• Korean Journal of Radiology
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• v.25 no.5
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• pp.459-472
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• 2024

Hyperpolarized (HP) carbon-13 (¹³C) MRI represents an innovative approach for noninvasive, real-time assessment of dynamic metabolic flux, with potential integration into routine clinical MRI. The use of [1-¹³C]pyruvate as a probe and its conversion to [1-¹³C]lactate constitute an extensively explored metabolic pathway. This review comprehensively outlines the establishment of HP ¹³C-MRI, covering multidisciplinary team collaboration, hardware prerequisites, probe preparation, hyperpolarization techniques, imaging acquisition, and data analysis. This article discusses the clinical applications of HP ¹³C-MRI across various anatomical domains, including the brain, heart, skeletal muscle, breast, liver, kidney, pancreas, and prostate. Each section highlights the specific applications and findings pertinent to these regions, emphasizing the potential versatility of HP ¹³C-MRI in diverse clinical contexts. This review serves as a comprehensive update, bridging technical aspects with clinical applications and offering insights into the ongoing advancements in HP ¹³C-MRI.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.12
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• pp.1124-1131
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• 2011

In this paper, image reconstruction algorithm for breast cancer detection using MT(Microwave Tomography) was investigated. The breast cancer detection system under development uses 16 transmit/receive antennas. The signal waveform was a sinusoidal wave at 900 MHz. To solve the 2D inverse scattering problem, we used the 2D FDTD (Finite Difference Time Domain) method for forward calculation and LMA(Levenberg-Marquardt Algorithm) for optimization. The result of the image reconstruction using the numerical phantom by MRI(Magnetic Resonance Imaging) obtained from real patient of breast cancer showed that we can detect the position of the tumor accurately.

• Journal of Yeungnam Medical Science
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• v.38 no.1
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• pp.78-82
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• 2021

Pancreatic metastasis from malignant phyllodes tumor (PT) of the breast is rare, and only a few cases have been reported in the literature. Here, we report a case of pancreatic metastasis from malignant PT of the breast in a 48-year-old woman. She had had three episodes of recurrence of malignant PT in her right breast. She presented with epigastric pain for 2 months. Computed tomography and magnetic resonance imaging revealed a 6 cm-sized, well-defined, heterogeneous mass with peripheral enhancement in the body of the pancreas. Endoscopic ultrasonography-guided fine-needle aspiration was performed, and the pathologic report suggested spindle cell mesenchymal neoplasm. Subsequently, surgical excision was performed, and the mass was confirmed as a metastatic malignant PT. The imaging findings are discussed and the literature is briefly reviewed in this report.

• Investigative Magnetic Resonance Imaging
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• v.18 no.1
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• pp.43-51
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• 2014

Purpose : To review MR imaging finding of papillary lesion identified as additional suspicious lesion on MR image in women with biopsy-proven breast cancer and to evaluate upgrading rates after subsequent surgical histopathological diagnosis. Materials and Methods: Among 1729 preoperative MR image of women with biopsy proven breast cancer, US-guided CNB-proven 22 papillary lesions from 21 patients, which showed additional suspicious contrast enhancement other than index cancer on MR image, were subjected to the study. Some of these lesions underwent surgery, thus the comparisons between the histopathologic results were able to be compared to the results of US-guided CNB. Also retrospective analysis was done for MR findings of these lesions by BI-RADS MRI lexicon. Results: On MR imaging, 8 mass lesions, 7 non-mass lesions, 7 focus lesions were detected. All of the focus lesion (100%, 7/7) was diagnosed as benign lesion and showed plateau and washout pattern in dynamic MR image. After excisional biopsy, one of 9 benign papilloma (11.1%), 3 of 3 papillary neoplasm with atypia component (100%), 3 of 5 papillary neoplasm (60%) were upgraded to malignancy such as ductal carcinoma in situ (DCIS), invasive ductal carcinoma (IDC), invasive lobular carcinoma (ILC). Conclusion: The MR images of papillary lesions diagnosed by US-guided CNB exhibit no significant differences between malignancy and benign lesion. Also 41.2% of the lesion (7/17) was upgraded after subsequent surgery. Thus all of the papillary lesions require excisional biopsy for definite diagnosis and the MR imaging, it's just not enough by itself.

• Investigative Magnetic Resonance Imaging
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• v.14 no.1
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• pp.21-30
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• 2010

Purpose : To examine the imaging findings of mucinous breast carcinoma and to evaluate the difference in these findings based on the histopathologic grade. Materials and Methods : We retrospectively analyzed the imaging features according to BI-RADS in 29 patients with surgically proven mucinous carcinoma. The histopathologic grade was classified as well-differentiated, moderately-differentiated and poorly-differentiated. Based on these criteria, the differences in imaging findings were statistically analyzed. Results : Mammography was available in 20 cases, which contained 17 mass lesions (85%) and 3 cases of normal findings. On ultrasonography (27 cases), mucinous carcinoma was observed as a mass with an oval shape (59.3%), a microlobulated margin (55.6%) or an inhomogeneous isoechogenicity (74.1%). On MRI (21 cases), mucinous carcinoma was commonly observed to have a lobular shape (76%), smooth margin (86%) or heterogeneous contrast-enhancement (61.9%). On the kinetic curve, there was a delayed wash-out pattern (52.3%). There were no significant differences in the imaging findings for each histopathologic grade except that a welldifferentiated tumor had an abrupt interface. Conclusion : A well-differentiated mucinous carcinoma tended to have an abrupt interface on ultrasonography, as compared with the moderately-differentiated one. Mucinous carcinoma showed a heterogeneous enhancement and a delayed washout kinetic curve pattern on dynamic MRI.

• Investigative Magnetic Resonance Imaging
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• v.17 no.1
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• pp.8-18
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• 2013

Purpose : The purpose of this study was to find and categorize the various magnetic resonance imaging (MRI) findings of spinal metastases that correlate with the type of primary cancer. Materials and Methods: We retrospectively reviewed gadolinium-enhanced magnetic resonance images of 30 patients with 169 spinal metastatic lesions from lung cancer (n = 56), breast cancer (n = 29), colorectal cancer (n = 20), hepatocellular carcinoma (HCC) (n = 17), and stomach cancer (n = 47). The size, location, extent of invasion, signal intensity, margin, enhancement pattern, and osteoblastic or osteolytic characteristics of each metastatic tumor were analyzed. Results: The metastatic lesions from HCC were larger than those from the other primary tumors (P < 0.05) except for colorectal cancer (P = 0.268). Well-defined metastatic tumor margins were more frequently seen in lung cancer and breast cancer (P < 0.01). All but HCC showed a tendency to invade the vertebral body rather than the posterior elements (P < 0.02). Colorectal cancer and HCC showed a tendency toward extraosseous invasion without statistical significance. HCC showed a characteristic enhancement pattern of 'worms-in-a-bag'. Rim enhancement with a sclerotic center was only seen in spinal metastases from stomach cancer. Conclusion: Despite many overlapping imaging features, spinal metastases of various primary tumors display some characteristic MRI findings that can help identify the primary cancer.

• Investigative Magnetic Resonance Imaging
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• v.17 no.3
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• pp.207-214
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• 2013

Purpose : To evaluate the MRI findings of breast cancer with BRCA mutation. Materials and Methods: We collected information of the breast cancer patients who underwent the test for BRCA gene mutation as well as preoperative breast MRI from January 2007 to December 2010. A total of 185 patients were enrolled; 33 of these patients had BRCA mutations and 152 patients did not. Among them, a total of 231 breast cancers were detected. Images of the 47 breast cancers with BRCA mutation and of the 184 breast cancers without mutations were evaluated to compare the morphologic and enhancement features on MRI. Results: With MR imaging, there were no significant difference in morphologic characteristic between two groups. However, enhancement pattern in the group with BRCA mutation were more likely to have persistent enhancement (p < 0.233), and LN metastasis was more common in breast cancers without BRCA mutation. Breast cancers with BRCA 2 mutation tend to show more persistent enhancement pattern than BRCA 1 mutation. Conclusion: In breast cancer patients with BRCA mutation, MRI didn't show significant difference in morphologic characteristics, however breast cancers with BRCA gene mutation carriers tend to have benign morphologic features on MRI, such as Type 1 kinetic curve enhancement.

• Investigative Magnetic Resonance Imaging
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• v.18 no.2
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• pp.133-143
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• 2014

Purpose : The aim of this study was to determine the magnetic resonance imaging (MRI) features associated with re-excision due to the presence of a positive margin after breast conserving therapy (BCT) in breast cancer patients. Materials and Methods: We reviewed the records of 286 consecutive breast cancer patients who received BCT between January 2006 and December 2007. Among 246 patients who had undergone BCT, 38 (15.4%) underwent immediate further surgery due to positive margin status. We analyzed the MRI findings using ${\chi}^2$ test, Fisher's exact test and t tests. Multivariate logistic regression was conducted for prediction of re-excision. Results: Tumor size (p < 0.001), lesion multiplicity (p = 0.003), and non-mass-like enhancement (NMLE) type on MRI (p < 0.001) were associated with margin involvement in BCT. On preoperative MRI, larger size (${\geq}5cm$) (odds ratio = 2.96), NMLE (odds ratio = 3.81), and multifocal lesions (odds ratio = 2.54) were positively associated with re-excision. In cases involving NMLE, segmental distribution was associated with a greater likelihood of immediate re-excision. Conclusion: Larger size, multiplicity, and NMLE on MRI are significantly associated with re-excision after BCT in breast cancer patients. For NMLE lesions, the segmental distribution pattern was predictive of re-excision.

• Investigative Magnetic Resonance Imaging
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• v.23 no.1
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• pp.46-54
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• 2019

Purpose: The aim of this study was to evaluate the diagnostic performance of a computer-aided detection (CAD) system used with automated breast ultrasonography (ABUS) for suspicious lesions detected on breast MRI, and CAD-false lesions. Materials and Methods: We included a total of 40 patients diagnosed with breast cancer who underwent ABUS (ACUSON S2000) to evaluate multiple suspicious lesions found on MRI. We used CAD ($QVCAD^{TM}$) in all the ABUS examinations. We evaluated the diagnostic accuracy of CAD and analyzed the characteristics of CAD-detected lesions and the factors underlying false-positive and false-negative cases. We also analyzed false-positive lesions with CAD on ABUS. Results: Of a total of 122 suspicious lesions detected on MRI in 40 patients, we excluded 51 daughter nodules near the main breast cancer within the same quadrant and included 71 lesions. We also analyzed 23 false-positive lesions using CAD with ABUS. The sensitivity, specificity, positive predictive value, and negative predictive value of CAD (for 94 lesions) with ABUS were 75.5%, 44.4%, 59.7%, and 62.5%, respectively. CAD facilitated the detection of 81.4% (35/43) of the invasive ductal cancer and 84.9% (28/33) of the invasive ductal cancer that showed a mass (excluding non-mass). CAD also revealed 90.3% (28/31) of the invasive ductal cancers measuring larger than 1 cm (excluding non-mass and those less than 1 cm). The mean sizes of the true-positive versus false-negative mass lesions were $2.08{\pm}0.85cm$ versus $1.6{\pm}1.28cm$ (P < 0.05). False-positive lesions included sclerosing adenosis and usual ductal hyperplasia. In a total of 23 false cases of CAD, the most common (18/23) cause was marginal or subareolar shadowing, followed by three simple cysts, a hematoma, and a skin wart. Conclusion: CAD with ABUS showed promising sensitivity for the detection of invasive ductal cancer showing masses larger than 1 cm on MRI.

• Investigative Magnetic Resonance Imaging
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• v.19 no.4
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• pp.212-217
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• 2015

Purpose: For a single time-point hyperpolarized $^{13}C$ magnetic resonance spectroscopy imaging (MRSI) of animal models, scan-time window after injecting substrates is critical in terms of signal-to-noise ratio (SNR) of downstream metabolites. Pre-scans of time-resolved magnetic resonance spectroscopy (MRS) can be performed to determine the scan-time window. In this study, based on two-site exchange model, protocol-specific simulation approaches were developed for $^{13}C$ MRSI and the optimal scan-time window was determined to maximize the SNR of downstream metabolites. Materials and Methods: The arterial input function and conversion rate constant from injected substrates (pyruvate) to downstream metabolite (lactate) were precalibrated, based on pre-scans of time-resolved MRS. MRSI was simulated using two-site exchange model with considerations of scan parameters of MRSI. Optimal scan-time window for mapping lactate was chosen from simulated lactate intensity maps. The performance was validated by multiple in vivo experiments of BALB/C nude mice with MDA-MB-231 breast tumor cells. As a comparison, MRSI were performed with other scan-time windows simply chosen from the lactate signal intensities of pre-scan time-resolved MRS. Results: The optimal scan timing for our animal models was determined by simulation, and was found to be 15 s after injection of the pyruvate. Compared to the simple approach, we observed that the lactate peak signal to noise ratio (PSNR) was increased by 230%. Conclusion: Optimal scan timing to measure downstream metabolites using hyperpolarized $^{13}C$ MRSI can be determined by the proposed protocol-specific simulation approaches.