 HCCs (size; 0.6–2.0 cm) that had been diagnosed by histology (n = 41) or imaging findings (n = 90). Two separate blind image analyses of the gadolinium set and the combined T2-weighted imaging and gadolinium sets were performed. Diagnostic accuracy was evaluated using the alternative-free response receiver operating characteristic method with four-point scale. Sensitivity and positive predictive value were also calculated.

Results

For both observers, the Az values and sensitivities with the combined T2-weighed imaging and gadolinium set (mean Az 0.806, sensitivity 84.7) were significantly higher than those with the gadolinium set (mean Az 0.660, sensitivity 59.9) (p < 0.05). The addition of T2-weighted imaging led to a change in diagnosis for 27 lesions by both observers, which at gadolinium set were assigned a confidence level of 1 or 2 but at additional reading of T2-weighted imaging were assigned a confidence level of 3 or 4. For the positive predictive values, each image set showed a similar value for each observer.

Conclusion

The addition of T2-weighted imaging to gadolinium-enhanced 3D dynamic imaging could be helpful in the detection of HCC by increasing reader confidence for HCCs with equivocal findings on gadolinium-enhanced MRIs.     

Seminal vesicle invasion in prostate cancer: prediction with combined T2-weighted and diffusion-weighted MR imaging

The aim of this study was to evaluate the usefulness of diffusion-weighted imaging (DWI) in detecting seminal vesicle invasion (SVI). A total of 283 patients underwent conventional MRI and DWI before prostate cancer surgery. The apparent diffusion coefficient (ADC) values of all PCa foci, SVI and seminal vesicle were measured. T2 images alone and then T2 images combined with DWI were scored for the likelihood of SVI. The area under the receiver operating characteristic curve (AUC) was used to assess accuracy. Statistical significance was inferred at P?<?0.05. On pathological analysis, 39 patients had SVI. The ADC values of SVI were significantly lower than those of SV. The AUC for T2-weighted imaging plus DW imaging (0.897) was significantly larger (P?<?0.05) than that for T2-weighted imaging alone (0.779). T2 images combined with DWI shows significantly higher accuracy than T2-weighted imaging alone in the detection of SVI.     

Prostate cancer detection with multi‐parametric MRI: Logistic regression analysis of quantitative T2, diffusion‐weighted imaging,and dynamic contrast‐enhanced MRI

Purpose

To develop a multi‐parametric model suitable for prospectively identifying prostate cancer in peripheral zone (PZ) using magnetic resonance imaging (MRI).

Materials and Methods

Twenty‐five radical prostatectomy patients (median age, 63 years; range, 44–72 years) had T2‐weighted, diffusion‐weighted imaging (DWI), T2‐mapping, and dynamic contrast‐enhanced (DCE) MRI at 1.5 Tesla (T) with endorectal coil to yield parameters apparent diffusion coefficient (ADC), T2, volume transfer constant (K^trans) and extravascular extracellular volume fraction (v_e). Whole‐mount histology was generated from surgical specimens and PZ tumors delineated. Thirty‐eight tumor outlines, one per tumor, and pathologically normal PZ regions were transferred to MR images. Receiver operating characteristic (ROC) curves were generated using all identified normal and tumor voxels. Step‐wise logistic‐regression modeling was performed, testing changes in deviance for significance. Areas under the ROC curves (A_z) were used to evaluate and compare performance.

Results

The best‐performing single‐parameter was ADC (mean A_z [95% confidence interval]: A_z,ADC: 0.689 [0.675, 0.702]; A_z,T2: 0.673 [0.659, 0.687]; A_z,Ktrans: 0.592 [0.578, 0.606]; A_z,ve: 0.543 [0.528, 0.557]). The optimal multi‐parametric model, LR‐3p, consisted of combining ADC, T2 and K^trans. Mean A_z,LR‐3p was 0.706 [0.692, 0.719], which was significantly higher than A_z,T2, A_z,Ktrans, and A_z,ve (P < 0.002). A_z,LR‐3p tended to be greater than A_z,ADC, however, this result was not statistically significant (P = 0.090).

Conclusion

Using logistic regression, an objective model capable of mapping PZ tumor with reasonable performance can be constructed. J. Magn. Reson. Imaging 2009;30:327–334. © 2009 Wiley‐Liss, Inc.     

Detection of non-palpable breast cancer in asymptomatic women by using unenhanced diffusion-weighted and T2-weighted MR imaging: comparison with mammography and dynamic contrast-enhanced MR imaging

Objective

To compare the detectability of non-palpable breast cancer in asymptomatic women by using mammography (MMG), dynamic contrast-enhanced MR imaging (DCE-MRI) and unenhanced MR imaging with combined diffusion-weighted and T2-weighted images (DWI?+?T2WI).

Methods

Forty-two lesions in 42 patients with non-palpable breast cancer in asymptomatic women were enrolled. For the reading test, we prepared a control including 13 normal and 8 benign cases. Each imaging set included biplane MMG, DCE-MRI and DWI?+?T2WI. Five readers were asked to rate the images on a scale of 0 to 100 for the likelihood of the presence of cancer and the BI-RADS category. Confidence level results were used to construct receiver operating characteristic analysis. Sensitivity and specificity were calculated for each technique.

Results

DWI?+?T2WI showed higher observer performances (area under the curve, AUC, 0.73) and sensitivity (50%) for the detection of non-palpable breast cancer than MMG alone (AUC 0.64; sensitivity 40%) but lower than those of DCE-MRI (AUC 0.93; sensitivity 86%). A combination of MMG and DWI?+?T2WI exhibited higher sensitivity (69%) compared with that of MMG alone (40%).

Conclusion

DWI?+?T2WI could be useful in screening breast cancer for patients who cannot receive contrast medium and could be used as a new screening technique for breast cancer.     

Enhanced mass on contrast-enhanced breast MR imaging: Lesion characterization using combination of dynamic contrast-enhanced and diffusion-weighted MR images

Purpose

To evaluate the diagnostic accuracy of a combination of dynamic contrast‐enhanced MR imaging (DCE‐MRI) and diffusion‐weighted MR imaging (DWI) in characterization of enhanced mass on breast MR imaging and to find the strongest discriminators between carcinoma and benignancy.

Materials and Methods

We analyzed consecutive breast MR images in 270 patients; however, 13 lesions in 93 patients were excluded based on our criteria. We analyzed tumor size, shape, margin, internal mass enhancement, kinetic curve pattern, and apparent diffusion coefficient (ADC) values. We applied univariate and multivariate analyses to find the strongest indicators of malignancy and calculate a predictive probability for malignancy. We added the corresponding categories to these prediction probabilities for malignancy and calculated diagnostic accuracy when we consider category 4b, 4c, and 5 lesions as malignant and category 4a, 3, and 2 lesions as benign. In a validation study, 75 enhancing lesions in 71 patients were examined consecutively.

Results

Irregular margin, heterogeneous internal enhancement, rim enhancement, plateau time–intensity curve (TIC) pattern, and washout TIC pattern were the strongest indicators of malignancy as well as past studies, and ADC values less than 1.1 × 10^?3 mm²/s were also the strongest indicators of malignancy. In a validation study, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 92% (56/61), 86% (12/14), 97% (56/58), 71% (12/17), and 91% (68/75), respectively.

Conclusion

The combination of DWI and DCE‐MRI could produce high diagnostic accuracy in the characterization of enhanced mass on breast MR imaging. J. Magn. Reson. Imaging 2008;28:1157–1165. © 2008 Wiley‐Liss, Inc.

     

Breast lesions: evaluation with dynamic contrast-enhanced T1-weighted MR imaging and with T2*-weighted first-pass perfusion MR imaging

PURPOSE: To evaluate the diagnostic value of an imaging protocol that combines dynamic contrast-enhanced T1-weighted magnetic resonance (MR) imaging and T2*-weighted first-pass perfusion imaging in patients with breast tumors and to determine if T2*-weighted imaging can provide additional diagnostic information to that obtained with T1-weighted imaging. MATERIALS AND METHODS: One hundred thirty patients with breast tumors underwent MR imaging with dynamic contrast-enhanced T1-weighted imaging of the entire breast, which was followed immediately with single-section, T2*-weighted imaging of the tumor. RESULTS: With T2*-weighted perfusion imaging, 57 of 72 carcinomas but only four of 58 benign lesions had a signal intensity loss of 20% or more during the first pass, for a sensitivity of 79% and a specificity of 93%. With dynamic contrast-enhanced T1-weighted imaging, 64 carcinomas and 19 benign lesions showed a signal intensity increase of 90% or more in the first image obtained after the administration of contrast material, for a sensitivity of 89% and a specificity of 67%. CONCLUSION: T2*-weighted first-pass perfusion imaging can help differentiate between benign and malignant breast lesions with a high level of specificity. The combination of T1-weighted and T2*-weighted imaging is feasible in a single patient examination and may improve breast MR imaging.     

Pancreatic neuroendocrine tumor: added value of fusion of T2-weighted imaging and high b-value diffusion-weighted imaging for tumor detection

Objectives

To investigate the added value of fusion of high b-value diffusion-weighted images (DWI) and T2-weighted (T2) MR images for the detection of pancreatic neuroendocrine tumors (PNT).

Methods

18 patients with 18 histologically proven PNT were included. Two radiologists independently and retrospectively reviewed four randomized images sets (T2+T1, DWI, T2+DWI, and DWI+T2 fusion). Lesion detection confidence level was assessed using a three grade score (no lesion; uncertain lesion and certain lesion); lesion size and signal intensity were recorded. Apparent diffusion coefficients (ADC) of tumor and adjacent pancreas were measured.

Results

Readers 1 and 2 respectively detected 14/18 and 16/18 lesions on T2+T1, 13/18 and 12/18 on DWI, 16/18 and 15/18 on T2+DWI and 17/18 and 16/18 on DWI+T2 fusion. Lesion median size was 16 mm (range: 7 mm–40 mm), 22% were hyperfunctioning (all insulinomas) and 72% were low-grade (Rindi 1). All tumors except one (with cystic component) showed lower ADC than adjacent pancreatic parenchyma. Fusion imaging had significantly better detection score by both authors (p < 0.005) and provided the higher inter-reader agreement (kappa 0.7). DWI alone had the worst score for both readers.

Conclusions

Fusion images improve the detection of PNT, especially in patients with small isointense lesions on conventional MR sequences.     

磁共振弥散加权成像、T2加权成像及动态增强联合运用对前列腺癌的诊断价值

目的 探讨磁共振弥散加权成像(DWI)、T2加权像(T2WI)及动态增强(DCE)联合应用对前列腺癌的诊断价值.方法 100例前列腺疾病中前列腺癌49例和非癌病例51例(包括46例前列腺增生、3例外周带炎症及2例前列腺结核).所有病例在常规MR检查基础上加扫DCE及DWI序列,DWI的b值为800 s/mm2.比较T2WI、DCE、DWI及三者联合诊断前列腺癌的敏感性;统计分析前列腺组织与非癌组织的ADC值是否存在差异.结果 在DWI图像上,前列腺癌多呈明显高信号,6例局限于中央带前列腺癌得到正确诊断.前列腺癌组织的平均ADC值为(0.96±0.22)×10-3mm2/s,前列腺增生组织的平均ADC值为(1.56±0.23)×10-3mm2/s,两者之间有统计学差异(P＝0.001),但ADC值有小部分重叠.T2WI、DCE、DWI及三者联合诊断前列腺癌的敏感性分别为85.7%、87.8%、93.9%、100%.结论 T2WI、DCE及DWI三者联合应用可以弥补各自的缺点,提高前列腺癌诊断的敏感性.     

Assessment of diffusion-weighted MR imaging in liver fibrosis

PURPOSE: To assess whether hepatic fibrosis is associated with a restriction in the diffusion of water that can be analyzed with diffusion-weighted MR imaging (DWI) of the liver. MATERIALS AND METHODS: DWI was performed in 10 normal rats and 15 rats with liver fibrosis. Echo-planar DWI was performed in the living rats at 1.5 T and repeated immediately after the animals were killed. Afterwards the livers were explanted, fixed in Bouin solution, and imaged with a DW spin-echo sequence at 4.7 T. Fibrosis was quantified by densitometry on Sirius red-stained histological sections. RESULTS: In living rats the apparent diffusion coefficient (ADC) decreased with the severity of liver fibrosis (controls: 1535 +/- 294 mm(2)/second; CCl(4) (5 weeks) 1129 +/- 273 mm(2)/second; CCl(4) (9 weeks): 943 +/- 132 mm(2)/second; P = 0.002). An inverse correlation between ADC and liver fibrosis volume density was observed (r = -0.712, P < 0.001). In contrast, these findings were not observed in the rats after they were killed or in the fixated livers. CONCLUSION: Decreased ADC correlated with increased liver fibrosis in living rats, but not after death. These results suggest that restricted water diffusion cannot be assessed by DWI in liver fibrosis. Other factors, such as a decrease of perfusion, may explain the decrease of the hepatic ADC measured in vivo in rats with liver fibrosis.     

Body diffusion-weighted MR imaging using high b-value for malignant tumor screening: usefulness and necessity of referring to T2-weighted images and creating fusion images

RATIONALE AND OBJECTIVES: To evaluate the potential usefulness of high b-value body diffusion-weighted images (DWIs) as a screening tool in the depiction of abdominal malignant tumors. MATERIALS AND METHODS: We selected 110 abdominal magnetic resonance examinations (1.5 T; 60 men; age range, 25-90 years) with and without malignant tumors (n = 37 and n = 73, respectively). Axial DWIs were obtained by single-shot spin-echo (SE) type echo planar imaging (EPI) sequence with inversion pulse (repetition time, 6,800 msec; echo time, 100 msec; T1, 150 msec; b value, 1,000 sec/mm(2)) without breath-holding. Two radiologists independently interpreted the DWIs, T2-weighted images (T2-WI), all three types of images including DWIs, T2-WIs, and fusion images at the same time (DWIs + T2-WIs + fusion) with 7-14 days' interval, and the diagnostic confidence for each patient was scored. RESULTS: The area under the curve (AUC) of the composite receiver operating characteristic (ROC) curve of DWIs + T2-WIs + fusion (0.904) was significantly higher than those of DWIs (0.720; P < .001) and T2-WIs (0.822; P < .05). Both sensitivity and specificity were higher in DWIs + T2-WIs + fusion (89.5% and 81.9%, respectively) compared with those of DWIs (72.4% and 59.0%; P < .01 and P < .001, respectively). CONCLUSIONS: Abdominal high b-value DWIs have a high sensitivity and specificity for malignant tumors when T2-WIs are referred and image fusion technique is employed, suggesting that it may potentially be a new screening tool.