Comparing Perfusion Data of CE-MRI, SWI, and CTA with MR Perfusion in Stroke.

BACKGROUND: To evaluate the perfusion status of patients with acute stroke, different imaging tools are used depending on the condition. CT-CT Angiography and MRI are indispensable imaging tools to diagnose and manage stroke patients. Susceptibility-weighted imaging (SWI) also has been used lately to evaluate vascular structures and consequences of stroke in the brain. We aimed to compare CE-MRI, SWI, and CTA with DSC-MRP in terms of perfusion. METHODS: Stroke cases of CE-MRI, SWI, CTA and DSC-MRP of 44 patients were included. Collateralization was assessed on CTA; leptomeningeal-pial collateralization (LPC) and parenchymal enhancement (PE) on CE-MRI; prominent vessel sign (PVS) and hemorrhagic transformation on SWI. Results were compared with MRP maps and the ratio of penumbra/infarct core. RESULTS: LPC was correlated with increased CBV (p<0,001), decreased CBF (p=0,026), and prolonged MTT and TTP (p=0,001 and p=0,003). LPC was observed more often in cases with infarct zones with penumbra compared to those without penumbra (p=0,024). PE was positively correlated with prolonged MTT and TTP (p=0,015 and p=0,031). Moreover, there was a positive relationship between PE and increased penumbra ratio over the infarct core (p=0,037). Ipsilateral PVS was associated with increased CBV (p=0,004) and decreased CBF (p=0,002). No relationship was found between collateralization grading on CTA and perfusion metrics or penumbra ratio. CONCLUSION: In conclusion; ipsilateral PVS can be a measure of CBV and CBF. LPC on CE-MRI can be a sign of an increase in CBV. PE can show larger penumbra. CE-MRI with SWI can be used to evaluate perfusion status.

The value of adjacent vessel sign in malignant breast tumors.

PURPOSE The aim of this study was to evaluate the prognostic quality of adjacent vessel sign (AVS) in malignant breast tumors by comparing it with classical prognostic pathological biomarkers and magnetic resonance imaging (MRI) findings. METHODS A total of 124 patients with 133 malignant lesions were included. All the imaging was performed on a 1.5T Avanto scanner and the images were interpreted according to BI-RADS-MR® (fifth ed.) atlas. Maximum intensity projection (MIP) images were constructed from subtracted post-contrast images and were used to investigate AVS. Histopathological results and MRI findings were compared with AVS. RESULTS Interobserver agreement about AVS status was substantial (κ=0.64). AVS positive lesions were significantly bigger in size (P < .001, AVS negative: median 12 mm, AVS positive: median 31 mm). AVS was significantly associated with increased Ki-67 index and axillary lymph node metastasis (P=.009 and P=.019, respectively). Between AVS and lymphovascular invasion (LVI), there was a trend toward positive relationship (P=.076). MRI findings of T2 hypointensity, peritumoral edema, irregular shape, non-homogeneous contrast enhancement, rapid early contrast enhancement, and skin infiltration showed significant positive relation with AVS (P < .001, P < .001, P < .001, P=.02, P=.021, and P=.021, respectively). AVS is found to be associated with increased Ki-67 index, axillary lymph node metastasis, and some MRI findings that point to malignancy or poor prognosis. CONCLUSION AVS indicates poor prognosis since it is related to axillary lymph node metastasis, increased Ki-67 index, LVI, peritumoral edema, rapid early contrast enhancement, increased background enhancement, skin extension, T2 hypointensity, non-homogeneous contrast enhancement, irregular lesion shape, and larger tumor size. AVS is an easy to use sign that shows substantial interobserver agreement.

Dynamic Contrast-Enhanced MR Perfusion in Differentiation of Benign and Malignant Brain Lesions.

BACKGROUND: We aimed to differentiate Glioblastoma Multiforme (GBM) from benign lesions like Developmental Venous Anomaly (DVA) and Cavernous Malformation (CM) by Dynamic Contrast-Enhanced MR Perfusion (DCE-MRP) markers such as Ktrans, Ve, Kep, and IAUC. METHODS: We retrospectively evaluated 20 patients; 10 GBM as the malignant group, 5 CM and 5 DVA as the benign group. Ktrans, Kep, Ve, and IAUC parameters were measured by DCE-MRP, within the lesion, at perilesional nonenhancing white matter (PLWM) and contralateral normal appearing white matter (CLWM). RESULTS: All benign and malignant lesions exhibited significantly increased Ktrans, Ve, and IAUC values compared to PLWM and CLWM (p < 0.001, p=0.006 and p<0.001). Subtracted Kep values between lesion and PLWM were significantly different between the benign and malignant groups, as the malignant group exhibited higher subtracted Kep values (p 0.035). For the malignant group; Ktrans and IAUC values at the lesion were positively correlated (r 0.911), while Kep and Ve at CLWM were negatively and strongly correlated (r 0.798). For the benign group; Ktrans with Ve and Ktrans with IAUC at lesion (r 0.708 and r 0.816 respectively), Ktrans and IAUC at PLWM (r 0.809), Ktrans and IAUC at CLWM(r 0.798) were strongly and positively correlated. Ktrans, Ve, and IAUC values can be used to restrict the lesion in both groups. CONCLUSION: Ktrans strongly correlates with IAUC and they can be used instead of each other in both benign and malignant lesions. Classical DCE-MRP parameters cannot be used in the differentiation of malignant lesions from benign vascular lesions. However, subtracted Kep values can be used to differentiate GBM from benign vascular lesions.

Follow-Up of High-Grade Glial Tumor; Differentiation of Posttreatment Enhancement and Tumoral Enhancement by DCE-MR Perfusion.

PURPOSE: To search for the utility of DCE-MRP to differentiate between posttreatment enhancement (PT) and tumoral enhancement (TM) in high-grade glial tumors. MATERIALS AND METHODS: Thirty-four patients with glioma (11 grade 3; 23 grade 4) were enrolled. Enhancement in the vicinity of the resection cavity demonstrated by DCE-MRP was taken into consideration. Based on the follow-up scans, reoperation or biopsy results, the enhancement type was categorized as PT or TM. Measurements were performed at the enhancing area near the resection cavity (ERC), nearby (NNA) and contralateral nonenhancing areas (CLNA). Perfusion parameters of the ERC were also subtracted from NNA and CLNA. Intragroup comparison (paired sample t-test) and intergroup comparison (Student's t-test) were made. RESULTS: There were 7 PTs and 27 TMs. In the PT, the subtracted values of Ve and IAUC from the CLNA and NNA and the subtracted value of Kep from NNA were statistically different. In TM, all metrics were significantly different comparing the CLNA and NNA. Comparing PT with TM, Ktrans, IAUC, Kep, and subtracted values of Ktrans and IAUC from both NNA and CLNA were significantly different. CONCLUSIONS: In PT, only Ktrans values did not reveal any difference comparing NNA and CLNA. To differentiate PT from TM, Ktrans, Kep, IAUC, and subtracted values of Ktrans and IAUC from NNA and CLNA can be used. These findings are in concordance with literature.

Normal Pressure Hydrocephalus: Clinical Symptoms, Cerebrospinal Fluid Flow Metrics and White Matter Changes.

PURPOSE: The aim of this study was to investigate correlations between clinical symptoms, cerebrospinal fluid flow metrics, hydrocephalus index, small-vessel disease, and white matter (WM) changes in normal pressure hydrocephalus (NPH). METHODS: Aquaductal stroke volumes (ASVs), Z Evans index, Fazekas grading (FG), and diffusion tensor imaging measurements from WM bundles of 37 patients with NPH were retrospectively evaluated. Mann-Whitney U test between clinical symptoms and other variables and Spearman ρ correlations for relationships between variables and Kruskal-Wallis to correlate FG with nonclinical variables were used. RESULTS: Patients with NPH had increased ASV (median 53 µL). No correlation was found between Z Evans index and ASV. Three groups of patients with dementia or ataxia or incontinence had increased ASV values than their counterparts without symptoms (55 vs 48.5 µL, 75 vs 47 µL, 64 vs 49.5 µL, respectively). Patients having 2 common symptoms of dementia and ataxia and patients having all 3 symptoms of dementia, ataxia, and incontinence were compared with ASV values of 63.5 versus 78 µL, respectively. Patients with FG 1 had median ASV values of 45 µL; FG 2, 82.5 µL; and FG 3, 59 µL. Patients with dementia had significantly higher apparent diffusion coefficient (ADC) values of corona radiata (CR) on both sides. There were no significant WM changes in patients with ataxia and incontinence. The Z Evans index was positively correlated with ADC values of CR on both sides and genu of corpus callosum. Fazekas grading was found positively correlated with ADC and negatively correlated with FA values of CR. CONCLUSIONS: Patients with NPH, regardless of stages of the diseases, have increased ASV values and could benefit from shunting. Decreasing ASV values of patients with FG 3 comparing with those with FG 2 support the hypothesis of decreasing compliance of brain with aging and increasing severity of small-vessel disease.