To solve the problem that the method based on tumor morphology or overall average parameters of tumor cannot conduct the early evaluation of tumor treatment response, we proposed a voxel-wise method. The voxel-wise method uses the method combining rigid and elastic registration algorithm to align the tumor area before and after treatment on the images which are acquired by the dynamic contrast enhanced magnetic resonance imaging (DCE-MRI). We calculated voxel-wise volume transport constant (Ktrans) using pharmacokinetic model, and designed a threshold d to get the volume fraction of voxels which Ktrans increased significantly (F+), Ktrans decreased significantly (F-) or had no significant change (F0). Linear regression analysis was performed to get the correlation between volume fractions and pathological tumor cell necrosis rate (TCNR). We then determined the ability of volume fractions to evaluate treatment response at early stage by receiver operating characteristic (ROC) curve analysis. We performed experiments on 10 patients with soft tissue sarcomas. The results indicated that F- had significant negative correlation with TCNR (R2=0.832 8, P=0.0002), F0 has significant positively correlation with TCNR (R2=0.788 4, P=0.0006). In addition, F-(AUC=0.905,P=0.053), F0 (AUC=0.857,P=0.087) had a good ability in early tumor treatment response evaluation. Therefore, F- and F0 can be used as effective imaging biomarkers for early evaluation of tumor treatment.
Objective To explore the differential diagnosis significance of 3.0T MRI united-sequences examination in the diagnosis of benign and malignant breast lesions. Methods A total of 67 breast lesions of 59 patients were collected prospectively, which be treated at the Sichuan Provincial People’s Hospital during July 2015 to January 2017. All patients were underwent bilateral breast 3.0T magnetic resonance plain scan, diffusion weighted imaging, and dynamic enhanced scan successively before surgical operation. Analysis of morphological features of the benign and malignant breast lesions, the time-signal intensity curve (TIC), the apparent diffusion coefficient (ADC), and the combination diagnosis of them were performed. Results Of all 59 patients, 67 lesions were confirmed by histopathology, including 18 benign lesions and 49 malignant lesions. The morphological features (including margin, shape, border, and evenness), the types of TIC of dynamic enhancement, and ADC value between the benign lesions and malignant lesions were statistically significant (P<0.05). The sensitivity and specificity of Fischer scoring system was 89.8% (44/49) and 61.1% (11/18) respectively. The sensitivity and specificity of TIC types was 83.7% (41/49) and 77.8% (14/18) respectively. The diagnostic threshold of ADC value was 1.012×10–3 mm2/s, with the sensitivity and specificity for the diagnosis was 91.8% (45/49) and 83.3% (15/18) respectively. The sensitivity and specificity of the combination of Fischer scoring system and TIC type for diagnosis between benign and malignant breast lesions was 95.9% (47/49) and 72.2% (13/18) respectively. The sensitivity and specificity of the combination of Fischer scoring system, TIC type, and ADC value for benign and malignant breast lesions was 98.0% (48/49) and 83.3% (15/18) respectively. Conclusion The combination of Fischer scoring system, TIC type, and diffusion-weighted imaging for the differential diagnosis between benign lesions and malignant lesions was more effective than single imaging method.
ObjectiveTo study the value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in predicting and evaluating the efficacy of neoadjuvant chemoradiotherapy (NCRT) in the middle-low locally advanced rectal cancer (LARC).MethodsThe patients were included prospectively who were clinically diagnosed as the LARC and were scheduled to undergo the NCRT and total mesorectal excision (TME) in the Sichuan Provincial People’s Hospital from February 2018 to November 2019. The routine MRI and DCE-MRI were performed before and after the NCRT, then the TME was performed. According to the score of tumor regression grade (TRG), the patients with TGR score of 0, 1 or 2 were classified as the response to NCRT group, and those with TRG score of 3 were classified as the non-response to NCRT group; in addition, the patients with TGR score of 0 or 1 were classified as the good-response group, with TRG score of 2 or 3 were classified as the poor-response group. The differences of quantitative perfusion parameters of DCE-MRI between two groups were compared, including the volume transfer constant (Ktrans), flux rate constant (Kep), and extravascular extracellular volume fraction (Ve) and the change rates of these parameters (ΔKtrans, ΔKep, and ΔVe).ResultsForty-one patients who met the inclusion criteria were included in this study, including 27 cases in the response to NCRT group and 14 cases in the non-response to NCRT group; 11 cases in the the good-response group and 30 cases in the poor-response group. ① The values of Ktrans before the NCRT and the ΔKtrans in the response to NCRT group were higher than those in the non-response to NCRT (P<0.05), while the other indexes had no significant differences between these two groups (P>0.05). The area under the receiver operating characteristic curve (AUCs) of Ktrans and ΔKtrans in predicting the efficacy of NCRT were 0.954 and 0.709, respectively. When the optimal thresholds of Ktrans and ΔKtrans were 0.122/min and –24.2%, the specificity and sensitivity were 85.7%, 96.3% and 100%, 51.7%, respectively. ② The Ktrans value in the good-response group was higher before NCRT and which was lower after NCRT as compared with the poor-response group (P<0.05). The absolute value of the the ΔKtrans and ΔKep in the good-response group were higher than those in the poor-response group (P<0.05). The other indexes had no significant differences between these two groups (P>0.05). The AUC of Ktrans before NCRT in predicting the efficacy of NCRT was 0.953. When the optimal thresholds of Ktrans before NCRT was 0.158 /min, the specificity and sensitivity were 88.7% and 90.9%, respectively. The AUC of ΔKtrans in predicting the efficacy of NCRT was higher than that of the ΔKep (0.952 versus 0.764, Z=2.063, P=0.039). When the optimal threshold of ΔKtrans was –38.8%, the specificity and sensitivity were 76.7% and 100%, respectively.ConclusionsDCE-MRI can predict and evaluate the effect of NCRT in patients with middle-low LARC, especially Ktrans and ΔKtrans (change rate before and after NCRT) have a high diagnostic efficiency.
ObjectiveTo compare the effectiveness of magnetic resonance spectroscopy (MRS) and Dynamic Contrast-enhancement (DCE-MRI) with 1.5 T MR scanner in diagnosing prostate cancer. MethodsFrom April 2011 to December 2012, based on the results of biopsy, we measured 216 regions of interest (ROIs) in images of MRS and DCE-MRI, comprised of 131 ROIs from cancer zone and 85 ROIs from non-cancer zone. The data were analyzed with statistical methods, including receiver operating characteristic (ROC) curve. ResultsThere were significant differences between the malignant group and the benign group (P<0.05) in Cit integral, Cho integral, CC/Cit ratio, the type of time-signal intensity curve, initial value, enhancement rate and ratio of enhancement. According to ROC curve, the area under curve (AUC) of CC/Cit and enhancement rate was 0.853 and 0.719, respectively. AUC of time to peak, time difference, enhancement rate and Cit integral was lower than 0.400. The optimal operating point (OOP) of CC/Cit was 0.775, with a specificity of 0.85 and a sensitivity of 0.79, and the AUC was 0.853. The OOP of the ratio of enhancement was 60.89, with a specificity of 0.66 and a sensitivity of 0.71, and the AUC was 0.719. ConclusionMRS is more sensitive and specific than DCE-MRI to diagnose prostate cancer when an 1.5 T MR scanner is used. On the other hand, MRS is susceptible to interference, but DCE-MRI can make up for these deficiencies.
ObjectiveTo compare the effectiveness of T2 weighted image (T2WI) and some compounded MRI techniques, including T2WI combined with magnetic resonance spectroscopy (T2WI+MRS), T2WI combined with diffusion weighted imaging (T2WI+DWI) and T2WI combined with dynamic contrast-enhancement [T2WI+(DCE-MRI)] respectively, with 1.5 T MR scanner in diagnosing prostate cancer through a blinding method. MethodsBetween March 2011 and April 2013, two observers diagnosed 59 cases with a blinding method. The research direction of radiologist A was to diagnose prostate cancer. The observers diagnosed and scored the cases with T2WI, T2WI+(DCE-MRI), T2WI+MRS, T2WI+DWI and compositive method respectively. The data were statistically analyzed with receiver operating characteristic (ROC) curve. ResultsAccording to the ROC curve, both observers got the sequence of area under curve (AUC) as T2WI+DWI > T2WI+(DCE-MRI) > T2WI+MRS > T2WI. On the basis of the result from observer A, the AUC from each technique was similar. The AUC of T2+DWI was slightly bigger than others. The specificity of single T2WI was the lowest; the sensitivity of T2WI was slightly higher. The AUC of the compositive method was marginally larger than T2WI+DWI. According to the result from observer B, the AUC of T2WI+DWI was obviously larger than the others. The AUC of single T2WI was much smaller than the other techniques. The single T2WI method had the lowest sensitivity and the highest specificity. The AUC of T2WI+DWI was slightly larger than the compositive method. The AUC of T2WI+(DCE-MRI), T2WI+MRS, single T2WI methods from observer A was obviously higher than those from the score of observer B. The AUC of T2WI+DWI from the two observers was similar. ConclusionThe method of combined T2WI and functional imaging sequences can improve the diagnosing specificity when a 1.5 T MR scanner is used. T2WI+DWI is the best method in diagnosing prostate cancer with least influence from the experience of observers in this research. The compositive method can improve the diagnosis of prostate cancer effectively, but when there are contradictions between different methods, the T2WI+DWI should be considered as a key factor.
【摘要】 目的 探讨MRI动态增强扫描在子宫内膜癌手术前诊断中的价值。 方法 回顾分析2008年2月-2010年3月38例经手术病理证实为子宫内膜癌患者的动态增强MRI检查资料，判断内膜癌子宫肌层和宫颈浸润情况，与病理结果对照，计算T2WI及动态增强序列诊断肌层及宫颈浸润的敏感度、特异度、准确度等，分析两种序列诊断准确度有无差异；计算内膜癌组织与子宫肌层在动态增强各期的对比信噪比，并分析其在各期间有无差异。 结果 动态增强序列诊断内膜癌肌层和宫颈受侵的敏感度、特异度、阳性预测值、阴性预测值分别为96.8%、85.7%、96.8%、85.7%和85.7%、91.7%、85.7%、91.7%；动态增强序列诊断内膜癌深肌层浸润的准确度为94.7%，显著高于T2WI诊断深肌层浸润的准确度78.9%（Plt;0.05）；平衡期内膜癌组织与子宫肌层的对比信噪比显著高于动脉期和静脉期（Plt;0.01）。 结论 MRI动态增强扫描能够在手术前准确的判断内膜癌肌层及宫颈浸润，有助于子宫内膜癌治疗方式的选择。【Abstract】 Objective To investigate the role of dynamic-enhanced MRI in the diagnosis of endometrial carcinoma. Methods Thirty-eight patients with endometrial carcinoma confirmed by surgicopathology undergone dynamic-enhanced MRI scans were analyzed retrospectively. The invasion in myometrium and uterine cervix were analyzed. The tumor and myometrium contrast-to-noise ratios during different phases of dynamic imaging were calculated. MR imaging findings were compared with pathologic findings. Sensitivity, specificity, diagnostic accuracy, positive and negative predictive values of MR imaging in depicting myometrial and cervical infiltration were calculated. Results Respective sensitivity, specificity, and positive and negative predictive values in assessing myometrial infiltration were 968%,85.7%,96.8%,85.7%;those for cervical infiltration were 85.7%,91.7%,85.7%,91.7%,respectively. The diagnostic accuracy (94.7%) of dynamic imaging in depicting deep myometrial infiltration were significantly higher than that of T2WI (78.9%) (Plt;0.05).There was a significant improvement in tumor and myometrium contrast-to-noise ratios during the equilibrium phase compared with the arterial and venous phases (Plt;0.01). Conclusion Dynamic-enhanced MRI is highly accurate in preoperative diagnosis of endometrial carcinoma, which will benefit for the treat of endometrial carcinoma.
ObjectiveTo explore the value of magnetic resonance diffusion weighted imaging (DWI) in preoperative Bismuth-Corlette classification of hilar cholangiocarcinoma (HCCA). MethodsA total of 53 HCCA patients confirmed by postoperative pathology were retrospectively included. The accuracy of two sequence combinations, namely dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) + magnetic resonance cholangiopancreatography (MRCP) and DCE-MRI + MRCP + DWI, in evaluating the longitudinally involved bile duct segments and Bismuth-Corlette classification of HCCA was compared. Additionally, the correlation between apparent diffusion coefficient (ADC) values and tumor Bismuth-Corlette classification as well as degree of differentiation was analyzed. ResultsThere were 318 bile duct segments in 53 HCCA patients. The accuracy rate of DCE-MRI + MRCP was 93.7% (298/318), the sensitivity was 91.5% (161/176), and the specificity was 96.5% (137/142). The accuracy rate of DCE-MRI + MRCP + DWI was 96.5% (307/318), the sensitivity was 96.0% (169/176), and the specificity was 97.2% (138/142). Receiver operating characteristic (ROC) curve analysis showed that the area under the ROC curve (AUC) of DCE-MRI + MRCP + DWI was 0.966 [95%CI (0.940, 0.983), P＜0.001], and its diagnostic efficacy was superior to that of DCE-MRI + MRCP [AUC=0.940, 95%CI (0.908, 0.963), P＜0.001]. The DeLong test indicated a statistically significant difference in AUC between the two sequences (Z=2.633, P＜0.01). The accuracy rates of preoperative Bismuth-Corlette classification of HCCA evaluated by DCE-MRI + MRCP and DCE-MRI + MRCP + DWI were 86.8% (46/53) and 94.3% (50/53), respectively. After adding the DWI sequence, the consistency between Bismuth-Corlette classification results and surgical pathological classification results (Kappa=0.922, P<0.001) was higher than that of DCE-MRI + MRCP sequence (Kappa=0.820, P<0.001), with a statistically significant difference (χ2=160.370, P<0.001). In addition, the ADC value of HCCA was negatively correlated with tumordegree of differentiation (rs=–0.524, P<0.001), but had no significant correlation with its Bismuth-Corlette classification (rs=–0.058, P=0.682). ConclusionsDCE-MRI + MRCP + DWI sequence can effectively improve the accuracy in preoperative evaluation of the involvement of bile duct segments and Bismuth-Corlette classification of HCCA, which provides guidance for precise preoperative surgical planning in clinical practice. In addition, the ADC value can provide additional information required for non-invasive preoperative prediction of the prognosis of HCCA patients.
Objective To investigate the application of the dynamic contrast enhanced MRI (DCE-MRI ) combined with magnetic resonance spectroscopy (MRS) in the diagnosis of prostate cancer. Method A total of 60 patients with prostate cancer and 60 patients with benign prostatic hyperplasia diagnoses in Sichuan Cancer Hospital from January 2011 to January 2014 were included as prostate cancer group and proliferative group respectively. Sixty healthy individuals during the same period were included as the control group. We used Siemens Avanto 1.5 T high field superconducting MRI for DCE-MRI scan and MRS scan. After the MRS scan was finished, we used the workstation spectroscopy tab spectral analysis. Eventually we got the crest lines of prostate metabolites choline (Cho), creatine (Cr) and citrate (Cit). Then we calculated Cho/Cit, (Cho+Cr)/Cit and their average. Results Comparing the signal value in 21 seconds, 1 minute, 2 minutes of DCE-MRI, the differences among the three groups were statistically significant (P<0.05). Comparing the results of spectral analysis, the differences among the three groups were statistically significant (P<0.05). The sensitivity was 89.67%, the specificity was 95.45% and the accuracy was 94.34% when using DCE-MRI combined with MRS. Conclusion DCE-MRI combined with MRS greatly improves the sensitivity, specificity and accuracy of the diagnosis of prostate cancer; it has a great application value in the diagnosis of prostate cancer.