Magnetic Resonance Imaging in Focal Liver Lesions with Diffusion Weighted Imaging (DWI) and Pathological Correlation

Background: Magnetic resonance signal intensity of focal liver lesions is affected by numerous pathologic factors. Lesion histologic features, such as cellularity, vascularity, stromal component, and intratumoral necrosis or hemorrhage, strongly affect T1 and T2 relaxation times. Aim and objectives: To assess the lesion characterization potential of MRI by evaluating unenhanced and dynamic gadolinium enhanced sequences, Histopathological correlation of the lesions to explain the major MRI findings and Assessment of the lesions by diffusion weighted imaging and investigating the role of b value in differentiating malignant and benign lesions Materials and methods: The study was done on 42 patients where contrast was given in 38 members. Focal liver lesions were analyzed based on clinical findings, laboratory investigations and MR imaging. Sonographically detected focal lesions were included in the study. Tissue diagnosis (FNAC/ Biopsy), surgery were done in feasible cases. In other cases, where surgery/ tissue diagnosis is not possible, follow up was done (range 3 months - 12 months, average 7.2 months). Results: MRI features of forty two patients with focal liver lesions were studied and morphological features and signal intensities of the masses were described. Contrast study was done in 39 cases. Of the 42 cases, 24 lesions were benign and 18 lesions were malignant. The mean age group ranged from 18 to 74 years with majority between 40 to 60 years. 61% of the lesions were located in right lobe of the liver. Contrast enhancement was done in 39 cases. Contrast enhancement was able to better delineate the cases. Specific pattern of contrast enhancement was typical of certain lesions as Karuna V, R Vikash Babu. Magnetic Resonance Imaging in Focal Liver Lesions with Diffusion Weighted Imaging (DWI) and Pathological Correlation. IAIM, 2019; 6(11): 81-93. Page 82 homogenous early arterial phase enhancement for hepatocellular carcinoma and ring enhancement in arterial phase for metastases. Delayed enhancement was specific for cholangiocarcinoma. Hemangiomas showed peripheral puddling and delayed central enhancement. Diffusion weighted imaging can be used as an additional tool in differentiating benign and malignant focal liver lesions. ADC value using a cut-off of 1.43 X 10 – 3 sec/ mm2 was a useful adjunct for determining benign cystic lesions and hemangiomas from malignant lesions. Conclusion: MRI was able to predict diagnosis in 38 of the 42 tumors. It could suggest the nature of all lesions in benign cysts, hemangiomas, focal nodular hyperplasia and metastases. But it was not possible to achieve a specific diagnosis in two early abscesses, one multifocal hepatocellular carcinoma and one case of regenerative nodules. This accounted for a detection rate of 90%. Thus MR imaging is a powerful tool for the evaluation of focal liver lesions. Pre contrast T1 weighted gradient echo images, T2 weighted images, in phase and out phase imaging, EPI – DWI and gadolinium enhanced T1 weighted images provide accurate characterization of the lesions.

Multiple focal nodular hyperplasia, an incidental finding on autopsy.

Focal nodular hyperplasia (FNH) is a benign condition of the liver often discovered incidentally on radiological investigation. Although FNH is a well-described lesion in the literature considerable diagnostic problems regarding this entity still remains. We report a case of multiple FNH in a 23-year-old male patient detected as an incidental finding in autopsy. On gross examination FNH was not suspected because of the multiple lesions and the lack of central scar which is characteristically described in FNH. The diagnosis was established on histopathology after examination of multiple sections of the lesions.

Diagnosis and treatment of hepatic focal nodular hyperplasia / 中国基层医药

Objective To study the diagnosis and treatment of hepatic focal nodular hyperplasia(FNH).Methods The clinical data of 15 FNH patients proved by pathological examination were retrospectively analyzedResults Most cases of FNH were asymptomatic,and some had nonspecific symptom such as dull pain of upper abdomen.Most cases of FNH showed nodular lesion on liver imaging with isodensity or hypodensity on pre-contrast CT scan and strong enhancement during arterial phase.of the 15 FNH patients,5 eases were diagnosed by needle biopsy pathology,10 cases were diagnosed by postoperative pathology.And 10 cases underwent surgical resection(7 cages with irregular hepatectomy,1 case with resection of segment 7,2 cases with left lateral lobeetomy),2 cases underwent percutaneous transhepafic chemical ablation,3 cases underwent clinical observation.All cases were followed up,and no recurence or malignancy were found.Conclusion FNH is a kind of benign tumor of liver without specific clinical manifestation.Accurate diagnosis needs pathological examination.Surgical treatment is recommended in most cages.Close follow-up is recommended in cases without operation.

Focal nodular hyperplasia-like nodules in a young man with congenital liver cirrhosis / 대한내과학회지

Focal nodular hyperplasia-like nodules (FNH-like nodules) are hypervascular lesions that occur in the cirrhotic liver. Histologically,they are similar to classical FNH in an otherwise normal liver. Radiologically, FNH-like nodules may mimic hepatocellular carcinoma (HCC), and they have been misdiagnosed as HCC based on radiological findings. Their pathogenesis and etiology are unclear, but they may arise from a local hyperplastic response to vascular alterations like classical FNH. Rarely, these nodules transform into malignant tumors and cause complications. We report the case of a 28-year-old man with multiple FNH-like nodules in congenital liver cirrhosis.

A Case of Focal Nodular Hyperplasia of the Liver / 대한간학회지

Focal nodular hyperplasia (FNH) is a rare benign hepatic tumor occurring predominantly in women of childbearing age. Generally oral contraceptive is not associated with FNH but might accentuate the vascular abnormalities which may cause the lesion to enlarge and, very rarely, to rupture. FNH is typically asymptomatic and seldom bleeds. Often it is incidentally observed during imaging procedures performed for some other reasons. The histologic feature of FNH is characterized by areas of localized growth of mature hepatocytes and septal fibrosis. Surgical resection is seldom required because of the benign nature of the lesion and its lack of significant complication. We experienced a case of focal nodular hyperplasia without liver cirrhosis confirmed by surgical resection and histologic examination. in a 47-year-old man.