Magnetic resonance diffusion tensor imaging following major ozonated autohemotherapy for treatment of acute cerebral infarction

Major ozonated autohemotherapy has been shown to promote recovery of upper limb motor function in patients with acute cerebral infarction, but whether naajor ozonated autohelnotherapy affects remote in）ury remains poorly understood. Here, we assumed that major ozonated autohemotherapy contributes to recovery of clinical function, possibly by reducing remote injury after acute cerebral infarction. Sixty acute cerebral infarction patients aged 30-80 years were equally and randomly allocated to ozone treatment and control groups. Patients in the ozone treatment group received medical treatment and major ozonated autohemotherapy （47 mg/L, 100 mL ozone） for 10 ± 2 days. Patients in the control group received medical treatment only. National Institutes of Health Stroke Scale score, modified Rankin scale score, and reduced degree of fractional anisotropy values of brain magnetic resonance diffusion tensor imaging were remarkably decreased, brain function improved, clinical efficiency significantly increased, and no obvious adverse reactions detected in the ozone treatment group compared with the control group. These findings suggest that major ozonated autohemotherapy promotes recovery of neurological function in acute cerebral infarction patients by reducing re,note injury, and additionally, exhibits high safety.

Value of multiple models of diffusion-weighted imaging to predict hepatic lymph node metastases in colorectal liver metastases patients

BACKGROUND About 10%-31% of colorectal liver metastases(CRLM)patients would concomitantly show hepatic lymph node metastases(LNM),which was considered as sign of poor biological behavior and a relative contraindication for liver resection.Up to now,there’s still lack of reliable preoperative methods to assess the status of hepatic lymph nodes in patients with CRLM,except for pathology examination of lymph node after resection.AIM To compare the ability of mono-exponential,bi-exponential,and stretchedexponential diffusion-weighted imaging(DWI)models in distinguishing between benign and malignant hepatic lymph nodes in patients with CRLM who received neoadjuvant chemotherapy prior to surgery.METHODS In this retrospective study,97 CRLM patients with pathologically confirmed hepatic lymph node status underwent magnetic resonance imaging,including DWI with ten b values before and after chemotherapy.Various parameters,such as the apparent diffusion coefficient from the mono-exponential model,and the true diffusion coefficient,the pseudo-diffusion coefficient,and the perfusion fraction derived from the intravoxel incoherent motion model,along with distributed diffusion coefficient(DDC)andαfrom the stretched-exponential model(SEM),were measured.The parameters before and after chemotherapy were compared between positive and negative hepatic lymph node groups.A nomogram was constructed to predict the hepatic lymph node status.The reliability and agreement of the measurements were assessed using the coefficient of variation and intraclass correlation coefficient.RESULTS Multivariate analysis revealed that the pre-treatment DDC value and the short diameter of the largest lymph node after treatment were independent predictors of metastatic hepatic lymph nodes.A nomogram combining these two factors demonstrated excellent performance in distinguishing between benign and malignant lymph nodes in CRLM patients,with an area under the curve of 0.873.Furthermore,parameters from SEM showed substantial repeatability.CONCLUSION The developed nomogram,incorporating the pre-treatment DDC and the short axis of the largest lymph node,can be used to predict the presence of hepatic LNM in CRLM patients undergoing chemotherapy before surgery.This nomogram was proven to be more valuable,exhibiting superior diagnostic performance compared to quantitative parameters derived from multiple b values of DWI.The nomogram can serve as a preoperative assessment tool for determining the status of hepatic lymph nodes and aiding in the decision-making process for surgical treatment in CRLM patients.

Diffusion tensor imaging of optic nerve and optic radiation in primary chronic angle-closure glaucoma using 3T magnetic resonance imaging

AIM: To evaluate the value of quantitative diffusion tensor imaging (DTI) in assessing the axonal and myelin damage of the optic nerves and optic radiations in patients with chronic primary angle -closure glaucoma (PACG) by using high -field magnetic resonance (MR) imaging (3T). METHODS: Twenty patients with bilateral chronic PACG and twenty age - and sex matched disease -free control subjects were enrolled. Conventional MRI and DTI were performed on all subjects using 3T MR scanner. Mean diffusivity (MD), fractional anisotropy (FA), axial diffusivities (AD) and radial diffusivities (RD) of each optic nerve and each optic radiation were measured by using post -processing software of DTI studio 2.3, and then compared between left eyes and right eyes and between patients group and control group. The pairedsample t- test were used. RESULTS: There was no abnormality in the shape and signal intensity of the optic nerves and optic radiations in patients group and control group on the conventional MRI. No significant differences were observed in the FA, MD, AD and RD between the right and left optic nerves and optic radiations within patients group and control group (P>0.05). The optic nerves and optic radiations of patients with chronic PACG, as compared with control subjects, had significantly higher MD, AD, RD and significantly lower FA (P<0.05). CONCLUSION: The diffusivity of optic nerves and optic radiations in chronic PACG group showed abnormal and diffusivity parameters could be used markers of axonal and myelin injury in glaucoma.

Magnetic resonance diffusion tensor imaging and fibertracking diffusion tensor tractography in the management of spinal astrocytomas

Some specially imaging of magnetic resonance imaging,the diffusion-weighted imaging(DWI),the diffusion tensor imaging and fractional anisotropy(FA),are useful to described,detect,and map the extent of spinal cord lesions.FA measurements may are used to predicting the outcome of patients who have spinal cord lesions.Fiber tracking enable to visualizing the integrity of white matter tracts surrounding some lesions,and this information could be used to formulating a differential diagnosis and planning biopsies or resection.In this article,we will describe the current uses for DWI and fiber tracking and speculate on others in which we believe these techniques will be useful in the future.

Magnetic resonance diffusion tensor imaging of optic nerve and optic radiation in healthy adults at 3T

AIM:To investigate the diffusion characteristics of water of optic nerve and optic radiation in healthy adults and its related factors by diffusion tensor imaging（DTI）at3T.METHODS:A total of 107 healthy volunteers performed head conventional MRI and bilateral optic nerve and optic radiation DTI.The primary data of DTI was processed by post-processing software of DTI studio 2.3,obtaining fractional anisotropy value,mean diffusivity value,principal engine value,orthogonal engine value by measuring,and analyzed by the SPSS13.0 statistical software.RESULTS:The bilateral optic nerve and optic radiation fibers presented green color in directional encoded color（DEC）maps and presented high signal in fractional anisotropy（FA）maps.The FA value of the left optic nerve was 0.598±0.069 and the right was 0.593±0.065;the mean diffusivity（MD）value of the left optic nerve was（1.324±0.349）×10-3mm2/s and the right was（1.312±0.350）x10-3mm2/s;the principal engine value(λ?)of the left optic nerve was（2.297±0.522）×10-4mm2/s and the right was（2.277±0.526）×10-3mm2/s;the orthogonal engine value（λ⊥）of the left optic nerve was（0.838±0.285）×10-3mm2/s and the right was（0.830±0.280）×10-3mm2/s;the FA value of the left optic radiation was 0.636±0.057 and the right was0.628±0.056;the mean diffusivity（MD）value of the left optic radiation was（0.907±0.103）×10-3mm2/s and the right was（0.889±0.125）×10-3mm2/s;the principal eigenvalue(λⅡ)of the left optic radiation was（1.655±0.210）×10-3mm2/s and the right was（1.614±0.171）×10-3mn2/s;the orthogonal enginvalue（λ⊥）of the left optic radiation was（0.531±0.103）×10-3mm2/s and the right was（0.524±0.152）×10-3mm2/s.There was no obvious difference between the FA,MD,λ‖,λ⊥of the bilateral optic radiation and the bilateral optic nerve（P】0.05）and no obvious differencebetween male and female group.The FA,MO,λ‖,λ⊥of the bilateral optic radiation and the bilateral optic nerve had no obvious correlations to the age.CONCLUSION:DTI is sensitive to the optic nerve and radiation and the relevant DTI parameters of the optic nerve and radiation are established preliminarily in this study.

Is combined functional magnetic resonance imaging and diffusion tensor tractography a useful tool for evaluation of somatosensory dysfunction recovery after intracerebral hemorrhage?

Diffusion tensor tractography allows the sensory fiber course of the medial lemniscus to be visualized. But diffusion tensor tractography for accurate evaluation of the repair of injured somatosensory tracts in stroke patients has been rarely reported. A 55-year-old female patient presented with severe somatosensory dysfunction of the left side caused by a spontaneous intracerebral hemorrhage on the right side. The somatosensory function of the affected side recovered to a nearly normal state at 7 weeks from onset. Functional magnetic resonance imaging revealed that at 3 weeks from onset, there was no cortical activation by touch at each hand; at 7 weeks, the contralateral cortex centered on the primary sensory cortex was found to be activated during touch and passive movements, and activation by passive movements was increased compared with that at 3 weeks. Diffusion tensor tractography revealed that a medial lemniscus on the affected （right） hemisphere was not observed at 3 weeks from onset, however, at 7 weeks, the unaffected （left） hemisphere passed along the medial lemniscus pathway from the pons to the primary sensory cortex. These findings indicate that combined functional magnetic resonance imaging and diffusion tensor tractography would allow more accurate evaluation of the architecture and integrity of somatosensory tracts and is a useful method to investigate the recovery of somatosensory dysfunction in stroke patients.

Imaging changes in neural circuits in patients with depression using 1 H-magnetic resonance spectroscopy and diffusion tensor imaging

1 H-magnetic resonance spectroscopy imaging and diffusion tensor imaging were performed in 19 patients with mild depression and in 13 controls.The mean age of the patients was 31 years.The mean Hamilton depression score of the patients was 22.5±13.2.N-acetylaspartate,choline and creatine concentrations and the average diffusion coefficient and fractional anisotropy values were measured in the bilateral hippocampus,striatum,thalamus and prefrontal deep white matter. Compared with the control group,the mild depressed patients had：（1）a higher choline/creatine ratio and a negative correlation between the choline/creatine ratio and the average diffusion coefficient in the hippocampus;（2）a lower choline/creatine ratio and a higher fractional anisotropy in the striatum;（3）a lower fractional anisotropy and a positive correlation between the fractional anisotropy and the choline/creatine ratio in the prefrontal deep white matter;and（4）a higher average diffusion coefficient and a positive correlation between the choline/creatine ratio and the N-acetylaspartate/creatine ratio in the thalamus,as well as positive correlation between the choline/creatine ratio and Hamilton depression scores.These data suggest evidence of abnormal connectivity in neurofibrotic microstructures and abnormal metabolic alterations in the limbic-cortical-striatal-pallidal-thalamic neural circuit in patients with mild depression.

Changes in brain function and anatomical structure following treatment of hyperbaric oxygen for visual pathway abnormalities in 16 cases Evaluation of functional magnetic resonance imaging combined with diffusion tensor imaging

BACKGROUND： There is a growing research focus on the combination of blood oxygenation level dependent functional magnetic resonance imaging （BOLD-fMRI） and diffusion tensor imaging （DTI） to evaluate visual cortical function and structural changes in the cerebrum, as well as morphological changes to the white matter fiber tracks, after visual pathway lesions. However, the combined application of BOLD-fMRI and DTI in treating of visual pathway abnormalities still requires further studies. OBJECTIVE： To observe and evaluate the effects of hyperbaric oxygen on visual pathway abnormalities, and to evaluate the characteristics of cerebral function and anatomic structural changes by using BOLD-fMRI combined with DTI technique. DESIGN： Case contrast observation. SETTING： Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA. PARTICIPANTS： Sixteen patients （9 males and 7 females, 15-77 years old） with lateral or bilateral visual disorder induced by visual pathway lesions were selected from the Department of Neurology, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA from January 2006 to May 2007. These patients comprised the lesion group. Measures of interventional therapy： hyperbaric oxygen of two normal atmospheres for three courses （10 d/course） and routine internal medicine treatment. In addition, 12 healthy subjects of similar sex and age to the lesion group were regarded as the control group. The control group underwent routine ophthalmological and ocular fundus examinations; diagnostic results were normal. The experiment received confirmed consent from the local ethic committee, and all patients provided informed consent. METHODS： BOLD-fMRI and DTI manifestations in the lesion group were observed before and after hyperbaric oxygen intervention, and the results were compared with the control group. The subjects were positioned on their back, and BOLD-fMRI images were collected with the following GRE EPI sequence： TR = 2 000 ms, TE = 40 ms, layer thickness = 5 mm, and 20-layer successive scanning to cover the whole brain. While, DTI images were collected with SE EPI sequence of single excitation： TR=10 000 ms, TE = 112 ms, layer thickness = 4 mm, layer spacing = 0.5 mm, and a 30-layer successive scanning, matrix = 128×128. A diffusion gradient was applied at 13 directions, and one layer without diffusion weighted imaging was collected at b =1 000 s/mm^2. Numbers of activated voxels in cortical-activated regions, and fractional anisotropy in bilateral cerebral optical radiation regions, were calculated. Displacement, continuity, and destruction of fibrous tracts were analyzed. MAIN OUTCOME MEASURES： Results of BOLD-fMRI and DTI examinations. RESULTS： All 16 patients and 12 controls were included in the final analysis. ① Numbers of activated voxels through the use of BOLD-fMRI： prior to hyperbaric oxygen therapy, the number of activated voxels in the bilateral cortex of occipital lobe were significantly less in the lesion group than in the control group （t =3.23, P 〈 0.01）. In addition, the number of activated voxels significantly increased after treatment compared to before treatment （t = 2.46, P 〈 0.05）. ② Fractional anisotropy in optical radiation regions of bilateral cerebrum： fractional anisotropy in the lesion group was significantly less than the control group （t =2.89, P 〈 0.05）. In addition, fractional anisotropy after treatment was significantly higher than before treatment （t = 2.48, P 〈 0.05）. Moreover, fractional anisotropy of optical neuropathy was significantly higher in 6 patients in the lesion group than the occipital lobe optical central lesion （t = 2.35, P 〈 0.05）. CONCLUSION： BOLD-fMRI combined with DTI can indicate the occurrence, development, and therapeutic course of action for optical pathway lesions. The results acquired from these methods can provide information for function and structure, which can provide reliable verification in the treatment of cerebral function.

Functional magnetic resonance imaging and diffusion tensor tractography of the corticopontocerebellar tract in the human brain

The anatomical organization of the corticopontocerebellar tract （CPCT） in the human brain remains poorly understood. The present study investigated probabilistic tractography of the CPCT in the human brain using diffusion tensor tractography with functional magnetic resonance imaging. CPCT data was obtained from 14 healthy subjects. CPCT images were obtained from functional magnetic resonance imaging and diffusion tensor tractography, revealing that the CPCT originated from the primary sensorimotor cortex and descended to the pontine nucleus through the corona radiata, the posterior limb of the internal capsule, and the cerebral peduncle. After crossing the pons through the transverse pontine fibers, the CPCT entered the cerebellum via the middle cerebral peduncle. However, some variation was detected in the midbrain （middle cerebral peduncle and/or medial lemniscus） and pons （ventral and/or dorsal transverse pontine fibers）. The CPCT was analyzed in 3 dimensions from the cerebral cortex to the cerebellum. These results could be informative for future studies of motor control in the human brain.

Magnetic resonance diffusion tensor imaging-based evaluation of optic-radiation shape and position in meningioma

Employing magnetic resonance diffusion tensor imaging, three-dimensional white-matter imaging and conventional magnetic resonance imaging can demonstrate the tumor parenchyma, peritumoral edema and compression on surrounding brain tissue. A color-coded tensor map and three-dimensional tracer diagram were applied to clearly display the optic-radiation location, course and damage. Results showed that the altered anisotropy values of meningioma patients corresponded with optic-radiation shape, size and position on both sides. Experimental findings indicate that the magnetic resonance diffusion tensor imaging technique is a means of tracing and clearly visualizing the optic radiation.

Quantitative volumetric analysis of the optic radiation in the normal human brain using diffusion tensor magnetic resonance imaging-based tractography

To attain the volumetric information of the optic radiation in normal human brains, we per- formed diffusion tensor imaging examination in 13 healthy volunteers. Simultaneously, we used a brain normalization method to reduce individual brain variation and increase the accuracy of volumetric information analysis. In addition, tractography-based group mapping method was also used to investigate the probability and distribution of the optic radiation pathways. Our results showed that the measured optic radiation fiber tract volume was a range of about 0.16% and that the fractional anisotropy value was about 0.53. Moreover, the optic radiation probability fiber pathway that was determined with diffusion tensor tractography-based group mapping was able to detect the location relatively accurately. We believe that our methods and results are help- ful in the study of optic radiation fiber tract information.

Diffusion tensor imaging and proton magnetic resonance spectroscopy in brain tumor Correlation between structure and metabolism

Proton magnetic resonance spectroscopy and diffusion tensor imaging are non-invasive techniques used to detect metabolites and water diffusion in vivo. Previous studies have confirmed a positive correlation of individual fractional anisotropy values with N-acetylaspartate/creatine and N-acetylaspartate/choline ratios in tumors, edema, and normal white matter. This study divided the brain parenchyma into tumor, pedtumoral edema, and normal-appearing white matter according to MRI data, and analyzed the correlation of metabolites with water molecular diffusion. Results demonstrated that in normal-appearing white matter, N-acetylaspartate/creatine ratios were positively correlated with fractional anisotropy values, negatively correlated with radial diffusivities, and positively correlated with maximum eigenvalues. Maximum eigenvalues and radial diffusivities in peritumoral edema showed a negative correlation with choline, N-acetylaspartate, and creatine. Radial diffusivities in tumor demonstrated a negative correlation with choline. These data suggest that the relationship between metabolism and structure is markedly changed from normal white matter to peritumoral edema and tumor. Neural metabolism in the peritumoral edema area decreased with expanding extracellular space. The normal relationship of neural function and microstructure disappeared in the tumor region.

Anisotropic WM conductivity reconstruction based on diffusion tensor magnetic resonance imaging: a simulation study

The present study aims to estimate the in vivo anisotropic conductivities of the White Matter (WM) tissues by means of Magnetic Resonance Electrical Impedance Tomography (MREIT) technique. The realistic anisotropic volume conductor model with different conductivity properties (scalp, skull, CSF, gray matter and WM) is constructed based on the Diffusion Tensor Magnetic Resonance Imaging (DT- MRI) from a healthy human subject. The Radius Basic Function (RBF)-MREIT algorithm of using only one magnetic flux density component was applied to evaluate the eigenvalues of the anisotropic WM with target values set according to the DT-MRI data based on the Wolter’s model, which is more physiologically reliable. The numerical simulations study performed on the five-layer realistic human head model showed that the conductivity reconstruction method had higher accuracy and better robustness against noise. The pilot research was used to judge the feasibility, meaningfulness and reliability of the MREIT applied on the electrical impedance tomography of the complicated human head tissues including anisotropic characteristics.

Diffusion tensor imaging reveals brain structure changes in dogs after spinal cord injury

Based on the Wallerian degeneration in the spinal cord pathways,the changes in synaptic connections,and the spinal cord-related cellular responses that alter the cellular structure of the brain,we presumed that brain diffusion tensor imaging(DTI)parameters may change after spinal cord injury.However,the dynamic changes in DTI parameters remain unclear.We established a Beagle dog model of T10 spinal cord contusion and performed DTI of the injured spinal cord.We found dynamic changes in DTI parameters in the cerebral peduncle,posterior limb of the internal capsule,pre-and postcentral gyri of the brain within 12 weeks after spinal cord injury.We then performed immunohistochemistry to detect the expression of neurofilament heavy polypeptide(axonal marker),glial fibrillary acidic protein(glial cell marker),and NeuN(neuronal marker).We found that these pathological changes were consistent with DTI parameter changes.These findings suggest that DTI can display brain structure changes after spinal cord injury.

Magnetic resonance imaging findings of spontaneous pyomyoma in a premenopausal woman managed with myomectomy:A case report

BACKGROUND Acute fibroid complications are rare.However,failure to recognize and treat acute complications expeditiously when they occur can lead to catastrophic,even deadly,complications.Pyomyoma is a rare but potentially fatal condition resulting from infarction and infection of a fibroid through bacterial seeding and direct,hematogenous,or lymphatic dissemination.Even though the diagnosis is established through clinical and laboratory findings,imaging is an important complementary method to support the suspected diagnosis.CASE SUMMARY Herein,we report a case of a pyomyoma in a nulliparous woman previously diagnosed with uterine leiomyomatosis according to ultrasound findings.The patient had previously attended the emergency room due to hypogastric pain unresponsive to analgesics.After a week of persistent pain,she developed sepsis without any identifiable foci.Magnetic resonance imaging revealed findings compatible with uterine myomatosis with red degeneration,and a possible diagnosis of a pyomyoma was made according to the imaging findings along with the patient’s clinical features.We decided to perform myomectomy(which is an infrequently performed surgical treatment due to the procedure’s intrinsic implic-ations)due to the patient’s desire to preserve fertility.Histopathologic results revealed a uterine leiomyoma with coagulative and liquefactive necrosis,while the tissue culture showed gram-negative cocci bacteria,which were successfully treated using antibiotic therapy.The patient’s health status improved after several days.CONCLUSION The main diagnostic tools to evaluate pyomyomas are the clinical and laboratory findings as well as tissue cultures.Nonetheless,magnetic resonance imaging can help to corroborate these findings as well as to better characterize myomas with its different complications.

Diffusion tensor imaging in the courtroom:Distinction between scientific specificity and legally admissible evidence

Interest and uptake of science and medicine peer-reviewed literature by readers outside of a paper’s topical subject,field or even discipline is ever-expanding.While the application of knowledge from one field or discipline to others can stimulate innovative solutions to problems facing modern society,it is also fraught with danger for misuse.In the practice of law in the United States,academic papers are submitted to the courts as evidence in personal injury litigation from both the plaintiff(complainant)and defendant.Such transcendence of an academic publication over disciplinary boundaries is immediately met with the challenge of application by a group that inherently lacks in-depth knowledge on the scientific method,the practice of evidence-based medicine,or the publication process as a structured and internationally synthesized process involving peer review and guided by ethical standards and norms.A modern-day example of this is the ongoing conflict between the sensitivity of diffusion tensor imaging(DTI)and the legal standards for admissibility of evidence in litigation cases of mild traumatic brain injury(mTBI).In this review,we amalgamate the peer-reviewed research on DTI in mTBI with the court’s rationale underlying decisions to admit or exclude evidence of DTI abnormalities to support claims of brain injury.We found that the papers which are critical of the use of DTI in the courtroom reflect a primary misunderstanding about how diagnostic biomarkers differ legally from relevant and admissible evidence.The clinical use of DTI to identify white matter abnormalities in the brain at the chronic stage is a valid methodology both clinically as well as forensically,contributes data that may or may not corroborate the existence of white matter damage,and should be admitted into evidence in personal injury trials if supported by a clinician.We also delve into an aspect of science publication and peer review that can be manipulated by scientists and clinicians to publish an opinion piece and misrepresent it as an unbiased,evidencebased,systematic research article in court cases,the decisions of which establish precedence for future cases and have implications on future legislation that will impact the lives of every citizen and erode the integrity of science and medicine practitioners.

Evaluation of diffusion weighted imaging of magnetic resonance imaging in small focal hepatic lesions:a quantitative study in 56 cases

Diffusion-weighted imaging (DWI) as a new technique of magnetic resonance imaging (MRI) is used to detect focal hepatic lesions. This study was designed to evaluate the significance of DWI to differentiate focal hepatic lesions less than 3 cm in diameter by the quantitation of apparent diffusion coefficient (ADC) values. METHODS:DWI using 1.5T MRI scanner unit was performed with a spin-echo single-shot echo planar imaging (EPI) in 56 cases of small focal hepatic lesions, including hepatocellular carcinoma (11), hepatic metastatic tumor (15 ), hepatic cavernous hemangioma (14), and hepatic cyst (16).The ADC values of these lesions were calculated respectively. The ratios of the ADC values of lesion/liver in hepatocellular carcinomas and hepatic metastatic tumors were also estimated. RESULTS:The mean ADC values (mm2/s) were (0.93±0.06) ×10-3 in hepatocellular carcinomas, (1.09±0.18)×10-3 in hepatic metastatic tumors,(1.95±0.38)×10-3 in hepatic cavernous hemangiomas, and (3.18±0.33) ×10-3 in hepatic cysts. The ratios of ADC values of lesion/liver were 0.90±0.06 and 1.15±0.14 in hepatocellular carcinoma and hepatic metastatic tumors respectively, which were significantly different (P<0.05). CONCLUSION:The measurement of ADC values and the ratios of ADC values of lesion/liver are helpful in MR diagnosis and differentiation of focal hepatic lesions.

Diffusion weighted magnetic resonance imaging of liver: Principles, clinical applications and recent updates

Diffusion-weighted imaging(DWI), a functional imaging technique exploiting the Brownian motion of water molecules, is increasingly shown to have value in various oncological and non-oncological applications. Factors such as the ease of acquisition and ability to obtain functional information in the absence of intravenous contrast, especially in patients with abnormal renal function, have contributed to the growing interest in exploring clinical applications of DWI. In the liver, DWI demonstrates a gamut of clinical applications ranging from detecting focal liver lesions to monitoring response in patients undergoing serial follow-up after loco-regional and systemic therapies. DWI is also being applied in the evaluation of diffuse liver diseases such as non-alcoholic fatty liver disease, hepatic fibrosis and cirrhosis. In this review, we intend to review the basic principles, technique, current clinical applications and future trends of DW-MRI in the liver.

Diffusion-weighted magnetic resonance imaging for predicting the response of rectal cancer to neoadjuvant concurrent chemoradiation

AIM:To evaluate the clinical value of diffusion-weighted magnetic resonance imaging(DW-MRI)in predicting the response of rectal cancer to neoadjuvant chemoradiation.METHODS:This prospective study was approved by our institutional review board,and informed consent was obtained from each patient.Fifteen patients(median age 56 years)with locally advanced rectal cancer were treated in our hospital from June 2006 to December 2007.All patients were stageⅢB-C according to the results of MRI and endorectal ultrasound examinations.All patients underwent pelvic irradiation with 45 Gy/25 fx per 35 days.The concurrent chemotherapy regimen consisted of capecitabine 625mg/m2,bid(Monday-Friday),and oxaliplatin 50 mg/m2,weekly.The patients underwent surgery 5-8 wk after the completion of neoadjuvant therapy.T downstaging was defined as the downstaging of the tumor from cT3to ypT0-2 or from cT4 to ypT0-3.Good regression was defined as TRG 3-4,and poor regression was defined as TRG 0-2.Diffusion-weighted magnetic resonance images were obtained prior to and weekly during the course of neoadjuvant chemoradiation,and the apparent diffusion coefficient(ADC)values were calculated from the acquired tumor images.RESULTS:Comparison with the mean pretreatment tumor ADC revealed an increase in the mean tumor ADC during the course of neoadjuvant chemoradiation,especially at the 2ndweek(P=0.004).We found a strong negative correlation between the mean pretreatment tumor ADC and tumor regression after neoadjuvant chemoradiation(P=0.021).In the T downstage and tumor regression groups,we found a significant increase in the mean ADC at the 2ndweek of neoadjuvant therapy(P=0.011;0.004).CONCLUSION:DW-MRI might be a valuable clinical tool to help predict or assess the response of rectal cancer to neoadjuvant chemoradiation at an early timepoint.

Apparent diffusion coefficient by diffusion-weighted magnetic resonance imaging as a sole biomarker for staging and prognosis of gastric cancer

Objective： To investigate the role of apparent diffusion coefficient （ADC） from diffusion-weighted magnetic resonance imaging （DW-MRI） when applied to the 7th TNM classification in the staging and prognosis of gastric cancer （GC）. Methods： Between October 2009 and May 2014, a total of 89 patients with non-metastatic, biopsy proven GC underwent 1.5T DW-MRI, and then treated with radical surgery. Tumor ADC was measured retrospectively and compared with final histology following the 7th TNM staging （local invasion, nodal involvement and according to the different groups -- stage Ⅰ, Ⅱ and Ⅲ）. Kaplan-Meier curves were also generated. The follow-up period is updated to May 2016. Results： Median follow-up period was 33 months and 45/89 （51%） deaths from GC were observed. ADC was significantly different both for local invasion and nodal involvement （P〈0.001）. Considering final histology as the reference standard, a preoperative ADC cut-offof 1.80×10-3 mm^2/s could distinguish between stages I and Ⅱ and an ADC value of ≤1.36-10-3 mm^2/s was associated with stage Ⅲ（P〈0.001）. Kaplan-Meier curves demonstrated that the survival rates for the three prognostic groups were significantly different according to final histology and ADC cut-offs （P〈0.001）. Conclusions： ADC is different according to local invasion, nodal involvement and the 7th TNM stage groups for GC, representing a potential, additional prognostic biomarker. The addition of DW-MRI could aid in the staging and risk stratification of GC.