Diffusion-Weighted Imaging of a Prostate Cancer Xenograft Model Seen on a 7 Tesla Animal MR Scanner: Comparison of ADC Values and Pathologic Findings

정대철,이학종,서진원,박소연,이상진,이주혁,김인후 대한영상의학회 2012 Korean Journal of Radiology Vol.13 No.1

Objective: To assess the relationship between apparent diffusion coefficient (ADC) values on diffusion-weighted magnetic resonance (MR) imaging and pathologic measures of a tumor using a prostate cancer xenograft model. Materials and Methods: Eighteen athymic nude mice with 36 PC-3-induced tumors were sacrificed to obtain specimens immediately after MR imaging in order to compare the findings on MR images with those seen on pathological specimens. Using a high-field small-animal MR scanner, T1- and T2-weighted imaging and DW MR imaging was performed. Tumors were then processed for Hematoxylin and Eosin staining to evaluate tumor cellularity, intratumoral necrosis and immunostaining using antibodies directed against CD31 and vascular endothelial growth factor (VEGF) to determine the levels of microvessel density (MVD). Mean ADC values that were measured on the solid portion within each tumor were compared with tumor volume, cellularity, degree of necrosis, VEGF expression, and MVD in the corresponding section of the pathological specimen. Results: Mean ADC values of the solid portion within the PC-3-induced high-grade tumors were significantly correlated with the degree of intratumoral necrosis (r = 0.63, p < 0.0001) and MVD (r = -0.44, p = 0.008) on pathologic slides. The ADC values were not significantly correlated with tumor cellularity, VEGF expression, or tumor volume in high-grade prostate cancer tissues. Conclusion: In the xenografted prostate cancer model, the ADC values of the solid portion of the tumors are significantly correlated with tumor necrosis and MVD of the pathologic specimens. The ADC values may be utilized as surrogate markers for the noninvasive assessment of tumor necrosis and MVD in high-grade prostate cancer. Objective: To assess the relationship between apparent diffusion coefficient (ADC) values on diffusion-weighted magnetic resonance (MR) imaging and pathologic measures of a tumor using a prostate cancer xenograft model. Materials and Methods: Eighteen athymic nude mice with 36 PC-3-induced tumors were sacrificed to obtain specimens immediately after MR imaging in order to compare the findings on MR images with those seen on pathological specimens. Using a high-field small-animal MR scanner, T1- and T2-weighted imaging and DW MR imaging was performed. Tumors were then processed for Hematoxylin and Eosin staining to evaluate tumor cellularity, intratumoral necrosis and immunostaining using antibodies directed against CD31 and vascular endothelial growth factor (VEGF) to determine the levels of microvessel density (MVD). Mean ADC values that were measured on the solid portion within each tumor were compared with tumor volume, cellularity, degree of necrosis, VEGF expression, and MVD in the corresponding section of the pathological specimen. Results: Mean ADC values of the solid portion within the PC-3-induced high-grade tumors were significantly correlated with the degree of intratumoral necrosis (r = 0.63, p < 0.0001) and MVD (r = -0.44, p = 0.008) on pathologic slides. The ADC values were not significantly correlated with tumor cellularity, VEGF expression, or tumor volume in high-grade prostate cancer tissues. Conclusion: In the xenografted prostate cancer model, the ADC values of the solid portion of the tumors are significantly correlated with tumor necrosis and MVD of the pathologic specimens. The ADC values may be utilized as surrogate markers for the noninvasive assessment of tumor necrosis and MVD in high-grade prostate cancer.

Diffusion-Weighted MR Imaging of Unicystic Odontogenic Tumors for Differentiation of Unicystic Ameloblastomas from Keratocystic Odontogenic Tumors

Yifeng Han,Xindong Fan,Lixin Su,Zhenfeng Wang 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.1

Objective: Differentiating unicystic ameloblastomas from keratocystic odontogenic tumors (KCOT) is necessary for the planning of different treatment strategies; however, it is difficult based on conventional CT and MR sequences alone. The purpose of this study was to investigate the utility of diffusion-weighted imaging (DWI) and apparent diffusion coefficients (ADCs) in the differentiation of the two tumors. Materials and Methods: We prospectively studied 40 patients with odontogenic cysts and tumors of the maxillomandibular region using conventional MR imaging and DWI. ADCs were measured using 2 b factors (500 and 1000). Results: Unicystic ameloblastomas (n = 11) showed free diffusion on DWI and a mean ADC value of 2.309 ± 0.17 x 10-3 mm2/s. KCOT (n = 15) showed restricted diffusion on DWI with a mean ADC value of 0.923 ± 0.20 x 10-3 mm2/s. The ADC values of unicystic ameloblastomas were significantly higher than those of KCOT (p < 0.001, Mann-Whitney U-test). An ADC cut-off value of 2.0 x 10-3 mm2/s to differentiate KCOT and unicystic ameloblastomas resulted in a 100% sensitivity and 100% specificity. Dentigerous cysts (n = 3) showed restricted diffusion on DWI and similar ADC values (1.257 ± 0.05 x 10-3 mm2/s) to those of KCOT. Conclusion: Diffusion-weighted imaging and ADC determination can be used as an adjuvant tool to differentiate between unicystic ameloblastomas and KCOT, although the ADC values of dentigerous cysts overlap with those of KCOT.

MR Spectroscopy and Diffusion Weighted Imaging Findings of Primary Non-Hodgkin Lymphoma of the Breast: Two Case Reports

남상유,유은영,최혜영 대한자기공명의과학회 2014 Investigative Magnetic Resonance Imaging Vol.18 No.2

Primary non-Hodgkin lymphoma (NHL) of the breast is a very rare disease, and the mammographic and ultrasonographicfindings of breast lymphoma are variable. There are several reports of magnetic resonance (MR) imaging findings inpatients with breast lymphomas; however, few reports have described the findings observed on MR spectroscopy or thefeatures of diffusion weighted (DW) imaging. The authors report the findings of classical MR imaging, MR spectroscopyand DW imaging of a 48-year-old woman and a 40-year-old woman with primary non-Hodgkin’s lymphoma of breasts. Mammography and breast ultrasonography revealed a mass with circumscribed margin. The mass showed strongenhancement after contrast injection on MR imaging. DW imaging showed reduced diffusion and high-amplitude choline(Cho) peak at 3.22 ppm was detected by single voxel MR spectroscopy which was consistent with malignancy

두개강내 종양의 확산강조자기공명영상: 임상적 유용성

이영철,서정진,정광우,강형근,김윤현 대한자기공명의과학회 2000 Investigative Magnetic Resonance Imaging Vol.4 No.1

목적: 두개강내 종양의 감별진단에 있어서 확산강조자기공명영상(DWi: diffusion weighted MR imaging)의 임상적 유용성을 알아 보고자 하였다. 대상 및 방법: 19예의 두개강내 종양(전이암 10예, 고등급 교종 4예, 저등급 성상세포종 4예, 핍지교종 1예)을 대상으로 1.5T 장치를 이용하여 통상적인 자기공명영상과 EPI기법을 사용한 DWI(TR/TE=6500/107, b value 1000)를 얻었다. DWI에서 종%$\varepsilon$을 고형성분, 괴사나 낭성 부위, 주위 부종으로 나누어 신호강도(뇌설과 뇌실질을 기준으로 5등급으로 나눔)와 벙변과 반 대쪽 정상 뇌설질의 상대적 신호강도비(SIR: signal intensity ratio)를 구하였다. 이렇게 얻어진 종양간의 신호강도와 신호강도비의 차이를 독립표본 T 검정을 이용하여 비교 분석하였다. 결과: DWI에서 고형성분의 경우 전이암과 고등급 교종은 전예에서 뇌실질보다 고신호강도를 보 였으며, 저등급 성상세포종과 핍지교종은 뇌실질과 등신호 또는 약간 높은 신호강도를 보였다. 각각의 고형성분에서 평균 신호강도비는 전이암 1.52, 고등급 교종 1.48, 저등급 성상세포종 1.16, 핍지교종 1.31로 측정되어서 전반적으로 악성도가 증가할수록 높은 신호강도비를 보였다(P(0.05). 종양 주위 부종은 전이암 10예와 고등급 교종 4예에서 관찰되었으며 이중 전이암 7예, 고등급 교종 2예에서는 뇌실질과 유사한 신호강도를 보인 반면 나머지 5예들에서는 뇌실 질보다 높은 신호강도로 관찰되었다. 부종에서의 평균 신호강도비는 전이암이 1.14, 고등급 교종 1.31로 전이암에서 낮게 관찰되었지만 통계적 의의는 없었다(p >0.05). 괴사나 낭성부위의 평균 신호강도비는 0.63이였다. 조영증강되지 않았던 6예의 고형성분중 3예는 주위 부종보다 고신호강도를보여 종양의 경계가통상적인 자기공명영상에 비해 우수하였다. 결론: DWI에서 뇌종양의 고형성분의 신호강도는 종양의 악성도가 높을수록 고신호강도를 보였고 종양 주위 부종은 DWI기법에 기인된 고유효과인 "T2 shine through effect"와 혈관성 부종의 정도 간의 우열에 따라 다양한 소견을 보였으며, 또한 DWI에서 종양과 주위 부종과의 관계를 좀더 명확하게 구분 할 수 있었다. Purpose: To evaluate the clinical usefulness of diffusion weighted MR imaging(DWI) in the differential diagnosis of brain tumors. Materials and methods: DWI and conventional MR images of nineteen patients with brain tumors(10 metastatic tumors, 4 high grade gliomas, 4 low grade astrocytomas, one oligodendroglioma)were obtained on 1.5T unit. DWI was obtained using single shot spin echo planar imaging with b-value near 1000. We analyzed the signal intensities of lesions including solid portion, necrotic or cystic portion and peritumoral edema of brain tumors (classified five grades comparison with the signal intensities of brain parenchyma and CSF)and calculate the SIR(signal intensity ratio)of lesions to the contralateral normal brain parenchyma. We analyzed statistically the signal intensities and SIR of tumors using independence T test. Results: In solid portions of tumors, all the metastatic tumors and high grade gliomas showed high signal intensities, but low grade astrocytomas and oligodendroglioma showed iso or slight high signal intensities to the normal brain parenchyma. The SIR of solid portion has positive correlation with malignant pot ential(metastatic tumors 1.52, high grade gliomas 1.38, low grade astrocytomas 1.16, oligodendroglioma 1.31)(p < 0.05). In peritumoral edema where seen in 14 tumors, seven of 10 metastatic tumors and two of 4 high grade gliomas showed iso signal intensities, whereas edemas in other 5 brain tumors showed hyperintense to the normal brain parenchyma. The SIRs of peritumoral edemas in metastatic tumors (1.14) was lower than high grade gliomas(1.31),but statistically insignificant. The SIR of cystic or necrotic portion of brain tumors was 0.63. In non enhancing solid portions, three of six cases showed hyperintense to the adjacent peritumoral edema. Conclusion: On DWI, the signal intensities of solid portion has positive correlation with malignant potential, and perilesional edema of brain tumors appear various signal intensities owing to "T2 shine through effect" and the extensiveness of vasogenic edema. Another merit using DWI on the evaluation of brain tumors is to improved better delineation of tumor margins from the adjacent edemas, especially at the non enhancing solid portion of the tumors.

단풍단뇨증의 확산강조영상 소견 : 증례보고 I A case report

장윤우 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.2

Maple syrup urine disease (MSUD) is rare metabolic disease, which is an autosomic recessive disease with a frequency of about 1:200,00 neonates. We report the MR imaging of a 7-month old boy with maple syrup urine disease and to evaluate usefulness of diffusion MR imaging. MR imaging showed marked hyperintensity of the globus palladi, the brainstem, the cerebral peduncle, the thalami, the mesencephalon on T2-weighted and diffusion weighted images. The apparent diffusion coefficient (ADC) of these regions was markedly decreased. Diffusion-weighted MR imaging may be a valuable tool to assess the extent and progression of cytotoxicity in MSUD.

Hepatic Cavernous Hemangiomas: Relationship between Speed of Intratumoral Enhancement during Dynamic MRI and Apparent Diffusion Coefficient on Diffusion-Weighted Imaging

남세진,박계영,유정식,정재준,김주희,김기황 대한영상의학회 2012 Korean Journal of Radiology Vol.13 No.6

Objective: To investigate the relationships between the apparent diffusion coefficients (ADCs) on diffusion-weighted imaging (DWI) and the speed of contrast-enhancement in hepatic hemangiomas. Materials and Methods: Sixty-nine hepatic hemangiomas (≥ 1 cm) were evaluated with DWI, by using multiple b values (b = 50, 400, 800 s/mm2), followed by a gadolinium-enhanced dynamic MRI. The lesions were classified into three groups, according to the speed of contrast-enhancement on the portal phase. ADCs were measured on the ADC map automatically, and were calculated by using the two different b values (mADC50-400 with b values = 50 and 400; mADC400-800 with b values = 400 and 800 s/mm2). Results: The mean ADCs (x 10-3 mm2/s) were significantly higher in the rapid group (1.9 ± 0.44) than in the intermediate (1.7 ± 0.35, p = 0.046) or the slow groups (1.4 ± 0.34, p = 0.002). There were significant differences between the rapid and the slow groups in mADC50-400 (2.12 vs. 1.48; p = 0.008) and mADC400-800 (1.68 vs. 1.22, p = 0.010), and between the rapid and the intermediate groups in mADC50-400 (2.12 vs. 1.79, p = 0.049). Comparing mADC50-400 with mADC400-800, there was a significant difference only in the rapid group (p = 0.001). Conclusion: Higher ADCs of rapidly-enhancing hemangiomas may be related to richer intralesional vascular perfusion. Also, the restricted diffusion may be attributed to the difference of structural characteristics of hemangioma. Objective: To investigate the relationships between the apparent diffusion coefficients (ADCs) on diffusion-weighted imaging (DWI) and the speed of contrast-enhancement in hepatic hemangiomas. Materials and Methods: Sixty-nine hepatic hemangiomas (≥ 1 cm) were evaluated with DWI, by using multiple b values (b = 50, 400, 800 s/mm2), followed by a gadolinium-enhanced dynamic MRI. The lesions were classified into three groups, according to the speed of contrast-enhancement on the portal phase. ADCs were measured on the ADC map automatically, and were calculated by using the two different b values (mADC50-400 with b values = 50 and 400; mADC400-800 with b values = 400 and 800 s/mm2). Results: The mean ADCs (x 10-3 mm2/s) were significantly higher in the rapid group (1.9 ± 0.44) than in the intermediate (1.7 ± 0.35, p = 0.046) or the slow groups (1.4 ± 0.34, p = 0.002). There were significant differences between the rapid and the slow groups in mADC50-400 (2.12 vs. 1.48; p = 0.008) and mADC400-800 (1.68 vs. 1.22, p = 0.010), and between the rapid and the intermediate groups in mADC50-400 (2.12 vs. 1.79, p = 0.049). Comparing mADC50-400 with mADC400-800, there was a significant difference only in the rapid group (p = 0.001). Conclusion: Higher ADCs of rapidly-enhancing hemangiomas may be related to richer intralesional vascular perfusion. Also, the restricted diffusion may be attributed to the difference of structural characteristics of hemangioma.

확산강조영상의 원리 및 임상적용 - 자기공명영상

김주호,지영석,한만석 한국자기학회 2024 韓國磁氣學會誌 Vol.34 No.1

확산자기공명영상(Diffusion MR Image: DWI)은 병변에 의해 변화된 체내 조직의 특성을 비침습적으로 정량적인 값을 얻어 분석하여 영상화하여 병변의 확진에 정확히 표현하기에 임상에서 사용하고 있다 확산자기공명영상(Diffusion MR Image: DWI)와 현성 확산 계수(Apparent Diffusion Coefficient: ADC) 기법은 T2 강조영상(T2 Weighted Image: T2W과 달리 수 시간 내로 경색(Infarction) 신호가 나타나 급성경색(Acute Infarction) 진단에 매우 유용하다 최근 뇌뿐만 아니라 간 종양 검사 시 적절한 확산경사자장(b-value) 값을 통해 악성 고형성 종양과 양성, 낭성 종양의 감별에 널리 이용하고 있다. 이에 현재 활용되고 있는 확산자기공명영상의 원리와 임상적 이용에 관해 소개하고자 한다. Diffusion MR Image (DWI) detects lesions Non-invasively quantifies the characteristics of body tissues changed by Obtain and analyze the values and image them to determine the diagnosis of the lesion. It is used clinically because it can be expressed clearly. DWI and Apparent Diffusion Coefficient (ADC) techniques .Unlike T2 Weighted Image (T2W), it takes several hours to Infarction signal appears internally, supporting acute infarction diagnosis. Recently, when examining not only brain but also liver tumors, Malignant solid tumors and benign, cystic tumors can be distinguished through the appropriate b-value value. It is widely used for sheep identification. Accordingly, we would like to introduce the clinical use and future direction of diffusion magnetic resonance imaging currently being used.

골반 T2강조 MR 영상과 확산강조 MR 영상 간 자동 융합

강혜원(Hyewon Kang),정주립(Julip Jung),홍헬렌(Helen Hong) 한국정보과학회 2012 정보과학회 컴퓨팅의 실제 논문지 Vol.18 No.12

본 논문은 T2강조 MR 영상과 확산강조 MR영상의 강체 정합을 통해 자궁내막암의 위치를 자동으로 찾는 방법을 제안한다. 첫째, 정합의 정확성 향상을 위해 영상의 잡음을 제거한 후 두 영상간 밝기값 신호 분포의 유사성을 강화시킨다. 둘째, 두 영상의 크기, 위치, 회전 변환 왜곡을 보정하기 위해 정규화 상호정보를 최대화 하는 강체 정합을 반복적으로 수행한다. 셋째, 악성 종양을 쉽게 판별할 수 있도록 종양후보군을 추출하여 현상확산계수지도의 컬러맵을 종양후보군에 매핑한다. 본 논문에서 제안한 유사성 강화의 효과를 평가하기 위해 유사성 강화를 적용했을 때와 적용하지 않았을 때 초기 정규화 상호정보와 최적화된 정규화 상호정보의 차이를 비교하였다. 종양 위치화의 정확성을 확인하기 위해 융합 후 종양 영역이 매핑되는 것을 임상의의 육안평가를 통해 분석하였다. 제안방법을 통하여 T2강조 MR 영상과 확산강조 MR 영상을 융합함으로써 종양 위치를 자동으로 파악하고 자궁내막암의 병기를 확정하는데 활용할 수 있다. In this paper, we propose a method for automatic fusion of T2WI and DWI in pelvis MRI for localization of endometrial cancer. In order to improve the accuracy of rigid registration, similarity of signal distribution between the two images is enhanced. And then to correct a positional and rotational distortion between T2WI and DWI, normalized mutual information based rigid registration is performed. Finally, to easily recognize an extent of malignant lesions, ADC map is color-coded in yellow-to-red range and the rigidly transformed color map is overlaid to T2WI. To evaluate an effect on similarity enhancement, the difference of NMI increase between rigid registration with and without similarity enhancement was measured. In order to evaluate an accuracy of tumor localization, the results of tumor mapping were visually assessed by radiologists. Our method can be used to discriminate between benign and malignant uterine lesions and to help assess the extent of peritoneal spread from gynecologic malignancies.

Multidisciplinary Functional MR Imaging for Prostate Cancer

Kim, Jeong Kon,Jang, Yun-Jin,Cho, Gyunggoo The Korean Society of Radiology 2009 KOREAN JOURNAL OF RADIOLOGY Vol.10 No.6

<P>Various functional magnetic resonance (MR) imaging techniques are used for evaluating prostate cancer including diffusion-weighted imaging, dynamic contrast-enhanced MR imaging, and MR spectroscopy. These techniques provide unique information that is helpful to differentiate prostate cancer from non-cancerous tissue and have been proven to improve the diagnostic performance of MRI not only for cancer detection, but also for staging, post-treatment monitoring, and guiding prostate biopsies. However, each functional MR imaging technique also has inherent challenges. Therefore, in order to make accurate diagnoses, it is important to comprehensively understand their advantages and limitations, histologic background related with image findings, and their clinical relevance for evaluating prostate cancer. This article will review the basic principles and clinical significance of functional MR imaging for evaluating prostate cancer.</P>

Multidisciplinary Functional MR Imaging for Prostate Cancer

김정곤,장윤진,조경구 대한영상의학회 2009 Korean Journal of Radiology Vol.10 No.6

Various functional magnetic resonance (MR) imaging techniques are used for evaluating prostate cancer including diffusion-weighted imaging, dynamic contrast-enhanced MR imaging, and MR spectroscopy. These techniques provide unique information that is helpful to differentiate prostate cancer from non-cancerous tissue and have been proven to improve the diagnostic performance of MRI not only for cancer detection, but also for staging, post-treatment monitoring, and guiding prostate biopsies. However, each functional MR imaging technique also has inherent challenges. Therefore, in order to make accurate diagnoses, it is important to comprehensively understand their advantages and limitations, histologic background related with image findings, and their clinical relevance for evaluating prostate cancer. This article will review the basic principles and clinical significance of functional MR imaging for evaluating prostate cancer.