Distinguishing intrahepatic cholangiocarcinoma from poorly differentiated hepatocellular carcinoma using precontrast and gadoxetic acid-enhanced MRI

PURPOSEWe aimed to gain further insight in magnetic resonance imaging characteristics of mass-forming intrahepatic cholangiocarcinoma (mICC), its enhancement pattern with gadoxetic acid contrast agent, and distinction from poorly differentiated hepatocellular carcinoma (pHCC).METHODSFourteen mICC and 22 pHCC nodules were included in this study. Two observers recorded the tumor shape, intratumoral hemorrhage, fat on chemical shift imaging, signal intensity at the center of the tumor on T2-weighted image, fibrous capsule, enhancement pattern on arterial phase of dynamic study, late enhancement three minutes after contrast injection (dynamic late phase), contrast uptake on hepatobiliary phase, apparent diffusion coefficient, vascular invasion, and intrahepatic metastasis.RESULTSLate enhancement was more common in mICC (n=10, 71%) than in pHCC (n=3, 14%) (P < 0.001). A fat component was observed in 11 pHCC cases (50%) versus none of mICC cases (P = 0.002). Fibrous capsule was observed in 13 pHCC cases (59%) versus none of mICC cases (P < 0.001). On T2-weighted images a hypointense area was seen at the center of the tumor in 43% of mICC (6/14) and 9% of pHCC (2/22) cases (P = 0.018). Other parameters were not significantly different between the two types of nodules.CONCLUSIONThe absence of fat and fibrous capsule, and presence of enhancement at three minutes appear to be most characteristic for mICC and may help its differentiation from pHCC

イッテルビウムを使用したPARACEST造影剤によるCESTイメージングの臨床MR撮像装置での実用化に関する研究

Introduction / Materials and Methods / Results / Discussion / ReferencesSubmitted by 真弓 小柳 ([email protected]) on 2012-04-24T01:42:25Z No. of bitstreams: 2 med2496.pdf: 686905 bytes, checksum: 37f32f8e8956274bb0a655ff606c0231 (MD5) med2496_abstract.pdf: 142389 bytes, checksum: 1f24b7fcef0d278e24ef171d9e790985 (MD5)Made available in DSpace on 2012-04-24T01:42:25Z (GMT). No. of bitstreams: 2 med2496.pdf: 686905 bytes, checksum: 37f32f8e8956274bb0a655ff606c0231 (MD5) med2496_abstract.pdf: 142389 bytes, checksum: 1f24b7fcef0d278e24ef171d9e790985 (MD5) Previous issue date: 2012-03-27医学系学府_機能制御医学Purpose : We investigated the feasibility of performing chemical exchange saturation transfer (CEST) imaging using ytterbium-based paramagnetic CEST (PARACEST) agents on a clinical magnetic resonance (MR) scanner. Materials and Methods : We prepared solutions of 3 different ytterbium-based PARACEST agents at concentrations of 5, 10, 20, and 50 mM at a pH of 7.4 and at a concentration of 50 mM at pHs of 3.0, 5.0, 7.4, and 9.5. We acquired images with a turbo spin echo technique using a quadrature head coil and a clinical 3.0-tesla MR system in accordance with the safety limits of the specific absorption rate (SAR). We acquired CEST images with presaturation offset frequencies from −5,000 Hz (−39.1 ppm) to 5,000 Hz (39.1 ppm) with an interval of 500 Hz (3.9 ppm) for each condition. We repeated each scan 3 times and then calculated the mean and standard deviations of the magnitude of the CEST effect at different concentrations and pH values for each agent. We used one-way analysis of variance and Tukey\u27s honestly significant difference post hoc test to compare mean values of the magnitude of the CEST effect obtained at different concentrations and pH values. P<0.05 was considered significant. Results : PARACEST agents showed a strong CEST effect at their specific presaturation offset frequencies. For each agent, the CEST effect showed significant concentration dependency (P<0.05), increasing with agent concentration, and significant pH dependency (P<0.05), with strong effect near physiological pH. Conclusion : CEST imaging using ytterbium-based PARACEST agents might be feasible on a clinical MR scanner with further modifications, such as adjustments of the presaturation radiofrequency pulse and imaging protocols

Reduciton of a High-field Dielectric Artifact with Homemade Gel

We developed an original dielectric-equivalent gel (Japanese Patent Application ID:P2004-236876A, February 6, 2003) pad that could improve inhomogeneous images causedprimarily by B1 homogeneity on a high-tesla magnetic resonance (MR) system. Made easily from various ingredients, our gel could rduce interference from radiofrequency waves at an object\u27s surface and show changes in B1 inhomogeneity.We herein assess the gel\u27s effect using a plastic-bottle phantom on a 3T MR system

Evaluating glycogen signal contamination in muscle by 13C MRS of the liver

To evaluate the contamination of glycogen signal synthesized in skeletal muscle by that in the liver, long-term monitoring of over 7 h of in vivo [1-13C] glycogen synthesis/degradation at the right abdomen and left shoulder was achieved using a 3.0-T clinical MR system. 13C MR spectra without localization were obtained from five healthy volunteers before and after oral administration of 85 g of D-glucose, including 10 g of 99% [1-13C] glucose. In all volunteers, the relative signal intensities at the abdomen to those at shoulder were about two- to fivefold,and those of time-course changes at the abdomen and shoulder were dissimilar. It is considered that the quantity of muscle-synthesized glycogen signal at the abdomen is less than that at the shoulder because of the lesser muscle volume at the abdomen, and it may be less affected for evaluating glycogen synthesis/degradation in the liver even without localization pulses

Prediction of early response to radiotherapy of uterine carcinoma with dynamic contrast-enhanced MR imaging using pixel analysis of MR perfusion imaging

[Purpose]To assess the predictability of the response to radiotherapy of uterine carcinoma, this study retrospectively analyzed dynamic contrast-enhanced magnetic resonance images (DCE-MRI) taken before radiotherapy.[Materials and Methods]Forty-two patients with uterine carcinoma were studied, of whom 22 had adenocarcinoma and 20 had squamous cell carcinoma (SCC). In DCE-MRI analysis, two parameters, SIe and Rdown, were measured. SIe is a median value for the degree of signal intensity change in all selected pixels in the tumor at 1-2 min after contrast agent injection. Rdown is the ratio of the number of down-sloped pixels to that of all selected pixels 3-7 min after injection. The tumor volume reduction rate (TVRR) was measured by MRI-based volumetry in pre- and post-radiotherapy transverse T2-weighted images.[Results]Overall, TVRR was significantly correlated to both SIe (r=0.37, P=.015) and Rdown (r=0.73, P<.0001). In the separate patient groups, SIe but not Rdown was significantly different between the adenocarcinoma and SCC patients (t=3.64, P<.001). TVRR was not correlated to SIe in any group. TVRR was significantly correlated to Rdown in adenocarcinoma patients (r=0.78, P<.001) but not in SCC patients.[Conclusion]SIe may reflect differences in histological characteristics. Rdown may be useful for predicting the response to radiotherapy of uterine carcinoma

Monitoring of glycogen synthesis in liver of diabetic patients using 13C-MR spectroscopy

In order to explore the feasibility of a clinical 3.0 T MR system, long-term monitoring of in vivo [1-13C] glycogen storage/degradation in the liver was achieved in healthy volunteers (n=5) and diabetic patients (n=5). The correlation between the fasting levels of plasma glucose and the increasing rate of glycogen in the liver was statistically significant (Spearman: r=-0.758, p<0.05, n=10). This indicates that improvement in glycogen synthesizing ability may be beneficial for reducing the blood glucose level. 13C MR spectroscopy is useful for monitoring glycogen synthesis in vivo.Joint Annual Meeting ISMRM-ESMRMB 200

Monitoring of glycogen synthesis in liver of diabetic patients using 13C-MR spectroscopy

In order to explore the feasibility of a clinical 3.0 T MR system, long-term monitoring of in vivo [1-13C] glycogen storage/degradation in the liver was achieved in healthy volunteers (n=5) and diabetic patients (n=5). The correlation between the fasting levels of plasma glucose and the increasing rate of glycogen in the liver was statistically significant (Spearman: r=-0.758, p<0.05, n=10). This indicates that improvement in glycogen synthesizing ability may be beneficial for reducing the blood glucose level. 13C MR spectroscopy is useful for monitoring glycogen synthesis in vivo

ADC value and Diffusion Tensor Imaging of Prostate Cancer; Therapeutic changes with Heavy Ion Charged Particl Radiation Therapye

INTRODUCTIONThe usefulness of diffusion weighted image (DWI) and apparent diffusion coefficient (ADC) values has been reported for detecting prostate cancer (Pca), as Pca shows lower ADC values than normal regions of the prostate (1, 2). However, the combination of several pulse sequences is needed for more accurate diagnosis. Diffusion tensor imaging (DTI) is a new, promising technique for assessing the prostate (2). Although a normal prostate generally shows a symmetrical and concentric form, it is suspected that the structure will show deformities if Pca exists. In this study, we assessed the changes of ADC values and DTI between pre- and post-radiation.Joint Annual Meeting ISMRM-ESMRMB 200