Comparison of contrast-enhanced T1-weighted imaging using DANTE-SPACE, PETRA, and MPRAGE: a clinical evaluation of brain tumors at 3 Tesla.

BACKGROUND: We aimed to compare the performance of three contrast-enhanced T1-weighted three-dimensional (3D) magnetic resonance (MR) sequences to detect brain tumors at 3 Tesla. The three sequences were: (I) delay alternating with nutation for tailored excitation sampling perfection with application-optimized contrasts using different flip angle evolution (DANTE-SPACE), (II) pointwise encoding time reduction with radial acquisition (PETRA), and (III) magnetization-prepared rapid acquisition with gradient echo (MPRAGE). METHODS: This study involved 77 consecutive patients, including 34 patients with known primary brain tumors and 43 patients suspected of intracranial metastases. All patients underwent each of the three sequences with comparable spatial resolution and acquisition time post-injection. Signal-to-noise ratios (SNRs) for gray matter (GM) and white matter (WM), contrast-to-noise ratios (CNRs) for lesion/GM, lesion/WM, and GM/WM were quantitatively compared. Two radiologists determined the total number of enhancing lesions by consensus. Intraclass correlation coefficients (ICCs) between the two radiologists for metastases presence, qualitative ratings for image quality, and acoustic noise level of each sequence were assessed. RESULTS: Among the three sequences, SNRs and CNRs between lesions and surrounding parenchyma were highest using DANTE-SPACE, but CNRWM/GM was the lowest with DANTE-SPACE. SNRs for PETRA images were significantly higher than those for MPRAGE (P<0.001). CNRs between lesions and surrounding parenchyma were similar for PETRA and MPRAGE (P>0.05). Significantly more brain metastases were detected with DANTE-SPACE (n=94) compared with MPRAGE (n=71) and PETRA (n=72). The ICCs were 0.964 for MPRAGE, 0.975 for PETRA, and 0.973 for DANTE-SPACE. Qualitative scores for lesion imaging using DANTE-SPACE were significantly higher than those obtained with PETRA and MPRAGE (P=0.002 and P=0.004, respectively). The acoustic noise level for PETRA (64.45 dB) was significantly lower than that for MPRAGE (78.27 dB, P<0.01) and DANTE-SPACE (80.18 dB, P<0.01). CONCLUSIONS: PETRA achieves comparable detection of brain tumors with MPRAGE and is preferred for depicting osseous metastases and meningeal enhancement. DANTE-SPACE with blood vessel suppression showed improved detection of cerebral metastases compared with MPRAGE and PETRA, which could be helpful for the differential diagnosis of tumors.

Radiological Aspect of Klippel-Trénaunay Syndrome: A Case Series With Review of Literature.

Klippel-Trénaunay syndrome (KTS) is a rare angio-osteo-hypertrophic syndrome characterized by vascular malformations, soft tissue and/or bone hypertrophy, and varicose veins. For the purpose of describing the imaging findings and elucidating the role of medical imaging in the diagnosis and assessment of patient with KTS, we have reviewed the imaging data of 14 KTS patients. The imaging features on different imaging modalities were analyzed. Unilateral lower limb involvement was evident in 71% of cases (n=10) and bilateral but asymmetric lower limb involvement in the remaining 29% of cases (n=4). The most commonly depicted imaging features were varicosities in 93% (n=13), muscle hypertrophy in 79% (n=11) and venous anomalies in 64% (n=9). Other less common imaging findings included lymphedema in 29% (n=4), arterial malformations 29% (n=4), soft tissue hemangiomas 21% (n=3), pelvic and thigh phleboliths 21% (n=3), venous aneurysms 21% (n=3), bone abnormalities 14% (n=2) and lymphadenopathy 14% (n=2). A severe unilateral lower limb deformity resulting in contractures and muscle atrophy of the whole limb was depicted in 1 case. The pathognomonic marginal vein of Servelle was identified in 2 cases. AV shunt was highly suspected in 4 cases and was confirmed by DSA in 1 case, making Klippel-Trénaunay-Weber syndrome a more apt diagnosis. Associated ipsilateral duplicated renal artery was found in 1 case. We have concluded that medical imaging is the cornerstone in the diagnosis and assessment of severity and complications, follow-up and differentiation of KTS from other similar conditions. Different imaging modalities play complementary roles in the evaluation of KTS patients.

G-CSF and hypoxic conditioning improve the proliferation, neural differentiation and migration of canine bone marrow mesenchymal stem cells.

Transplantation using bone marrow mesenchymal stem cells (BMSCs) is emerging as a potential regenerative therapy after ischemic attacks in the brain. However, it has been questioned because very few transplanted BMSCs are detected homing to and survived in the ischemic region. Improving the cell viability and migration ability under the complex ischemic condition seems very important. The aim of our study is to identify whether hypoxic condition and granulocyte colony-stimulating factor (G-CSF) could improve the cell survival and migration ability of transplanted cells or hypoxic condition could promote BMSC's neural differentiation. BMSCs were treated under either normoxic (21% O2) or hypoxic (1% O2) (HP-BMSCs) conditions, no significant apoptosis was observed in hypoxic precondition (HP) group, our study confirmed that HP improves BMSCs proliferation and migration. Meanwhile, neural induction of BMSCs under hypoxic condition exhibited significant superior results than normoxic condition. Additionally, the addition of G-CSF in HP-BMSCs culture media promoted HP efficiency on BMSCs. These findings shed light on novel efficient strategy on the prosperity of BMSCs. Hypoxic preconditioning and cultured with G-CSF may become a promising therapeutics for cell-based therapy in the treatments of ischemia stroke.

Comparative study of the relative signal intensity on DWI, FLAIR, and T2 images in identifying the onset time of stroke in an embolic canine model.

In acute stroke magnetic resonance imaging, many attempts have been made to identify the onset time of ischemic events using the simply quantitative judgment of relative signal intensity (rSI) from various MR images. However, no uniform opinion has been achieved broadly till now. The controversy might derive from the potential patients' selection bias of clinical retrospective study, the discrepant MR parameters, and the various sample sizes among different studies. Thus, we evaluated the temporal change of the relative DWI signal intensity (rDWI), relative ADC value (rADC), relative FLAIR signal intensity (rFLAIR), and relative T2 signal intensity (rT2), and further compare their diagnostic value in identifying the hyperacute lesions based on our embolic canine model with clear onset time. Twenty ischemic models were successfully established. All rSI values were linearly correlated to time with significance until 24 h after model establishment (P < 0.05). Paired comparison of ROC curves showed that significant difference was found between rADC and other three rSIs (P < 0.0001). However, no significant difference was found among rDWI, rT2 and rFLAIR. Our results indicated that rDWI, rFLAIR and rT2 may be helpful to predict the onset time of ischemic events with the similar diagnostic value. However, the rADC does not have comparable predictive value in our embolic canine model.