Hepatobiliary MRI Research Articles

Baseline hepatobiliary MRI for predicting chemotherapeutic response and prognosis in initially unresectable colorectal cancer liver metastases

PurposeTo evaluate the performance of hepatobiliary MRI parameters as predictors of clinical response to chemotherapy in patients with initially unresectable colorectal cancer liver metastases (CRLM).MethodsEighty-five patients with initially unresectable CRLM were retrospectively enrolled from two hospitals and scanned using gadobenate dimeglumine-enhanced MRI before treatment. Therapy response was evaluated based on the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Conventional parameters (i.e., signal intensity [SI]) and radiomics features of portal venous phase (PVP) and hepatobiliary phase (HBP) images were analyzed between the responders and non-responders. Next, the combined model was constructed, and the area under the receiver operating characteristic (ROC) curve (AUC) was calculated. The relationship between the combined model and progression-free survival (PFS) was analyzed using Cox regression.ResultsOf the 85 patients from two hospitals, 42 were in the response group, and 43 were in the non-response group. Upon conducting five-fold cross-validation, the normalized relative enhancement (NRE) of CRLM during the PVP yielded an AUC of 0.625. Additionally, a radiomics feature derived from the tumor area in the HBP achieved an AUC of 0.698, while a separate feature extracted from the peritumoral region in the HBP recorded an AUC of 0.709. The model that integrated these three features outperformed the individual features, achieving an AUC of 0.818. Furthermore, the combined model exhibited a significant correlation with PFS (P < 0.001).ConclusionThe combined model, based on baseline hepatobiliary MRI, aids in predicting chemotherapeutic response and PFS in patients with initially unresectable CRLM.

Safety of Gadoxetate Disodium for Hepatobiliary MRI in Children and Adolescents.

Background Despite a proven role in the characterization of liver lesions, use of the gadolinium-based contrast agent (GBCA) gadoxetate disodium at MRI is limited in children due to a lack of comparative safety data. Purpose To evaluate the safety of the GBCA gadoxetate disodium (a linear ionic hepatobiliary contrast agent [HBA]) in children and adolescents, compared with extracellular contrast agents (ECA). Materials and Methods A retrospective analysis was conducted in children and adolescents aged 18 years or younger who underwent HBA-enhanced MRI at one of three tertiary hospitals from January 2010 to December 2022. The incidence of GBCA-associated acute adverse events was compared between MRI examinations with a HBA and those with ECA. Severity was categorized according to American College of Radiology guidelines (mild, moderate, or severe). (a) Propensity score matching using multivariable logistic regression models and (b) inverse probability of treatment weighting analysis based on nine covariates (age, sex, asthma, allergic rhinitis, chronic urticaria or atopy, food allergy, drug allergy, premedication, and history of GBCA-associated adverse events) were used for confounder adjustment. Results A total of 1629 MRI examinations (ECA, n = 1256; HBA, n = 373) in 1079 patients were included (mean age, 8.6 years ± 6.5; 566 girls). The per-examination incidence of GBCA-associated acute adverse events showed no evidence of a difference, with rates of 0.9% (11 of 1256 examinations) for ECA and 1.3% (five of 373 examinations) for HBA (odds ratio [OR], 1.55 [95% CI: 0.54, 4.46]; P = .42). Acute adverse events were all mild with ECA, whereas with HBA, they were mild for four patients and moderate for one patient. There was no evidence of a difference in the incidence of acute adverse events, even in propensity score matching (OR, 1.33 [95% CI: 0.30, 5.96]; P = .71) and inverse probability of treatment weighting analysis (OR, 0.84 [95% CI: 0.25, 2.86]; P = .78). Conclusion Gadoxetate disodium showed no difference in acute adverse events compared with ECA in children and adolescents, with further large-scale pediatric studies required to confirm its safety. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Otero in this issue.

Automated 3D liver segmentation from hepatobiliary phase MRI for enhanced preoperative planning

Recent advancements in deep learning have facilitated significant progress in medical image analysis. However, there is lack of studies specifically addressing the needs of surgeons in terms of practicality and precision for surgical planning. Accurate understanding of anatomical structures, such as the liver and its intrahepatic structures, is crucial for preoperative planning from a surgeon’s standpoint. This study proposes a deep learning model for automatic segmentation of liver parenchyma, vascular and biliary structures, and tumor mass in hepatobiliary phase liver MRI to improve preoperative planning and enhance patient outcomes. A total of 120 adult patients who underwent liver resection due to hepatic mass and had preoperative gadoxetic acid-enhanced MRI were included in the study. A 3D residual U-Net model was developed for automatic segmentation of liver parenchyma, tumor mass, hepatic vein (HV), portal vein (PV), and bile duct (BD). The model’s performance was assessed using Dice similarity coefficient (DSC) by comparing the results with manually delineated structures. The model achieved high accuracy in segmenting liver parenchyma (DSC 0.92 ± 0.03), tumor mass (DSC 0.77 ± 0.21), hepatic vein (DSC 0.70 ± 0.05), portal vein (DSC 0.61 ± 0.03), and bile duct (DSC 0.58 ± 0.15). The study demonstrated the potential of the 3D residual U-Net model to provide a comprehensive understanding of liver anatomy and tumors for preoperative planning, potentially leading to improved surgical outcomes and increased patient safety.

Diagnosis of functional strictures in patients with primary sclerosing cholangitis using hepatobiliary contrast-enhanced MRI: a proof-of-concept study

ObjectivesPSC strictures are routinely diagnosed on T2-MRCP as dominant- (DS) or high-grade stricture (HGS). However, high inter-observer variability limits their utility. We introduce the “potential functional stricture” (PFS) on T1-weighted hepatobiliary-phase images of gadoxetic acid-enhanced MR cholangiography (T1-MRC) to assess inter-reader agreement on diagnosis, location, and prognostic value of PFS on T1-MRC vs. DS or HGS on T2-MRCP in PSC patients, using ERCP as the gold standard.MethodsSix blinded readers independently reviewed 129 MRIs to diagnose and locate stricture, if present. DS/HGS was determined on T2-MRCP. On T1-MRC, PFS was diagnosed if no GA excretion was seen in the CBD, hilum or distal RHD, or LHD. If excretion was normal, “no functional stricture” (NFS) was diagnosed. T1-MRC diagnoses (NFS = 87; PFS = 42) were correlated with ERCP, clinical scores, labs, splenic volume, and clinical events. Statistical analyses included Kaplan–Meier curves and Cox regression.ResultsInterobserver agreement was almost perfect for NFS vs. PFS diagnosis, but fair to moderate for DS and HGS. Forty-four ERCPs in 129 patients (34.1%) were performed, 39 in PFS (92.9%), and, due to clinical suspicion, five in NFS (5.7%) patients. PFS and NFS diagnoses had 100% PPV and 100% NPV, respectively. Labs and clinical scores were significantly worse for PFS vs. NFS. PFS patients underwent more diagnostic and therapeutic ERCPs, experienced more clinical events, and reached significantly more endpoints (p < 0.001) than those with NFS. Multivariate analysis identified PFS as an independent risk factor for liver-related events.ConclusionT1-MRC was superior to T2-MRCP for stricture diagnosis, stricture location, and prognostication.Clinical relevance statementBecause half of PSC patients will develop clinically-relevant strictures over the course of the disease, earlier more confident diagnosis and correct localization of functional stricture on gadoxetic acid-enhanced MRI may optimize management and improve prognostication.Key Points• There is no consensus regarding biliary stricture imaging features in PSC that have clinical relevance.• Twenty-minute T1-weighted MRC images correctly classified PSC patients with potential (PFS) vs with no functional stricture (NFS).• T1-MRC diagnoses may reduce the burden of diagnostic ERCPs.Graphical abstract

Imaging Diagnosis of Hepatocellular Carcinoma: A State-of-the-Art Review.

Hepatocellular carcinoma (HCC) remains not only a cause of a considerable part of oncologic mortality, but also a diagnostic and therapeutic challenge for healthcare systems worldwide. Early detection of the disease and consequential adequate therapy are imperative to increase patients' quality of life and survival. Imaging plays, therefore, a crucial role in the surveillance of patients at risk, the detection and diagnosis of HCC nodules, as well as in the follow-up post-treatment. The unique imaging characteristics of HCC lesions, deriving mainly from the assessment of their vascularity on contrast-enhanced computed tomography (CT), magnetic resonance (MR) or contrast-enhanced ultrasound (CEUS), allow for a more accurate, noninvasive diagnosis and staging. The role of imaging in the management of HCC has further expanded beyond the plain confirmation of a suspected diagnosis due to the introduction of ultrasound and hepatobiliary MRI contrast agents, which allow for the detection of hepatocarcinogenesis even at an early stage. Moreover, the recent technological advancements in artificial intelligence (AI) in radiology contribute an important tool for the diagnostic prediction, prognosis and evaluation of treatment response in the clinical course of the disease. This review presents current imaging modalities and their central role in the management of patients at risk and with HCC.

Multimodality Imaging of Cholecystectomy Complications.

Cholecystectomy is one of the most common surgeries performed in the United States. Although complications are uncommon, the high incidence of this surgery means that a radiologist will likely encounter these complications in practice. Complications may arise in the immediate postoperative period or can be delayed for weeks, months, or years after surgery. Vague and nonspecific symptoms make clinical diagnosis challenging. As a result, multimodality imaging is important in postoperative evaluation. US and multidetector CT are the usual first-line imaging modalities. Hepatobiliary scintigraphy, SPECT/CT, and MRI with conventional or gadoxetate hepatobiliary contrast material are important and complementary modalities that are used for workup. The authors begin with a brief discussion of surgical technique and expected postoperative findings and then describe complications organized into four groups: (a) biliary complications, (b) stone-related complications, (c) iatrogenic complications, and (d) gallbladder complications. Biliary complications include bile leaks and bilomas, acute biliary obstruction, and biliary stricture. Stone-related complications include retained and recurrent stones and spillage of stones into the peritoneum. Iatrogenic complications include hemorrhage, vasculobiliary injury, arterial pseudoaneurysms, duodenal injury, and migration of clips. Gallbladder complications include recurrent cholecystitis after subtotal reconstituting cholecystectomy and unexpected gallbladder cancer. An invited commentary by Mullens and Ibrahim is available online. Online supplemental material is available for this article. ©RSNA, 2022.

Extrahepatic Disease in Hepatocellular Carcinoma: Do We Always Need Whole-Body CT or Is Liver MRI Sufficient? A Subanalysis of the SORAMIC Trial.

Background: To investigate whole-body contrast-enhanced CT and hepatobiliary contrast liver MRI for the detection of extrahepatic disease (EHD) in hepatocellular carcinoma (HCC) and to quantify the impact of EHD on therapy decision. Methods: In this post-hoc analysis of the prospective phase II open-label, multicenter, randomized controlled SORAMIC trial, two blinded readers independently analyzed the whole-body contrast-enhanced CT and gadoxetic acid-enhanced liver MRI data sets of 538 HCC patients. EHD (defined as tumor manifestation outside the liver) detection rates of the two imaging modalities were compared using multiparametric statistical tests. In addition, the most appropriate treatment recommendation was determined by a truth panel. Results: EHD was detected significantly more frequently in patients with portal vein infiltration (21% vs. 10%, p < 0.001), macrovascular infiltration (22% vs. 9%, p < 0.001), and bilobar liver involvement (18% vs. 9%, p = 0.006). Further on, the maximum lesion diameter in patients with EHD was significantly higher (8.2 cm vs. 5.8 cm, p = 0.002). CT detected EHD in significantly more patients compared to MRI in both reader groups (p < 0.001). Higher detection rates of EHD in CT led to a change in management only in one patient since EHD was predominantly present in patients with locally advanced HCC, in whom palliative treatment is the standard of care. Conclusions: Whole-body contrast-enhanced CT shows significantly higher EHD detection rates compared to hepatobiliary contrast liver MRI. However, the higher detection rate did not yield a significant impact on patient management in advanced HCC.

Describe imaging features of four cases diagnosed with cystic biliary atresia micmicking choledocal cyst on MRI

Purpose: to describle in detail the significant signs in hepatobiliary MRI, that help to give different diagnosis between biliary atresia (BA) with big cyst at hepatic hilar and choledochal cyst in small childrent and infant.Method: presenting 4 cases with clinical diagnosed of biliary atresia that based on clinical signs and US, MRI results, all 4 cases were operated, taken cholangiogram in surgery to confirm the diagnosis of cystic biliary atresia and had pathological results.Results: All 4 patients were under 3 months old, all are female with enlarged liver; gallbladder were in the normal size limit but all of them had abnormal shape: deformation, irregular wall, communicated directly with common bile duct. All 4 cases have cystic diameter over 10mm. No case of all has further biliary signal that above or under the cyst on MRI but one case has contrast material filling intraliver bile duct draining directly to cystic lesion on cholangiogram intraoperation . These are 3 cases of cystic BA type III and 1 cases of cystic BA type I. 2 cases has positive triangular cord sign (TC sign).Conclusion: Hepatobiliary MRI with its basic sequences, specially with MRCP is helpful to give difirential diagnosis of cystic BA and choledochal cyst in the young childrent.

LI-RADS Tumor in Vein at CT and Hepatobiliary MRI.

Background Diagnostic performance of the Liver Imaging Reporting and Data System tumor in vein (LR-TIV) category at CT and/or MRI has not yet been evaluated, to the knowledge of the authors. Purpose To assess the diagnostic performance of the LR-TIV category in detecting macroscopic tumors in veins (TIVs) at CT and hepatobiliary contrast agent-enhanced (HBA) MRI, with pathologic results used as the reference standard. Materials and Methods Between January 2010 and December 2019, consecutive patients with or without macroscopic TIV who underwent both CT and HBA MRI before hepatic resection or liver transplant were retrospectively included. Three radiologists independently assessed the LR-TIV features of enhancing soft tissue in vein and features suggestive of TIV (FSTIV) and reached a consensus. Macroscopic TIV at pathologic examination was the reference standard. Sensitivities and specificities of the LR-TIV category without and with FSTIV were calculated, and the added value of FSTIV was evaluated by using the McNemar test. Results In the 1322 patients with (n = 101) or without (n = 1221) macroscopic TIV (median age, 64 years [interquartile range, 58-70 years]; 1053 men), without consideration of FSTIV, the sensitivity and specificity of enhancing soft tissue in vein for detecting macroscopic TIV at pathologic examination were 64.4% (65 of 101) and 99.8% (1218 of 1221) with CT and 62.4% (63 of 101) and 99.8% (1218 of 1221) with HBA MRI, respectively. With consideration of FSTIV, the sensitivity and specificity of the LR-TIV category became 67.3% (68 of 101 patients) and 99.7% (1217 of 1221 patients) at both CT and HBA MRI. No difference was found between measurements without and with FSTIV (sensitivity, 62% vs 67% for CT [P = .45] and 64% vs 67% for HBA MRI [P = .18]; specificity, 99% for both CT and HBA MRI [P > .99 for both]). Conclusion The Liver Imaging Reporting and Data System tumor in vein category showed moderate sensitivity and high specificity in the detection of macroscopic tumors in veins at both CT and hepatobiliary contrast agent-enhanced MRI, with pathologic examination used as the reference standard. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Morrell in this issue.

Analysis of dynamic hepatobiliary contrast-enhanced MRI signal intensity after Yttrium-90 radioembolization with glass microspheres for the treatment of hepatocellular carcinoma.

To analyze hepatobiliary specific contrast agent (HBA) dynamic MRI signal intensity (SI) differences between treatedliver (TL) and untreated liver (UL) parenchyma in patients following transarterial radioembolization (TARE) for hepatocellular carcinoma (HCC) usingyttrium-90 containing glass microspheres. This was a single institution retrospective study of patients with HCC treated with lobar or segmental TARE who received pre- and post-treatment HBA multiphase MRI within a 3-year period. Patients with prior locoregional therapies or multiple TAREs were excluded. SI was obtained by drawing a 2D ROI on T1-weighted non-contrast, arterial (25s.), portal venous (60s.), transitional (180s.), and hepatobiliary (HB) (1200s.) phase sequences in the (TL) angiosome and UL. HB phase signal enhancement characteristics were correlated with TARE dose thresholds (< 120Gy, 120-190Gy, and > 190Gy)using the medical internal radiation dose (MIRD) methodology. 282 patients received TARE using glass microspheres during the study period and 58 patients who met inclusion criteria were analyzed. Median dose was 141.5Gy MIRD [IQR 122.0, 161.5; range 100-540Gy]). Statistically significant differences were present between treated and non-treated liver on non-contrast (-28.0, p = 0.003), arterial (38.5, p = 0.013), and HB phases (-95.8, p ≤ 0.001). Median follow-up time to furthest post-treatment MRI was 6 months (range 3-11 months).There was no significant SI difference on portal venous or transitional phases. HB phase SI changesin the TL compared to UL were significant at all TARE dose thresholds(p< 0.05). SI differences between treated and untreated liver after TARE are most significant on the HB phase and present at all evaluated dose levels at a median of 6 monthsafter treatment. These findings support the parenchymal ablative potential for TARE and the necessity to consider liver function loss within targeted liver volumes.

The role of MDCT and MRI in the diagnosis of focal liver diseases

Despite the great technical achievements in the field of tomographic examinations (CT, MRI), the problem of differentiation of focal liver lesions cannot always be solved only in a non-invasive way. At the same time, MRI with a hepatospecific agent, gadoxetic acid, can solve many problems, primarily related to the diagnosis of liver metastases and monitoring of nodules in cirrhotic liver. The aim. To show the advantages of MRI with hepatobiliary MRI contrast agents as the final phase of non-invasive diagnosis of focal liver lesions. Material and methods . Abstracts of 183 scientific articles (2010–2019) were selected in the PubMed information and analytical system for the keywords “focal liver lesion” and “gadoxetic acid”. Articles about special aspects of MRI examination or general information were excluded. 29 full-text articles were selected for analysis. Results . The analysis data are grouped in three categories as “diagnosis of liver metastases”, “diagnosis of HCC against the background of normal hepatic parenchyma”, “MRI diagnosis of HCC against the background of cirrhosis”. Conclusion. The main achievement of MRI diagnostics with gadoxetic acid is the differentiation of small focal liver lesions, including metastases, regenerative nodes, dysplastic nodes, and highly differentiated HCC. This allows you to increasingly avoid invasive methods in the diagnosis of focal liver lesions. Integrated MRI technologies (MRI-DVI and MRI with gadoxetic acid) are currently the most informative, safe and in demand. In MRI with hepatobiliary contrast agents, the intensity of the HCC signal in the hepatospecific phase is considered as an imaging tumor biomarker. Border small liver nodules are usually not hypervascular, they are hypointensive in the hepatospecific phase.

03:09 PM Abstract No. 287 Dosimetry and dynamic signal intensity changes in treatment angiosome vs non-treated liver on hepatobiliary contrast-enhanced MRI after Y-90 TARE for HCC

03:09 PM Abstract No. 287 Dosimetry and dynamic signal intensity changes in treatment angiosome vs non-treated liver on hepatobiliary contrast-enhanced MRI after Y-90 TARE for HCC

Central vascular structures as a characteristic finding of regenerative nodules using hepatobiliary phase gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid-enhanced MRI and arterial dominant phase contrast-enhanced US

Central vascular structures as a characteristic finding of regenerative nodules using hepatobiliary phase gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid-enhanced MRI and arterial dominant phase contrast-enhanced US

Hepatobiliary MRI: Signal intensity based assessment of liver function correlated to 13C-Methacetin breath test

Gadoxetic acid (Gd-EOB-DTPA) is a paramagnetic MRI contrast agent with raising popularity and has been used for evaluation of imaging-based liver function in recent years. In order to verify whether liver function as determined by real-time breath analysis using the intravenous administration of 13C-methacetin can be estimated quantitatively from Gd-EOB-DTPA-enhanced MRI using signal intensity (SI) values. 110 patients underwent Gd-EOB-DTPA-enhanced 3-T MRI and, for the evaluation of liver function, a 13C-methacetin breath test (13C-MBT). SI values from before (SIpre) and 20 min after (SIpost) contrast media injection were acquired by T1-weighted volume-interpolated breath-hold examination (VIBE) sequences with fat suppression. The relative enhancement (RE) between the plain and contrast-enhanced SI values was calculated and evaluated in a correlation analysis of 13C-MBT values to SIpost and RE to obtain a SI-based estimation of 13C-MBT values. The simple regression model showed a log-linear correlation of 13C-MBT values with SIpost and RE (p < 0.001). Stratified by 3 different categories of 13C-MBT readouts, there was a constant significant decrease in both SIpost (p ≤ 0.002) and RE (p ≤ 0.033) with increasing liver disease progression as assessed by the 13C-MBT. Liver function as determined using real-time 13C-methacetin breath analysis can be estimated quantitatively from Gd-EOB-DTPA-enhanced MRI using SI-based indices.

Inflammatory hepatic adenomas: Characterization with hepatobiliary MRI contrast agents

PurposeTo characterize the MRI appearance of inflammatory hepatic adenomas using hepatobiliary contrast agents. Materials and methodsMRI was performed using hepatobiliary contrast agents (3 with gadobenate dimeglumine and 24 with gadoxetic acid) in 27 patients with immunohistochemistry-confirmed diagnosis of inflammatory hepatic adenoma. The appearance of the lesions on T2 and diffusion-weighted images, pre-gadolinium T1-weighted images, dynamic post-gadolinium images, and hepatobiliary phase images was assessed. ResultsSeven lesions (26%) showed predominant hyperenhancement on hepatobiliary phase images in comparison with adjacent hepatic parenchyma: 1 lesion showed diffuse, mildly heterogeneous hyperenhancement, and the remaining 6 lesions showed peripheral hyperenhancement and central hypoenhancement. Twenty lesions (74%) were predominantly hypoenhancing compared to adjacent liver on hepatobiliary phase images. Nine lesions showed a pattern of peripheral hyperenhancement and central hypoenhancement on hepatobiliary phase images; in 6 of these lesions a majority of the mass appeared hyperenhancing, while the remaining 3 lesions showed predominant hypoenhancement. ConclusionsThis investigation shows that a significant percentage of inflammatory hepatic adenomas appear isointense or hyperintense in comparison to adjacent normal liver on hepatobiliary phase images, and therefore this feature should not be used to distinguish hepatic adenomas from focal nodular hyperplasia without additional supporting evidence.

Case Report: Spontaneous cholecystocutaneous fistula, a rare cholethiasis complication.

One of the most unusual complications in cholethiasis is spontaneous cholecystocutaneous fistula, which has only been reported a few times in the literature. We report the case of a 76 year old man who presented with a right hypochondrium subcutaneous abscess, with pain evoked through palpation. No comorbidity in the patient's medical history were noted. Confirmation of cholecystocutaneous fistula was made using the proper diagnostic process, which is computed tomography with contrast media, followed by hepatobiliary MRI. This confirmed the presence of a fistulous pathway between the gallbladder and the skin. The patient underwent cholecystectomy surgery and open laparotomy with en block aponeurotic muscle, skin and fistula orifice excision.

Fontan-associated liver disease: Spectrum of US findings

PurposeTo describe ultrasonography (US) findings of Fontan-associated liver disease (FALD) and to determine whether screening US examinations can identify FALD before biochemical hepatic dysfunction. MethodsThis retrospective study included 55 patients who underwent Fontan procedure over a 20-year period. Hepatobiliary US findings (n=55), CT or MRI findings (n=19), biochemical hepatic function tests (n=49), and histopathological results (n=4) were analyzed. Images were reviewed focusing on the hepatic parenchymal changes, presence of focal lesions, and signs of portal hypertension. ResultsHepatic parenchymal changes (either heterogeneous echotexture or surface nodularity) evident on US were present in 67% (37/55) and showed positive correlation with the Fontan duration. Hyper-echoic lesions were noted in 35% (19/55) and showed a predilection for multiplicity, small size, right lobe location, and irregular margin on high-frequency transducer. These lesions were not demonstrated by CT or MRI or by low-frequency transducer. Histopathological results of targeted biopsy for hyper-echoic lesions revealed lesser degree of patchy sinusoidal and portal fibrosis than seen in cases with surface nodularity. Abnormal parenchymal enhancement was commonly seen with CT or MRI in 63% (12/19) and hypervascular nodules in 21% (4/19). Most patients (82%, 40/49) showed normal biochemical hepatic function tests, despite the presence of hepatic parenchymal changes on imaging. ConclusionThe common US findings of FALD included heterogeneous parenchymal echotexture, surface nodularity, and hyper-echoic lesions. We suggest that hyper-echoic lesions without surface nodularity detected by high-frequency transducer may represent the early stage of fibrosis. US examination may be useful for identifying the progression of FALD before biochemical hepatic dysfunction.

Single-breath-hold thin-slice gadoxetic acid-enhanced hepatobiliary MR imaging using a newly developed three-dimensional fast spoiled gradient-echo sequence

PurposeTo prospectively evaluate the efficacy of a new three-dimensional gradient-echo sequence (Turbo LAVA) that uses undersampled k-space acquisition combined with a two-dimensional parallel imaging technique for hepatobiliary MRI. Materials and methodsSixty patients underwent T1-weighted gadoxetic acid-enhanced hepatobiliary axial MRI during a single breath-hold using both Turbo LAVA (thickness/interval=1.6/0.8mm) and conventional three-dimensional gradient-echo (4/2mm; LAVA) sequences at 3T. Axial 4-mm-thick reformation was performed from Turbo LAVA images. Portal vein-to-liver contrast (PLC), bile duct-to-liver contrast (BLC), and lesion-to-liver contrast (LLC) were compared. Two radiologists independently assessed image quality using a five-point scale. Sagittal 4-mm-thick multiplanar reconstructions (MPR) were performed from both sequences and assessed together with directly obtained 4-mm-thick sagittal LAVA images in terms of sharpness. The paired t-test was used to compare PLC, BLC, and LLC. The Wilcoxon signed rank test was used to compare five-point scales. ResultsThe mean PLC (P<0.001), BLC (P<0.001), and LLC (P<0.005) were significantly higher for Turbo LAVA than for LAVA; the scores for image noise and sharpness were inferior (P=0.000 and 0.005) and superior (0.005 and 0.157) for Turbo LAVA. There were no significant differences in the scores for bile duct visualization, artifacts, fat suppression quality, overall quality, and focal lesion conspicuity. For sagittal images, MPR Turbo LAVA showed significantly better sharpness than MPR LAVA but showed significantly worse sharpness compared with directly obtained LAVA. ConclusionHigh-spatial-resolution single-breath-hold hepatobiliary MRI using Turbo LAVA was feasible. Diagnostic-quality MPR images can be obtained using this sequence.

Age dependence of spleen- and muscle-corrected hepatic signal enhancement on hepatobiliary phase gadoxetate MRI.

To identify correlations of signal enhancements (SE) and SE normalized to reference tissues of the spleen, kidney, liver, musculus erector spinae (MES) and ductus hepatocholedochus (DHC) on hepatobiliary phase gadoxetate-enhanced MRIwith patient age in non-cirrhotic patients. A heterogeneous cohort of 131 patients with different clinical backgrounds underwent a standardized 3.0-T gadoxetate-enhanced liver MRI between November 2008 and June 2013. After exclusion of cirrhotic patients, a cohort of 75 patients with no diagnosed diffuse liver disease was selected. The ratio of signal intensity 20min post- to pre-contrast administration (SE) in the spleen, kidney, liver, MES and DHC, and the SE of the kidney, liver and DHC normalized to the reference tissues spleen or MES were compared to patient age. Patient age was inversely correlated with the liver SE normalized to the spleen and MES SE (both p < 0.001) and proportionally with the SE of the spleen (p = 0.043), the MES (p = 0.030) and the kidney (p = 0.022). No significant correlations were observed for the DHC (p = 0.347) and liver SE (p = 0.606). The age dependence of hepatic SE normalized to the enhancement in the spleen and MES calls for a cautious interpretation of these quantification methods. • Patient age was inversely correlated with spleen- and MES-corrected liver rSE (p < 0.001). • Patient age was correlated with spleen (p = 0.043) and MES SE (p = 0.030). • Patient age may confound quantitative liver function assessment using gadoxetate-enhanced liver MRI.

Simultaneous (68)Ga-DOTA-TOC PET/MRI with gadoxetate disodium in patients with neuroendocrine tumor.

To evaluate a simultaneous PET/MRI approach to imaging patients with neuroendocrine tumor using a combination of (68)Ga-DOTA-TOC as a PET contrast agent and gadoxetate disodium as a hepatobiliary MRI contrast agent. Ten patients with neuroendocrine tumor with known or suspected hepatic disease were imaged using a (68)Ga-DOTA-TOC PET/CT immediately followed by a 3.0T time-of-flight PET/MRI, using a combined whole body and liver specific imaging. The presence of lesions and DOTA-TOC avidity were assessed on CT, PET from PET/CT, diffusion weighted imaging, hepatobiliary phase imaging (HBP), and PET from PET/MRI. Maximum standardized uptake values (SUVmax) in hepatic lesions and nodal metastases were compared between PET/CT and PET/MRI, as were detection rates using each imaging approach. A total of 101 hepatic lesions were identified, 47 of which were DOTA-TOC avid and able to be individually measured on both PET/CT and PET/MRI. HBP imaging had a higher sensitivity for detection of hepatic lesions compared to CT or PET (99% vs. 46% and 64%, respectively; p values <0.001). There was a strong correlation between SUVmax of liver lesions obtained with PET/CT compared to PET/MR imaging (Pearson's correlation = 0.91). For nodal disease, CT had a higher sensitivity compared to whole body MRI (p = 0.015), although PET acquired from PET/MRI detected slightly more lesions compared to PET from PET/CT. A simultaneous PET/MRI using both (68)Ga-DOTA-TOC and gadoxetate disodium was successful in whole body staging of patients with neuroendocrine tumor. HBP imaging had an increased detection rate for hepatic metastases.