Diffusion-weighted Imaging In Differential Diagnosis Research Articles

DWI in differential diagnosis between dysembryoplastic neuroepithelial tumors and low-grade glioma

Clinical and imaging data of 11 patients with dysembryoplastic neuroepithelial tumors (DNET) and 15 patients with low-grade glioma (LGG) admitted in Northern Jiangsu People′s Hospital were analyzed retrospectively. Routine MRI scan, diffusion weighted imaging (DWI) and enhanced scan were performed. The workstation automatically generated apparent diffusion coefficient (ADC) maps and then to obtain ADC values of the tumor parenchymal area and the contralateral normal reference area. Relative tumor/reference ADC values (rADC) were also calculated. The ADC values of parenchymal regions of tumor and contralateral normal reference areas and the rADC between DNET and LGG were compared. There was significant difference in age distribution between the two groups [(16.6±13.1) vs. (43.0±19.2) years, t=3.938, P 0.05). The ADC values of tumor parenchymal regions in both groups were significantly higher than those in contralateral reference regions (both P<0.01), the rADC of DNET was significantly higher than that of LGG (P<0.01). It is difficult to identify DNET and LGG by conventional image morphology, however the rADC value of DNET in DWI is significantly higher than that of LGG, and can provide important reference for differential diagnosis between them. Key words: Neuroectodermal tumors, primitive; Glioma; Diffusion magnetic resonance imaging; Apparent diffusion coefficient

Usefulness of Apparent Diffusion Coefficient of Diffusion-Weighted Imaging for Differential Diagnosis of Primary Solid and Cystic Renal Masses.

SummaryBackgroundTo evaluate the value of diffusion-weighted imaging (DWI) for distinguishing between benign and malignant renal masses.Material/MethodsSeventy-five patients with 75 unilateral renal lesions were included, and 75 normal contralateral kidneys served as controls. The lesions were categorized into four groups as malignant cystic, malignant solid, benign cystic and benign solid. The apparent diffusion coefficients (ADCs) were evaluated for two different b values (b=600 s/mm2 and b=1000 s/mm2). Receiving operating characteristic analysis was performed to identify threshold ADCs.ResultsSensitivity and specificity were 67% and 77% (p=0.003) at the cutoff value of 1.5 for b=600 s/mm2, and 79% and 62% (p=0.004) at the cutoff value of 1.99 for b=1000 s/mm2 as regards the differentiation between solid benign and malignant renal lesions. Sensitivity and specificity were 78% and 79% (p=0.001) at the cutoff value of 3.1 for b=600 s/mm2, and 86% and 61% (p=0.003) at the cutoff value of 2.9 for b=1000 s/mm2 as regrads the differentiation between benign and malignant cystic renal lesions.ConclusionsDWI can be an effective diagnostic method for distinguishing between benign and malignant renal masses.

Value of intravoxel incoherent motion diffusion-weighted imaging in differential diagnosis of benign and malignant hepatic lesions and blood perfusion evaluation

Objective: To investigate the value of intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) in the differential diagnosis and blood perfusion evaluation of benign and malignant hepatic lesions. Methods: A retrospective analysis was performed for 86 patients (96 lesions) with pathologically or clinically confirmed hepatic lesions or hepatic lesions diagnosed based on follow-up results, among whom 48 had malignant lesions (53 lesions) and 38 had benign lesions (43 lesions). The patients underwent conventional magnetic resonance (MR) plain scan, contrast-enhanced scan, and diffusion-weighted imaging (DWI) with different b values (b = 0, 50, 100, 150, 200, 400, 600, 800, 1 000, and 1 200 s/mm2) to determine the parameters of the double exponential model for intravoxel incoherent motion (IVIM): fast diffusion coefficient Dfast, slow diffusion coefficient Dslow, and percentage of fast-diffusion constituent F value. The patients were divided into groups according to the blood supply to lesions on conventional MR plain scan and contrast-enhanced scan, and there were 47 lesions in abundant blood supply group and 49 in poor blood supply group. The data for analysis were Dfast, Dslow, and F values of benign/malignant lesion groups and abundant/poor blood supply groups. The independent samples t-test was used for statistical analysis; the independent samples non-parametric test Mann-Whitney U test was used for the comparison of F value; the receiver operating characteristic (ROC) curve was used to evaluate the value of above parameters in the differentiation of benign and malignant lesions and blood supply evaluation. Results: Compared with the malignant lesion group, the benign lesion group had significantly higher Dslow, and F values (P< 0.001 orP= 0.001) and a higher Dfast value (P= 0.053). Compared with the poor blood supply group, the abundant blood supply group had significantly higher Dfast and F values (P< 0.001 orP= 0.001) and a higher Dslow value (P= 0.185). According to the ROC curve, the cut-off values of Dslow, Dfast, and F values in the diagnosis of benign/malignant hepatic lesions and evaluation of abundant/poor blood supply were 1.18×10-3mm2/s, 27.20×10-3mm2/s, 20.25%, 1.17×10-3mm2/s, 20.30×10-3mm2/s, and 17.80%, respectively, with sensitivities, specificities, accuracy, and areas under the ROC curve of 90.69%/92.45%/91.66%/0.938, 46.51%/73.58%/61.45%/0.589, 74.41%/50.94%/62.50%/0.653, 59.57%/57.14%/58.33%/0.559, 55.32%/63.26%/59.37%/0.618, and 93.61%/89.79%/90.62%/0.961, respectively. Conclusion: The parameter of the double exponential model for IVIM, Dslow value, has a certain value in the differential diagnosis of benign and malignant hepatic lesions, and F value can show blood perfusion in benign and malignant hepatic lesions without the need for contrast-enhanced scan, which provides a reference for the qualitative diagnosis of liver tumor.

Apparent diffusion coefficient value of diffusion-weighted imaging for differential diagnosis of ductal carcinoma in situ and infiltrating ductal carcinoma

The present meta-analysis investigated the clinical value of apparent diffusion coefficient (ADC) values in diffusion-weighted imaging (DWI) for differential diagnosis of ductal carcinoma in situ (DCIS) and infiltrating ductal carcinoma (IDC). Electronic databases searches were employed to identify relevant scientific literature, and the search results were screened to selected high-quality studies for this meta-analysis. Methodological quality of the enrolled studies was evaluated by quality evaluation of diagnostic accuracy studies (QUADAS). Summary odds ratios (ORs) and its corresponding 95% confidence interval (95% CI) were calculated for DCIS versus IDC category of ADC value using Z test. Our meta-analysis contained a combined total of 1,097 subjects (928 patients with IDC and 169 patients with DCIS) from 9 relevant high-quality cohort studies. Pooled ORs demonstrated that ADC value in IDC patients was significantly lower than DCIS patients. Subgroup analysis stratified by ethnicity indicated a higher ADC value in DCIS patients compared to IDC, in Asian population, but not in Caucasians. Magnetic resonance imaging (MRI) machine type-stratified analysis revealed that the ADC value of DWI obtained from both non- General Electric Company (GE) 1.5T and GE 1.5T machines were highly reliable in the differential diagnosis of DCIS and IDC. Our meta-analysis provides evidence that ADC values in DWI accurately conveys the differences in tumor architecture between IDC and DCIS, which has high clinical value in differentiatal diagnosis of IDC and DCIS. This may lead to improved BC prediction and treatment.

Apparent diffusion coefficient measurements with diffusion-weighted imaging for differential diagnosis of soft-tissue tumor.

To evaluate the diagnostic potential of apparent diffusion coefficient (ADC) values of diffusion-weighted imaging (DWI) in distinguishing malignant and benign soft-tissue tumors. Published studies were retrieved through comprehensive search in various computerized databases. High-quality studies relevant to ADC values of DWI in differential diagnosis of soft-tissue tumors were screened using our stringent inclusion and exclusion criteria for this meta-analysis. The standard mean difference with 95% confidence interval (95% CI) was estimated. Statistical analyses were performed using the STATA statistical software (Stata Co., College Station, TX, USA). Thirteen cohort studies were finally included, and these studies provided the required information on the diagnostic value of diffusion magnetic resonance imaging in soft-tissue tumors. The 13 studies contained a combined total of 344 malignant soft tumors and 315 benign soft tumors. The results of our meta-analysis revealed that mean ADC value in patients with malignant soft-tissue tumor decreased significantly in comparison with the ADC values obtained in patients with benign soft-tissue tumor (P < 0.001). Country-stratified analysis suggested that ADC value might play a predictive role in the differential diagnosis of soft-tissue tumors in China (P = 0.007), Egypt (P < 0.001), Germany (P = 0.001), Japan (P = 0.049), and The Netherlands (P < 0.001). Our results provide strong evidence that patients diagnosed with malignant soft-tissue tumors have low ADC values of DWI compared to those with benign soft-tissue tumors. Therefore, ADC measurements with DWI may be reliable in differential diagnosis of soft-tissue tumors.

Value of 3T magnetic resonance dynamic contrast-enhanced and diffusion-weighted imaging in differential diagnosis of musculoskeletal tumors

To evaluate the value of magnetic resonance dynamic contrast-enhanced (MR-DCE) and magnetic resonance diffusion-weighted imaging (MR-DWI) in the differentiation of benign and malignant musculoskeletal tumors. Sixty-three patients with pathologically confirmed musculoskeletal tumors were examined with MR-DCE and MR-DWI. Using single shot spin echo planar imaging sequence and different b values of 400, 600, 800 and 1000 s/mm(2), we obtained the apparent diffusion coefficient (ADC) of the lesions. ADC values were measured before and after MR-DCE, with a b value of 600 s/mm(2). The 3D fast acquired multiple phase enhanced fast spoiled gradient recalled echo sequence was obtained for multi-slice of the entire lesion. The time-signal intensity curve (TIC), dynamic contrast-enhanced parameters, maximum slope of increase (MSI), positive enhancement integral, signal enhancement ratio, and time to peak (T(peak)) were also recorded. ADC showed no significant difference between benign and malignant tumors when the b value was 400, 600, 800, or 1000 s/mm(2), and it was not significantly different between benign and malignant tumors in both pre-MR-DCE and post-MR-DCE with b value of 600 s/mm(2). TIC were classified into four types type1 showed rapid progression and gradual drainage; type2 showed rapid progression but had no or slight progression; type 3 showed gradual progression; and type 4 had no or slight progression. Most lesions of type1 or type2 were malignant, whereas most lesions of type 3 or type 4 were benign. When using type1 and type 2 as the standards of malignancy, the diagnostic sensitivity and specificity was 87.23% and 50.00%, respectively. The types of TIC showed significant difference between benign and malignant musculoskeletal tumors(χ(2)=17.009,P=0.001). When using MSI 366.62 ± 174.84 as the standard of malignancy, the diagnostic sensitivity and specificity was 86.78% and 78.67%, respectively. When using T(peak)≤70s as the standard of malignancy, the diagnostic sensitivity and specificity was 82.89%and 85.78%, respectively. Positive enhancement integral and signal enhancement ratio showed no significant difference between benign and malignant musculoskeletal tumors. TIC, MSI and T(peak) of MR-DCE are valuable in differentiating benign from malignant musculoskeletal tumors. T(peak) has the highest diagnostic specificity, and TIC has the highest diagnostic sensitivity. The mean ADC value are no significant difference between benign and malignant tumors.

Use of perfusion- and diffusion-weighted imaging in differential diagnosis of acute and chronic ischemic stroke and multiple sclerosis

Objective: To investigate differences in lesions and surrounding normal appearing white matter (NAWM) by perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) in patients with acute and chronic ischemic stroke and multiple sclerosis (MS).Methods: Study subjects included 45 MS patients, 22 patients with acute ischemic stroke and 20 patients with chronic ischemic stroke. All subjects underwent T2-weighted imaging (WI), flair attenuated inversion recovery (FLAIR), DWI and dynamic contrast enhanced PWI. Apparent diffusion coefficient (ADC) and mean transit time (MTT) maps were generated and values were calculated in the acute and chronic ischemic and demyelinating lesions, and in NAWM for distances of 5, 10 and 15 mm. Fifty-three acute ischemic and 33 acute demyelinating lesions, and 775 chronic ischemic and 998 chronic demyelinating lesions, were examined. Univariate, multivariate and data mining analyses were used to examine the feasibility of a prediction model between different lesion types. Correctly and incorrectly classified lesions, true positive (TP), false positive (FP) and precision rates were calculated.Results: Patients with acute ischemic lesions presented more prolonged mean MTT values in lesions (p=0.002) and surrounding NAWM for distances of 5, 10 and 15 mm (all p<0.0001) than those with acute demyelinating lesions. In multinomial logistic regression analysis, 65 of 86 acute lesions were correctly classified (75.6%). The TP rates were 81.1% for acute ischemic lesions and 66.7% for acute demyelinating lesions. The FP rates were 33.3% for acute ischemic and 18.9% for acute demyelinating lesions. The precision was 79.6% for classification of acute ischemic lesions and 68.8% for prediction of acute demyelinating lesions. The logistic model tree decision algorithm revealed that prolonged MTT of surrounding NAWM for a distance of 15 mm (≥7459.2 ms) was the best classifier of acute ischemic versus acute demyelinating lesions. Patients with chronic ischemic lesions presented higher mean ADC (p<0.0001) and prolonged MTT (p=0.013) in lesions, and in surrounding NAWM for distances of 5, 10 and 15 mm (all p<0.0001), compared to the patients with chronic demyelinating lesions. Data mining analyses did not show reliable predictability for correctly discerning between chronic ischemic and chronic demyelinating lesions. The precision was 56.7% for classification of chronic ischemic and 58.9% for prediction of chronic demyelinating lesions.Discussion: We found prolonged MTT values in lesions and surrounding NAWM of patients with acute and chronic ischemic stroke when compared to MS patients. The use of PWI is a promising tool for differential diagnosis between acute ischemic and acute demyelinating lesions. The results of this study contribute to a better understanding of the extent of hemodynamic abnormalities in lesions and surrounding NAWM in patients with MS.

MR diffusion-weighted imaging in differential diagnosis of intracranial cystic lesions

目的 探讨MR扩散加权成像(DWI)在颅内囊性病变中的鉴别诊断价值.方法 对76例经临床及手术病理证实的颅内囊性病变患者,行常规MR、DWI及增强MR检查,其中脑脓肿19例,原发性脑胶质瘤20例,小脑血管母细胞瘤4例,脑转移瘤10例,蛛网膜囊肿7例,表皮样囊肿16例.回顾性分析颅内囊性病变的DWI信号特征,定量测定囊性变区表观扩散系数(ADC)值.结果 DWI上19例脑脓肿呈高信号;34例脑肿瘤患者中,除3例脑胶质瘤呈高信号、1例呈等信号,1例脑转移瘤呈高信号外,其余29例均呈低信号.各种病变ADC值分别为:脑脓肿(0.62±0.15)×10-3mm2/s、脑胶质瘤(2.39±0.78)×10-3mm2/s、脑血管母细胞瘤(2.68±0.40)×10-3mm2/s、脑转移瘤(2.79±0.79)×10-3mm2/s.脑脓肿与脑胶质瘤、脑血管母细胞瘤、脑转移瘤的囊变坏死区ADC值比较,差异均有统计学意义(P＜0.01);脑胶质瘤与脑血管母细胞瘤、脑转移瘤的囊变坏死区ADC值比较,差异均无统计学意义(P＞0.05).7例颅内蛛网膜囊肿的DWI呈低信号;16例表皮样囊肿DWI呈明显高信号.颅内蛛网膜囊肿和表皮样囊肿的ADC值分别为(2.96±0.36)×10-3mm2/s和(0.94±0.13)×10-3mm2/s,二者之间差异有统计学意义(P＜0.01).结论 DWI及ADC值对鉴别脑脓肿和囊性或坏死性脑肿瘤具有重要的价值,DWI表现为低信号的颅内囊性病变可除外脑脓肿。