Objective To summarize the principle and application of functional MR imaging of pancreatic carcinoma and chronic mass-forming type pancreatitis. Methods Articles about diffusion-weighted imaging (DWI), magnetic resonance spectrum imaging (MRSI) and dynamic contrast-enhanced MR imaging of pancreatic carcinoma and chronic pancreatitis were reviewed and analyzed. Results Functional MR imaging could reflected the differences in molecules diffusion, metabolism and tissue perfusion between pancreatic carcinoma and chronic pancreatitis. Conclusion As a non-invasive protocol, functional MR imaging can provide useful information in differential diagnosis between chronic mass-forming type pancreatitis and pancreatic carcinoma.
目的 探讨3D-多体素磁共振波谱（MRS）在评估脑胶质瘤手术切除程度的价值。 方法 对2011年6月－2012年4月32例脑胶质瘤患者术后行常规MRI及MRS检查，测定分析手术周边区域主要代谢产物N-乙酰天门冬氨酸（NAA）、胆碱（Cho）、肌酸（Cr）、Cho/NAA、Cho/Cr及NAA/Cr比值，对术后胶质瘤切除程度进行评价。同时通过术后病理检查结果评估肿瘤切除程度，再与MRS评估结果相比较。 结果 32例中病理评估为9例全切除，23例为大部分切除；MRS评估为11例全切除，21例为大部分切除，评估结果与术后病理评估结果差异无统计学意义（P＞0.05）。 结论 MRS可以无创评价胶质瘤切除程度，为胶质瘤预后判定及进一步治疗提供了重要的依据。
摘要:目的: 探讨磁共振波谱(MRS)对鉴别桥小脑角神经鞘瘤与脑膜瘤的价值。 方法 :对8例神经鞘瘤和8例脑膜瘤病例进行MRI平扫和增强扫描,并采用点分辨波谱序列(PRESS,TR/TE=2000/136ms)进行单体素波谱分析。从事磁共振诊断专业的医师根据肿瘤的MRI及MRS表现特征进行鉴别诊断。 结果 :尽管多数神经鞘瘤(5/8)和脑膜瘤(6/8)具有典型的MRI表现特征并仅经MRI即可得到正确鉴别,但部分病例(5/16)为不典型表现者,如脑膜瘤呈长T1长T2信号并伴有囊变,以及神经鞘瘤呈等信号、均匀强化且不伴有囊变或内听道扩大者,鉴别诊断困难。MRS显示脑膜瘤的胆碱/肌酸比值(Cho/Cr)(2.74±1.47)略高于神经鞘瘤(2.70±1.21),但差异无统计学意义。丙氨酸(Ala)在脑膜瘤中的出现率(4/8)显著高于神经鞘瘤(0/8)(Plt;0.05),谷氨酸盐/谷氨酰胺(Glx)在脑膜瘤中的出现率(5/8)也高于神经鞘瘤(2/8);而肌醇(Ins)在神经鞘瘤中的出现率(4/8)高于脑膜瘤(2/8)。结合MRS表现,在MRI上尚难鉴别的病例可被明确诊断,并与最终病理结果相符。 结论 : MRI有助于多数桥小脑角神经鞘瘤与脑膜瘤的鉴别诊断,但对不典型病例有一定局限性;MRS对不典型病例的鉴别具有重要的参考价值。Abstract: Objective: To explore the value of magnetic resonance spectroscopy (MRS) in the differentiation of neurinoma and meningioma in the cerebellopontine angle. Methods : 16 cases, including 8 cases of meningiomas and 8 cases of neurinomas, underwent MRI (plan and gadoliniumenhanced scan) and singlevoxel proton MRS (PRESS series, TR/TE=2000/136ms). MRI and MRS results were reviewed and differential diagnoses were made by professional radiologists. Results : Although most cases (11/16) were typical and clearly classified on MRI, atypical cases were also observed, such as meningioma of long T1/T2 signal intensity with small cystic foci, and neurinoma of isointensity and homogenous enhancement without cystic change or enlargement of internal acoustic meatus. The choline to creatine ratio (Cho/Cr) of meningioma (2.74±1.47) was higher than that of neurinoma (2.70±1.21), however the difference was not significant (Pgt;0.05). Alanine was observed in 4/8 meningiomas but none of neurinomas (Plt;0.05), and glutamine/glutamate was more frequently visualized in meningiomas (5/8) than in neurinomas (2/8), whilemyoinositol was more frequently observed in neurinomas (4/8) than in meningiomas (2/8). With MRS, cases difficult to differentiate were clearly and correctly classified. Conclusion : Although most CPA neurinomas and meningiomas can be diagnosed by MRI, MRS is useful for the differential diagnosis of atypical cases.
Objective To investigate the diagnostic value of proton magnetic resonance spectroscopy （1 H-MRS） on the quantification of hepatic steatosis at 3.0 T MR united.Methods Twenty-two patients who were candidated for liver surgery (living liver transplantation donor candidates, lobectomy or segmental resection for focal liver diseases, etc.) were enrolled in this study. 1 H-MRS was conducted with point resolved selective spectroscopy （PRESS） sequence, using SAGE software packages. The values of water peak (PW), lipid peak (PL) were measured, the area under water peak (AW) and lipid peak (AL), and then the relative lipid content of liver cells (RLC1, RLC2) was calculated. All subjects underwent surgical resection of liver shortly after MR scanning, fresh frozen specimens were obtained for Sudan Ⅲ staining, and staging was conducted.Results In all 22 patients, 7 patients without fatty liver, 11 patients with mild fatty liver, 4 patients with moderate or severe fatty liver. Intercomparison between different histopathological grades showed following findings: the values of PL, AL, RLC1 and RLC2 had statistical significance (Plt;0.05). The values of PL， AL， RLC1 and RLC2 were positively correlated with the proportion of fatty degenerative cells (PFDC), Plt;0.05, and the highest correlation factor was 0.771 (RLC1 to the PFDC).Conclusion 1 H-MRS can accurately quantify liver fat content and reflect the severity of hepatic steatosis. It has the potential to replace invasive liver biopsy.
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.
Objective To summarize applications and research progress of common magnetic resonance imaging lipid detection techniques in abdomen and pelvis. Method The latest domestic and foreign research literatures related to the applications and research progress of common magnetic resonance imaging lipid detection techniques in the abdomen and pelvis in recent years were collected and reviewed. Results The fat-selective spectral-spatial imaging, 1H-magnetic resonance spectroscopy (1H-MRS), and Dixon & IDEAL are three main magnetic resonance imaging lipid detection techniques, and they can estimate the fat content in the normal tissues and lesions noninvasively and longitudinally, which make the ectopic fat-induced diseases’ early diagnosis, treatment and follow-up possible. Conclusion Magnetic resonance imaging lipid detection techniques have obvious clinical values in quantitative measurement of fat content, and each method gets its own advantage, especially modified Dixon, which is more convenient and accurate and shows an enormous potential in clinical practice.
ObjectiveTo explore the application value of MRS combined with VEEG on the surgical treatment of temporal lobe epilepsy. MethodsThere were 31 males and 20 females, age between 4 and 62 years.Their illness duration ranged from 4 to 10 years.The clinical manifestations showed complex partial seizure in 10 cases, secondary generalized seizure in 12 and generalized tonic-clonic seizure in 29. Based on their results of clinical manifestations, MRS and VEEG results, all the patients underwent anterior temporal lobectomy(including the most parts of the hippocampus and amydala). ResultsThe follow-up of 1~3 years after the operation showed seizure free in 36 cases(Engle Ⅰ), and significant improvement in 11(Engle Ⅱ), no improvement in 4 cases(Engle Ⅳ). The overall effective rate was 92.16%. ConclusionsMRS combined with VEEG has significant localization value for temporal lobe epilepsy. The prognosis of postoperative result is quiet good to the patient of typical temporal lobe epilepsy after anterior temporal lobectomy.
ObjectiveTo investigate the feasibility of proton magnetic resonance spectroscopy (1H-MRS) imaging, by which to quantitatively analyze liver fat content for therapeutic evaluation of fatty liver at 3.0 T MRI. MethodsTwenty-six patients who diagnosed with fatty liver were examined with proton MRS at Siemens Trio Tim 3.0 T MRI before treatment and 3, 6 months after treatment, respectively. The water peak, fat peak, water peak area, and fat peak area were detected, and the relative lipid content 1 (RLC1) and relative lipid content 2 (RLC2)were calculated. Fatty liver index (FLI) was referred to the standard which was calculated from triglycerides (TG), gammaglutamyl-transferase (GGT), waist circumference, and body mass index. ResultsThere were significantly different differences of RLC1 and RLC2 among before treatment and 3, 6 months after treatment (Plt;0.05). Compared with before treatment, the RLC1 and RLC2 values significantly decreased on month 3 or 6 after treatment (Plt;0.05). There were positive correlation between RLC1 or RLC2 and FLI (r=0.476, Plt;0.00; r=0.475, Plt;0.001). The intraclass correlation coefficient was more than 0.75 before treatment, the repeatability was better. ConclusionsProton MRS can quantitatively measure liver fat content. It can be reliably used for dynamic monitoring the therapeutic effects for fatty liver. Proton MRS is accurate, and has a good clinical application in dynamically monitoring the progression of fatty liver and evaluating the therapeutic effects of various treatments.