Polycystic liver disease: multimodality imaging for complications and transplant evaluation

Polycystic liver: automatic segmentation using deep learning on CT is faster and as accurate compared to manual segmentation

OBJECTIVE

This study aimed to develop and investigate the performance of a deep learning model based on a convolutional neural network (CNN) for the automatic segmentation of polycystic livers at CT imaging.

METHOD

This retrospective study used CT images of polycystic livers. To develop the CNN, supervised training and validation phases were performed using 190 CT series. To assess performance, the test phase was performed using 41 CT series. Manual segmentation by an expert radiologist (Rad1a) served as reference for all comparisons. Intra-observer variability was determined by the same reader after 12 weeks (Rad1b), and inter-observer variability by a second reader (Rad2). The Dice similarity coefficient (DSC) evaluated overlap between segmentations. CNN performance was assessed using the concordance correlation coefficient (CCC) and the two-by-two difference between the CCCs; their confidence interval was estimated with bootstrap and Bland-Altman analyses. Liver segmentation time was automatically recorded for each method.

RESULTS

A total of 231 series from 129 CT examinations on 88 consecutive patients were collected. For the CNN, the DSC was 0.95 ± 0.03 and volume analyses yielded a CCC of 0.995 compared with reference. No statistical difference was observed in the CCC between CNN automatic segmentation and manual segmentations performed to evaluate inter-observer and intra-observer variability. While manual segmentation required 22.4 ± 10.4 min, central and graphics processing units took an average of 5.0 ± 2.1 s and 2.0 ± 1.4 s, respectively.

CONCLUSION

Compared with manual segmentation, automated segmentation of polycystic livers using a deep learning method achieved much faster segmentation with similar performance.

KEY POINTS

• Automatic volumetry of polycystic livers using artificial intelligence method allows much faster segmentation than expert manual segmentation with similar performance. • No statistical difference was observed between automatic segmentation, inter-observer variability, or intra-observer variability.

Isolated Polycystic Liver Disease: A Rare Genetic Disorder

Polycystic liver disease is a rare clinical condition that causes portal hypertension. It constitutes a group of disorders with liver lesions resulting from abnormal development of the embryological ductal system. Isolated polycystic disease with the absence of polycystic kidney disease is considered a rare condition. We present the case of a 46-year-old man who presented with epigastric pain and episodes of hematemesis. Abdominal examination revealed enlarged liver. He underwent a computed tomography scan that revealed innumerable cystic liver lesions with the presence of ascites. Further investigations confirmed abnormal liver functions and portal hypertension. Physicians need to consider this diagnosis in the appropriate clinical settings. Extensive involvement of the liver may lead to persistent severe symptoms requiring liver transplantation.

Polycystic liver disease with lethal abdominal wall rupture: a case report

Background

Polycystic liver disease is a clinical feature of autosomal dominant polycystic kidney disease, and it can sometimes cause health damage more serious than polycystic kidney. Dialysis therapy can be used for renal failure, but liver transplantation is the only method available for liver failure. Thus, giant and multiple hepatic cysts may affect mortality. However, liver transplantation is not indicated in many cases because of the preserved liver function.

Case presentation

A 54-year-old Japanese woman with polycystic liver disease was transferred back to our hospital for abdominal pain caused by liver cyst infection with abdominal wall herniation. She had been diagnosed with polycystic liver disease associated with sporadic autosomal dominant polycystic kidney disease 25 years earlier. Although she had several surgical interventions to reduce her liver volume, including right hepatic lobectomy and fenestration for liver cysts in another hospital, she needed further repair of the recurrent incisional herniation with patch graft surgery using fascia lata to cover the herniation site. However, new herniation sites reemerged in the fragile abdominal wall area around the patch, and therefore, she reduced the recurrent abdominal wall herniation by herself. Recurrent intestinal obstructions were luckily released by fasting with decompression treatment via nasogastric tube insertion, but multiple skin ulcers around the enlarged hernia sac gradually developed, and ascites was extremely difficult to control with any medication. At final admission, her abdominal wall was even more prominent, causing shortness of breath, and it spontaneously ruptured many times, which was accompanied by discharge of around 5 liters of ascites each time. She died from sepsis caused by drug-resistant Enterococcus.

Conclusions

We report a case of autosomal dominant polycystic kidney disease with ruptured abdominal wall resulting from a hepatic cyst enlargement despite multiple laparotomy operations. Throughout the entire disease course, her liver volume increased rapidly, and her quality of life was severely impaired, but she could not undergo liver transplantation after readmission to our hospital. We will discuss the therapeutic strategy for this patient, including the timing and indication for liver transplantation.

Imaging in ductal plate malformations

Ductal plate malformations are a heterogenous group of congenital fibrocystic liver diseases resulting from insult to the ductal plate at various stages of embryogenesis. As a result various biliary malformations, cysts, hamartomas and congenital hepatic fibrosis may be seen. We present a radiological pictorial of ductal plate malformations, accurate diagnosis of which is important for clinical management.

Incidental Liver Findings on Cross-sectional Imaging

Hepatic incidental findings often are seen on cross-sectional imaging examinations of the chest, spine, pelvis, or other nondedicated hepatic imaging. Radiologists are tasked with appropriately triaging, which requires further evaluation, even in the setting of an otherwise limited evaluation. This article reviews common benign entities encountered on ultrasound, computed tomography, or magnetic resonance imaging, along with their characteristic imaging features. Imaging features that are suspicious for malignancy or suggest the need for further evaluation also are discussed. Two algorithms are proposed to guide radiologists in their recommendations based on patient risk factors, focal hepatic abnormality size, and available imaging features.

Non-neoplastic cholangiopathies: an algorithmic approach

Cholangiopathies are chronic diseases that affect the bile ducts, comprising a heterogeneous group of progressive and potentially fatal entities. The diagnosis of these diseases is a great challenge for radiologists because of the overlapping of their clinical, biochemical, and imaging findings. Nevertheless, identifying the precise etiology is crucial, given that the therapeutic options are distinct and influence the prognosis of the patient. The purpose of this review article is to discuss some of the non-neoplastic causes of cholangiopathies and to provide a useful diagnostic algorithm.

Magnetic resonance imaging of fibropolycystic liver disease: the spectrum of ductal plate malformations

Fibropolycystic liver diseases, also known as ductal plate malformations, are a group of associated congenital disorders resulting from abnormal development of the biliary ductal system. These disorders include congenital hepatic fibrosis, biliary hamartomas, polycystic liver disease, choledochal cysts and Caroli disease. Recently, it has been thought to include biliary atresia in this group of diseases, because ductal plate malformations could be implicated in the pathogenesis of this disease. Concomitant associated renal anomalies can also be present, such as autosomal recessive polycystic kidney disease (ARPKD), medullary sponge kidney and nephronophthisis. These disorders can be clinically silent or can cause abnormalities such as cholangitis, portal hypertension, gastrointestinal bleeding and infections. The different types of ductal plate malformations show typical findings at magnetic resonance (MR) imaging. A clear knowledge of the embryology and pathogenesis of the ductal plate plays a pivotal role to understand the characteristic imaging appearances of these complex diseases. Awareness of these MR imaging findings is central to the detecting and differentiating between various fibropolycystic liver diseases and is important to direct appropriate clinical management and prevent misdiagnosis.

Typical and atypical benign liver lesions: A review

Focal liver lesions are routinely encountered by clinical radiologists and represent a wide spectrum of pathology. Majority of these lesions are likely to be benign in nature, especially in the absence of chronic liver disease or primary cancer. A radiologist must be aware of common and uncommon imaging features of benign lesions across the various imaging modalities. This review discusses pathognomonic imaging features of common benign focal liver lesions seen on ultrasound, computed tomography and magnetic resonance, and adds to existing knowledge with the recent updates to have emerged in this area.

Cystic hepatic lesions: a review and an algorithmic approach

OBJECTIVE

The purpose of this article is to review the different cystic hepatic lesions, with an emphasis on the imaging features that help to differentiate them, and to propose a practical algorithm for approaching the diagnosis of these lesions.

CONCLUSION

The number and morphology of the lesions and determination of whether there is a solid component are key imaging features that are helpful for approaching the diagnosis of cystic hepatic lesions. Familiarity with these features and knowledge of the clinical associations will help the radiologist to establish a definitive diagnosis or provide a reasonable differential diagnosis.

Polycystic liver disease: an overview of pathogenesis, clinical manifestations and management

Polycystic liver disease (PLD) is the result of embryonic ductal plate malformation of the intrahepatic biliary tree. The phenotype consists of numerous cysts spread throughout the liver parenchyma. Cystic bile duct malformations originating from the peripheral biliary tree are called Von Meyenburg complexes (VMC). In these patients embryonic remnants develop into small hepatic cysts and usually remain silent during life. Symptomatic PLD occurs mainly in the context of isolated polycystic liver disease (PCLD) and autosomal dominant polycystic kidney disease (ADPKD). In advanced stages, PCLD and ADPKD patients have massively enlarged livers which cause a spectrum of clinical features and complications. Major complaints include abdominal pain, abdominal distension and atypical symptoms because of voluminous cysts resulting in compression of adjacent tissue or failure of the affected organ. Renal failure due to polycystic kidneys and non-renal extra-hepatic features are common in ADPKD in contrast to VMC and PCLD. In general, liver function remains prolonged preserved in PLD. Ultrasonography is the first instrument to assess liver phenotype. Indeed, PCLD and ADPKD diagnostic criteria rely on detection of hepatorenal cystogenesis, and secondly a positive family history compatible with an autosomal dominant inheritance pattern. Ambiguous imaging or screening may be assisted by genetic counseling and molecular diagnostics. Screening mutations of the genes causing PCLD (PRKCSH and SEC63) or ADPKD (PKD1 and PKD2) confirm the clinical diagnosis. Genetic studies showed that accumulation of somatic hits in cyst epithelium determine the rate-limiting step for cyst formation. Management of adult PLD is based on liver phenotype, severity of clinical features and quality of life. Conservative treatment is recommended for the majority of PLD patients. The primary aim is to halt cyst growth to allow abdominal decompression and ameliorate symptoms. Invasive procedures are required in a selective patient group with advanced PCLD, ADPKD or liver failure. Pharmacological therapy by somatostatin analogues lead to beneficial outcome of PLD in terms of symptom relief and liver volume reduction.

Spectrum of multilocular cystic hepatic lesions: CT and MR imaging findings with pathologic correlation

A multilocular cystic hepatic lesion detected at computed tomography (CT) and magnetic resonance (MR) imaging is a common but nonspecific radiologic finding that can cause potential challenges for differential diagnosis. This imaging pattern may be observed in a wide spectrum of common and uncommon neoplastic or nonneoplastic entities. Neoplastic lesions include cystadenoma, cystadenocarcinoma, hepatocellular carcinoma (HCC), metastases, mesenchymal hamartoma, and inflammatory myofibroblastic tumor. Nonneoplastic lesions include hepatic abscess, echinococcal cyst, intrahepatic hematoma, and biloma. The multiple coalescent cysts seen in polycystic liver disease may exhibit an imaging pattern similar to that of a multilocular cystic lesion. Mural nodularity, irregular thickness of the septa, ragged inner surface, and typical enhancement pattern in the solid portion of the lesion are often indicative of malignancy, although multilocular primary or secondary malignant tumors are uncommon. Recognition of the more common necrosis or cystic change of HCC and metastases induced by locoregional or systemic treatment also is important. The nonenhanced cystic component may be composed of different types of fluids (eg, serous, mucinous, proteinaceous, hemorrhagic, bilious, or mixed) or spontaneous or treatment-related necrosis, whereas the septa may be formed by a wide range of tissues depending on the lesion type. An understanding of the CT and MR imaging findings of these lesions and their respective pathologic correlation aids in accurate diagnosis.

Renal relevant radiology: radiologic imaging in autosomal dominant polycystic kidney disease

Autosomal-dominant polycystic kidney disease is a systemic disorder and the most common hereditary renal disease, which is characterized by cyst growth, progressive renal enlargement, and development of renal failure. The cystic nature of autosomal dominant polycystic kidney disease and its renal and extrarenal complications (kidney stones, cyst hemorrhage, intracerebral aneurysm, liver cysts, cardiac valve abnormalities, etc.) give radiologic imaging studies a central role in the management of these patients. This article reviews the indications, comparative use, and limitation of various imaging modalities (ultrasonography, magnetic resonance imaging, computerized tomography scan, Positron emission tomography scan, and renal scintigraphy) for the diagnosis and management of complications in autosomal dominant polycystic kidney disease. Finally, this work provides evidence for the value of total kidney volume to predict disease progression in autosomal dominant polycystic kidney disease.

Rare cystic liver lesions: A diagnostic and managing challenge

Cystic formations within the liver are a frequent finding among populations. Besides the common cystic lesions, like simple liver cysts, rare cystic liver lesions like cystadenocarcinoma should also be considered in the differential diagnosis. Thorough knowledge of each entity’s nature and course are key elements to successful treatment. Detailed search in PubMed, Cochrane Database, and international published literature regarding rare cystic liver lesions was carried out. In our research are included not only primary rare lesions like cystadenoma, hydatid cyst, and polycystic liver disease, but also secondary ones like metastasis from gastrointestinal stromal tumors lesions. Up-to date knowledge regarding diagnosis and management of rare cystic liver lesions is provided. A diagnostic and therapeutic algorithm is also proposed. The need for a multidisciplinary approach by a team including radiologists and surgeons familiar with liver cystic entities, diagnostic tools, and treatment modalities is stressed. Patients with cystic liver lesions must be carefully evaluated by a multidisciplinary team, in order to receive the most appropriate treatment, since many cystic liver lesions have a malignant potential and evolution.

Congenital hepatic fibrosis and portal hypertension in autosomal dominant polycystic kidney disease

OBJECTIVES

Autosomal dominant (ADPKD) and recessive (ARPKD) polycystic kidney diseases are the most common hepatorenal fibrocystic diseases (ciliopathies). Characteristics of liver disease of these disorders are quite different. All of the patients with ARPKD have congenital hepatic fibrosis (CHF) often complicated by portal hypertension. In contrast, typical liver involvement in ADPKD is polycystic liver disease, although rare atypical cases with CHF are reported. Our goal was to describe the characteristics of CHF in ADPKD.

PATIENTS AND METHODS

As a part of an intramural study of the National Institutes of Health on ciliopathies (www.clinicaltrials.gov, trial NCT00068224), we evaluated 8 patients from 3 ADPKD families with CHF. We present their clinical, biochemical, imaging, and PKD1 and PKHD1 sequencing results. In addition, we tabulate the characteristics of 15 previously reported patients with ADPKD-CHF from 11 families.

RESULTS

In all of the 19 patients with ADPKD-CHF (9 boys, 10 girls), portal hypertension was the main manifestation of CHF; hepatocelllular function was preserved and liver enzymes were largely normal. In all of the 14 families, CHF was not inherited vertically, that is the parents of the index cases had PKD but did not have CHF-suggesting modifier gene(s). Our 3 families had pathogenic mutations in PKD1; sequencing of the PKHD1 gene as a potential modifier did not reveal any mutations.

CONCLUSIONS

Characteristics of CHF in ADPKD are similar to CHF in ARPKD. ADPKD-CHF is caused by PKD1 mutations, with probable contribution from modifying gene(s). Given that both boys and girls are affected, these modifier(s) are likely located on autosomal chromosome(s) and less likely X-linked.

[Benign non-parasitic hepatic cystic tumours]

Hepatic cystic tumours are a heterogeneous group of diseases with different aetiology and incidence, and with similar clinical signs and symptoms. They are classified as congenital, traumatic, parasitic, or neoplastic cysts. The congenital cystic tumours are the most prevalent, and include the simple cyst and polycystic hepatic disease. Other less common lesions are, hepatic cystadenoma, ciliated embryonic cyst, and a miscellaneous group. We have carried out a review of all benign non-parasitic hepatic cystic tumours, placing special emphasis on therapeutic strategies.

Imaging features of ductal plate malformations in adults

Ductal plate malformations, also known as fibrocystic liver diseases, are a group of congenital disorders resulting from abnormal embryogenesis of the biliary ductal system. The abnormalities include choledochal cyst, Caroli's disease and Caroli's syndrome, adult autosomal dominant polycystic liver disease, and biliary hamartoma. The hepatic lesions can be associated with renal anomalies such as autosomal recessive polycystic kidney disease (ARPKD), medullary sponge kidney, and nephronophthisis. A clear knowledge of the embryology and pathogenesis of the ductal plate is central to the understanding of the characteristic imaging appearances of these complex disorders. Accurate diagnosis of ductal plate malformations is important to direct appropriate clinical management and prevent misdiagnosis.

Hepatic cysts and liver abscess

Benign pathologies of the liver often include several cystic diseases, such as simple cysts, autosomal dominant polycystic liver disease, and Caroli's disease. The differential of hepatic cysts also includes infectious pathologies, such as pyogenic liver abscess, hydatid cysts, and parasitic infections if the appropriate clinic setting. Understanding of the various causes, clinical presentation, and treatment options is required to ensure the appropriate surgical management of these patients.

Liver and kidney disease in ciliopathies

Hepatorenal fibrocystic diseases (HRFCDs) are among the most common inherited human disorders. The discovery that proteins defective in the autosomal dominant and recessive polycystic kidney diseases (ADPKD and ARPKD) localize to the primary cilia and the recognition of the role these organelles play in the pathogenesis of HRFCDs led to the term "ciliopathies." While ADPKD and ARPKD are the most common ciliopathies associated with both liver and kidney disease, variable degrees of renal and/or hepatic involvement occur in many other ciliopathies, including Joubert, Bardet-Biedl, Meckel-Gruber, and oral-facial-digital syndromes. The ductal plate malformation (DPM), a developmental abnormality of the portobiliary system, is the basis of the liver disease in ciliopathies that manifest congenital hepatic fibrosis (CHF), Caroli syndrome (CS), and polycystic liver disease (PLD). Hepatocellular function remains relatively preserved in ciliopathy-associated liver diseases. The major morbidity associated with CHF is portal hypertension (PH), often leading to esophageal varices and hypersplenism. In addition, CD predisposes to recurrent cholangitis. PLD is not typically associated with PH, but may result in complications due to mass effects. The kidney pathology in ciliopathies ranges from non-functional cystic dysplastic kidneys to an isolated urinary concentration defect; the disorders contributing to this pathology, in addition to ADPKD and ARPKD, include nephronophithisis (NPHP), glomerulocystic kidney disease and medullary sponge kidneys. Decreased urinary concentration ability, resulting in polyuria and polydypsia, is the first and most common renal symptom in ciliopathies. While the majority of ADPKD, ARPKD, and NPHP patients require renal transplantation, the frequency and rate of progression to renal failure varies considerably in other ciliopathies. This review focuses on the kidney and liver disease found in the different ciliopathies.

Fibropolycystic liver disease in children

Fibropolycystic liver diseases are a group of associated congenital disorders that present most often in childhood. These disorders include congenital hepatic fibrosis, biliary hamartomas, autosomal dominant polycystic liver disease, choledochal cysts and Caroli disease. We present a discussion and illustrations of the embryology, genetics, anatomy, pathology, imaging approach and key imaging features that distinguish fibropolycystic liver disease in children. The pathogenesis of these disorders is believed to be abnormal development of the embryonic ductal plates, which ultimately form the liver and biliary systems. An understanding of the abnormal embryogenesis helps to explain the characteristic imaging features of these disorders.

Benign hepatic tumors and iatrogenic pseudotumors

Myriad benign tumors may be found in the liver; they can be classified according to their cell of origin into tumors of hepatocellular, cholangiocellular, or mesenchymal origin. Common benign hepatic tumors may pose a diagnostic dilemma when they manifest with atypical imaging features. Less frequently encountered benign hepatic tumors such as inflammatory pseudotumor or biliary cystadenoma demonstrate less specific imaging features; however, awareness of their findings is useful in narrowing differential diagnostic considerations. In addition, certain iatrogenically induced abnormalities of the liver may be confused with more ominous findings such as infection or neoplasia. However, knowledge of their common imaging appearances, in addition to the clinical history, is critical in correctly diagnosing and characterizing iatrogenic abnormalities of the liver. Familiarity with both expected and unexpected imaging appearances of common benign hepatic tumors, less commonly encountered benign hepatic tumors, and iatrogenic abnormalities potentially masquerading as hepatic tumors allows the radiologist to achieve an informed differential diagnosis.