Ultrasound findings in peliosis hepatis

Washout on Contrast-Enhanced Ultrasound of Benign Focal Liver Lesions-A Review on Its Frequency and Possible Causes

In all imaging methods, including contrast-enhanced ultrasound (CEUS), enhancement in the late phase (LP) is an important criterion for differentiating between benign and malignant focal liver lesions (FLLs). In general, malignant liver lesions are characterized by hypoenhancement and washout in the LP. A lesion with LP hyperenhancement or isoenhancement in the non-cirrhotic liver is usually benign. However, LP hypoenhancement in benign lesions is not so rare, and is even normal and the standard for some lesions, and there are exceptions for each tumor entity that can represent a diagnostic challenge. Knowing these contrast patterns and exceptions is key for correct diagnosis and patient management. The following narrative review describes the contrast behaviors and the frequency of washout and LP hypoenhancement for common as well as rare benign liver lesions and analyzes its causes.

Hyperechogenicity and histopathological features of focal liver lesions

The identification and accurate diagnosis of focal liver lesions are important in modern medicine, where diagnostic radiology plays an essential role. This review aimed to examine the hyperechogenicity and histopathological features of focal liver lesions. Hyperechogenic liver lesions can be either benign or malignant. Evidence shows that hyperechogenicity is caused by factors such as fat deposition, sinusoidal dilation, peliotic changes, and pseudoglandular patterns. Fat deposition is a common cause of increased echogenicity in hepatocellular carcinoma (HCC). Meanwhile, sinusoidal dilation and peliotic changes are more frequently observed in larger HCC nodules. Pseudoglandular patterns, characterized by the reflection of ultrasound waves at the walls of numerous acini, are associated with hyperechogenicity in well-to-moderately differentiated HCCs. Moreover, this review comprehensively examined the histological features that may cause hyperechogenic internal echoes in not only HCCs but also localized liver lesions (metastases of adenocarcinoma and neuroendocrine neoplasm, intrahepatic cholangiocarcinoma, cavernous hemangioma, focal nodular hyperplasia, and angiomyolipoma). To make an accurate diagnosis and provide appropriate management, it is important to understand the histopathological basis for hyperechogenicity in focal liver lesions. By maximizing the accuracy of imaging studies and enhancing the radiology-pathology correlation, unnecessary biopsies can be avoided, thereby reducing potential complications and mortality. This review can help facilitate the effective management of patients with focal liver lesions, thereby resulting in timely and appropriate treatment decision-making.

Imaging in Vascular Liver Diseases

Vascular liver diseases (VLDs) include different pathological conditions that affect the liver vasculature at the level of the portal venous system, hepatic artery, or venous outflow system. Although serological investigations and sometimes histology might be required to clarify the underlying diagnosis, imaging has a crucial role in highlighting liver inflow or outflow obstructions and their potential causes. Cross-sectional imaging provides a panoramic view of liver vascular anatomy and parenchymal patterns of enhancement, making it extremely useful for the diagnosis and follow-up of VLDs. Nevertheless, multiparametric ultrasound analysis provides information useful for differentiating acute from chronic portal vein thrombosis, distinguishing neoplastic invasion of the portal vein from bland thrombus, and clarifying the causes of venous outflow obstruction. Color Doppler analysis measures blood flow velocity and direction, which are very important in the assessment of VLDs. Finally, liver and spleen elastography complete the assessment by providing intrahepatic and intrasplenic stiffness measurements, offering further diagnostic information.

Peliosis of the spleen as an unusual cause of splenic rupture: A case report and a review of literature

Isolated splenic peliosis is an extremely rare condition characterized by the presence of multiple blood-filled cavities, occasionally resulting in non-traumatic splenic rupture with fatal bleeding. In our case, a 64-year-old man was brought by ambulance due to weakness and abdominal pain without nausea or febrility. On clinical examination, the patient was sensitive to palpation with significant tenderness over the abdomen but no associated features of peritonitis. He collapsed during the imaging examination and became unconscious and asystolic. Cardiopulmonary resuscitation was not successful. The patient died approximately within 2 hours of admission to the hospital. Postmortal examination showed 2800 ml of intraperitoneal blood with clots and a laceration of the lower pole of the spleen. Macroscopic examination of the spleen revealed huge nodular splenomegaly, measuring 21 cm x 19 cm x 5 cm, weighing 755 g. On the cut surfaces, multiple randomly distributed blood-filled cavities ranging from 0,5 to 2 cm in diameter were seen. At microscopic examination, the specimens showed multiple irregular haemorrhagic cyst-like lesions that were not lined by any epithelium or sinusoidal endothelium, consistent with the diagnosis of peliosis lienis. Although the condition is often clinically silent, the forensic pathological significance arises from the differential diagnosis of resultant intraperitoneal haemorrhage and sudden death, mimicking a violent death.

Value of contrast-enhanced ultrasound for vascular diseases of the liver - current indications and open questions

Contrast-enhanced ultrasonography (CEUS) is a widely available and well-tolerated technique that can expand the diagnosis of a variety of vascular liver diseases. This paper presents an overview of the current possibilities of the use of CEUS in vascular liver diseases. Particularly where Doppler sonography has technical limitations, CEUS provides additional opportunities to visualize vascular thrombosis and other obstructions restricting blood flow. When CT or MRI contrast agents cannot be used because of severe allergy or renal insufficiency, CEUS can be a valuable diagnostic alternative and has demonstrated comparable diagnostic performance in at least some vascular liver diseases, such as portal vein thrombosis. In addition, CEUS works without radiation and, therefore, might be particularly suitable for young patients and children. This may be useful, for example, in congenital disorders such as persistent umbilical vein or preduodenal portal vein. Vascular liver disease is rare and comprehensive data are still lacking, but the available literature provides promising insights into potential new ways to study vascular liver disease. Although most studies are based on small sample sizes or even case reports, the high diagnostic utility is undisputed.

MRI of Peliosis Hepatis: A Case Series Presentation With a 2022 Systematic Literature Update

BACKGROUND

Peliosis hepatis (PH) is a rare benign condition, characterized by hepatic sinusoidal dilatation and blood-filled cystic cavities, often found incidentally, with still challenging diagnosis by imaging due to polymorphic appearance.

PURPOSE

Based on a retrospective analysis of our series (12 patients) and systematic literature review (1990-2022), to organize data about PH and identify features to improve characterization.

STUDY TYPE

Retrospective case series and systematic review.

POPULATION

Twelve patients (mean age 48 years, 55% female) with pathology-proven PH and 49 patients (mean age 52 years, 67% female) identified in 33 studies from the literature (1990-2022).

FIELD STRENGTH/SEQUENCE

1,5-T; T1-weighted (T1W), T2-weighted (T2W), diffusion-weighted (DW), contrast-enhanced (CE) T1W imaging.

ASSESSMENT

We compared our series and literature data in terms of demographic (gender/age/ethnicity), clinical characteristics (symptoms/physical examination/liver test), associated conditions (malignancies/infectious/hematologic/genetic or chronic disorders/drugs or toxic exposure) percentage. On magnetic resonance imaging lesion numbers/shape/mean maximum diameter/location/mass effect/signal intensity were compared. PH pathological type/proposed imaging diagnosis/patient follow-up were also considered.

STATISTICAL TESTS

Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Case Reports/Series quality assessment. Intraclass correlation and Cohen's kappa coefficients for levels of inter/intrareader agreement in our experience.

RESULTS

Patients were mainly asymptomatic (92% vs. 70% in our study and literature) with associated conditions (83% vs. 80%). Lesions showed homogeneous T1W-hypointensity (58% vs. 65%) and T2W-hyperintensity (58% vs. 66%). Heterogeneous nonspecific (25% vs. 51%), centrifugal (34% vs. 8%), or rim-like centripetal (25% vs. 23%) patterns of enhancement were most frequent, with hypointensity on the hepatobiliary phase (HBP), without restricted diffusivity. Good inter- and intrareader agreement was observed in our experience. Concerning JBI Checklist, 19 out of 31 case reports met at least 7 out of 8 criteria, whereas 2 case series fulfilled 5 and 6 out of 10 items respectively.

DATA CONCLUSION

A homogeneous, not well-demarcated T1W-hypointense and T2W-hyperintense mass, with heterogeneous nonspecific or rim-like centripetal or centrifugal pattern of enhancement, and hypointensity on HBP, may be helpful for PH diagnosis. Among associated conditions, malignancies and drug exposures were the most frequent.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY: Stage 2.

Solitary peliosis hepatis mimics a liver metastasis on contrast-enhanced ultrasound

Peliosis hepatis remains a rare focal liver lesion with inconclusive imaging features. The unknown pathogenesis represents a wide possible range of etiologies including the breakdown of the sinusoidal borders, a potential hepatic outflow obstruction or dilatation of the central vein of a hepatic lobule. In histopathology, a blood-filled cystlike appearance with sinusoidal dilatation was reported. On ultrasound, B-mode features are not specific demonstrating a irregular, moreover hypoechogenic focal liver lesions. Postcontrast imaging features on Contrast-Enhanced-Ultrasound may mimic a malignant lesion with irregular contrast inflow and washout during late phase. Our case demonstrates a peliosis hepatis with malignant image features on contrast-enhanced ultrasound, ruled out by PET-CT and core needle biopsy with corresponding histopathological workup.

Incidental Findings in Pediatric Patients: How to Manage Liver Incidentaloma in Pediatric Patients

The World Federation for Ultrasound in Medicine and Biology (WFUMB) is addressing the issue of incidental findings (IFs) with a series of publications entitled "Incidental imaging findings-the role of ultrasound". IFs in the liver of newborns and children are rare and much less commonly encountered than in adults; as a result, they are relatively much more frequently malignant and life-threatening, even when they are of benign histology. Conventional B-mode ultrasound is the well-established first line imaging modality for the assessment of liver pathology in pediatric patients. US technological advances, resulting in image quality improvement, contrast-enhanced ultrasound (CEUS), liver elastography and quantification tools for steatosis have expanded the use of ultrasound technology in daily practice. The following overview is intended to illustrate incidentally detected liver pathology covering all pediatric ages. It aims to aid the examiner in establishing the final diagnosis. Management of incidentally detected focal liver lesions (FLL) needs to take into account the diagnostic accuracy of each imaging modality, the patient's safety issues (including ionizing radiation and nephrotoxic contrast agents), the delay in diagnosis, the psychological burden on the patient and the cost for the healthcare system. Moreover, this paper should help the pediatric clinician and ultrasound practitioner to decide which pathologies need no further investigation, which ones require interval imaging and which cases require further and immediate diagnostic procedures.

Intrahepatic splenosis: Contrast enhanced ultrasound and magnetic resonance imaging findings

OBJECTIVE

To evaluate the contrast enhanced ultrasound (CEUS) and contrast enhanced magnetic resonance imaging (CEMRI) features of intrahepatic splenosis (IHS).

METHODS & MATERIALS

Five patients (three males and two females, median age, 44 years; range,32-73 years) with seven IHSs were retrieved from the database of our hospital from March 2012 to October 2021. All IHSs were confirmed histologically by surgery. The CEUS and CEMRI characteristics of individual lesion were fully analyzed.

RESULTS

All IHS patients were asymptomatic and four out of five patients had history of splenectomy. On CEUS, all IHSs were hyperenhancement in arterial phase. 71.4% (5/7) of IHSs manifested overall filling within few seconds, the other two lesions showed centripetal filling. Subcapsular vascular hyperenhancement and feeding artery was seen in 28.6% (2/7) and 42.9% (3/7) of IHSs, respectively. During portal venous phase, IHSs presented hyperenhancement (2/7) or isoenhancement (5/7). Moreover, rim-like hypoenhanced area was uniquely observed surrounding 85.7% (6/7) of IHSs. In late phase, seven IHSs remained continuous hyper- or isoenhancement. On CEMRI, five IHSs showed mosaic hyperintense in early arterial phase, the other two lesions showed homogeneous hyperintense. In portal venous phase, all IHSs revealed continuous hyper- (71.4%, 5/7) or iso-intense (28.6%, 2/7). During late phase, one IHS (14.3%, 1/7) became hypointense, the other lesions remained hyper- or isointense.

CONCLUSION

Diagnosis of IHS can be based on typical CEUS and CEMRI features in patients with history of splenectomy.

Imaging Features of Hepatocellular Carcinoma in the Non-Cirrhotic Liver with Sonazoid-Enhanced Contrast-Enhanced Ultrasound

PURPOSE

To investigate the Sonazoid-enhanced contrast-enhanced ultrasound (CEUS) features of hepatocellular carcinoma (HCC) in a non-cirrhosis liver background, in comparison to those in liver cirrhosis.

METHODS

In this retrospective study, 19 patients with surgery and histopathologically proven HCC lesions in non-cirrhosis liver background were included regarding Sonazoid-enhanced CEUS characteristics. Two radiologists evaluated the CEUS features of HCC lesions according to the WFUMB (World Federation of Societies for Ultrasound in Medicine and Biology) guidelines criteria. Thirty-six patients with HCC lesions in liver cirrhosis were included as a control group. Final diagnoses were confirmed by surgery and histopathological results.

RESULTS

Liver background of the non-cirrhosis group including normal liver (n = 7), liver fibrosis (n = 11), and alcoholic liver disease (n = 1). The mean size of non-cirrhosis HCC lesions was 60.8 ± 46.8 mm (ranging from 25 to 219 mm). During the arterial phase of Sonazoid-enhanced CEUS, most HCCs in non-cirrhotic liver (94.7%, 18/19) and in cirrhotic liver (83.3%, 30/36) presented non-rim hyperenhancement. During the portal venous phase, HCC lesions in the non-cirrhosis liver group showed relatively early washout (68.4%, 13/19) (p = 0.090). Meanwhile, HCC lesions in liver cirrhosis background showed isoenhancement (55.6%, 20/36). All lesions in the non-cirrhotic liver group showed hypoenhancement in the late phase and the Kupffer phase (100%, 19/19). Five cases of HCC lesions in liver cirrhosis showed isoenhancement during the late phase and hypoenhancement during the Kupffer phase (13.9%, 5/36). The rest of the cirrhotic HCC lesions showed hypoenhancement during the late phase and the Kupffer phase (86.1%, 31/36). Additional hypoenhanced lesions were detected in three patients in the non-cirrhosis liver group and eight patients in the liver cirrhosis group (mean size: 13.0 ± 5.6 mm), which were also suspected to be HCC lesions.

CONCLUSIONS

Heterogeneous hyperenhancement during the arterial phase as well as relatively early washout are characteristic features of HCC in the non-cirrhotic liver on Sonazoid-enhanced CEUS.