Contrast-Enhanced MR Imaging of Lymph Nodes in Cancer Patients

최승홍,문우경 대한영상의학회 2010 Korean Journal of Radiology Vol.11 No.4

The accurate identification and characterization of lymph nodes by modern imaging modalities has important therapeutic and prognostic significance for patients with newly diagnosed cancers. The presence of nodal metastases limits the therapeutic options, and it generally indicates a worse prognosis for the patients with nodal metastases. Yet anatomic imaging (CT and MR imaging) is of limited value for depicting small metastatic deposits in normal-sized nodes, and nodal size is a poor criterion when there is no extracapsular extension or focal nodal necrosis to rely on for diagnosing nodal metastases. Thus, there is a need for functional methods that can be reliably used to identify small metastases. Contrast-enhanced MR imaging of lymph nodes is a non-invasive method for the analysis of the lymphatic system after the interstitial or intravenous administration of contrast media. Moreover, some lymphotrophic contrast media have been developed and used for detecting lymph node metastases, and this detection is independent of the nodal size. This article will review the basic principles, the imaging protocols, the interpretation and the accuracies of contrast-enhanced MR imaging of lymph nodes in patients with malignancies, and we also focus on the recent issues cited in the literature. In addition, we discuss the results of several pre-clinical studies and animal studies that were conducted in our institution.

Glymphatic MRI application for exercise effect on brain

최승홍 한국운동재활학회 2022 한국운동재활학회 학술대회 Vol.2022 No.06

Unusual MR Features of Extravasation of Contrast Material in Hyperacute Intracerebral Hemorrhage

최승홍,장기현,전우선,김지훈,강현승,권배주,나동규,김재형,한문희 대한자기공명의과학회 2005 Investigative Magnetic Resonance Imaging Vol.9 No.1

초급성 두개내 출혈에 있어서 조영제의 혈관외 누출은 급성 출혈을 의미하며, 혈종의 크기 증가를 예견하는 소견이다. 또한, 임상 의사들에게는 적절한 치료 방침 결정에 있어 중요한 소견이다. 우리는 세 명의 초급성 두개내 출혈 환자에서 비전형적인 조영제의 혈관외 누출을 보인 자기공명 영상을 보고하고자 한다. 첫 번째 증례는 우측 기저핵과 좌측 측뇌실에 동시에 발생한 조영제 혈관외 누출의 예이며, 두 번째 증례는 혈관염이 의심되는 환자에서 조영증강을 보이는 종양이나 혈관 질환을 감별하였던 비교적 다량의 조영제의 혈관외 누출을 보인 증례이다.마지막으로, 세 번째 증례는 고혈압 환자에서 자기공명 영상을 얻는 중에 발생한 급성 출혈의 예이다.

Miniaturized Ionic Polymer Transducers for Biomedical Applications

윤벼리,최승홍,오진선,한문희,이계한,조재영 한국고분자학회 2011 한국고분자학회 학술대회 연구논문 초록집 Vol.2011 No.1

Differentiation of True Recurrence from Delayed Radiation Therapy-related Changes in Primary Brain Tumors Using Diffusion-weighted Imaging, Dynamic Susceptibility Contrast Perfusion Imaging, and Susceptibility-weighted Imaging

김동현,최승홍,류인선,윤태진,김태민,이세훈,박철기,손철호,박성혜,김일한 대한자기공명의과학회 2014 Investigative Magnetic Resonance Imaging Vol.18 No.2

Purpose : To compare dynamic susceptibility contrast imaging, diffusion-weighted imaging, and susceptibility-weightedimaging (SWI) for the differentiation of tumor recurrence and delayed radiation therapy (RT)-related changes in patientstreated with RT for primary brain tumors. Materials and Methods: We enrolled 24 patients treated with RT for various primary brain tumors, who showed newlyappearing enhancing lesions more than one year after completion of RT on follow-up MRI. The enhancing-lesions wereconfirmed as recurrences (n=14) or RT-changes (n=10). We calculated the mean values of normalized cerebral blood volume(nCBV), apparent diffusion coefficient (ADC), and proportion of dark signal intensity on SWI (proSWI) for theenhancing-lesions. All the values between the two groups were compared using t-test. A multivariable logistic regressionmodel was used to determine the best predictor of differential diagnosis. The cutoff value of the best predictor obtainedfrom receiver-operating characteristic curve analysis was applied to calculate the sensitivity, specificity, and accuracy forthe diagnosis. Results: The mean nCBV value was significantly higher in the recurrence group than in the RT-change group (P=.004),and the mean proSWI was significantly lower in the recurrence group (P<.001). However, no significant difference wasobserved in the mean ADC values between the two groups. A multivariable logistic regression analysis showed thatproSWI was the only independent variable for the differentiation; the sensitivity, specificity, and accuracy were 78.6% (11of 14), 100% (10 of 10), and 87.5% (21 of 24), respectively. Conclusion: The proSWI was the most promising parameter for the differentiation of newly developed enhancing-lesionsmore than one year after RT completion in brain tumor patients.

Measurement of Apparent Diffusion Coefficient Values from Diffusion-Weighted MRI: A Comparison of Manual and Semiautomatic Segmentation Methods

김성호,최승홍,윤태진,김태민,이세훈,박철기,김지훈,손철호,박성혜,김일한 대한자기공명의과학회 2015 Investigative Magnetic Resonance Imaging Vol.19 No.2

Purpose: To compare the interobserver and intraobserver reliability of mean apparentdiffusion coefficient (ADC) values using contrast-enhanced (CE) T1 weightedimage (WI) and T2WI as structural images between manual and semiautomaticsegmentation methods. Materials and Methods: Between January 2011 and May 2013, 28 patients whounderwent brain MR with diffusion weighted image (DWI) and were pathologicallyconfirmed as having glioblastoma participated in our study. The ADC values weremeasured twice in manual and semiautomatic segmentation methods using CE-T1WIand T2WI as structural images to obtain interobserver and intraobserver reliability. Moreover, intraobserver reliabilities of the different segmentation methods wereassessed after subgrouping of the patients based on the MR findings. Results: Interobserver and intraobserver reliabilities were high in both manualand semiautomatic segmentation methods on CE-T1WI-based evaluation, whileinterobserver reliability on T2WI-based evaluation was not high enough to be used ina clinical context. The intraobserver reliability was particularly lower with the T2WIbasedsemiautomatic segmentation method in the subgroups with involved lobes ≤2, with partially demarcated tumor borders, poorly demarcated inner margins of thenecrotic portion, and with perilesional edema. Conclusion: Both the manual and semiautomatic segmentation methods on CET1WI-based evaluation were clinically acceptable in the measurement of mean ADCvalues with high interobserver and intraobserver reliabilities.

True Progression versus Pseudoprogression in the Treatment of Glioblastomas: A Comparison Study of Normalized Cerebral Blood Volume and Apparent Diffusion Coefficient by Histogram Analysis

송용섭,최승홍,박철기,이경식,이웅재,윤태진,김태민,이세훈,김지훈,손철호,박성혜,김일한,장건호,장기현 대한영상의학회 2013 Korean Journal of Radiology Vol.14 No.4

Objective: The purpose of this study was to differentiate true progression from pseudoprogression of glioblastomas treated with concurrent chemoradiotherapy (CCRT) with temozolomide (TMZ) by using histogram analysis of apparent diffusion coefficient (ADC) and normalized cerebral blood volume (nCBV) maps. Materials and Methods: Twenty patients with histopathologically proven glioblastoma who had received CCRT with TMZ underwent perfusion-weighted imaging and diffusion-weighted imaging (b = 0, 1000 sec/mm2). The corresponding nCBV and ADC maps for the newly visible, entirely enhancing lesions were calculated after the completion of CCRT with TMZ. Two observers independently measured the histogram parameters of the nCBV and ADC maps. The histogram parameters between the true progression group (n = 10) and the pseudoprogression group (n = 10) were compared by use of an unpaired Student’s t test and subsequent multivariable stepwise logistic regression analysis to determine the best predictors for the differential diagnosis between the two groups. Receiver operating characteristic analysis was employed to determine the best cutoff values for the histogram parameters that proved to be significant predictors for differentiating true progression from pseudoprogression. Intraclass correlation coefficient was used to determine the level of inter-observer reliability for the histogram parameters. Results: The 5th percentile value (C5) of the cumulative ADC histograms was a significant predictor for the differential diagnosis between true progression and pseudoprogression (p = 0.044 for observer 1; p = 0.011 for observer 2). Optimal cutoff values of 892 x 10-6 mm2/sec for observer 1 and 907 x 10-6 mm2/sec for observer 2 could help differentiate between the two groups with a sensitivity of 90% and 80%, respectively, a specificity of 90% and 80%, respectively, and an area under the curve of 0.880 and 0.840, respectively. There was no other significant differentiating parameter on the nCBV histograms. Inter-observer reliability was excellent or good for all histogram parameters (intraclass correlation coefficient range: 0.70-0.99). Conclusion: The C5 of the cumulative ADC histogram can be a promising parameter for the differentiation of true progression from pseudoprogression of newly visible, entirely enhancing lesions after CCRT with TMZ for glioblastomas.

Prediction of Response to Concurrent Chemoradiotherapy with Temozolomide in Glioblastoma: Application of Immediate Post-Operative Dynamic Susceptibility Contrast and Diffusion-Weighted MR Imaging

이은경,최승홍,윤태진,강경미,김태민,이세훈,박철기,박성혜,김일한 대한영상의학회 2015 Korean Journal of Radiology Vol.16 No.6

To determine whether histogram values of the normalized apparent diffusion coefficient (nADC) and normalized cerebral blood volume (nCBV) maps obtained in contrast-enhancing lesions detected on immediate post-operative MR imaging can be used to predict the patient response to concurrent chemoradiotherapy (CCRT) with temozolomide (TMZ). Twenty-four patients with GBM who had shown measurable contrast enhancement on immediate post-operative MR imaging and had subsequently undergone CCRT with TMZ were retrospectively analyzed. The corresponding histogram parameters of nCBV and nADC maps for measurable contrast-enhancing lesions were calculated. Patient groups with progression (n = 11) and non-progression (n = 13) at one year after the operation were identified, and the histogram parameters were compared between the two groups. Receiver operating characteristic (ROC) analysis was used to determine the best cutoff value for predicting progression. Progression-free survival (PFS) was determined with the Kaplan-Meier method and the log-rank test. The 99th percentile of the cumulative nCBV histogram (nCBV C99) on immediate post-operative MR imaging was a significant predictor of one-year progression (p = 0.033). ROC analysis showed that the best cutoff value for predicting progression after CCRT was 5.537 (sensitivity and specificity were 72.7% and 76.9%, respectively). The patients with an nCBV C99 of < 5.537 had a significantly longer PFS than those with an nCBV C99 of ≥ 5.537 (p = 0.026). The nCBV C99 from the cumulative histogram analysis of the nCBV from immediate post-operative MR imaging may be feasible for predicting glioblastoma response to CCRT with TMZ.

Pseudo Continuous Arterial Spin Labeling MR Imaging of Status Epilepticus

이민경,최승홍,정근화,윤태진,김지훈,손철호,장기현 대한자기공명의과학회 2012 Investigative Magnetic Resonance Imaging Vol.16 No.2

Purpose : The purpose of this study was to describe arterial spin labeling MR image findings of status epilepticus. Materials and Methods: A retrospective chart review within our institute revealed six patients who had been clinically diagnosed as status epilepticus and had also undergone MR imaging that included ASL in addition to routine sequences. Results: Six patients with status epilepticus were studied by conventional MR and arterial spin labeling imaging. All patients showed increased regional CBF correlating with EEG pathology. Notably, in two patients, conventional MRI and DWI showed no abnormal findings whereas pCASL demonstrated regional increased CBF in both patients. Conclusion: Arterial spin labeling might offer additional diagnostic capabilities in the evaluation of patients with status epilepticus.

Application of Synthetic MRI for Direct Measurement of Magnetic Resonance Relaxation Time and Tumor Volume at Multiple Time Points after Contrast Administration: Preliminary Results in Patients with Brain Metastasis

강경미,최승홍,Moonjung Hwang,유노을,윤태진,김지훈,손철호 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.4

Objective: The purpose of this study was to investigate the time-dependent effects of contrast medium on multi-dynamic, multi-echo (MDME) sequence in patients with brain metastases. Materials and Methods: This study included 7 patients with 15 brain metastases who underwent magnetic resonance (MR) examination which included MDME sequences at 1 minute, 10 minutes and 20 minutes after contrast injection. Two volumes of interests, covering an entire tumor (whole tumor) and the enhancing portion of the tumor, were derived from postcontrast synthetic T1-weighted images. Statistical comparisons were performed for three different time delays for histogram parameters of the longitudinal relaxation rate (R1) and the transverse relaxation rate (R2), and lesion volumes. Results: The mean and the median of R1 and the mean of R2 in both the whole tumor and the inner enhancing portion were larger on the 10 minutes delayed images than on the 1 minute or 20 minutes delayed images (mean of R1 in the whole tumor on the 1 minute, 10 minutes, and 20 minutes delayed images: 1.26 ms, 1.39 ms, and 1.37 ms; mean of R1 in the inner enhancing portion: 1.43 ms, 1.53 ms and 1.44 ms; all p < 0.017). The volumes of the whole tumor and the inner enhancing portion were significantly larger in the 10 minutes and 20 minutes delayed images than on the 1 minute delayed images (all p < 0.017). Conclusion: Magnetic resonance relaxation times and the volumes of the whole tumor and the inner enhancing portion were measured larger on the 10 minutes or 20 minutes delayed images than on the 1 minute delayed images. The MDME sequence immediately after contrast injection cannot fully reflect the effects of gadolinium-based contrast agent leakage in the tissue.