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Objective To explore the value of apparent diffusion coefficient(ADC)values of magnetic resonance diffusion weighted imaging(MR-DWI)in predicting the prognosis of primary hepatocellular carcinoma(HCC)treated by radiofrequency ablation(RFA).Methods A prospective study was conducted on 178 patients with HCC.All patients were treated with RFA and followed up for 1 year after treatment.MR-DWI was performed before RFA and one month after RFA,and the changes in ADC value were calculated.These changes of the cancer in patients with different clinicopathological parameters were compared.The factors affecting the prognosis of HCC patients with RFA,and the value of ADC value changes in predicting the prognosis were analyzed.Results The changes of ADC values in patients with high alpha-fetoprotein,Barcelona clinic live cancer(BCLC)stage C,and poorly differentiated were lower than those in patients with low alpha-fetoprotein,BCLC stage B,and moderately well-differentiated(P<0.05).Six cases were lost to follow-up,and 120 of the remaining 172 patients survived.Cox regression analysis showed that the changes in ADC value,tumor stage and degree of differentiation were independent factors affecting the prognosis of HCC patients with RFA(P<0.05).Receiver operating characteristic(ROC)curve results showed that the best cut-off point,sensitivity,specificity and area under the curve(AUC)of ADC value change in predicting the prognosis of HCC patients with RFA were 0.42×10-3 mm2/s,75.00%,78.33%and 0.801.There were 16 deaths in the high change group of ADC value(>0.42)and 36 deaths in the low change group(≤0.42).The overall survival curve of the high change group of ADC value was better than that of the low change group(P<0.05).Conclusion The change in ADC value of MR-DWI sequence before and after short-term RFA treatment in HCC patients is related to the patient's pathology and prognosis,with a good predictive effect.The low change in ADC value has a higher risk of poor prognosis.
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Objective To explore the clinical value of magnetic resonance diffusion-weighted imaging ( MR-DWI ) in the early diagnosis of cervical lymph node recurrence after radiotherapy of nasopharyngeal carcinoma, aiming to provide reference for targeted diagnosis and treatment of these patients. Methods The MR-DWI features of 17 patients with recurrent cervical lymph nodes after radiotherapy from 2005 to 2016 were retrospectively analyzed. The results of diagnosis and treatment after lymph node recurrence were summarized. Results The recurrent lymph nodes of 17 patients showed a high signal or mixed signal on MR-DWI images. The sensitivity of MR-DWI and T2WI fat suppression sequence was 100% and 60%. Positron emission tomography-computed tomography ( PET-CT) or biopsy was performed to validate the diagnosis in patients with highly suspected single cervical recurrence. Besides, surgical treatment yielded better clinical prognosis. Conclusions MR-DWI is highly sensitive to recurrent cervical lymph nodes of nasopharyngeal carcinoma after radiotherapy, especially for the small lymph nodes of 5-10 mm in diameter, which are easily ignored. PET-CT examination should be performed, the nature of the lymph nodes should be confirmed by multi-modality imaging diagnosis, and timely operation has important clinical significance in improving the therapeutic effect and quality of life for patients with cervical lymphnode recurrence.
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Objective To discuss the clinical value of magnetic resonance diffusion-weighted imaging (MR-DWI) in distinguishing tumor remnants from tumor necrosis of pancreatic carcinoma after cryoablation treatment.Methods Conventional MRI T1WI,T2WI scan,DWI sequence and dynamic enhanced MRI scan were performed in 26 patients with pancreatic carcinoma who were received cryoablation treatment.The changes in MRI signals after cryoablation treatment were recorded.The apparent diffusion coefficient (ADC) values of the normal pancreas,preoperative tumor tissue,postoperative remnants and necrosis tissue were calculated,and the results were compared.The correlation between the ADC values and the size of the tumor was evaluated,and the differences in ADC values among the tumors that had different diameter,location and staging were statistically analyzed.Results Of the 26 patients,complete necrosis of tumor was obtained in 16.The necrotic tumor tissue displayed low-signal on T1WI,high-signal on T2WI and low-signal on DWI,with no enhancement on dynamic enhanced imaging.Active residual tumor tissue was detected in 9 patients,among them the residual tumor diameter ＞5 cm was seen in 7 patients;the residual rate was 34.6％.ADC values of the following tissue,from low to high in order,were preoperative pancreatic tumor tissue (1.022± 0.126)x10-3 mm2/s,postoperative residual tumor tissue (1.130±0.155)x10-3 mm2/s,normal pancreatic tissue (1.924±-0.124)×10-3 mm2/s and postoperative necrosis tissue (2.312-±0.214)×10-3 mm2/s.No statistically significant difference in ADC values existed between preoperative pancreatic tumor tissue and postoperative residual tumor tissue (P=0.452),while statistically significant difference in ADC values existed between normal pancreatic tissue and postoperative necrosis tissue (P＜0.001).The ADC values of pancreatic tumor tissue bore a negative correlation with the tumor size (R=-0.43,P=0.027 2),while the ADC values lacked the relationship to the tumor location as well as to the tumor staging (P=0.738 8 and P=0.089 5 respectively).Conclusion MR-DWI can effectively distinguish the residual tumor tissue from the necrotic tumor tissue of pancreatic carcinoma after cryoablation treatment,which provides reliable basis for further clinical diagnosis and treatment.
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Objective To determine the value of the apparent diffusion coefficient (ADC) of magnetic resonance diffusion-weighted imaging (MRDWI) combined with squamous cell carcinoma antigen (SCC) and carcinoembryonic antigen (CEA) in the evaluation of the efficacy and prognosis of concurrent chemoradiotherapy for cervical carcinoma.Methods A total of 80 patients with cervical squamous cell carcinoma confirmed by histology or cytology in our hospital from 2013 to 2016 were included in this study.Of the 80 patients, 39 were FIGO stage ⅡB, 7 were stage ⅢA, 26 were stage ⅢB, and 8 were stage ⅠVA.MRDWI examination and SCC and CEA measurements were first performed for the patients following group assignment, and the patients were then given extrapelvic radiotherapy (45-50 Gy)+platinum-based chemotherapy plus brachytherapy (20-25 Gy) based on their conditions.MRDWI, SCC, and CEA examinations were performed again after treatment to determine the changes in ADC, SCC, and CEA.In addition, ADC, SCC, and CEA were examined in the middle stage of treatment for 40 patients.Data were analyzed using the paired t-test or ANOVA.Results The overall response rate of the 80 patients after concurrent chemoradiotherapy was 100%.No disease progression was identified in any of the patients until the end of treatment, and the overall survival time of the patients was all above 6 months.Serum SCC and CEA were reduced after treatment (P=0.000,0.000), whereas the ADC value was increased after treatment (P=0.000).The increase in ACD following the decreases in SCC and CEA after treatment (P=0.000, 0.000) was indicative of increased efficacy of the concurrent chemotherapy and radiotherapy.Conclusions MRDWI combined with SCC and CEA is highly reliable for the evaluation of efficacy and prognosis of concurrent chemoradiotherapy for cervical cancer.
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Transcatheter arterial chemoembolization (TACE) has already been a mature and an effective treatment for advanced hepatocellular carcinoma (HCC).Clinically,it is very important to quickly and accurately evaluate the postoperative curative effect with minimally invasive technique so as to determine the next treatment options.At present,postoperative conventional CT and MRI are the main means to assess the curative effect of TACE,but it is a pity that after the treatment the functional changes of the tumor occur earlier than the morphological changes.In recent years,functional MRI techniques,such as diffusionweighted imaging (DWI),multi-b value DWI,dynamic contrast-enhanced (DCE) imaging,etc.have been more and more used for quantitative evaluation of the diffusion of water molecules and the blood microcirculation perfusion within the tumor tissue,and some progresses have been achieved in the evaluation of curative efficacy for tumor.This paper aims to make a comprehensive review about the research progress of the above mentioned functional imaging methods as well as their current application status in evaluation of the curative effect of TACE.
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Objective To study the value of magnetic resonance diffusion weighted imaging (DWI)and dynamic enhanced imaging (DCE)in endometrial carcinoma staging.Methods 200 cases with endometrial carcinoma were selected,DWI and DCE were given before operation.The diagnostic value of two kinds of examination methods for the diagnosis of endometrial carcinoma in general and basic level was compared.Results The overall accuracy of muscle invasion of magnetic resonance DWI was 91.5%(183 /200),which was significantly higher than 77.5%(155 /200)of magnetic resonance DCE,the difference was statistically significant (χ2 =11.231,P <0.05 ).The accuracy,sensitivity and positive predictive value of the magnetic resonance DWI superficial and deep muscular layer were significantly higher than those of the magnetic resonance DCE (χ2 =9.283,8.231,9.021,8.927,8.142, 9.405,all P <0.05).Compared with pathological results,Kappa value of magnetic resonance DWI was 0.807,Kappa value of magnetic resonance DCE was 0.587.Conclusion Magnetic resonance DWI compared with magnetic reso-nance DCE,the accuracy and sensitivity of the infiltration of endometrial carcinoma was higher.
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Objective Magnetic resonance imaging ( MRI ) was used in patients with cerebral ischemic penumbra,to analyze the coincidence of MRI findings and the patients'condition,thus to explore the clinical value of diffusion-weighted MRI imaging in the diagnosis of cerebral infarction .Methods 104 patients with primary cerebral infarction were selected as the research subjects , they received the basic diffusion-weighted MRI imaging and diffusion-weighted magnetic resonance imaging ( DWI) scans to analyze the apparent diffusion coefficient and apparent diffusion coefficient ratios of the central area of the sick side lesion , ischemic penumbra , contralateral mirror area . Results The apparent diffusion coefficient of the central area of the lesion , contralateral mirror area , the ischemic penumbra,contralateral mirror area of ischemic penumbra were (3.783 ±1.032) ×10-4,(7.992 ±0.828) ×10 -4, (6.588 ±0.717) ×10 -4 ,(8.292 ±2.046) ×10 -4;apparent diffusion coefficient of ischemic penumbra was reduced to a certain extent ,the apparent diffusion coefficient of the central area of the lesion was reduced to a large extent ,the change was more obvious .In patients with prevalence <6 hours,the apparent diffusion coefficient ratios of the central area of the lesion,the ischemic penumbra were (43.4 ±10.3),(67.9 ±3.8); those in patients with prevalence of 6-24 hours were (50.3 ±10.5),(76.8 ±8.7); those in patients with prevalence of 24-64 hours were (57.2 ± 11.5),(86.3 ±7.4).With the prolong of sick time,the apparent diffusion coefficient ratio gradually increased ,the apparent diffusion coefficient ratio of hyper acute and acute ischemic penumbra was significantly higher than that of the central area of the lesion .Conclusion MRI combined with the application of the apparent diffusion coefficient and apparent diffusion coefficient ratio to reflect the condition of patients with cerebral infarction and predict position of ischemia penumbra have a great supporting role ,it can improve the survival rate of patients with cerebral infarction to a large extent,and provide an accurate basis for the treatment .
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Objective To investigate the feasibility of magnetic resonance diffusion-weighted intravoxel incoherent motion (DW-IVIM)imaging and its reproducibility in normal liver.Methods Thirty-five young healthy volunteers underwent liver DW-IVIM ex-amination twice on a 1 .5 Tesla Philips MR scanner.Parameter maps of D,D* and f were generated by using a manufacturer-sup-plied software.Six Region-of-interests (ROIs)(3 ROIs in left and right liver lobe,respectively)were drawn on three consecutive middle slices,respectively.The average values of D,D* and f were measured and compared between the left and right liver lobe. The reproducibility of D,D* and f measurement were assessed with Bland-Altman method.Results The values of D,D* and f of left liver lobe [D(×10-3 mm2/s):1.250±0.210,D*(×10-3 mm2/s):101.906±15.063 ,f(%):22.954±5.268]were statistically higher than those of right liver lobe[D(×10-3 mm2/s):1.039±0.124,D*(×10-3 mm2/s):100.127±20.757,f(%),18.317± 3.671](D,f,P<0.001,D*,P<0.232-0.605),however ,their reproducibility of left liver lobe [limit of agreement(LOA):22.55%,51.05%,39.3%,respectively]were lower than those of right liver lobe (LOA:20.3%,39.25%,33.9%).The D values had the best reproducibility in both the left and right liver lobe.Conclusion The liver DW-IVIM is feasible.The values of D,D*and f in left liver lobe were higher that those in right liver lobe but with worse reproducibility of measurement.The D value was most reproducible in both liver lobes.
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Objective To compare the clinical value of fluid attenuated inversion recovery imaging (FLAIR),magnetic resonance diffusion-weighted imaging(DWI) and magnetic resonance angiography(MRA) in diagnosis of early cerebral infarction.Methods 70 cerebral infarction patients were chosen.They underwent FLAIR,DWI and MRA examination.Results 70 patients with early cerebral infarction mostly were multiple lessions accouting for 60％.Supper actue period had 22 cases and acute period had 48 cases.DWI had the highest detection rate of cerebral infarction,particularly in the hyperacute period the detection rate reached 100％,which was significantly higher than the FLAIR and MRA(x2 =12.4,P ＜ 0.05).Conclusion Especially in the early diagnosis of hyperacute cerebral infarction,DWI is superior to FLAIR and MRA.FLAIR showed better on the cortex and periventricular lesions,MRA can check out the blood vessel lesions in the infarction area.
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Objective To observe the cerebral infarction types and distributions under MRI in patients with arteriosclerotic middle cerebral artery (MCA) stenosis,and investigate the pathophysiological mechanism of cerebral infarction induced by arteriosclerotic MCA stenosis.Methods We retrospectively analyzed the infarction characteristics under MRI diffusion weighted imaging (DWI) of 71 patients with ≥50％ MCA stenosis (not associating with ipsilateral internal carotid artery stenosis or occlusion,and having at least one atherosclerosis risk factors),diagnosed by digital subtraction angiography (DSA) of the whole brain in our hospital from January 2009 to December 2010;and the cerebral infarction types were also analyzed.Results MCA stenosis was noted in 65 cases and MCA occlusion in 6 cases by DSA; MRI-DWI showed that subcortical infarctions were the most common,followed by external border-zone infarctions (n=26,36.6％) and shallow perforator infarctions (n=14,19.7％); subcortical infarctions included deep perforator infarctions (n=31,43.7％) and internal border-zone infarctions (n=30,42.3％); external border-zone infarctions included anterior border-zone infarctions (n=9) and posterior ones (n=17); shallow perforator infarctions included cortical spotty lesions (n=10,14.1％) and territorial infarctions (n=2,2.8％).The same patient had multiple infarction types.Conclusion Patients with arteriosclerotic MCA stenosis might appear various types of cerebral infarction,suggesting that MCA stenosis can lead to different pathophysiological mechanisms of cerebral infarction; therefore,different treatments should be adopted accordingly.
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ObjectiveTo investigate the risk of cerebral infarction on pat ients with transient ischemicattack (TIA) by combining ABCD2 score and three imaging methods.MethodsFive hundred and seventy-eight patients with TIA visiting our hospital from January 2007 to December 2011 were assessed for the risk of cerebral infarction after TIA by ABCD2 score method,magnetic resonance diffusion weighted imaging (DWI),magnetic resonance angiography (MRA) and carotid artery color Doppler imaging (CDFI).Cases were followed up on 2 d,7 d and 30 d for incidence of cerebral infarction.ResultsCerebral infarction occurred in 37 cases (6.40％),47 cases ( 8.13％ ) and 61 cases ( 10.55％ ) on day 2,day 7 and day 30.The occurrence of cerebral infarction after TIA in high risk group (35 cases ) by single ABCD2 score was found in 15 cases (42.86％ ),18 cases (51.43％) and 21 cases (60.00％) on day 2,day 7 and day 30.Twenty-eight cases (54.90％),31cases (60.78％ ),and 38 cases (74.51％ ) of patients after TIA with ABCD2 ＞ 3 and DWI positivity (51cases) suffered cerebral infarction on day 2,day 7 and day 30.Cerebral infarction occurred in 22 cases (61.11％),24 cases (66.67％ ) and 30 cases (83.33％) of patients with ABCD2 ＞ 3 points and cerebral artery stenosis (36 cases) on day 2,day 7 and day 30 after TIA.The occurrence of cerebral infarction after TIA on day 2,day 7 and day 30 were in 21 cases ( 60.00％ ),23 cases ( 65.71％ ),28 cases ( 80.00％ ) of the patients with ABCD2 ＞ 3 points and the carotid artery atheroma-caused bureaucratic stenosis (35 cases).There were no significant difference in the value of three methods to assess the risk of cerebral infarction in high-risk TIA groups (P ＞ 0.05).ConclusionTIA patients can progress to cerebral infarction in the short term.There are some predictive value by ABCD2 score from 2 to 30 days for cerebral infarction occurring after TIA,but it is only a simple clinical assessment method.ABCD2 score ＞ 3 points must be combined with DWI,MRA,and other tests in high-risk patients to identify the risk of cerebral infarction,thus improving the accuracy of the prediction.The combined evaluation of TIA patients will help the clinicians give better treatment and decision to this group of patients
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Objective To evaluate the efficacy of mechanical thrombectomy on embolic cerebral infarction with magnetic resonance diffusion weighted imaging (DWI). Methods Forty New Zealand white rabbits were performed carotid artery injection of blood clot emboli to induce the animal models of acute cerebral infarction; these models were equally randomized into 4 groups (n=10);non-treatment group was given no treatment; mechanical thrombectomy via femoral artery was performed under DSA 6, 8 and 12 h after the inducement in the 3 treatment groups, respectively. MR-DWI, T1WI and T2WI were performed and the apparent diffusion coefficient (ADC) and infarct volume were calculated in each group 6, 8, 12 and 24 h after the inducement. Results DWI demonstrated the ischemic area in all the 40 rabbit models at hyper-acute stage (within 6 h of inducement) with hyperintensity, while T1WI and T2WI showed normal signals. MR-DWI, T1WI and T2WI had significant difference in the relevance ratio of cerebral infarction in these rabbit models at acute stage (within 24 h of inducement, P＜0.05). The DAC value was gradually decreased and the ischemic area was gradually increased at acute stage in the rabbit models of non-treatment group and group of performing mechanical thrombectomy at the 12thh of inducement, however, rabbit models of groups of performing mechanical thrombectomy at the 6th and 8th h of inducement enjoyed the opposite position. The DAC value was higher and the ischemic area was lower 24 h after the inducement in the rabbit models of groups of performing mechanical thrombectomy the 6th and 8th h of inducement as compared with those in the non-treatment group and group of performing mechanical thrombectomy at the 12th h of inducement. Conclusion Mechanical thrombectomy at early stage enjoys significant good results; MR-DWI is a sensitive way in dynamic observing the treatment efficacy of acute cerebral infarction.
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@#ObjectiveTo explore the effect of Yinaotongluo Capsule on diffuse weighting image and enenery metabolism of ischemia-reperfuing rat.MethodsMagnetic resonance diffusion-weighted imaging(DWI) and 1H and magnetic resonance spectroscopy(MRS) were performed in different brain regions in focal cerebral ischemic-reperfusion injury model rats. ResultsYinaotongluo Capsule could significantly reduce the area and the intensity of infarction of rats by DWI 3 h and 5 d after treatment compared with the model group.The result of 1H MRS examination demonstrated Lac peak was lower and NAA peak higher than that of the model group. ConclusionYinaotongluo Capsule can effectually improve enenery metabolism during cerebral ischemia and reperfuing, so that to reduce the neuronal dysfunction and death in infarcts at the late stage.
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The chronological and spatial rules of changes during focal cerebral ischemia and reperfusion in different brain regions with magnetic resonance diffusion-weighted imaging (DWI) in a model of occlusion of middle cerebral artery (MCAO) and the development of cytotoxic edema in acute phase were explored. Fifteen healthy S-D rats with MCA occluded by thread-emboli were randomly divided into three groups. 15 min after the operation, the serial imaging was scanned on DWI for the three groups. The relative mean signal intensity (RMSI) of the frontal lobe, parietal lobe, lateral cauda-putamen, medial cauda-putamen and the volume of regions of hyperintense signal on DWI were calculated. After the last DWI scanning, T2 WI was performed for the three groups. After 15min ischemia, the rats was presented hyperintense signals on DWI. The regions of hyperintense signal were enlarged with prolonging ischemia time. The regions of hyperintense signal were back to normal after 60 min reperfusion with a small part remaining to show hyperintense signal. The RMSIs of parietal lobe and lateral cauda-putamen were higher than that of the frontal lobe and medial cauda-putamen both in ischemia phase and recanalization phase. The three groups werenormal on T2WI imaging. DWI had good sensitivity to acute cerebral ischemia, which was used to study the chronological and spatial rules of development of early cell edema in ischemia regions.
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Different from conventional MRI, Diffusion-weighted(DW) magnetic resonance(MR)imaging is dependent on the molecular motion of water, and provides information on the physiologic state of the brain. In the diagnosis of acute cerebral infarction,the sensitivity is 94% and specificity is 100%. On MRDW imaging, the epidermoid tumors and cerebrospinal fluid or arachnoid cysts, subdura effusions and subdural empyemas,abscess cavities or empyemas and necrotic tumors could be differentiated accurately. MRDW imaging also provides adjunctive information for the diagnosis and evaluation of other cerebral diseases including neoplasms, intracranial infections, traumatic brain injury, and demyelinating processes. As a valuable technique, diffusion-weighted MR imaging should be considered an essential sequence on the diagnosis of brain stroke, and its use in most brain MR studies is recommended.
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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.