ObjectiveTo evaluate the values of diffusion weighted imaging (DWI) sequence in the diagnosis of node metastases in breast cancer by meta-analysis. MethodsThe articles concerning the diagnosis of node metastases by using DWI until September 2016 were searched in databases including The Cochrane Library, PubMed, EMbase, Web of Science, CBM, VIP, WanFang Data and CNKI. Two reviewers independently screened literature, extracted data, and assessed the risk of bias of included studies by using the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies-2) tool. Then, meta-analysis was performed by using Stata 12.0 software. The pooled weighted sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated, the summary receiver operating characteristic curve (SROC) was drawn and the area under the curve was calculated. ResultsA total of 21 articles were included, involving 25 studies. The results of meta-analysis showed that, the pooled sensitivity, specificity, DOR and area under SROC curve of DWI for diagnosing node metastases were 0.85 (95%CI 0.80 to 0.89), 0.83 (95%CI 0.78 to 0.87), 4.99 (95%CI 3.74 to 6.67), 0.18 (95%CI 0.13 to 0.24), 3.32 (95%CI 2.82 to 3.82), and 0.91 (95%CI 0.88 to 0.93), respectively. The results of subgroup analysis showed that DWI had better Spe in b value=750-1 000 than b value=400-600; The 1.5T DWI had better Sen and Spe in diagnosing node metastases compared with 1.5T DWI. ConclusionDWI has more diagnostic efficiency for assessing lymph node metastases, especially in b value=750-1 000 and 1.5T field MR syetem. Due to limited quantity and quality of the included studies, more high-quality studies are required to verify the above conclusion.
ObjectiveTo explore the differences in the detection of vigabatrin-associated brain abnormalities on MRI by different MRI sequences, so as to further guide the clinical understanding of VABAM and improve the appropriate imaging sequences. MethodsA total of 353 patients with infantile spasm or epileptic spasm who were admitted to the Epilepsy Center of Yuquan Hospital of Tsinghua University from January 2020 to January 2023 were retrospectively included. MRI was performed in 131 cases, including 3D T1, T2, T1- fluid-attenuated inversion recovery sequence (FLAIR) images, DWI and ADC sequences, of which 65 cases taking VGB. We aim to evaluate the detection of vigabatrin-associated brain abnormalities on MRI by different MRI sequences in these children. Results Among the 65 patients, VABAM was detected in 23 cases, the detection rate was 35.4%. The average dosage of vigabatrin was 100.73±35.54 mg/(kg·d). The positive detection rates of VABAM were 95.7% in DWI sequence, 26.1% in ADC sequence, 21.3% in FLAIR sequence, 4.3% in T2 sequence and 0 in T1 sequence. The detection rate of ADC sequence was significantly different from DWI sequence and T1 sequence, but not from T2 sequence and FLAIR group. ConclusionDWI sequence has irreplaceable advantages in the detection rate of VABAM. Therefore, for patients with infantile spasm and epileptic spasm who take vigabatrin, we should try our best to add DWI sequence scanning to improve the positive detection rate and avoid clinical symptoms, so as to avoid further brain damage.
ObjectiveTo investigate the value of diffusion weighted imaging (DWI) combined with three-dimensional volumetric interpolated breath-hold examination (3D-VIBE) in evaluating metastatic lymph nodes secondary to hilar cholangiocarcinoma. MethodsFrom July 2009 to March 2011, DWI examination was performed in 37 patients with hilar cholangiocarcinoma, which was compared with 3D-VIBE sequences. The morphological characteristics and distribution were analyzed for metastatic and nonmetastatic lymph nodes. Signal intensity (SI) was measured on DWI images and apparent diffusion coefficient (ADC) was calculated for each lymph node. The SI of lymph nodes (SILN） and liver (SIliver) were also measured and the ratio of SI was calculated. The ADC and the ratio of SI were compared between metastatic and nonmetastatic lymph nodes. ResultsThere were fifty-nine groups of lymph nodes in 37 patients with hilar cholangiocarcinoma, fifty-one groups were revealed in both DWI and 3D-VIBE sequences, and eight groups were only demonstrated in one sequence (P=0.070). The short diameters were (1.05±0.42) cm and (0.78±0.22) cm on 3D-VIBE images for metastatic and nonmetastatic lymph nodes, respectively (P=0.030). The ADC value in metastatic lymph nodes was (1.64±0.3)×10-3 mm2/s, which was significantly lower than that in nonmetastatic lymph nodes 〔(2.28±0.79)×10-3 mm2/s〕 on DWI images (P=0.033). There were no significant differences in SILN/SIliver between metastatic and nonmetastatic lymph nodes on images of portal venous phase and 3 min delayed contrast-enhanced phase. ConclusionsDifferences of ADC and short diameter can provide valuable information to differentiate metastatic lymph nodes with nonmetastatic lymph nodes. When combined with 3D-VIBE sequence, DWI is more effective in evaluating metastatic lymph nodes secondary to hilar cholangiocarcinoma.
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.
ObjectiveTo discuss the evaluation of clinical grading for neonates with hypoxic-ischemic encephalopathy (HIE) by diffusion weighted imaging (DWI). MethodsWe retrospectively analyzed the DWI findings of 39 neonates with HIE diagnosed by clinical criteria from December 2009 to July 2013. Abnormal signals were observed for 23 neonates (59%). These neonates were divided into three groups (group A, B and C) according to the shape and range of abnormal signals. Then Kappa test was performed between groups of different clinical grading (light, medium, severe). ResultsFor groups arranged based on abnormal signals and clinical grading, the Kappa value of the consistency test was 0.797 (P < 0.001). ConclusionsDWI negativity cannot exclude the existence of HIE. However, when abnormal signals occur, we can infer the severity in neonates with HIE according to the shape and range of abnormal signals by DWI.
Objective To review the examination techniques and the current research progress of the magnetic resonance diffusion weighted-imaging (DWI) used in liver. Methods The recent and relevant literatures about the principles and the current study situation of liver DWI were scrutinized and analyzed retrospectively. In addition, the existing problems of liver DWI were discussed. Results DWI could demonstrate the normal and abnormal structure and function through measuring the diffusion motions of water molecule in the liver. With the improving technology and better understanding of diffusion dynamics, DWI has been used for the diagnosis and differential diagnosis for hepatic diseases. Conclusion DWI as a non-invasive examine method, may provide valuable functional information for clinical diagnosis and treatment.
ObjectiveTo analyze findings of 3.0 T diffusion weighted magnetic resonance (MR) in hepatic alveolar echinococcosis and evaluate potential role of apparent diffusion coefficients (ADC) in hepatic alveolar echinococcosis. MethodsThe clinical data of 26 patients with hepatic alveolar echinococcosis from November 2013 to January 2015 in this hospital were analyzed retrospectively. Hepatic MR scannings with diffusion weighted imaging (DWI) sequences (b-value=0, 600, 1 000, and 1 200 s/mm2) were performed in 26 patients with hepatic alveolar echinococcosis. The data of all the patients were stored to the PACS. The lesion features including type, size, distribution, location, and calcification (on the CT) were assessed by two deputy radiologists. TheADCvalues of marginal area, centre area, surrounding area of liver parenchyma tissue were measured at different b values (0, 600, 1 000, and 1 200 s/mm2) and compared. Results①There were 26 patients with a total of 29 lesions, of which involved multiple liver segments, 21 (72%) lesions located in the right lobe, 4 lesions involved simultaneously the left and right lobes. Twenty-four lesions invaded the hepatic vein or portal vein, 20 lesions invaded the intrahepatic bile duct, 10 lesions invaded the right adrenal gland. Seven patients occurred hilar and retroperitoneal lymph nodes metastases, 5 patients occurred pulmonary metastasis, 3 patients occurred brain metastasis, while 3 patients occurred lung and brain metastases simultaneously. ②There were 20 liquefied necrotic lesions, of which 5 lesions marginal area had multiple small round cysts in T2WI, 15 were only solid and without small cyst; The DWI of the centre area in 12 lesions showed a high signal, 8 lesions showed a low signal. There were 9 solid lesions, of which 2 lesions marginal area had multiple small round cysts in T2WI, 7 lesions marginal area were only solid and without cyst in T2WI. The DWI of the solid lesions showed a low signal, there was a "ring" high signal in the edge of lesions. ③At the same b value, theADCvalue of the centre area in the liquefied necrosis lesions were significantly higher than that in the solid lesions (P<0.01). At different b values, theADCvalue of the surrounding liver parenchyma tissue was significantly lower than that of the marginal area (P<0.01) and the centre area (P<0.01) in the liquefied necrosis lesions; theADCvalue of the centre area was significantly higher than that of the marginal area or surrounding liver parenchyma tissue (P<0.05, P<0.01) in the solid lesions. ConclusionsDWI could clearly distinguish structure and composition of hepatic alveolar echinococcosis and has a higher value in distinguishing from other liver dieases. The averageADCvalue of centre area in liquefied necrotic lesions is higher than that in solid lesions.
This study aims to detect early changes of kidney in patients with primary hypertension by 3.0 T functional magnetic resonance imaging (fMRI). 26 patients with primary hypertension (hypertension group) and 33 healthy volunteers (control group) underwent conventional and functional magnetic resonance scans, which included blood oxygen level-dependent (BOLD) MRI, diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI). We measured renal cortical thickness (CT), parenchymal thickness (PT), and functional values of renal cortex and medulla including R2* value, apparent diffusion coefficient (ADC) value and fractional anisotropy (FA) value in each group, and then calculated the cortical/parenchymal thickness ratio (CPR). Compared with those in the control group, CT and CPR in hypertension group were larger (P<0.01), cortical and medullar R2* values increased (P<0.01) whereas medullar FA values decreased (P<0.05). It could be well concluded that noninvasive 3.0 T functional MRI would have important clinical significance in identifying early abnormalities of kidney in hypertension patients.