Influence of fluid-attenuated inversion-recovery on stroke apparent diffusion coefficient measurements and its clinical application.

BACKGROUND AND PURPOSE: The application of a fluid-attenuated inversion-recovery pulse with a conventional diffusion-weighted MRI sequence (FLAIR DWI) decreases the partial volume effects from cerebrospinal fluid on apparent diffusion coefficient (ADC) measurements. For this reason, FLAIR DWI may be more useful in the evaluation of ischemic stroke, but few studies have looked at the effect of FLAIR on ADC measurements in this setting. This study quantitatively compares FLAIR DWI and conventional DWI in ischemic stroke of varying ages to assess the potential advantages of this technique. METHODS: We respectively analyzed 139 DWI studies in patients with ischemic stroke with and without FLAIR at varying time points ranging from hyperacute to chronic. ADC values were measured in each lesion, as well as in the contralateral normal side. Comparisons were made between the ADC values obtained from the DWI sequences with and without FLAIR for both the lesion and the normal contralateral side. RESULTS: The ADC measurements within the ischemic lesion were very similar on FLAIR DWI and conventional DWI for lesions less than 14 days old (p>0.05), but were significantly decreased on FLAIR DWI for lesions between 15 and 30 days old and in lesions >31 days old (chronic stage) (p<0.01). The contralateral ADC values were all significantly decreased on the FLAIR DWI sequence compared with conventional DWI (p<0.01). CONCLUSIONS: The application of an inversion pulse does not significantly affect the ADC values for early stage ischemic stroke (less than 14 days from symptom onset), but results in a more accurate relative ADC measurement by reducing the cerebrospinal fluid partial volume effects of the normal contralateral side. In addition, combined with the conventional DWI, FLAIR DWI may be helpful in determining the age of ischemic lesions.

Regional diffusion changes of cerebral grey matter during normal aging--a fluid-inversion prepared diffusion imaging study.

BACKGROUND AND PURPOSE: Although diffusion characteristics of white matter (WM) and its aging effects have been well described in the literature, diffusion characteristics of grey matter (GM), especially the cortical GM, have not been fully evaluated. In the present study, we used the fluid-inversion prepared diffusion imaging (FLIPD) technique to determine if there are age-related water diffusivity changes in GM. MATERIALS AND METHODS: 120 healthy volunteers were recruited for our study. They were divided into three age groups: group one (20-39 years old), group two (40-59 years old) and group three (60 years or older). All patients were evaluated with MRI using FLIPD at 3.0T. Apparent diffusion coefficient (ADC) values of the frontal GM, cingulate cortex and thalami were determined bilaterally by region-of-interest analysis. RESULTS: Group three had significantly higher ADC values in both thalami and the left frontal GM compared to group two or group one. No ADC value difference was found among the three groups in the right frontal GM and bilateral cingulate cortex. There was a significant positive correlation between individual ADC values and age in both thalami and left frontal GM. For the cingulate cortex and the right frontal GM, ADC values did not correlate significantly with advancing age. CONCLUSION: Statistically significant age-related diffusion changes were observed in both thalami and the left frontal cortex. The data reported here may serve as a reference for future studies.

Lipid signal in evaluation of intracranial meningiomas.

BACKGROUND: Using magnetic resonance imaging, diagnosis of malignant meningioma from benign meningioma with atypical features is uncertain. We evaluated the value of lipid signal in differentiating intracranial meningiomas. METHODS: 1H-magnetic resonance spectroscopy (MRS) using a point resolved spectroscopy (TR/TE 1000/144 ms) sequences were performed on 34 patients on a 3.0 T scanner. Lipid peak located at 1.3 ppm was evaluated. MRS data from these tumours were compared with histopathological findings (including hematoxylin and eosin staining and KP-1 staining). RESULTS: Twenty-nine meningiomas were histologically benign (eleven meningothelial, thirteen fibrous, four transitional and one microcystic), three were atypical, and two were anaplastic. Lipid signal was detected in ten cases: two anaplastic, three atypical, two fibrous and three meningothelial meningiomas. All voxels with lipid peak in the spectrum from the tumour were evaluated. With creatinine peak in the normal white matter chosen as internal standard, lipid/creatinine ratios of anaplastic, atypical and benign meningiomas were 0.844 +/- 0.027 (range from 0.725 to 0.994), 0.465 +/- 0.023 (range from 0.239 to 0.724), and 0.373 +/- 0.016 (range from 0.172 to 0.571) respectively. Highly significant differences were noted between anaplastic and the other two subtypes. Patchy necrosis was observed in anaplastic meningioma, while focal necrosis was noted in atypical meningioma with HE stain. However, no necrosis was found in benign group. KP-1 stain demonstrated histocytes containing lipids in the necrotic region of anaplastic and atypical meningioma. CONCLUSION: The lipid signal at 1.3 ppm is a useful marker in evaluating the malignancy of intracranial meningiomas, especially in the differential diagnosis of anaplastic meningioma.

Diagnostic value of contrast-enhanced fluid-attenuated inversion-recovery MRI for intracranial tumors in comparison with post-contrast T1W spin-echo MRI.

BACKGROUND: Contrast-enhanced fluid-attenuated inversion-recovery (FLAIR) magnetic resonance imaging (MRI) has been reported to have higher sensitivity for detecting leptomeningeal disease compared with contrast-enhanced T1-weighted MRI (CE T1WI). However, currently there are no studies showing the potential value of clinical applications of contrast-enhanced FLAIR (CE FLAIR) sequence in diagnosing intracranial tumors in a larger group of patients. The purpose of this study was to evaluate the diagnostic value of CE FLAIR in comparison with CE T1WI for intracranial tumors and to provide more information for clinical diagnosis and therapy. METHODS: One hundred and four consecutive cases of intracranial tumors referred for CE brain MRI were analyzed with regard to FLAIR and T1WI pre- and post-administration of Gd-DTPA. The CE FLAIR and CE T1WI were evaluated independently by two radiologists for the number of examinations with one or more enhanced lesions, the number and location of enhanced lesions per examination, signal-to-noise ratio (SNR) and contrast-enhancement ratio (CER) of lesions, as well as the size and extent of the enhanced lesions. RESULTS: In 98 of 104 cases, enhanced lesions were seen both on the FLAIR and T1W images. More lesions were seen on CE T1WI (n = 120) than those on CE FLAIR sequence (n = 117), but no differences of statistical significance were found between the two sequences (P > 0.05). Four lesions were revealed only on the CE FLAIR images whereas 7 lesions were only found on CE T1WI. Enhanced lesions located in the cerebral hemisphere or the forth ventricle were revealed much more on CE T1WI than on CE FLAIR images. However, CE FLAIR images may be useful in showing superficial abnormalities and those located in the sulcus or lateral ventricle. The CER and contrast-to-noise ratio (CNR) on CE T1WI was significantly higher (t = 7.10, P = 0.00; t = 9.67, P = 0.00, respectively), but grey matter/white matter contrast was lower (t = 2.46, P = 0.02) than those on CE FLAIR images. The SNR did not show any statistically significant difference between the two sequences (t = 1.1, P = 0.27). The size and extent of lesions on the CE FLAIR images were significantly larger than those on CE T1WI (t = 4.13, P = 0.00). CONCLUSIONS: CE FLAIR and CE T1WI may complement each other in showing intracranial tumors and the CE FLAIR sequence should be selected as a routine MRI sequence.

[Diffusion tensor tracking of cerebral white matter fibers: a preliminary study].

OBJECTIVE: To study the efficacy of diffusion tensor tracking (DTT) in study of the normal and abnormal cerebral white matter fiber. METHODS: Ten normal adult volunteers, 5 males and 5 females, aged 40.9 (24-65), and 28 patients with cranial tumors, 9 males and 19 females, aged 43.0 (11-77), underwent MR diffusion tensor. The data thus obtained were transferred to a personal computer and processed with dTV. RESULTS: The main cerebral white matter fiber pathways were successfully observed. Association fibers, including arcuate fibers, cingulum, superior and inferior longitudinal fasciculus, and inferior fronto-occipital fasciculus, commissural fibers (corpus callosum), and projection fibers (corticospinal tract) were revealed. The arcuate fibers, cingulum, superior and inferior longitudinal fasciculus, corticospinal tract, external capsule, optic radiation, and corpus callosum were all involved by intracranial tumors. The abnormality of cerebral white matter could be classified into 4 groups: disruption + infiltration (7 cases), disruption + displacement (10 cases), infiltration + displacement (3 cases), and displacement (8 cases). CONCLUSION: DTT is useful for showing the main normal and abnormal cerebral white mater fiber tracts, thus opening a new field foe research of cerebral white matter fiber in vitro.

[The value of diffusion MR imaging in judging pathological changes of brain multiple sclerosis].

OBJECTIVE: To analyze the findings of MR diffusion weighted imaging (DWI) and diffusion tensor Imaging (DTI) in patients with multiple sclerosis (MS), and to explore their role in reflecting the pathological changes of MR lesions. METHODS: DWI and DTI were performed on 41 MS cases and 25 sub-acute brain infarct cases which used as control group. The appearances of ADC maps, EADC maps and FA maps in patients of both groups were analyzed. Quantitative analysis of the values of ADC, EADC and FA in the center and periphery of the lesions of acute MS, chronic MS and sub-acute brain infarct was carried out separately. RESULT: In DWI, the small chronic lesions were iso-intensity, and the large acute MS lesions and the sub-acute-infarct lesions had a high signal intensity to various degrees. In the EADC map, only in 13 cases with acute MS around the peripheral zone of the lesions there was a high signal intensity, and all other cases, including the cases with chronic MS and brain infarct had no high signal lesions. The ADC values of chronic and infarct lesions were similar (P > 0.05), both of them had the highest ADC value which were higher than the signal intensity in the center (both P < 0.05) and the periphery (both P < 0.05) of the MS lesions. The FA values in the infarct lesions were the lowest, much more lower than that in the chronic MS lesions (P < 0.05). The FA value in the center of acute MS lesions was lower than that in the peripheral zone (P < 0.05), and higher than the FA value both in the chronic MS and infarct lesions (P < 0.05). The lowest ADC value outside the peripheral zone of acute MS lesions and the highest EADC value were found. CONCLUSION: The significance of DWI high signal in the diagnosis and differential diagnosis of MS is not reliable, so the patient's history and the findings found in the routine MRI must be conjugated when an imaging diagnosis is made. The EADC map is more accurate than ADC map for showing the diffusion restriction of water molecular in the MS lesions. The degree of increase of the ADC value and the degree of decease of the FA value are proportional to the degree of severity of the pathological changes of the MS lesions.

[Value of magnetization transfer imaging in judging microchanges lesions in normal-appearing white matter of multiple sclerosis].

OBJECTIVE: To explore the value of magnetization transfer imaging (MTI) in judging microscopic lesions in normal-appearing white matter of multiple sclerosis (MS). METHODS: Forty-one patients with brain MS, 17 males and 24 females, aged 13 approximately 65, and 21 healthy people, 8 males and 13 females, aged 18 approximately 57, used as controls underwent magnetic resonance imaging (MRI) using 3D-spoiled grass (3D-SPGR) series, to scan the whole brain with saturated pulses on and off respectively. The signal values were measured directly in the pictures of these 2 series. The formula MTR = (M(0)-MS)/M(0) x 100% was used, where M0 represents the signal value of region of interest with the saturated pulses off, and Ms represents signal value of region of interest with the saturated pulses on, to calculate the MTR value. With reference to T(2)WI imaging, the MTR values of 17 regions of interest (ROI) in the normal-appearing brain white matter, including the white matter of pons, bilateral cerebellar peduncles, knees of internal capsules, splenium and genu of corpus callosum, and the white matter by the anterior horn and posterior horn of lateral ventricle, body of lateral ventricle, and deep in the frontal and parietal lobes, were measured. The average MTR value of the 17 ROI was used to represent the MTR value of the whole normal-appearing brain and used to make comparison with that of the healthy samples statistically. RESULTS: Compared with those of the healthy samples, the average MTR values of each ROI of the MS patients were lower at different degrees. The difference in the MTR values of the white matter of splenium of corpus callosum, and by lateral ventricle and deep in parietal lobe were especially bigger. The MTR value of the whole brain white matter in the healthy persons ranged from 22.76% to 25.42%, with an average value of 23.97%, both significantly higher than those of the MS patients (19.45% to 24.15%, and 22.44% respectively, both P < 0.05). CONCLUSION: MTI can be used to detect the microchange of normal appearing white matter in MS. MTR is a sensitive indicator to reflect the damage of structure of tissues.

[Prognostic value of MRI and 1H MRS in patients with temporal lobe epilepsy].

OBJECTIVE: To evaluate the prognostic value of hippocampal MRI scan, MRI volumetry and 1H MRS in patients with temporal lobe epilepsy (TLE). METHODS: 50 intractable TLE patients operated in Huashan hospital were studied. Before surgery, traditional MRI scans were used to exclude tumor and vascular malformation of the brain. All patients were examined by tilted coronal images which were perpendicular to the long axis of the hippocampus, using T1-weighted, T2-weighted and FLAIR sequence. MRI volumetric measurement of both hippocampal formation were performed. 38 patients also took 1H MRS scan. Unilateral anterior temporal lobectomy was performed in all patients and pathology showed different degrees of hippocampal sclerosis. The prognosis was categorized into three grades with grade I being assigned to the group of good outcome, and grade II and III being assigned to the bad outcome group. Correlative analysis between the results of several examinations and the prognosis were performed respectively. RESULTS: MRI-positive cases with hippocampal scans were about 84% of the 50 cases. Hippocampal atrophy, increase of signal intensity or the loss of internal morphological structure were detected. 98% of the MRI-positive patients had good outcome, and 38% of the MRI-negative patients had good outcome. The prognosis between MRI-positive group and MRI-negative group had significant difference (chi(2) = 23.00, P = 0.000). Among the right-side operated cases, the average hippocampal volume on the operated side of the bad outcome group was larger than that of the good outcome group. While among the left-side operated cases, the hippocampal volume on the non-operated side of the bad outcome group was smaller than that of the good outcome group. Significant differences were found in statistics respectively. In both groups, prognosis was found to be statistically related to the DHF value (difference of bilateral hippocampal volume). The DHF value of the good outcome group was larger than that of the bad outcome group. 38 patients took 1H MRS examination. The average NAA/(Cr + Cho) ratio on the operated side of the patients in the bad outcome group was greater than that of the good outcome group. The average NAA/(Cr + Cho) ratio on the contralateral side of the patients in the bad outcome group was lower than that of the good outcome group. But no significant differences were found in statistics respectively. 90% cases of MRS unilateral abnormalities had good outcome, while 77% cases of MRS bilateral abnormalities had good outcome. But no statistically significant difference was found among different groups (chi(2) = 0.493, P = 0.781). CONCLUSION: Hippocampal MRI scan, MRI volumetry and 1H MRS may be used as prognostic tools in TLE patients before surgery. The combination of several noninvasive methods before surgery can help choose suitable patients for surgery, and, as a result, improve surgical outcome.

Postmastectomy radiotherapy in premenopausal Vietnamese and Chinese women with breast cancer treated in an adjuvant hormonal therapy study.

BACKGROUND: Adjuvant postmastectomy radiotherapy (RT) decreases the risk of local recurrence of breast cancer and may increase overall survival (OS). METHODS AND MATERIALS: After mastectomy, 656 premenopausal Vietnamese and Chinese women with clinical Stage II-IIIA breast cancer, in a clinical trial of adjuvant surgical oophorectomy and tamoxifen, were treated with adjuvant RT according to the availability in the institution. The short-term disease recurrence and OS experience of these 656 women were analyzed using univariate and multivariate methods. RESULTS: The 193 patients who did not receive RT differed from the 463 who did in that they had larger tumors and more frequently Grade 3 tumors. With a median follow-up of 3.6 years, in univariate analysis, RT was associated with improved disease-free survival (DFS) (relative risk 0.66; 95% confidence interval 0.49-0.89; p = 0.007) and OS (relative risk 0.71; 95% confidence interval 0.50-1.00; p = 0.051). In multivariate analysis, the relative risk for DFS and OS associated with RT was 0.78 and 0.94, respectively (p = not significant for both). Kaplan-Meier estimates showed better 5-year DFS (72% vs. 59%; p = 0.006) and OS (78% vs. 70%; p = 0.05) rates with RT. CONCLUSION: In the absence of detailed CT planning capacity, adjuvant RT for premenopausal Vietnamese women was associated statistically with short-term improvement in DFS and OS in univariate, but not multivariate, analysis.

Mastectomy and oophorectomy by menstrual cycle phase in women with operable breast cancer.

BACKGROUND: It is unclear whether the phase of the menstrual cycle in which primary surgical treatment occurs influences disease-free survival (DFS) and overall survival (OS) in premenopausal women with breast cancer. We investigated this question in the context of a clinical trial comparing mastectomy alone with mastectomy plus adjuvant oophorectomy and tamoxifen in premenopausal women with operable breast cancer. METHODS: The date of the first day of the last menstrual period (LMP) was used to estimate the phase of the menstrual cycle when the surgeries were done. Follicular phase was defined as day 1-14 from LMP. Luteal phase was defined as day 15-42 from LMP. DFS and OS statistics were determined and analyzed by Cox proportional hazards ratios and Kaplan-Meier methods. All statistical tests were two-sided. RESULTS: We analyzed results for 565 women who reported an LMP within 42 days before surgery. For women in the mastectomy only arm (n = 289), there were no differences in DFS or OS by menstrual cycle phase. For women in the adjuvant treatment arm (n = 276), those whose surgery occurred during the luteal phase (n = 158) had better DFS (relative risk [RR] = 0.54; 95% confidence interval [CI] = 0.32 to 0.96; P =.02) and OS (RR = 0.53; 95% CI = 0.30 to 0.95; P =.03) than those whose surgery occurred during the follicular phase (n = 118). Moreover, women whose surgery occurred during the luteal phase and who received adjuvant therapy had better 5-year DFS than did women whose surgery occurred during the follicular phase (84%; 95% CI = 78% to 90% versus 67%; 95% CI = 58% to 78%; P =.02); they also had better OS (85%; 95% CI = 78% to 92% versus 75%; 95% CI = 66% to 84%; P =.03). CONCLUSIONS: The phase of the menstrual cycle at which surgery was done had no impact on survival for women who received mastectomy only. However, women who received a mastectomy and surgical oophorectomy and tamoxifen during the luteal phase had better outcomes than women who received surgery during the follicular phase.

Oophorectomy and tamoxifen adjuvant therapy in premenopausal Vietnamese and Chinese women with operable breast cancer.

PURPOSE: In 1992, the Early Breast Cancer Trialists' Collaborative Group reported that a meta-analysis of six randomized trials in European and North American women begun from 1948 to 1972 demonstrated disease-free and overall survival benefit from adjuvant ovarian ablation. Approximately 350,000 new cases of breast cancer are diagnosed annually in premenopausal Asian women who have lower levels of estrogen than western women. PATIENTS AND METHODS: From 1993 to 1999, we recruited 709 premenopausal women with operable breast cancer (652 from Vietnam, 47 from China) to a randomized clinical trial of adjuvant oophorectomy and tamoxifen (20 mg orally every day) for 5 years or observation and this combined hormonal treatment on recurrence. At later dates estrogen- and progesterone-receptor protein assays by immunohistochemistry were performed for 470 of the cases (66%). RESULTS: Treatment arms were well balanced. With a median follow-up of 3.6 years, there have been 84 events and 69 deaths in the adjuvant treatment group and 127 events and 91 deaths in the observation group, with 5-year disease-free survival rates of 75% and 58% (P =.0003 unadjusted; P =.0075 adjusted), and overall survival rates of 78% and 70% (P =.041 unadjusted) for the adjuvant and observation groups, respectively. Only patients with hormone receptor-positive tumors benefited from the adjuvant treatment. In Vietnam, for women unselected for hormone receptor status, a cost-effectiveness analysis suggests that this intervention costs $350 per year of life saved. CONCLUSION: Vietnamese and Chinese women with hormone receptor-positive operable breast cancer benefit from adjuvant treatment with surgical oophorectomy and tamoxifen.