• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.119-124
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• 1997

Purpose: To assess the utility of magnetic resonance(MR) cerebral blood volume (CBV) map in the evaluation of brain tumors. Materials and Methods: We performed perfusion MR imaing preoperatively in the consecutive IS patients with intracranial masses(3 meningiomas, 2 glioblastoma multiformes, 3 low grade gliomas, 1 lymphoma, 1 germinoma, 1 neurocytoma, 1 metastasis, 2 abscesses, 1 radionecrosis). The average age of the patients was 42 years (22yr -68yr), composed of 10 males and S females. All MR images were obtained at l.ST imager(Signa, CE Medical Systems, Milwaukee, Wisconsin). The regional CBV map was obtained on the theoretical basis of susceptibility difference induced by first pass circulation of contrast media. (contrast media: IScc of gadopentate dimeglumine, about 2ml/sec by hand, starting at 10 second after first baseline scan). For each patient, a total of 480 images (6 slices, 80 images/slice in 160 sec) were obtained by using gradient echo(CE) single shot echo-planar image(EPI) sequence (TR 2000ms, TE SOms, flip angle $90^{\circ}$, FOV $240{\times}240mm,{\;}matrix{\;}128{\times}128$, slice-thick/gap S/2.S). After data collection, the raw data were transferred to CE workstation and rCBV maps were generated from the numerical integration of ${\Delta}R2^{*} on a voxel by voxel basis, with home made software (${\Delta}R2^{*}=-ln (S/SO)/TE). For easy visual interpretation, relative RCB color coding with reference to the normal white matter was applied and color rCBV maps were obtained. The findings of perfusion MR image were retrospectively correlated with Cd-enhanced images with focus on the degree and extent of perfusion and contrast enhancement. Results: Two cases of glioblastoma multiforme with rim enhancement on Cd-enhanced Tl weighted image showed increased perfusion in the peripheral rim and decreased perfusion in the central necrosis portion. The low grade gliomas appeared as a low perfusion area with poorly defined margin. In 2 cases of brain abscess, the degree of perfusion was similar to that of the normal white matter in the peripheral enhancing rim and was low in the central portion. All meningiomas showed diffuse homogeneous increased perfusion of moderate or high degree. One each of lymphoma and germinoma showed homogenously decreased perfusion with well defined margin. The central neurocytoma showed multifocal increased perfusion areas of moderate or high degree. A few nodules of the multiple metastasis showed increased perfusion of moderate degree. One radionecrosis revealed multiple foci of increased perfusion within the area of decreased perfusion. Conclusion: The rCBV map appears to correlate well with the perfusion state of brain tumor, and may be helpful in discrimination between low grade and high grade gliomas. The further study is needed to clarify the role of perfusion MR image in the evaluation of brain tumor.

• Investigative Magnetic Resonance Imaging
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• v.22 no.1
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• pp.56-60
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• 2018

Therapeutic hypothermia in cardiac arrest patients is associated with favorable outcomes mediated via neuroprotective mechanisms. We report a rare case of a 32-year-old male who demonstrated complete recovery of signal changes on perfusion-weighted imaging after therapeutic hypothermia due to cardiac arrest. Brain MRI with perfusion-weighted imaging, performed three days after ending the hypothermia therapy, showed a marked decrease in relative cerebral blood flow (rCBF) and delay in mean transit time (MTT) in the bilateral basal ganglia, thalami, brain stem, cerebellum, occipitoparietal cortex, and frontotemporal cortex. However, no cerebral ischemia was not noted on diffusion-weighted imaging (DWI) or fluid-attenuated inversion recovery (FLAIR) sequences. A follow-up brain MRI after one week showed complete resolution of the perfusion deficit and the patient was discharged without any neurologic sequelae. The mechanism and interpretation of the perfusion changes in cardiac arrest patients treated with therapeutic hypothermia are discussed.

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.168-168
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• 2001

Purpose： Cerebral perfusion, as measured by interictal SPECT and PET, is known to be decreased in the affected hippocampus of the patients with hippocampal sclerosis. The purpose of th study is to evaluate the capability of perfusion MR imaging to demonstrate ipsilate hypopefusion in patients with hippocampal sclerosis.

• Biomedical Science Letters
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• v.10 no.4
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• pp.515-521
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• 2004

To measure regional cerebral blood volume (rCBV) with perfusion MR imaging of cerebral fat embolism by neutral fat and free fatty acids in cats. Triolein (group 1, n=15), oleic acid (group 2, n=9) and linoleic acid (group 3, n=11) were infused into unilateral internal carotid artery using microcatheter through the transfemoral approach. PVA particle was used as a non-fat embolic material in a control group (group 4, n=9). Perfusion-weighted MR image was obtained at 30 minutes and 2 hours postembolization, based on T2-and diffusion-weighted images. The data of lesion and contralateral normal area were transferred to personal computer, time-to-signal intensity curve was drawn and trans for used to △R2/sup */ curve in regular order. The process in the personal computer was done by using the author's developmental image processing program and interactive data language (IDL) softwares. Statistical significance was approved by paired t-test and ANOVA. rCBV of the lesion was decreased comparing to the normal area in all groups. The ratios of rCBV were as follows (group No, at 30 minutes, at 2 hours); group 1,32％, 51％; group 2, 30％, 44％; group 3, 39％, 61％; group 4, 21％, 36％. rCBVs of 2 hours was significantly increased compared to those of 30 minutes in all groups (P<0.005). rCBV was decreased at 30 minutes in cerebral fat embolism and recovered a little, but significantly at 2 hours. Perfusion-weighted images was useful method in offering hemodynamic information in cerebral fat embolism.

• Journal of the Korean Society of Radiology
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• v.6 no.1
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• pp.19-26
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• 2012

It is very important for early diagnosis and therapy with ischamic cerebral infarction patients. This study was to know the ischemic penumbra lesion which compared CT-perfusion and diffusion weighted MRI(DWMRI) with acute cerebral infarction patients. 12 acute cerebral infarction patients had performed perfusion CT and performed DWMRI. Perfusion images including cerebral blood volume(CBV), cerebral blood flow(CBF), time to peak(TTP) and mean transit time(MTT) maps obtained the values with defect lesion and contralateral normal cerebral hemisphere and DWMRI was measured by signal intensity and compared of lesion size between each perfusion map. All perfusion CT maps showed the perfusion defect lesions in all patients. There were remarkable TTP and MTT delay in perfusion defect lesions. The lesions on CBF map was the most closely correlated with the lesions on DWMRI. The size of perfusion defect lesions on TTP and MTT map was larger than that of lesions on DWMRI, suggesting that MTT map can evaluate the ischemic penumbra. Perfusion CT maps make it possible to evaluate not only ischemic core and ischemic penumbra, but also hemodynamic status in the perfusion defect area. These results demonstrate that perfusion CT can be useful to the diagnosis and treatment in the patients with acute cerebral ischemic infarction.

• Investigative Magnetic Resonance Imaging
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• v.21 no.1
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• pp.9-19
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• 2017

Background: Normalized cerebral blood volume (nCBV) can be measured using manual or semiautomatic segmentation method. However, the difference in diagnostic performance on brain tumor differentiation between differently measured nCBV has not been evaluated. Purpose: To compare the diagnostic performance of manually obtained nCBV to that of semiautomatically obtained nCBV on glioblastoma (GBM) and primary central nervous system lymphoma (PCNSL) differentiation. Materials and Methods: Histopathologically confirmed forty GBM and eleven PCNSL patients underwent 3T MR imaging with dynamic susceptibility contrast-enhanced perfusion MR imaging before any treatment or biopsy. Based on the contrast-enhanced T1-weighted imaging, the mean nCBV (mCBV) was measured using the manual method (manual mCBV), random regions of interest (ROIs) placement by the observer, or the semiautomatic segmentation method (semiautomatic mCBV). The volume of enhancing portion of the tumor was also measured during semiautomatic segmentation process. T-test, ROC curve analysis, Fisher's exact test and multivariate regression analysis were performed to compare the value and evaluate the diagnostic performance of each parameter. Results: GBM showed a higher enhancing volume (P = 0.0307), a higher manual mCBV (P = 0.018) and a higher semiautomatic mCBV (P = 0.0111) than that of the PCNSL. Semiautomatic mCBV had the highest value (0.815) for the area under the curve (AUC), however, the AUCs of the three parameters were not significantly different from each other. The semiautomatic mCBV was the best independent predictor for the GBM and PCNSL differential diagnosis according to the stepwise multiple regression analysis. Conclusion: We found that the semiautomatic mCBV could be a better predictor than the manual mCBV for the GBM and PCNSL differentiation. We believe that the semiautomatic segmentation method can contribute to the advancement of perfusion based brain tumor evaluation.

• Investigative Magnetic Resonance Imaging
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• v.22 no.2
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• pp.131-134
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• 2018

Susceptibility-weighted imaging (SWI) is well known for detecting the presence of hemorrhagic transformation, microbleeds and the susceptibility of vessel signs in acute ischemic stroke. But in some cases, it can provide the tissue perfusion state as well. We describe a case of a patient with hyperacute ischemic infarction that had a slightly hypodense, patchy lesion at the left thalamus on the initial SWI, with a left proximal posterior cerebral artery occlusion on a magnetic resonance (MR) angiography and delayed time-to-peak on an MR perfusion performed two hours after symptom onset. No obvious abnormal signals at any intensity were found on the initial diffusion-weighted imaging (DWI). On a follow-up MR image (MRI), an acute ischemic infarction was seen on DWI, which is the same location as the lesion on SWI. The hypointensity on the initial SWI reflects the susceptibility artifact caused by an increased deoxyhemoglobin in the affected tissue and vessels, which reflects the hypoperfusion state due to decreasing arterial flow. It precedes the signal change on DWI that reflects a cytotoxic edema. This case highlights that, in some hyperacute stages of ischemic stroke, hypointensity on an SWI may be a finding before the hyperintensity is seen on a DWI.

• Proceedings of the KSMRM Conference
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• 1996.10a
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• pp.79-84
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• 1996

• Proceedings of the KSMRM Conference
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• 1997.03a
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• pp.112-119
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• 1997

• Proceedings of the KSMRM Conference
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• 2000.11a
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• pp.15-15
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• 2000