Magnetic resonance imaging (MRI) and diseases of the liver and biliary tract. Part 1. Basic principles, MRI in the assessment of diffuse and focal hepatic disease (original) (raw)
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Focal liver lesions: Practical magnetic resonance imaging approach
World Journal of Hepatology, 2015
With the widespread of cross-sectional imaging, a growth of incidentally detected focal liver lesions (FLL) has been observed. A reliable detection and characterization of FLL is critical for optimal patient management. Maximizing accuracy of imaging in the context of FLL is paramount in avoiding unnecessary biopsies, which may result in post-procedural complications. A tremendous development of new imaging techniques has taken place during these last years. Nowadays, Magnetic resonance imaging (MRI) plays a key role in management of liver lesions, using a radiation-free technique and a safe contrast agent profile. MRI plays a key role in the non-invasive correct characterization of FLL. MRI is capable of providing comprehensive and highly accurate diagnostic information, with the additional advantage of lack of harmful ionizing radiation. These properties make MRI the mainstay for the noninvasive evaluation of focal liver lesions. In this paper we review the state-of-the-art MRI liver protocol, briefly discussing different sequence types, the unique characteristics of imaging non-cooperative patients and discuss the role of hepatocyte-specific contrast agents. A review of the imaging features of the most common benign and malignant FLL is presented, supplemented by a schematic representation of a simplistic practical approach on MRI.
ROLE OF MRI IN CHARACTERIZATION OF FOCAL LIVER LESIONS
National Journal of Medical Research, 2020
Introduction: The increasing and widespread use of imaging studies has led to an increase in detection of incidental Focal Liver Lesions. It is important to diagnose not only malignant liver lesions, but also benign solid and cystic liver lesions. Objectives: Role of MRI imaging in characterization of various focal liver lesions detected incidentally on Ultrasonography. Methods: The present study included 50 patients with various focal Liver Lesions detected incidentally on Ultrasonography. MRI Liver of the patients having incidentally detected Focal Liver Lesions on Ultrasonography and Inconclusive Ultrasonography findings was done to characterize the various focal liver lesions. Biopsy was done in patients with findings raising a possibility of a malignant lesion. Result: Of the 50 patients, 30 patients were male and 20 were female. Age of patients ranged from 1 year to 79 years. Spectrum of diseases based on imaging findings includes: Simple hepatic cyst (5/50, 10%), Hemangioma(5/50, 10%) , Focal nodular hyperplasia(2/50, 4%), Hydatid cyst(4/50, 8%), abscess(3/50, 6%), hepatocellular carcinoma(9/50, 18%), metastases(12/50, 24%) and indeterminate radiological diagnosis(10/50, 20%). USG guided liver biopsy was done in 31 patients revealed Hepatocellular carcinoma in 7, Cholangiocarcinoma in 2, metastases in 20 patients and Hepatic adenoma in 2 patients. Conclusion: MRI has an excellent lesion detection rate. Nearly all the lesions detected on Ultrasonography were detected on MRI imaging. MRI is excellent for the characterization of various Focal Liver Lesions. It was possible to reach to a specific radiological diagnosis in most of the patients.
La Radiologia medica, 2016
To assess the diagnostic performance of magnetic resonance imaging (MRI) with gadoxetic acid in the identification of hepatocellular carcinoma (HCC) nodules by comparison with histological findings. In a cohort of patients suffering from cirrhosis of various etiologies (chronic hepatitis C virus (HCV) or hepatitis B virus (HBV), alcohol abuse, cryptogenic forms), we selected 17 patients affected by HCC who were eligible for liver transplantation on the basis of a computed-tomography (CT) total-body examination. Such patients also underwent an MRI examination under basal conditions, and with four dynamic phases, as well as a hepatobiliary phase acquired after at least 20 min and recognized by the excretion of contrast agent into the bile duct, following intravenous administration of 0.05 mol/kg of gadoxetic acid (gadoxetate disodium, Primovist(®); Bayer, Osaka, Japan). The MRI images were then evaluated in a double-blinded experimental setup by two radiologists experienced in imaging...
World J Hepatol 2022 July 27; 14(7): 1459-1469, 2022
Abstract BACKGROUND Challenging lesions, difficult to diagnose through non-invasive methods, constitute an important emotional burden for each patient regarding a still uncertain diagnosis (malignant x benign). In addition, from a therapeutic and prognostic point of view, delay in a definitive diagnosis can lead to worse outcomes. One of the main innovative trends currently is the use of molecular and functional methods to diagnosis. Numerous liver-specific contrast agents have been developed and studied in recent years to improve the performance of liver magnetic resonance imaging (MRI). More recently, one of the contrast agents introduced in clinical practice is gadoxetic acid (gadoxetate disodium). AIM To demonstrate the value of the hepatobiliary phases using gadoxetic acid in MRI for the characterization of focal liver lesions (FLL) in clinical practice. METHODS Overall, 302 Lesions were studied in 136 patients who underwent MRI exams using gadoxetic acid for the assessment of FLL. Two radiologists independently reviewed the MRI exams using four stages, and categorized them on a 6-point scale, from 0 (lesion not detected) to 5 (definitely malignant). The stages were: stage 1- images without contrast, stage 2- addition of dynamic phases after contrast (analogous to usual extracellular contrasts), stage 3- addition of hepatobiliary phase after 10 min (HBP 10’), stage 4- hepatobiliary phase after 20 min (HBP 20’) in addition to stage 2. RESULTS The interobserver agreement was high (weighted Kappa coefficient: 0.81- 1) at all stages in the characterization of benign and malignant FLL. The diagnostic weighted accuracy (Az) was 0.80 in stage 1 and was increased to 0.90 in stage 2. Addition of the hepatobiliary phase increased Az to 0.98 in stage 3, which was also 0.98 in stage 4. CONCLUSION The hepatobiliary sequences improve diagnostic accuracy. With growing potential in the era of precision medicine, the improvement and dissemination of the method among medical specialties can bring benefits in the management of patients with FLL that are difficult to diagnose. Key Words: Liver; Liver neoplasms; Liver transplantation; Medical oncology; Diagnostic imaging; Magnetic resonance imaging ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved. Core Tip: The translational objective was to determine the value of hepatobiliary phases using gadoxetic acid as a liver-specific agent in magnetic resonance imaging (MRI) in the characterization of benign and malignant focal liver lesions (FLL) in clinical practice. Morphofunctional MRI with gadoxetic acid in addition to the usual dynamic phases after contrast medium (arterial, portal and transitional/ equilibrium) increased the proportion of hits for differentiation between benign and malignant FLL in relation to the definitive diagnosis. The results suggest a relevant impact on the definition of strategies for the approach of focal hepatic lesions, as well as in the assessment of the treatment employed.
MR characterization of focal liver lesions: pearls and pitfalls
Magnetic resonance imaging clinics of North America, 2014
Magnetic resonance (MR) can characterize specific tissue subtypes, thus facilitating focal liver lesion diagnosis. Focal liver lesions that are isointense to hyperintense to liver on T1-weighted images are usually hepatocellular in origin. Chemical shift imaging can narrow the differential diagnosis by detecting the presence of lipid or iron. T2 and heavily T2-weigthed fast spin echo imaging can differentiate solid from nonsolid focal liver lesions. The authors illustrate these MR imaging pearls and the uncommon exceptions (pitfalls). The authors hope that you will find this less traditional contribution to the Magnetic Resonance Clinics of North America helpful in clinical practice.
Consensus report from the 7th International Forum for Liver Magnetic Resonance Imaging
European radiology, 2015
Liver-specific MRI is a fast-growing field, with technological and protocol advancements providing more robust imaging and allowing a greater depth of information per examination. This article reports the evidence for, and expert thinking on, current challenges in liver-specific MRI, as discussed at the 7th International Forum for Liver MRI, which was held in Shanghai, China, in October 2013. Topics discussed included the role of gadoxetic acid-enhanced MRI in the differentiation of focal nodular hyperplasia from hepatocellular adenoma and small hepatocellular carcinoma (HCC) from small intrahepatic cholangiocarcinoma (in patients with chronic liver disease), the differentiation of low-grade dysplastic nodule (DN) from pre-malignant high-grade DN and early HCC, and treatment planning and assessment of treatment response for patients with HCC and colorectal liver metastasis. Optimization of the gadoxetic acid-enhanced MRI protocol to gain robust arterial and hepatobiliary phase image...