• Investigative Magnetic Resonance Imaging
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• 제21권1호
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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.

• 한국자기공명학회논문지
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• 제9권2호
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• pp.93-102
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• 2005

Purpose: To develop an advanced non-linear curve fitting (NLCF) algorithm for dynamic susceptibility contrast study of brain. Materials and Methods: The first pass effects give rise to spuriously high estimates of $K^{trans}$ in voxels with large vascular components. An explicit threshold value has been used to reject voxels. Results: By using this non-linear curve fitting algorithm, the blood perfusion and the volume estimation were accurately evaluated in T2*-weighted dynamic contrast enhanced (DCE)-MR images. From the recalculated each parameters, perfusion weighted image were outlined by using modified non-linear curve fitting algorithm. This results were improved estimation of T2*-weighted dynamic series. Conclusion: The present study demonstrated an improvement of an estimation of kinetic parameters from dynamic contrast-enhanced (DCE) T2*-weighted magnetic resonance imaging data, using contrast agents. The advanced kinetic models include the relation of volume transfer constant $K^{trans}\;(min^{-1})$ and the volume of extravascular extracellular space (EES) per unit volume of tissue $\nu_e$.

• Korean Journal of Radiology
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• 제22권8호
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• pp.1369-1378
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• 2021

Objective: Few attempts have been made to investigate the prognostic value of dynamic contrast-enhanced (DCE) MRI or dynamic susceptibility contrast (DSC) MRI of non-enhancing, T2-high-signal-intensity (T2-HSI) lesions of glioblastoma multiforme (GBM) in newly diagnosed patients. This study aimed to investigate the prognostic values of DCE MRI and DSC MRI parameters from non-enhancing, T2-HSI lesions of GBM. Materials and Methods: A total of 76 patients with GBM who underwent preoperative DCE MRI and DSC MRI and standard treatment were retrospectively included. Six months after surgery, the patients were categorized into early progression (n = 15) and non-early progression (n = 61) groups. We extracted and analyzed the permeability and perfusion parameters of both modalities for the non-enhancing, T2-HSI lesions of the tumors. The optimal percentiles of the respective parameters obtained from cumulative histograms were determined using receiver operating characteristic (ROC) curve and univariable Cox regression analyses. The results were compared using multivariable Cox proportional hazards regression analysis of progression-free survival. Results: The 95th percentile value (PV) of Ktrans, mean Ktrans, and median Ve were significant predictors of early progression as identified by the ROC curve analysis (area under the ROC curve [AUC] = 0.704, p = 0.005; AUC = 0.684, p = 0.021; and AUC = 0.670, p = 0.0325, respectively). Univariable Cox regression analysis of the above three parametric values showed that the 95th PV of Ktrans and the mean Ktrans were significant predictors of early progression (hazard ratio [HR] = 1.06, p = 0.009; HR = 1.25, p = 0.017, respectively). Multivariable Cox regression analysis, which also incorporated clinical parameters, revealed that the 95th PV of Ktrans was the sole significant independent predictor of early progression (HR = 1.062, p < 0.009). Conclusion: The 95th PV of Ktrans from the non-enhancing, T2-HSI lesions of GBM is a potential prognostic marker for disease progression.

• Korean Journal of Radiology
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• 제20권6호
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• pp.863-879
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• 2019

Hepatocellular carcinoma (HCC) can be noninvasively diagnosed on the basis of its characteristic imaging findings of arterial phase enhancement and portal/delayed "washout" on computed tomography (CT) and magnetic resonance imaging (MRI) in cirrhotic patients. However, different specific diagnostic criteria have been proposed by several countries and major academic societies. In 2018, major guideline updates were proposed by the Association for the Study of Liver Diseases, European Association for the Study of the Liver (EASL), Korean Liver Cancer Association and National Cancer Center (KLCA-NCC) of Korea. In addition to dynamic CT and MRI using extracellular contrast media, these new guidelines now include magnetic resonance imaging (MRI) using hepatobiliary contrast media as the first-line diagnostic test, while the KLCA-NCC and EASL guidelines also include contrast-enhanced ultrasound (CEUS) as the second-line diagnostic test. Therefore, hepatobiliary MR contrast media and CEUS will be increasingly used for the noninvasive diagnosis and staging of HCC. In this review, we discuss the emerging role of hepatobiliary phase MRI and CEUS for the diagnosis of HCC and also review the changes in the HCC diagnostic criteria in major guidelines, including the KLCA-NCC practice guidelines version 2018. In addition, we aimed to pay particular attention to some remaining issues in the noninvasive diagnosis of HCC.

• 대한방사선기술학회지:방사선기술과학
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• 제26권3호
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• pp.33-39
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• 2003

잡견의 간흡충증에서 조영기법의 역동적 CT 영상과 MIP 기법을 적용한 자기공명 영상의 질을 비교하여 임상적 적용 가능성을 알아보고자 하였다. 20마리의 잡견(평균 20kg)에 실험적으로 간흡충증을 유발한 후 13주 동안에 간을 중심으로 CT 영상과 MR 영상을 얻었다. CT는 이중나선식방법으로 영상을 획득하였고, bolustracking 방법으로 조영제를 주입하여 arterial phase는 5초 후에 정맥기는 동맥기 scan후 15초에 시작하여 single dynamic scan을 하고, 데이터를 다 단면 영상을 얻기 위해 MnP로 재구성을 하였다. MR 영상은 circularly polarized phased away body coil을 사용하였고, HASTE, FLASH, TSE 기법을 이용하여 모두 2차원 영상을 얻었다. HASTE와 TSE는 해상력을 증가시키기 위하여 interpolation과 지방소거기법을 적용하였다. 데이터를 획득하는 방식으로는 담관을 중심으로 3방향으로 수집한 다음 최대강도투사법으로 재구성하였다. CT와 MR 영상의 평가 방법으로서는 간내담관의 확장, 동맥기에 담관벽의 조영증강, 담관 말단부의 확장, 간의 실질조직묘사, 배경유무를 기점으로 병리학과 의사 1명과 방사선과 의사 3명, 방사선사 5명이 시각적으로 평가를 하였다. MR 영상의 경우 sequence 비교를 위해 정량적분석방법인 CNR과 CR로 평가를 하였다. 감염 후 5마리의 잡견은 죽었으며, 15마리 잡견에서 CT와 MR 검사에서 간내 담관의 만성 확장을 보여 주었다. 조영증강기법인 CT 영상에서는 간 실질조직을 비롯하여 담관벽의 조영증강이 보였고, MR 영상에서는 간내담관 형태와 담관의 말단부의 확장이 MIP 기법을 이용하여 3차원적으로 관찰되었고, CNR과 CR 값이 HASTE($16{\pm}0.83$, 73.3%), TSE($7.06{\pm}3.0$, 62.3%), FLASH($1.19{\pm}0.2$, 6.4%) 순으로 나타났다. CT와 MR 영상은 짧은 검사기법과 다양한 검사기법을 포함하고 있어 간흡충증을 영상화하는데 있어서 진단적 가치가 있다. CT와 MR 영상 검사의 장 단점을 서로 보안하여 검사를 시행한다면 높은 임상적 적용 가능성이 있다.

• Investigative Magnetic Resonance Imaging
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• 제19권2호
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• pp.127-130
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• 2015

Direct injection of foreign material, such as liquid paraffin and silicone, into the breast can induce a foreign body granulomatous reaction and fibrosis, resulting in hard, nodular breast masses and architectural distortion that can mimic neoplasm. Conventional methods, including physical examination, mammography, and ultrasonography are of little use to differentiate between foreign body-induced mastopathy and breast cancer. In patients with foreign body injection such as breast augmentation, dynamic contrast enhanced MR imaging is an excellent imaging modality. Here, the authors report the MR imaging and pathological findings of ductal carcinoma in situ (DCIS) with multicystic changes in a 41-year-old woman with a previous history of interstitial mammoplasty by paraffin injection.

• Korean Journal of Radiology
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• 제2권1호
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• pp.1-7
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• 2001

Objective: To determine the usefulness of perfusion MR imaging in assessing the histologic grade of cerebral gliomas. Materials and Methods: In order to determine relative cerebral blood volume (rCBV), 22 patients with pathologically proven gliomas (9 glioblastomas, 9 anaplastic gliomas and 4 low-grade gliomas) underwent dynamic contrast-enhanced T2^*-weighted and conventional T1- and T2-weighted imaging. rCBV maps were obtained by fitting a gamma-variate function to the contrast material concentration versus time curve. rCBV ratios between tumor and normal white matter (maximum rCBV of tumor / rCBV of contralateral white matter) were calculated and compared between glioblastomas, anaplastic gliomas and low-grade gliomas. Results: Mean rCBV ratios were 4.90°±1.01 for glioblastomas, 3.97°±0.56 for anaplastic gliomas and 1.75°±1.51 for low-grade gliomas, and were thus significantly different; p < .05 between glioblastomas and anaplastic gliomas, p < .05 between anaplastic gliomas and low-grade gliomas, p < .01 between glioblastomas and low-grade gliomas. The rCBV ratio cutoff value which permitted discrimination between high-grade (glioblastomas and anaplastic gliomas) and low-grade gliomas was 2.60, and the sensitivity and specificity of this value were 100% and 75%, respectively. Conclusion: Perfusion MR imaging is a useful and reliable technique for estimating the histologic grade of gliomas.

• Asian Pacific Journal of Cancer Prevention
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• 제16권8호
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• pp.3407-3412
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• 2015

Background: The aim of this study was to evaluate and compare the accuracy of diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) value, and time-intensity curve (TIC) type analysis derived from dynamic contrast-enhanced MR imaging (DCE-MRI) in differentiating benign from malignant adnexal masses. Materials and Methods: 47 patients with 56 adnexal masses (27 malignant and 29 benign) underwent DWI and DCE-MRI examinations, prior to surgery. DWI signal intensity, mean ADC value, and TIC type were determined for all the masses. Results: High signal intensity on DWI and type 3 TIC were helpful in differentiating benign from malignant adnexal masses (p<0.001). The mean ADC value was significantly lower in malignant adnexal masses (p<0.001). An ADC value< $1.20{\times}10^{-3}mm^2/s$ may be the optimal cutoff for differentiating between benign and malignant tumors. The negative predictive value for low signal intensity on DWI, and type 1 TIC were 100%. The pairwise comparison among the receiver operating characteristic (ROC) curves showed that the area under the curve (AUC) of TIC was significantly larger than the AUCs of DWI and ADC (p<0.001 for comparison of TIC and DWI, p<0.02 for comparison of TIC and ADC value). Conclusions: DWI, ADC value and TIC type derived from DCE-MRI are all sensitive and relatively specific methods for differentiating benign from malignant adnexal masses. By comparing these functional MR techniques, TIC was found to be more accurate than DWI and ADC.

• Korean Journal of Radiology
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• 제22권1호
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• pp.118-130
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• 2021

Objective: This study aimed to investigate the blood-brain barrier (BBB) disruption in mild traumatic brain injury (mTBI) patients with post-concussion syndrome (PCS) using dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging and automatic whole brain segmentation. Materials and Methods: Forty-two consecutive mTBI patients with PCS who had undergone post-traumatic MR imaging, including DCE MR imaging, between October 2016 and April 2018, and 29 controls with DCE MR imaging were included in this retrospective study. After performing three-dimensional T1-based brain segmentation with FreeSurfer software (Laboratory for Computational Neuroimaging), the mean K^trans and v_p from DCE MR imaging (derived using the Patlak model and extended Tofts and Kermode model) were analyzed in the bilateral cerebral/cerebellar cortex, bilateral cerebral/cerebellar white matter (WM), and brainstem. K^trans values of the mTBI patients and controls were calculated using both models to identify the model that better reflected the increased permeability owing to mTBI (tendency toward higher K^trans values in mTBI patients than in controls). The Mann-Whitney U test and Spearman rank correlation test were performed to compare the mean K^trans and v_p between the two groups and correlate K^trans and v_p with neuropsychological tests for mTBI patients. Results: Increased permeability owing to mTBI was observed in the Patlak model but not in the extended Tofts and Kermode model. In the Patlak model, the mean K^trans in the bilateral cerebral cortex was significantly higher in mTBI patients than in controls (p = 0.042). The mean v_p values in the bilateral cerebellar WM and brainstem were significantly lower in mTBI patients than in controls (p = 0.009 and p = 0.011, respectively). The mean K^trans of the bilateral cerebral cortex was significantly higher in patients with atypical performance in the auditory continuous performance test (commission errors) than in average or good performers (p = 0.041). Conclusion: BBB disruption, as reflected by the increased K^trans and decreased v_p values from the Patlak model, was observed throughout the bilateral cerebral cortex, bilateral cerebellar WM, and brainstem in mTBI patients with PCS.

• Parasites, Hosts and Diseases
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• 제45권2호
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• pp.77-85
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• 2007

Among several diagnostic tools for clonorchiasis (Clonorchis sinensis infection), radiologic examinations are commonly used in clinical practices. During the 2 past decades, many reports regarding imaging findings of clonorchiasis were introduced. The basic imaging finding of clonorchiasis is diffuse dilatation of the peripheral intra-hepatic bile ducts, without dilation of the large intrahepatic or extrahepatic bile ducts. By this finding, however, active clonorchiasis cannot be differentiated from cured infection. Some recent radiologic studies suggested specific findings of active clonorchiasis. Besides direct demonstration of worms, increased periductal echogenicity on sonography and periductal enhancement on dynamic contrast-enhanced CT or MR imaging possibly represent active clonorchiasis. Those images of the liver clonorchiasis are known to be correlated with worm burdens (EPG counts) in their frequency and also severity. The images of cholangiocarcinoma associated with clonorchiasis show both the tumor with obstruction images and diffuse dilatation of the peripheral intrahepatic bile ducts. Radiological images can be a good practical alternative diagnostic method of clonorchiasis.