Myocardial T1 values in healthy volunteers measured with saturation method using adaptive recovery times for T1 mapping (SMART1Map) at 1.5 T and 3 T.

Myocardial T1 mapping is clinically valuable for assessing the myocardium, and modified look-locker inversion-recovery (MOLLI) approaches have been commonly used for measuring myocardial T1 values. To date, several other sequences have been developed for measuring myocardial T1 values, and saturation-recovery-based sequences have been shown to be less dependent on various factors, such as T2 times and magnetization transfer, than inversion-recovery techniques. Systematic differences in T1 values between different sequences have been reported; therefore, definition of the normal range of native T1 values is required before clinical usage can begin. The purpose of this study was to evaluate the reference range and sex dependency of native T1 values in the myocardium measured using one such saturation-recovery sequence, i.e., saturation method using adaptive recovery times for cardiac T1 mapping (SMART1Map). Myocardial T1 values were compared between SMART1Map and MOLLI in 24 young healthy volunteers at 1.5 T and 3 T, and differences in the T1 values between the sexes were assessed. The mean native T1 values in the myocardium were significantly longer with SMART1Map than MOLLI [1530.4 ± 49.2 vs 1222.1 ± 48.9 ms at 3 T (p < 0.001) and 1227.3 ± 41.9 ms vs 1014.8 ± 49.4 ms at 1.5 T (p < 0.001)]. A significant difference between the sexes was observed in the T1 values obtained using each sequence, excluding SMART1Map at 3 T. The SMART1Map has a potential advantage to overcome the shortcoming of MOLLI, which underestimates T1 values; however, the sex-dependent difference remains obscure using SMART1Map.

Long-term complete response of advanced hepatocellular carcinoma treated with multidisciplinary therapy including reduced dose of sorafenib: case report and review of the literature.

An 83-year-old man underwent computed tomography during a routine check-up due to a history of surgical treatment for pancreatic cancer. Two tumors were detected in the anterior segment of the liver. A needle biopsy of the larger tumor was performed, and pathological examination showed that the tumor was a poorly differentiated hepatocellular carcinoma. Resection was not performed considering the patient's poor physical condition. Thus, transcatheter arterial chemoembolization and radiofrequency ablation of the tumors were performed. Three months later, residual tumor of the larger lesion and multiple pulmonary metastases were detected. This time, continuous hepatic arterial infusion chemotherapy was performed. Although the pulmonary metastases markedly reduced, tumor thrombi appeared in the right portal vein on computed tomography. Finally, sorafenib was administered, which led to disappearance of the tumor thrombi and no other signs of recurrence 8 months after initiation of sorafenib on computed tomography. Although sorafenib administration has continued at reduced doses of 200 mg per day or less due to hypertension, complete response has persisted for the past 34 months. It is noteworthy that sorafenib has been given at reduced doses, but a long-term complete response is maintained in a patient who had portal tumor thrombi and distant metastasis. Herein, we present this rare case of advanced hepatocellular carcinoma controlled with reduced doses of sorafenib following multidisciplinary therapy, describe our single center experience with sorafenib use in patients with hepatocellular carcinoma, and review previous reports that focused on dose reduction of sorafenib.

OATP1B3 expression is strongly associated with Wnt/ß-catenin signalling and represents the transporter of gadoxetic acid in hepatocellular carcinoma.

BACKGROUND & AIMS: In the current era of emerging molecular targeted drugs, it is necessary to identify before treatment the specific subclass to which a tumour belongs. Gadoxetic acid is a liver-specific contrast agent that is preferentially taken up by hepatocytes. Therefore, gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) should provide precise molecular information about hepatocellular carcinomas (HCCs). The aim of this study was to investigate the transporters of gadoxetic acid in HCC comprehensively and to analyse the molecular regulatory mechanism of such transporters. METHODS: Expression levels of transporters, transcriptional factors and Wnt target genes in clinical samples were examined by quantitative real-time reverse transcription polymerase chain reaction and immunohistochemistry. LiCl treatment of the HCC cell line KYN-2 was conducted in vitro to assess the effects of Wnt signalling activity. RESULTS: Comprehensive analyses of transporter mRNAs and protein expressions revealed that the organic anion transporting polypeptide 1B3 (OATP1B3) had the strongest correlation with tumour enhancement in hepatobiliary-phase images of EOB-MRI. Association analysis with OATP1B3 expression revealed significant correlation with the expression of Wnt/ß-catenin target genes. Further, LiCl treatment induced OATP1B3 mRNA expression in KYN-2 cells, indicating a strong association between OATP1B3 expression and Wnt/ß-catenin signalling. The sensitivity and specificity to predict Wnt/ß-catenin-activated HCC using tumour enhancement in EOB-MRI were 78.9% and 81.7%, respectively. CONCLUSIONS: OATP1B3 was confirmed as the most important transporter mediating HCC enhancement in EOB-MRI. OATP1B3 expression showed a strong association with the expression of Wnt/ß-catenin target genes, therefore, OATP1B3-upregulated HCC likely represents a specific subclass of Wnt/ß-catenin-activated HCC.

Prognostic value of preoperative multiparametric magnetic resonance imaging (MRI) for predicting biochemical recurrence after radical prostatectomy.

OBJECTIVE: To evaluate the suitability of preoperative multiparametric magnetic resonance imaging (MRI) positivity as a predictor of biochemical recurrence after radical prostatectomy (RP). PATIENTS AND METHODS: We reviewed the clinical records of patients who underwent either standard RP or laparoscopic RP between January 2005 and December 2009 at our institution. Patients who received radiotherapy or androgen deprivation therapy before surgery were excluded. A total of 314 patients met the study inclusion criteria. Cox proportional hazard regression models were used for analyses. In accordance with the criteria in the established guidelines, a radiologist scored the probability of the presence of prostate cancer using a five-point scale of diagnostic confidence level. The highest confidence level of any pulse sequence was considered as the evaluation result. RESULTS: MRI positivity was significantly associated with a high clinical stage (cT ≥ 2; P = 0.039), a high positive biopsy core rate (≥0.2; P < 0.001), a high biopsy Gleason score ([GS] ≥8; P < 0.001) and a high pathological GS (≥8; P = 0.005). Univariate analysis and multivariate analysis showed that MRI positivity was a prognostic indicator in the analysis that included only preoperative variables and also in the analysis including preoperative and pathological variables. CONCLUSION: Multiparametric MRI positivity can independently predict biochemical recurrence after RP.

Cystic tumor of the liver without ovarian-like stroma or bile duct communication: two case reports and a review of the literature.

We report two cases of cystic neoplasm of the liver with mucinous epithelium in which both ovarian-like stroma and bile duct communication were absent. The first case was a 41-year-old woman. She underwent right trisegmentectomy due to a multilocular cystic lesion, 15 cm in diameter, with papillary nodular components in the medial segment and right lobe. Histologically, arborizing papillae were seen in the papillary lesion. The constituent neoplastic cells had sufficient cytoarchitectural atypia to be classified as high-grade dysplasia. The second case was a 60-year-old woman. She underwent left lobectomy due to a unilocular cystic lesion, 17 cm in diameter, in the left lobe. Histologically, the cyst wall was lined by low columnar epithelia with slight cellular atypia. In both cases, neither ovarian-like stroma nor bile duct communications were found throughout the resected specimen. According to the most recent World Health Organization (WHO) classification in 2010, cystic tumors of the liver with mucinous epithelium are classified as mucinous cystic neoplasms when ovarian-like stromata are found, and as intraductal papillary neoplasm of bile duct when bile duct communication exists. Therefore, we diagnosed the cystic tumors as 'biliary cystadenoma' according to the past WHO classification scheme from 2000. We believe that the combined absence of both ovarian-like stroma and bile duct communication is possible in mucinous cystic tumors of the liver. Herein, we have described the clinicopathologic features of the two cases and reviewed past cases in the literature.

Biliary findings assist in predicting enlargement of intraductal papillary mucinous neoplasms of the pancreas.

BACKGROUND & AIMS: There is controversy over the optimal management strategy for patients with branch-duct type intraductal papillary mucinous neoplasms of the pancreas (BD-IPMNs), precursors to pancreatic cancer. We aimed to identify factors associated with the presence of BD-IPMNs and changes in their diameter. METHODS: Two separate analyses were conducted in a cohort of patients who underwent magnetic resonance cholangiopancreatography (MRCP) in a single year (2006). MRCP findings and clinical outcomes of these patients were followed for a maximum of 6 years. We evaluated initial MRCP findings and demographics associated with the presence of BD-IPMNs at baseline and increase in BD-IPMN diameter over time. RESULTS: During the follow-up period, 154 patients developed BD-IPMN and 322 patients did not. Older age, diabetes mellitus, gallbladder adenomyomatosis, and absence of gallstones were associated with the presence of BD-IPMNs at baseline. Increases in diameter of BD-IPMNs were associated with 3 baseline factors: BD-IPMN diameter greater than 17 mm, gallbladder adenomyomatosis, and a common bile duct diameter less than 5.5 mm. Patients with BD-IPMNs could be stratified into 4 groups with varying risk for the enlargement of BD-IPMNs over time: those with 3 risk factors (hazard ratio [HR], 11.4; 95% confidence interval [CI], 3.4-37.8), 2 risk factors (HR, 4.7; 95% CI, 1.7-12.8), or 1 risk factor (HR, 3.1; 95% CI, 1.2-8.2) compared with those without risk factors. CONCLUSIONS: For patients with BD-IPMNs, careful follow-up evaluation is particularly important for those with BD-IPMN >17 mm in size, common bile duct diameter <5.5 mm, or gallbladder adenomyomatosis.

Lymphoepithelioma-like hepatocellular carcinoma: a case report and a review of the literature.

We report a rare case of lymphoepithelioma-like hepatocellular carcinoma. A 79-year-old Japanese man had undergone curative resection of extrahepatic bile ducts because of bile duct cancer 9 years prior. The bile duct cancer was diagnosed as mucosal adenocarcinoma, and the patient had been followed up every 6 months for the last 9 years. A recent computed tomography examination revealed a tumor, 4.2 cm in size, in the lateral segment of the liver. Based on the imaging findings, the tumor was diagnosed as hepatocellular carcinoma. Serology tests were negative for hepatitis B and C viruses. Chest and abdominal image analyses showed no evidence of metastasis, but a swollen lymph node was noted around the abdominal aorta. The patient subsequently underwent extended lateral segmentectomy and resection of the swollen lymph node. Microscopically, the tumor had the characteristic appearance of poorly differentiated hepatocellular carcinoma. Moreover, an abundant infiltration of inflammatory cells was observed in the tumor. Therefore, we diagnosed the tumor as lymphoepithelioma-like hepatocellular carcinoma. The resected para-aortic lymph node also had a carcinoma with features similar to those of the main tumor. The patient has been alive for 20 months since performance of the surgery. Since the first report of lymphoepithelioma-like hepatocellular carcinoma in 2000, only nine cases have been reported in the medical literature, and the clinicopathological features of the disease have not been well documented. Herein, we describe the clinicopathological features of this case for further understanding of the disease and review past cases in the literature.

Concomitant pancreatic endocrine neoplasm and intraductal papillary mucinous neoplasm: a case report and literature review.

We report a case of concomitant pancreatic endocrine neoplasm (PEN) and intraductal papillary mucinous neoplasm (IPMN). A 74-year-old man had been followed-up for mixed-type IPMN for 10 years. Recent magnetic resonance images revealed an increase in size of the branch duct IPMN in the pancreas head, while the dilation of the main pancreatic duct showed minimal change. Although contrast-enhanced computed tomography and magnetic resonance imaging did not reveal any nodules in the branch duct IPMN, endoscopic ultrasound indicated a suspected nodule in the IPMN. A malignancy in the branch duct IPMN was suspected and we performed pylorus-preserving pancreatoduodenectomy with lymphadenectomy. The resected specimen contained a cystic lesion, 10 x 10 mm in diameter, in the head of the pancreas. Histological examination revealed that the dilated main pancreatic duct and the branch ducts were composed of intraductal papillary mucinous adenoma with mild atypia. No evidence of carcinoma was detected in the specimen. Incidentally, a 3-mm nodule consisting of small neuroendocrine cells was found in the main pancreatic duct. The cells demonstrated positive staining for chromogranin A, synaptophysin, and glucagon but negative staining for insulin and somatostatin. Therefore, the 3-mm nodule was diagnosed as a PEN. Since the mitotic count per 10 high-power fields was less than 2 and the Ki-67 index was less than 2%, the PEN was pathologically classified as low-grade (G1) according to the 2010 World Health Organization (WHO) criteria. Herein, we review the case and relevant studies in the literature and discuss issues related to the synchronous occurrence of the relatively rare tumors, PEN and IPMN.

Radiological findings of primary localized amyloidosis of the ureter.

Localized amyloidosis is a rare condition, especially that involving the ureter. Because of its rarity and the difficulty in differentiating this condition from urothelial carcinoma by intravenous urography and computed tomography, nephroureterectomy has often been performed unnecessarily for this disease. The authors encountered two cases of this disease, both of which showed a negative urine cytology, no obvious mass effect, and a hypointensity on T2-weighted imaging. Because these findings are very rare in urothelial carcinoma, ureteroscopy-guided biopsy was performed, which yielded the diagnosis of amyloidosis. The patients were then treated and followed up at our institute. Primary localized amyloidosis of the ureter should be considered when evaluating ureteric lesions visualized as hypointensities on T2-weighted images that do not show an obvious mass effect, which could help in the avoidance of unnecessary surgery.

Prognostic value of cardiac magnetic resonance imaging for idiopathic pulmonary arterial hypertension before initiating intravenous prostacyclin therapy.

BACKGROUND: Because few have reported the prognostic significance of cardiac magnetic resonance imaging (CMR) for idiopathic pulmonary arterial hypertension (IPAH), in this study we evaluated the value of CMR measurements as a prognostic predictor of IPAH before starting intravenous prostacyclin therapy. METHODS AND RESULTS: A total of 121 consecutive CMR studies for evaluating right ventricular (RV) function were reviewed. Forty-one patients were diagnosed with IPAH and served as the study group. Factors, such as age, sex, New York Heart Association functional class (NYHAFC), 6-min walk test, plasma brain natriuretic peptide level, serum uric acid level and CMR measurements were analyzed as predictors of first hospitalization and death. The mean follow-up period was 1,350±769 days. Nine patients were hospitalized because of heart failure, and 4 patients died from cardiopulmonary causes. The univariate analyses suggested that the left ventricular (LV) mass index, the left and right ventricular end-diastolic volume indices (LVEDVI, RVEDVI), the LV and RV end-systolic volume indices (LVESVI, RVESVI) and NYHAFC predicted the risk for hospitalization and that RVEDVI, RVESVI and NYHAFC predicted mortality. The multivariate analyses suggested that RVEDVI and NYHAFC are independent predictors of both hospitalization and mortality. The effects of RVEDVI and NYHAFC on hospitalization were not substantially affected by the concomitant medication. CONCLUSIONS: In IPAH patients, the RVEDVI predicts both hospitalization for right heart failure and mortality before initiating intravenous prostacyclin therapy.

Comparison of T2-weighted and contrast-enhanced T1-weighted MR imaging at 1.5 T for assessing the local extent of cervical carcinoma.

OBJECTIVE: To compare two MR sequences at 1.5 T-T2-weighted and contrast-enhanced T1-weighted images-by using macroscopic sections to determine which image type enables the most accurate assessment of cervical carcinoma. METHODS: Forty consecutive patients (mean age, 39.2 years) with biopsy-proven cervical carcinoma were included. Each MR sequence was assessed for tumour localisations, tumour margins, and cancer extent with the consensus of two readers, and tumour margins were rated on a five-point scale. MR findings were correlated with histopathological findings. Contrast-to-noise ratios (CNRs) obtained with each image were compared using nonparametric tests. RESULTS: Thirty-one of 40 patients underwent hysterectomies and nine of 40 underwent trachelectomies. In 36 patients, lesions were identified on at least one sequence. The tumours at stage 1B or higher were detected in 94.7% on contrast-enhanced T1-weighted images and in 76.3% on T2-weighted images (P < 0.05). Tumour margins appeared significantly more distinct on contrast-enhanced T1-weighted images than on T2-weighted images (P < 0.001). The CNRs obtained using contrast-enhanced T1-weighted images were significantly higher (P < 0.001) than those obtained using T2-weighted images. CONCLUSION: Contrast-enhanced T1-weighted imaging is more useful for assessing cervical carcinoma than T2-weighted imaging.

Intrahepatic cholangiocarcinoma arising 33 years after excision of a choledochal cyst: report of a case.

We report a case of intrahepatic cholangiocarcinoma arising 33 years after excision of a choledochal cyst. A 61-year-old woman was admitted to our hospital complaining of fever. Thirty-three years ago she had undergone extrahepatic choledochal cystectomy and choledochojejunostomy for a choledochal cyst. Computed tomography showed a tumor in the anterior segment of the liver, extending to the posterior and medial segments and the right portal vein. Intrahepatic biliary stones were seen in the bile ducts. We performed extended right lobectomy. Microscopically, the tumor was cholangiocarcinoma. Most of the tumor area was composed of invasive adenocarcinoma but a carcinoma-in-situ component was also observed in some regions including the hilar bile duct, where an intrahepatic biliary stone was seen. This suggests that the cancer development could be related to intrahepatic cholestasis. Patients with choledochal cyst may have to be carefully followed up for more than 30 years even after diversion surgery.

Cell-based in vivo dual imaging probes using genetically expressed tags and chemical contrast agents.

We report a method for specifically labelling the surface of cells with two kinds of chemical probes (near-infrared (NIR) fluorescent probes and magnetic resonance (MR) imaging probes) via two genetically expressed tags, and demonstrate the application for in vitro and in vivo dual imaging.

The clinical value of bilateral breast MR imaging: is it worth performing on patients showing suspicious microcalcifications on mammography?

The purpose of this study was to evaluate the clinical value of bilateral breast magnetic resonance (MR) imaging (MRI) in patients showing suspicious microcalcifications on mammography and negative ultrasound findings. Fifty patients underwent MRI before stereotactic vacuum-assisted breast biopsy (SVAB). MR findings were classified into five types for interpretation, and types 4 and 5 were considered malignant. SVAB revealed 13 carcinomas and 37 benign lesions. Malignant lesions were more frequently found in cases of positive MRI diagnoses than in negative MRI diagnoses (P < 0.001). Mammography had a sensitivity of 100%, a specificity of 24% and an accuracy of 44%, whereas mammography plus MRI had a sensitivity of 85%, a specificity of 100% and an accuracy of 96%. In the evaluation of mammographically detected microcalcifications, bilateral breast MRI is of good diagnostic value and may alter the indications for SVAB.

Consensus report of the 2nd International Forum for Liver MRI.

Discussion at the 2nd Forum for Liver MRI: The International Primovist User Meeting on the use of the hepatocyte-specific contrast agent gadolinium-ethoxybenzyl-diethylene triamine penta-acetic acid (Gd-EOB-DTPA) is reported. Changes to the currently recommended Gd-EOB-DTPA imaging protocol were identified that can reduce the overall examination time. The potential benefits of 3-T MR imaging using Gd-EOB-DTPA have yet to be fully explored. Data show that Gd-EOB-DTPA-enhanced MRI allows identification of liver lesions and provides a differential diagnosis of hepatocellular nodules in the noncirrhotic and cirrhotic liver, based on vascularity, during the dynamic arterial, portal-venous and late phases, and during the hepatocytespecific phase. Current European, American and Japanese guidelines for the diagnosis of hepatocellular carcinoma need to take into account the recent rapid advances in liver imaging. Based on published clinical trials and the experience of the attendees in the use of Gd-EOB-DTPA in liver imaging, a new simplified, non-invasive diagnostic algorithm was proposed that would be applicable to both Eastern and Western clinical practice in the evaluation of hepatocarcinogenesis and hepatocellular carcinoma. Preliminary clinical experience suggests that Gd-EOB-DTPA may also provide an innovative and cost-effective one-stop approach for staging rectal cancer using wholebody imaging.

Semiquantitative assessment of MR imaging in prediction of efficacy of gonadotropin-releasing hormone agonist for volume reduction of uterine leiomyoma: initial experience.

PURPOSE: To prospectively determine if semiquantitative assessment of R2* images and T1-weighted magnetic resonance (MR) images of leiomyomas correlates with the efficacy of gonadotropin-releasing hormone (GnRH) agonist treatment for volume reduction. MATERIALS AND METHODS: Internal review board approval and informed consent were obtained for this study. Twenty women (mean age, 36.3 years) with intramyometrial leiomyomas were enrolled in this study. Single-section double-echo dynamic MR imaging was performed before GnRH agonist administration. T2-weighted images were obtained before and after two or three GnRH agonist injections (1.88 mg leuprorelin acetate). The steepest signal intensity (SI) upslope on T1-weighted images and the area under the curve (AUC) on R2* images were determined by using a 16 x 16-voxel matrix that was placed in the center of a leiomyoma. Pearson correlation analysis was performed to compare the percentage of volume reduction with SI upslope and AUC. Unpaired t test was performed to evaluate the difference between leiomyomas with AUC and SI upslope values that were less than or greater than the mean. RESULTS: Percentage of volume reduction ranged from 6.2% to 51.1%. The mean AUC and mean SI upslope were 39.2 and 9.83% per second, respectively. There was a significant correlation between the AUC and the percentage of volume reduction (r = 0.81, P < .001), although no significant correlation was observed between the SI upslope and the percentage of volume reduction. A significant difference in percentage of volume reduction was observed in leiomyomas by using mean AUC as a cutoff value (P = .003). CONCLUSION: AUC on R2* images correlates with the efficacy of GnRH agonist before initiation of treatment for volume reduction of leiomyoma.

Diagnostic accuracy of stress myocardial perfusion MRI and late gadolinium-enhanced MRI for detecting flow-limiting coronary artery disease: a multicenter study.

The aim of this study was to determine the diagnostic performance of stress and rest perfusion magnetic resonance imaging (MRI) and late gadolinium-enhanced (LGE) MRI for identifying patients with obstructive coronary artery disease (CAD). A total of 50 patients with suspected CAD underwent stress-rest perfusion MRI, followed by LGE MRI with a 1.5-T system. Stress-rest perfusion MRI resulted in an area under the receiver-operating characteristic curve (AUC) of 0.92 for observer 1 and 0.84 for observer 2 with sensitivity and specificity of 89% (32/36) and 79% (11/14) by observer 1, 83% (30/36) and 71% (10/14) by observer 2, respectively, showing a moderate interobserver agreement (Cohen's kappa = 0.49). While combination of stress-rest perfusion and LGE MRI did not result in improved accuracy for the prediction of flow-limiting obstructive CAD (AUC 0.81 for observer 1 and 0.80 for observer 2), the sensitivity was increased to 92% in both observers with a substantial interobserver agreement (kappa = 0.70). Stress-rest myocardial perfusion MRI is an accurate diagnostic test for identifying patients with obstructive CAD.

Detection of bladder tumors with dynamic contrast-enhanced MDCT.

OBJECTIVE: In a small pilot study, we assessed whether early-phase dynamic contrast-enhanced MDCT can be used to detect bladder tumors and whether thin reconstruction improves the detection rate. SUBJECTS AND METHODS: Thirty-six patients (30 with 59 cystoscopy-proven bladder cancers and six with normal bladders) underwent dynamic contrast-enhanced MDCT of the pelvis and abdomen. Images were obtained from the symphysis pubis to the diaphragm 70 seconds after injection of 100 mL of contrast medium. McNemar test was used to compare sensitivity per patient, segment, and tumor and specificity per patient and segment for each of three reconstruction methods: 5-mm sections with no overlap (i.e., 5-mm axial images), 2.5-mm sections with 1.25-mm overlap (i.e., thin-section axial images), and 2.5-mm sections with 1.25-mm overlap and multiplanar reformation (MPR) (i.e., thin-section axial images with MPR). RESULTS: MDCT with a combination of thin, overlapped sections and MPR depicted all but one of 47 bladder tumors larger than 5 mm but only five of 12 tumors 5 mm or smaller. There were no false-positive findings. Per-tumor sensitivity was significantly better with thin-section images with MPR (90%) and thin-section images alone (86%) than with 5-mm axial images (80%) (p < 0.05). Per-segment sensitivity was significantly better with thin-section images with MPR (95%) and thin-section axial images alone (87%) than with 5-mm axial images (79%) (p < 0.05). Per-patient sensitivity and per-patient and per-segment specificity did not differ with the three methods. CONCLUSION: Dynamic contrast-enhanced MDCT of the pelvis shows promise for the detection of bladder tumors. Use of thin-section images with MPR and thin-section axial images alone had a significantly better rate of detection of bladder tumors than use of 5-mm axial images.

Basic design and synthesis of sulfonated contrast agents for magnetic resonance imaging based on gadolinium complexes.

Magnetic resonance angiography (MRA) is an imaging method to examine blood vessels based on the magnetic resonance imaging (MRI) technique. For this purpose, blood pool contrast agents have been developed to selectively increase the signal intensity of the intravascular lumen for improvement of the contrast-to-noise ratio in MR images. Here, we describe the design and the syntheses of six novel sulfonated contrast agents (KMR-Sulfo1 - 6), their chemical properties and their in vivo applications. In this study, we investigated the lipophilicity and the hydrophilicity of a gadolinium complex using a convenient two-step synthesis route, with the goal of prolonging the plasma half-life by binding mainly to human serum albumin. We confirmed that KMR-Sulfo5 fulfilled the requirements as a blood pool contrast agent: it showed a sufficient relaxivity r(1) of 5.9 mM(-1) s(-1), a long plasma half-life of 25.7 min and complete elimination from the body within 12 h after the administration.

Accuracy of preoperative prediction of microinvasion of portal vein in hepatocellular carcinoma using superparamagnetic iron oxide-enhanced magnetic resonance imaging and computed tomography during hepatic angiography.

BACKGROUND: Our aim was to diagnose microinvasion of the portal vein in hepatocellular carcinoma from preoperative radiological findings and to construct a scoring system. METHODS: Forty-seven patients (38 men and 9 women; median age, 66.8 years) who underwent hepatic resections for hepatocellular carcinoma were selected retrospectively. Microscopically, 22 had portal vein invasion (PVI) and 25 had no PVI. All patients were examined preoperatively with superparamagnetic iron oxide-enhanced magnetic resonance imaging and computed tomography during hepatic angiography (CTHA). Perilesional enhancement on T1-weighted imaging, tumorous arterioportal (AP) shunt, and corona enhancement (contrast enhancement of the adjacent liver appearing in the late phase of CTHA) were assessed. Relative risk for PVI in terms of clinical and tumor characteristics was also assessed. The relative contribution to PVI was determined by the coefficient of a stepwise logistic regression. Each variable was given a score relative to the coefficient. RESULTS: On univariate analysis, distortion of corona, tumorous AP shunt, and tumor size indicated a higher prevalence of PVI. The PVI predictive score was calculated as: total score = (maximum size in cm) + (T1 ring; + = 1, - = 0) + (tumorous AP shunt; + = 3, - = 0) + (distortion of corona; + = 10, - = 0). The PVI (+) group score was four times that of the PVI (-) group (16 vs 4). At a cutoff score of 10, the sensitivity, specificity, and accuracy were 82%, 84%, and 86%. CONCLUSIONS: Distortion of corona, tumorous AP shunt, and tumor size are good predictors of the risk of PVI. This scoring system is simple and worth using clinically.