The relationship between fractional anisotropy value and tumor microarchitecture in late-stage rat glioma

OBJECTIVE@#To explore the magnetic resonance diffusion tensor imaging (MR-DTI) features of in the late stage of Wistar rat C6 brain glioma, and the relationship between fractional anisotropy value and tumor microarchitecture.@*METHODS@#The concentration of more than 1.0 × 10/10 μL glioma cells and complete medium were injected stereotactically into the right caudate nucleus of the experimental group (n = 35) and control group (n = 10), respectively. Conventional MRI, DTI, and enhanced T1WI scans were Performed using the GE Signa HD × 3.0T MRI scanner about 3-4 weeks after implantation for the rats. Postprocessing was done using the DTI specific software Function Tool to gain FA image. Many ROIs were drawn avoiding hemorrhage, necrosis areas in tumor parenchyma, the value of FA was recorded. Each surviving rat brain was examined histologically using HE and immunohistochemical staining for VEGF and CD34. Pearson correlation analysis was used to determine the relationships between FA values and VEGF, MVD, cell density, respectively.@*RESULTS@#A total of 35 tumor-bearing rats were confirmed the tumor formation by the subsequent MRI and pathological examination. The mean FA values of the tumor and the contralateral brain tissue were 0.17 ± 0.03 and 0.31 ± 0.05 respectively, and the difference was statistically significant (t = 12.80, P  0.05). FA value in the late stage of Wistar rat C6 brain glioma has significant positive correlation to VEGF, MVD, cell density. The correlation coefficients between FA and VEGF, MVD, and cell density were 0.67, 0.65 and 0.71 (P < 0.05), respectively.@*CONCLUSIONS@#The FA value of rat glioma tumor in the late stage can preoperatively provide an accurate, reliable and noninvasive imaging monitoring method to evaluate the microstructure of glioma (cell density, the extent of angiogenesis, fiber bundle integrity and tumor cell infiltration and so on), predict the biological behavior of the tumor and make out surgical plan.

The relationship between fractional anisotropy value and tumor microarchitecture in late-stage rat glioma

Objective To explore the magnetic resonance diffusion tensor imaging (MR-DTI) features of in the late stage of Wistar rat C6 brain glioma, and the relationship between fractional anisotropy value and tumor microarchitecture. Methods The concentration of more than 1.0 × 10

Longitudinal follow-up of patients with mild traumatic brain injury by magnetic resonance spectroscopic technique

OBJECTIVE@#To explore the changes in the concentrations of neural markers immediately or several months after mild traumatic brain injury (mTBI).@*METHODS@#The metabolic markers of neurons in white matter tissues above the lateral ventricle were semi-quantitatively determined by employing 1H magnetic resonance spectroscopic technique (1-H-MRS) in 30 clinically diagnosed cases of mTBI. At the same time, the neurological functions of the subjects, including ability to pay attention, memory, working memory and operational capacity etc were also assessed.@*RESULTS@#The patients were followed up for, on average, 13 days after mTBI and the results showed that Cre, PCre and Glx in the white matter tissues were significantly elevated in mTBI patients. 17 patients (57%) recovered from the injury during the follow-up (median was defined as the 40th post-trauma day). Comparison in terms of intelligence among groups revealed that the levels of neural markers of intelligence development was positively related with intelligence scores).@*CONCLUSIONS@#Change in Glx concentrations is most sensitive during trauma or in ensuing repairing processes, and might be different from normal status in the following months and Glx level tends to be accompanied with change in Cre, another energy-related marker.

Characterization of neurovascular compression in facial neuralgia patients by 3D high-resolution MRI and image fusion technique

OBJECTIVE@#To describe the anatomical characteristics and patterns of neurovascular compression (NVC) in patients suffering trigeminal neuralgia (TN) by 3D high-resolution magnetic resonance imaging (MRI) method and image fusion technique.@*METHODS@#The anatomic structure of trigeminal nerve, brain stem and blood vessel was observed in 100 consecutive TN patients by 3D high resolution MRI (3D SPGR, contrast-enhanced T1 3D MP-RAGE and T2/T1 3D FIESTA). The 3D image sources were fused and visualized using 3D DOCTOR software.@*RESULTS@#One or several NVC sites, which usually appeared 0-9.8 mm away from brain stem, were found on the symptomatic side in 93% of the TN cases. Superior cerebellar artery was involved in 76% (71/93) of these cases. The other vessels including antero-inferior cerebellar artery, vertebral artery, basilar artery and veins also contributed to the occurrence of NVC. The NVC sites were found to be located in the proximal segment in 42% of these cases (39/93) and in the distal segment in 45% (42/93). Nerve dislocation or distortion was observed in 32% (30/93).@*CONCLUSIONS@#Various 3D high resolution MRI methods combined with the image fusion technique could provide pathologic anatomic information for the diagnosis and treatment of TN.

Application of 3D-computed tomography angiography technology in large meningioma resection

OBJECTIVE@#To discuss the role of 3D-computed tomography angiography (3D-CTA) technology in reducing injuries of large meningioma surgery.@*METHODS@#3D-CTA preoperative examinations were done in 473 patients with large meningioma (simulated group). The images were analyzed by 3D post-processing workstation. By observing the major intracranial blood vessels, venous sinus, and the compression and invasion pattern in the nerve region, assessing risk level of the surgery, simulating the surgical procedures, the surgical removal plan, surgical routes and tumor blood-supplying artery embolisation plan were performed. Two hundred and fifty seven large meningioma patients who didn't underwent 3D-CTA preoperative examination served as control group. The incidence of postoperative complications, intraoperative blood transfusion and the operation time were compared between these two groups.@*RESULTS@#Compared with the control group, the Simpson's grade I and II resection rate was 80.3% (380/473), similar with that of the control (81.3%, 209/257). The incidence of postoperative complications in 3D-CTA simulated group was 37.0% which was significantly lower than that (48.2%) of the control (P<0.01). The intraoperative blood supply for simulated group and the control was (523.4±208.1) mL and (592.0±263.3) mL, respectively, with significant difference between two groups (P<0.01). And the operation time [(314.8±106.3)] min was significantly lower in simulated group than that in the control [(358.4±147.9) min] (P<0.01).@*CONCLUSION@#Application of 3D-CTA imaging technology in risk level assessment before large-scaled meningioma resection could assist in the rational planning of tumor resectin, surgical routes, and is helpful in reducing injuries and complications and enhancing the prognosis of the patients.

Structural abnormalities of trigeminal root with neurovascular compression revealed by high resolution diffusion tensor imaging

OBJECTIVE@#To detect neurovascular compression-induced structural abnormalities of trigeminal nerves (TGN) by diffusion tensor imaging (DTI).@*METHODS@#The affected ipsilateral TGN (iTGN) and unaffected contralateral TGN (cTGN) of 20 trifacial neuralgia (TN) patients as well as the bilateral TGN of 10 normal controls (nTGN) were examined by DTI and 3D high resolution MRI using a 3.0 T MRI scanner. The fractional anisotropy and apparent diffusion coefficient (ADC) were determined.@*RESULTS@#Compared with the cTGN and nTGN, the iTGN had significantly lower fraction of anisotropy (FA), significantly higher ADC, and significantly smaller volume and cross-sectional area (P<0.05).@*CONCLUSIONS@#The increase in ADC and decrease in FA has a close relationship with morphological changes of TGN, and the DTI could provide valuable diagnostic information on TGN structure for TN patients.

Delay enhancement patterns in apical hypertrophic cardiomyopathy by phase-sensitive inversion recovery sequence

OBJECTIVE@#Late gadolinium enhancement (LGE) patterns of cardiovascular magnetic resonance (CMR) relying on PSIR (phase-sensitive inversion recovery sequence) techniques had been used to determine the characteristics of LGE in apical hypertrophic cardiomyopathy (ApHCM).@*METHODS@#Forty patients pure ApHCM [age, (60.2±10.4) years, 31 men] were enrolled. LGE images were acquired using PSIR, and analyzed using a 17-segment model. Summing the LGE areas in all short axis slices yielded the total volume of late enhancement, which was subsequently presented as a proportion of total LV myocardium (% LGE).@*RESULTS@#Mean maximal apical wall thickness was (17.9±2.3) mm, and mean left ventricular (LV) ejection fraction was (67.7±8.0)%. LGE was detected in 130 segments of 30 patients (75.0%), occupying (4.9±5.5)% of LV myocardium. LGE was mainly detected at the junction between left and right ventricles in 12 (30%) and at the apex in 28 (70%), although LGE-positive areas were widely distributed, and not limited to the apex. Focal LGE at the non-hypertrophic LV segments was found in some ApHCM patients, even without LGE of hypertrophied apical segments.@*CONCLUSIONS@#LGE was frequently observed not only in the thickened apex of the heart but also in other LV segments, irrespective of the presence or absence of hypertrophy. The simple presence of LGE on CMR was not representative of adverse prognosis in this population.

Comparison between magnitude reconstruction and phase-sensitive mR imaging in the detection of myocardial infarction

OBJECTIVE@#To determine the deference between phase sensitive magnetic resonance (MR) imaging and magnitude reconstruction to detect infracted myocardium.@*METHODS@#Twenty patients (16 men; 4 women; mean age, 56 years). experienced Q-wave myocardial infarction 2 weeks earlier were examined with a 3.0-T MR system 10 minutes after administration of 0.1 mmol/kg body weight gadobenate dimeglumine. To determine the optimal TI, a TI scout sequence was used. A segmented 2D IR true fast imaging with steady-state precession (trueFISP) sequence that produces both phase-sensitive and magnitude-reconstructed images were used at TI values of 200-600 msec (TI values were varied in 100-msec steps) and at optimal TI (mean value, 330 msec). Contrast-noise ratios (CNRs) of normal and infarcted myocardium and the area of infarcted myocardium were determined. Two-tailed unpaired sample Student t test was used to compare CNRs, and area of infarction.@*RESULTS@#MMean CNR phase-sensitive and magnitude-reconstructed images at optimal TI (mean value, 330 msec) were 6.2, and 6.1, respectively. For a TI of 200 msec, CNR values were 5.5, and 4.2, respectively; for TI of 600 msec, CNR values were 5.8 and 4.3, respectively. Area of infarcted myocardium was underestimated on magnitude-reconstruction images (P = 0.002-0.03) for short TI values (ie., 200 msec) but not on phase sensitive reconstructed when compared with IR tureFISP images obtained at optimal TI.@*CONCLUSIONS@#LPhase-sensitive image reconstruction results in reduced need for precise choice of TI and more consistent image quality.