• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6843-6848
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• 2014

Background: Diffusion-weighted magnetic resonance imaging (DWI) is reported to be useful for detecting malignant lesions. The purpose of this study is to clarify characteristics of imaging, detection rate and sensitivity of DWI for recurrence or metastasis of lung cancer. Methods: A total of 36 lung cancer patients with recurrence or metastasis were enrolled in this study. While 16 patients underwent magnetic resonance imaging (MRI), computed tomography (CT) and positron emission tomography-computed tomography (PET-CT), 17 underwent MRI and CT, and 3 underwent MRI and PET-CT. Results: Each recurrence or metastasis showed decreased diffusion, which was easily recognized in DWI. The detection rate for recurrence or metastasis was 100% (36/36) in DWI, 89% (17/19) in PET-CT and 82% (27/33) in CT. Detection rate of DWI was significantly higher than that of CT (p=0.0244) but not significantly higher than that of PET-CT (p=0.22). When the optimal cutoff value of the apparent diffusion coefficient value was set as $1.70{\times}10^{-3}mm^2/sec$, the sensitivity of DWI for diagnosing recurrence or metastasis of lung cancer was 95.6%. Conclusions: DWI is useful for detection of recurrence and metastasis of lung cancer.

• Imaging Science in Dentistry
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• 제49권1호
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• pp.53-58
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• 2019

Purpose: To present characteristic findings of Tc-99m hydroxymethylene diphosphonate (HMDP) scintigraphy, computed tomography (CT), and magnetic resonance (MR) imaging for osteonecrosis in the mandible, especially osteoradionecrosis(ORN) and medication-related osteonecrosis of the jaw(MRONJ). Materials and Methods: Thirteen patients with MRONJ and 7 patients with ORN in the mandible underwent Tc-99m HMDP scintigraphy, CT, and MR imaging (T1-weighted images[T1WI], T2-weighted images[T2WI], short inversion time inversion recovery images[STIR]), diffusion-weighted images[DWI], and apparent diffusion coefficient [ADC] mapping). The associations of scintigraphy, CT, and MR imaging findings with MRONJ and ORN were analyzed using the chi-square test with the Pearson exact test. Results: Thirteen patients with MRONJ and 7 patients with ORN in the mandible showed low signal intensity on T1WI and ADC mapping, high signal intensity on STIR and DWI, and increased uptake on scintigraphy. Periosteal bone proliferation on CT was observed in 69.2% of patients with MRONJ(9 of 13) versus 14.3% of patients with ORN(1 of 7)(P=0.019). Conclusion: This study presented characteristic imaging findings of MRONJ and ORN on scintigraphy, CT, and MR imaging. Our results suggest that CT can be effective for detecting MRONJ and ORN.

• Investigative Magnetic Resonance Imaging
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• 제25권4호
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• pp.338-344
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• 2021

Solitary fibrous tumors (SFT) are rare mesenchymal tumors that most commonly develop in the pleura; they rarely involve the diaphragm. MRI has not been widely used to evaluate SFTs of the thoracic cavity, though it may be highly useful in assessing local invasion, predicting malignant potential, and helping in the differential diagnosis. However, MRI findings of malignant SFTs of the diaphragmatic pleura have been described in only two cases. We report a rare case of a malignant solitary fibrous tumor of the diaphragmatic pleura in an 82-year-old man. We describe the clinical and characteristic imaging features, including computed tomography, conventional MRI, and diffusion-weighted imaging. Contrast-enhanced MRI is more accurate than is CT in identifying the origin of SFTs, predicting whether they ae benign or malignant, and assessing local invasion. This imaging modality proved helpful in deciding on the treatment strategy for these rare tumors.

• Investigative Magnetic Resonance Imaging
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• 제21권3호
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• pp.162-170
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• 2017

Purpose: To evaluate the imaging findings of desmoid tumors using various imaging modalities and to evaluate whether diffusion-weighted imaging (DWI) can help differentiate between desmoid and malignant tumors. Materials and Methods: The study included 27 patients with pathologically confirmed desmoid tumors. Two radiologists reviewed 23 computed tomography (CT), 12 magnetic resonance imaging (MRI) and 8 positron emission tomography-computed tomography (PET-CT) scans of desmoid tumors and recorded data regarding the shape, multiplicity, size, location, degree of enhancement, and presence or absence of calcification or hemorrhage. The signal intensity of masses on T1- and T2-weighted imaging and the presence or absence of whirling or band-like low signal intensity on T2-weighted imaging were recorded. The apparent diffusion coefficient (ADC) values of the desmoid tumors in nine patients with DWIs were compared with the ADC values of 32 malignant tumors. The maximum standardized uptake value ($SUV_{max}$) on PET-CT images was measured in 8 patients who underwent a PET-CT. Results: The mean size of the 27 tumors was 6.77 cm (range, 2.5-26 cm) and four tumors exhibited multiplicity. The desmoid tumors were classified by shape as either mass forming (n = 18), infiltrative (n = 4), or combined (n = 5). The location of the tumors was either intra-abdominal (n = 15), within the abdominal wall (n = 8) or extra-abdominal (n = 4). Among the 27 tumors, 21 showed moderate to marked enhancement and 22 showed homogeneous enhancement. Two tumors showed calcifications and one displayed hemorrhage. Eleven of the 12 MR T2-weighted images showed whirling or band-like low signal intensity areas in the mass. The mean ADC value of the desmoid tumors ($1493{\times}10^{-6}mm^2/s$) was significantly higher than the mean of the malignant soft tissue tumors ($873{\times}10^{-6}mm^2/s$, P < 0.001). On the PET-CT images, all tumors exhibited an intermediate $SUV_{max}$ (mean, 3.7; range, 2.3-4.5). Conclusion: Desmoids tumors showed homogenous, moderate to marked enhancement on CT and MRI scans and a characteristic whirling or band-like pattern on T2-weighted images. DWI can be useful for the differentiation of desmoid tumors from malignant soft tissue tumors.

• Investigative Magnetic Resonance Imaging
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• 제20권4호
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• pp.241-249
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• 2016

Purpose: To evaluate the added value of diffusion weighted imaging (DWI) to computed tomography (CT) for detecting pancreatic abnormality in patients with clinically suspected acute pancreatitis (AP). Materials and Methods: 203 patients who underwent abdomen CT and subsequent DWI to do a workup for epigastric pain were analyzed. Two blinded radiologists independently performed an interval reading based on CT image sets first, then based on combined CT and DWI image sets. The diagnostic criterion on DWI was the increased signal intensity in the pancreas to that of the spleen. For quantitative analysis, the third radiologist measured ADC value of the pancreas in each patient. Results: For AP (n = 43), the sensitivity for detecting pancreatic abnormality increased, from 42% to 70% for reader 1 (P < 0.05) and from 44% to 72% for reader 2 (P < 0.05). For borderline pancreatitis (n = 42), the sensitivity also increased, from 10% to 26% for reader 1 (P < 0.05) and from 7% to 29% for reader 2 (P < 0.05). The mean ADC values (unit, ${\times}10^{-3}mm^2/s$) were significantly different among the three groups (for AP, $1.09{\pm}0.16$; for borderline pancreatitis, $1.28{\pm}0.2$; for control, $1.46{\pm}0.15$, P < 0.05). Conclusion: Sensitivity for detecting pancreatic abnormality increased significantly after adding DWI to CT in patients with clinically suspected AP.

• Investigative Magnetic Resonance Imaging
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• 제20권4호
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• pp.259-263
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• 2016

Primary diffuse large B-cell lymphoma of the seminal vesicle is an extremely rare disorder, with only two cases reported in the English literature. Here, we present imaging findings of a case of primary diffuse large B-cell lymphoma of the seminal vesicle. On transrectal ultrasonography, the mass presented as a 3.0-cm-sized heterogeneous, hypoechoic lesion in the right seminal vesicle. Computed tomography (CT) revealed a mass with rim-like enhancement in the right seminal vesicle. On magnetic resonance imaging (MRI), the tumor showed iso-signal intensity on T1-weighted images and heterogeneously intermediate-high signal intensity on T2-weighted images. The tumor showed rim-like and progressive enhancement with non-enhancing portion on dynamic scanning. Diffusion restriction was observed in the mass. On fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT) imaging, a high standardized uptake value (maxSUV, 23.5) by the tumor was noted exclusively in the right seminal vesicle.

• Investigative Magnetic Resonance Imaging
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• 제15권2호
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• pp.154-159
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• 2011

고환 표피 낭종은 드문 양성 종양으로, 모든 고환 종양의 1-2%를 차지한다. 양성 질환으로 고환의 보존이 가능하므로 수술 전에 정확한 진단이 가능하다면 불필요한 고환 절제술을 피할 수 있다. 저자는 오른쪽 음낭의 무통성 종괴로 내원한 18세 남자의 고환 표피 낭종 한 례를 경험하여 보고하고자 한다. 종괴는 초음파상 양파환 징후를 보였고 컴퓨터 단층 촬영에서는 종괴 내부에 곡선의 석회화가 관찰되었다. 자기공명영상 T2 강조영상에서 종괴는 내부에 교차하는 저 신호의 환을 동반하는 고신호 강도로 보였다. 확산강조 영상에서 이 종괴는 고신호 강도를 보이고 현상확산계수(ADC) 영상에서는 낮은 값을 보였으며 이와 같은 소견은 두개내 표피 낭종에서 보고된 바와 동일한 것이다. 기존의 자기공명영상에 확산강조 영상과 현상확산계수 영상을 추가로 시행한다면 고환 표피 낭종의 진단에 도움이 될 것으로 기대된다.

• Investigative Magnetic Resonance Imaging
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• 제25권1호
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• pp.47-52
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• 2021

Paraganglioma is a rare tumor of paraganglia, derived from neural crest cells in sympathetic or parasympathetic ganglions. It can be widely distributed from the skull base to the bottom of the pelvis. The pancreas, however, is a rare location of this neoplasm, and only a limited number of cases have been reported in the English literature, especially with gadoxetic-acid-enhanced magnetic resonance imaging (MRI) and diffusion-weighted images (DWI). We herein report a case of pathologically proven paraganglioma in the pancreas head with a literature review on endoscopic ultrasonography (EUS), computed tomography (CT), gadoxetic-acid-enhanced MRI, and DWI sequence.

• Journal of Korean Neurosurgical Society
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• 제61권1호
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• pp.97-104
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• 2018

Objective : Diffusion-weighted magnetic resonance imaging (DW-MRI) has proven useful in the study of the natural history of ischemic stroke. However, the potential of DW-MRI for the evaluation of chronic subdural hematoma (CSDH) has not been established. In this study, we investigated DW-MRI findings of CSDH and evaluated the impact of the image findings on postoperative outcomes of CSDH. Methods : We studied 131 CSDH patients who had undergone single burr hole drainage surgery. The images of the subdural hematomas on preoperative DW-MRI and computed tomography (CT) were divided into three groups based on their signal intensity and density : 1) homogeneous (iso or low) density on CT and homogeneous low signal intensity on DW-MRI; 2) homogeneous (iso or low) density on CT and mixed signal intensity on DW-MRI; and 3) heterogeneous density on CT and mixed signal intensity on DW-MRI. On the basis of postoperative CT, we also divided the patients into 3 groups of surgical outcomes according to residual hematoma and mass effect. Results : Analysis showed statistically significant differences in surgical (A to B : p<0.001, A to C : p<0.001, B to C : p=0.129) and functional (A to B : p=0.039, A to C : p<0.001, B to C : p=0.108) outcomes and treatment failure rates (A to B : p=0.037, A to C : p=0.03, B to C : p=1) between the study groups. In particular, group B and group C showed worse outcomes and higher treatment failure rates than group A. Conclusion : CSDH with homogeneous density on CT was characterized by signal intensity on DW-MRI. In CSDH patients, performing DW-MRI as well as CT helps to predict postoperative treatment failure or complications.

• Investigative Magnetic Resonance Imaging
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• 제25권2호
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• pp.81-92
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• 2021

The role of neuroimaging in patients with acute ischemic stroke has been gradually increasing. The ultimate goal of stroke imaging is to make a streamlined imaging workflow for safe and efficient treatment based on optimized patient selection. In the era of multimodal comprehensive imaging in strokes, imaging based on computed tomography (CT) has been preferred for use in acute ischemic stroke, because, despite the unique strengths of magnetic resonance imaging (MRI), MRI has a longer scan duration than does CT-based imaging. However, recent improvements, such as multicoil technology and novel MRI acceleration techniques, including parallel imaging, simultaneous multi-section imaging, and compressed sensing, highlight the potential of comprehensive MR-based imaging for strokes. In this review, we discuss the role of stroke imaging in acute ischemic stroke management, as well as the strengths and limitations of MR-based imaging. Given these concepts, we review the current MR acceleration techniques that could be applied to stroke imaging and provide an overview of the previous research on each essential sequence: diffusion-weighted imaging, gradient-echo, fluid-attenuated inversion recovery, contrast-enhanced MR angiography, and MR perfusion imaging.