Yongmei Li

Evaluation of 64-Section CT Angiography for Detection and Treatment Planning of Intracranial Aneurysms by Using DSA and Surgical Findings

PURPOSE To investigate the diagnostic performance of 64-section computed tomographic (CT) angiography in the detection of intracranial aneurysms. MATERIALS AND METHODS This study was approved by the institutional review board; written informed consent was obtained. One hundred eight consecutive patients suspected of having intracranial aneurysms were recruited. All patients underwent both 64-detector CT angiography and digital subtraction angiography (DSA) for the detection of intracranial aneurysms. CT angiograms were reviewed by two independent blinded readers. Sensitivity, specificity, and positive and negative predictive values for aneurysm detection with CT angiography were calculated by using DSA and surgical findings as the reference standard. RESULTS One hundred seven aneurysms were seen in 96 patients. Of those, DSA helped detect 106. On a per-aneurysm basis, the sensitivity, specificity, and positive and negative predictive values for CT angiography were 99%, 100%, and 100% and 92.3%, respectively. For aneurysms smaller than 3 mm, sensitivity was 93.7% for reader 1 and 96.8% for reader 2. However, the sensitivity and specificity were both 100% for aneurysms larger than 3 mm. Therapeutic decisions could be made on the basis of information provided by CT angiography. CONCLUSION Sixty-four-detector CT angiography is an accurate imaging method for the detection of aneurysms. It may be used as the initial imaging technique in the diagnostic work-up of patients suspected of having intracranial aneurysms.

Subtraction CT angiography for evaluation of intracranial aneurysms: comparison with conventional CT angiography

The purpose of our study was to compare the diagnostic performance of subtraction computed tomography angiography (CTA) with conventional nonsubtracted CTA and digital subtraction angiography (DSA) for the detection of intracranial aneurysms. A total of 76 patients underwent both subtraction CTA and conventional CTA for the detection and therapy planning of suspected intracranial aneurysms. Subtraction and conventional CTA images were independently assessed by two readers in a blinded manner. The possibility of endovascular treatment or surgical clipping was also assessed based on information provided by CT angiograms alone. In 64 patients, 75 aneurysms were present on DSA. On a per-aneurysm basis, the sensitivity of subtraction CTA was 98.6% for reader 1, and 100% for reader 2. However, sensitivity of conventional CTA was 94.6% for reader 1, and 93.3% for reader 2. Therapeutic decisions could be made regarding 63 patients based on information provided by subtraction CTA images. However, conventional CTA provided sufficient information to make this decision for 55 patients. Conventional CTA has limited sensitivity in detecting very small aneurysms as well as aneurysms adjacent to bone. Subtraction CTA performed on a 64-row multidetector CT is an accurate and promising diagnostic tool that seems to be equivalent to 2D DSA for the detection and pretreatment planning of intracranial aneurysms.

Iron deposition of the deep grey matter in patients with multiple sclerosis and neuromyelitis optica: A control quantitative study by 3D-enhanced susceptibility-weighted angiography (ESWAN)

PURPOSE Previous studies have detected abnormal iron deposition in the deep grey matter (DGM) of multiple sclerosis (MS). The regional specificity of the DGM iron deposition in neuromyelitis optica (NMO) is still unclear. We compared the differences in the DGM iron concentration between MS and NMO patients. METHODS We enrolled 42 relapsing-remitting MS (RRMS) patients, 42 NMO patients and 42 healthy controls undergoing brain conventional MRI and three-dimensional (3D)-enhanced T(2)*-weighted angiography (ESWAN) sequences. We obtained the mean phase values (MPVs) for ESWAN-filtered phase images. An analysis of covariance (ANCOVA) was used to compare MPVs among three groups. The correlations of MPVs changes with disease duration and expanded disability status scale (EDSS) were analyzed. RESULTS The RRMS patients had higher DGM iron concentration than did the NMO and control groups, but only the bilateral substantia nigra (SN) showed a significant statistical difference among three groups (p<0.05). In the RRMS group, the iron concentration in the bilateral head of the caudate nucleus (HCN) (left: p<0.0001; right: p=0.0134) and the dentate nucleus (DN) (p<0.05 for both) were correlated with disease duration. In the NMO group, no correlation was found between the DGM iron concentration and disease duration (p>0.05). Furthermore, no correlations were found between the DGM iron concentration and EDSS (p>0.05). CONCLUSIONS We confirm the iron concentration in the DGM iron content of MS patients is more than NMO patients and healthy controls in the same age range. Furthermore, the disease duration was found to be a significant contributor to patients with MS.

Iron deposition in the precentral grey matter in patients with multiple sclerosis: A quantitative study using susceptibility-weighted imaging

PURPOSE Several studies suggest that iron deposition may play a role in multiple sclerosis (MS) pathology. Three-dimensional (3D) enhanced T2*-weighted angiography (ESWAN) at 3T was used to quantify iron deposition in the precentral grey matter in MS and its relationship with disease duration, atrophy and Expanded Disability Status Scale (EDSS) scores. METHODS We recruited 33 patients with diagnosis of clinically definite MS and 31 age- and sex-matched healthy controls who underwent conventional brain MRI, 3D-ESWAN and 3D T1sequences. We obtained the mean phase values (MPVs) of the precentral grey matter on ESWAN-filtered phase images and volume of the precentral gyrus on 3D T1 images. We investigated the correlation between precentral grey matter MPVs, precentral gyrus volume, disease duration and EDSS scores of MS patients and healthy controls. RESULTS The precentral grey matter MPVs in MS patients and controls were 1870.83 ± 56.61 and 1899.22 ± 51.73 respectively and had significant difference in the MS group vs. the control group (t=-2.09, P=0.04). There was significant negative correlation between precentral grey matter MPVs and disease duration (r=-0.365, P=0.03). No correlation was found between MPVs and EDSS scores. Mean precentral gyrus volume in MS patients was 4368.55 ± 867.78 whereas in controls was 5701.00 ± 1184.03 with significant difference between volume of the precentral gyrus in MS patients compared to healthy controls (t=-5.167, P<0.001). There was a positive correlation between MPVs and precentral gyrus volume (r=0.291, P=0.020). CONCLUSIONS Our study demonstrated that quantitative assessment of abnormal iron deposition in the precentral grey matter in MS patients can be measured using 3D-ESWAN.

Iron deposition in the gray matter in patients with relapse-remitting multiple sclerosis: A longitudinal study using three-dimensional (3D)-enhanced T2*-weighted angiography (ESWAN)

PURPOSE To investigate the relationship between the iron content by magnetic resonance imaging (MRI) and clinic correlation in patients with relapse-remitting multiple sclerosis (RRMS) over a two-year period. METHODS Thirty RRMS patients and 30 healthy control subjects were examined twice, two years apart, by undergoing brain conventional MRI and three-dimensional (3D)-enhanced T2*-weighted angiography (ESWAN) sequences at 3.0T. Quantitative differences in iron content in deep gray matter (GM) nuclei and precentral gyrus GM between patients and control subjects with repeated-measures the mean phase values (MPVs) for ESWAN-filtered phase images. Spearmans rank correlation coefficient analysis was used to evaluate correlations of the MPVs, both 2-year-difference and single-time measurements, to disease duration, expanded disability status scale (EDSS) and times of recurrence. RESULTS The RRMS patients had higher GM iron concentration than that of the healthy control subjects in both single-time measurements, but only the substantia nigra (SN), and the precentral gyrus GM (PGM) showed a significant statistical difference (p<0.05). Using the paired samples t test, we found that there were significant differences in two-year-difference measurements of the MPVs in the putamen (PUT), the globus pallidus (GP), the head of the caudate nucleus (HCN), the thalamus (THA), SN, the red nucleus (RN), the dentate nucleus (DN) and PGM, especially in SN (t=2.92, p=0.007) in RRMS patients. The MPVs of the PUT, GP, HCN, THA, SN, RN, DN and PGM for the subgroup with RRMS patients in times of recurrence less than twice were similar to the healthy controls. There was no significant difference in all regions of interests (ROIs). However, there were significant differences in all ROIs except THA and GP for the other subgroup with RRMS patients in times of recurrence more than and equal to twice. Spearmans rank correlation coefficient analysis showed there were significant negative correlations between disease duration and the MPVs in the HCN (r=-0.516, p=0.004), DN (r=-0.468, p=0.009) and PGM (r=-0.84, p=0). However, no correlations were found between the EDSS scores and the MPVs. CONCLUSIONS Iron content in the GM can be measurable using MRI and our results confirmed that iron concentration was increasing in the GM of MS patients during two-year period compared to healthy controls. Furthermore, this study had also shown significant and substantial correlation of iron concentration with disease severity.

Differentiation of intracranial tuberculomas and high grade gliomas using proton MR spectroscopy and diffusion MR imaging

OBJECTIVE The purpose of this study was to determine whether proton MR spectroscopy ((1)H MRS) and diffusion-weighted (DW) imaging can be used to differentiate intracranial tuberculomas from high grade gliomas (HGGs). MATERIALS AND METHODS A total of 41 patients (19 with intracranial tuberculomas and 22 with HGGs) were examined in our study. (1)H MRS and DW imaging were performed at a 1.5T MR scanner before operation or treatment. Concentrations of N-acetylaspartate (NAA), creatine (Cr), choline (Cho), and lipid and lactate (LL) in the contrast-enhancing rim of each lesion were expressed as metabolite ratios and were normalized to the contralateral hemisphere. The apparent diffusion coefficient (ADC) was also calculated. The metabolite ratios and ADC values in the enhancing rim of intracranial tuberculomas and HGGs were compared using the Wilcoxon rank sum test. Diagnostic accuracy was compared using receiver operating characteristic (ROC) analysis. RESULTS Significant differences were found in the maximum Cho/Cr (P=0.015), Cho/NAA (P=0.001) and Cho/Cho-n ratios (P=0.002), and minimum ADC value (P<0.001) between the intracranial tuberculomas and HGGs. Diagnostic accuracy was higher by minimum ADC value than maximum Cho/Cr, Cho/NAA and Cho/Cho-n ratios (93.8% versus 75.7%, 80.8% and 78.1%). CONCLUSION These results suggest a promising role for (1)H MRS and DW imaging in the differentiation between the intracranial tuberculomas and HGGs.

64-section multidetector CT angiography for evaluation of intracranial aneurysms: comparison with 3D rotational angiography

Background To assess the diagnostic performance of 64-section computed tomography angiography (CTA) for detection of cerebral aneurysms by comparison with the new gold standard three-dimensional (3D) digital subtraction angiography (DSA). Material and Methods A total of 128 patients who underwent both 64-section CTA and 3D DSA for suspected intracranial aneurysms were included. The location, size, and shape of the aneurysm were assessed and compared with 3D DSA results. The sensitivity, specificity, positive and negative predictive values of 64-section CTA were calculated by using 3D DSA as reference standard. Results According to the reference standard, a total of 145 aneurysms were detected at 3D DSA in 118 patients. Of these 145 aneurysms, 64-section CTA detected 139 aneurysms in 118 patients. The sensitivity of CTA for detection of aneurysm was 95.8% on a per-aneurysm basis. All missed aneurysms were non-causative very small aneurysms in patients harboring multiple aneurysms. On a per-patient basis, the sensitivity, specificity, positive and negative predictive values were 100%. Conclusion Compared with the new gold standard 3D DSA, 64-section CTA offers high sensitivity and specificity for detection of intracranial aneurysms. It could be readily used as a screening imaging method for detection of intracranial aneurysms.

Amplitude of low-frequency fluctuation (ALFF) and fractional ALFF in migraine patients: a resting-state functional MRI study

AIM To evaluate the amplitude of low-frequency oscillations (LFOs) of the brain in migraine patients using amplitude of low-frequency fluctuation (ALFF) and fractional ALFF in the interictal period, in comparison to healthy controls (HCs). MATERIALS AND METHODS A total of 54 subjects, including 30 migraineurs and 24 gender- and age-matched HCs completed the fMRI. All the data and ALFF, fALFF analyses were preprocessed with the Data Processing Assistant for Resting-State fMRI (DPARSF). All of the statistical analyses were performed using the REST software to explore the differences in ALFF and fALFF between migraine patients and HCs. RESULTS In contrast to HCs, migraine patients showed significant ALFF increase in the left medulla and pons, the bilateral cerebellum posterior lobe and right insula. The regions showing decreased ALFF in migraine patients included the bilateral cerebellum posterior lobe, left cerebellum anterior lobe, bilateral orbital cortex, right middle frontal gyrus, bilateral occipital lobe, right fusiform gyrus, and bilateral postcentral gyrus. The fALFFs in migraine patients were significantly increased in the bilateral insular and left orbital cortex, but were decreased in the left occipital lobe and bilateral cerebellum posterior lobe. CONCLUSION These ALFF and fALFF alterations in the brain regions of migraineurs are in keeping with the domains associated with pain and cognition. Such brain functional alteration may contribute to further understanding of migraine-related network imbalances demonstrated in previous studies.

Early life stress affects limited regional brain activity in depression

Early life stress (ELS) can alter brain function and increases the risk of major depressive disorder (MDD) in later life. This study investigated whether ELS contributes to differences in regional brain activity between MDD patients and healthy controls (HC), as measured by amplitude of low-frequency fluctuation (ALFF)/fractional (f)ALFF. Eighteen first-episode, treatment-naïve MDD patients and HC were assessed with the Childhood Trauma Questionnaire and resting-state functional magnetic resonance imaging. We compared ALFF/fALFF between MDD patients and HC, with or without controlling for ELS, and determined whether ELS level was correlated with regional brain activity in each group. After regressing out ELS, we found that ALFF increased in bilateral amygdala and left orbital/cerebellum, while fALFF decreased in left inferior temporal and right middle frontal gyri in MDD patients relative to controls. ELS positively correlated with regional activity in the left cerebellum in MDD and in the right post-central/inferior temporal/superior frontal cingulate, inferior frontal gyrus and bilateral cerebellum in HC. Our findings indicate that there is only very limited region showing correlation between ELS and brain activity in MDD, while diverse areas in HC, suggesting ELS has few impacts on MDD patients.

Cerebral vein changes in relapsing-remitting multiple sclerosis demonstrated by three-dimensional enhanced T 2 * -weighted angiography at 3.0 T

AbstractObjectiveTo investigate characteristics of the internal cerebral veins (ICVs) and their main tributaries and the deep medullary veins (DMVs) in patients with relapsing-remitting MS (RRMS) with enhanced T2*-weighted angiography imaging (ESWAN).MethodsFifty-three RRMS patients and 53 normal controls underwent conventional MRI and ESWAN. ESWAN venograms were created by performing minimum intensity projections of the phase images, and the resulting venograms were used to observe characteristic vascular changes, including scores of the ICVs and their main tributaries and manifestations of the DMVs. Two experienced radiologists analysed all data.ResultsPatients showed decreased mean scores of the ICVs and their main tributaries compared with controls. The mean score in acute patients was higher than in stable patients. Furthermore, the DMVs diminished and shortened in 48 patients with longer disease duration, whereas the DMVs increased and elongated in 5 patients with shorter disease duration. The penetrating veins were well defined in 30 active lesions, whereas the veins were ill defined in 69 non-active lesions. Interestingly, well-defined penetrating veins were shown in 15 non-active lesions in the stable patients.ConclusionsEnhanced T2*-weighted MR angiography can detect cerebral vein characteristics in relapsing-remitting MS patients, which may provide important information on the pathogenesis of MS.Key Points• Enhanced T2*-weighted magnetic resonance angiography (ESWAN) provides new insights into multiple sclerosis • ESWAN venograms clearly demonstrate the internal cerebral and deep medullary veins • The internal cerebral veins exhibit abnormalities in patients with relapsing-remitting MS • Deep medullary veins exhibit different manifestations in patients with different disease duration