Cystic focal liver lesions in the adult: differential CT and MR imaging features

Therapeutic effect of curcumin nanoemulsion on cystic echinococcosis in BALB/c mice: a computerized tomography (CT) scan and histopathologic study evaluation

BACKGROUND

This study aimed to determine the therapeutic efficacy of curcumin nanoemulsion (CUR-NE) in mice infected with Echinococcus granulosus sensu stricto protoscoleces.

METHODS

Forty-two inbred BALB/c mice were divided into seven groups of six animals each. Six groups were inoculated intra-peritoneally with 1500 viable E. granulosus protoscoleces, followed for six months and used as infected groups. The infected groups were named as: CEI1 to CEI6 accordingly. The 7th group was not inoculated and was named cystic echinococcosis noninfected group (CENI7). CEI1 and CEI2 groups received 40 mg/kg/day and 20 mg/kg/day curcumin nanoemulsion (CUR-NE), respectively. CEI3 received nanoemulsion without curcumin (NE-no CUR), CEI4 received curcumin suspension (CUR-S) 40 mg/kg/day, CEI5 received albendazole 150 mg/kg/day and CEI6 received sterile phosphate-buffered saline (PBS). CENI7 group received CUR-NE 40 mg/kg/day. Drugs administration was started after six months post-inoculations of protoscoleces and continued for 60 days in all groups. The secondary CE cyst area was evaluated by computed tomography (CT) scan for each mouse before treatment and on the days 30 and 60 post-treatment. The CT scan measurement results were compared before and after treatment. After the euthanasia of the mice on the 60th day, the cyst area was also measured after autopsy and, the histopathological changes of the secondary cysts for each group were observed. The therapeutic efficacy of CUR-NE in infected groups was evaluated by two methods: CT scan and autopsied cyst measurements.

RESULTS

Septal calcification in three groups of infected mice (CEI1, CEI2, and CEI4) was revealed by CT scan. The therapeutic efficacy of CUR-NE 40 mg/kg/day (CEI1 group) was 24.6 ± 26.89% by CT scan measurement and 55.16 ± 32.37% by autopsied cysts measurements. The extensive destructive effects of CUR-NE 40 mg/kg/day (CEI1 group) on the wall layers of secondary CE cysts were confirmed by histopathology.

CONCLUSION

The current study demonstrated a significant therapeutic effect of CUR-NE (40 mg/kg/day) on secondary CE cysts in BALB/c mice. An apparent septal calcification of several cysts revealed by CT scan and the destructive effect on CE cysts observed in histopathology are two critical key factors that suggest curcumin nanoemulsion could be a potential treatment for cystic echinococcosis.

A rare case of resection of a mucinous cystic neoplasm originating from the extrahepatic bile duct with cholangioscopic imaging

A 29-year-old woman was admitted to our hospital for examination of obstructive jaundice and an extrahepatic bile duct lesion. Contrast-enhanced computed tomography revealed a 20 mm cystic lesion with a thin external capsule in the common hepatic duct. Cholangioscopy revealed translucent oval masses with capillary vessels attached to the bile duct walls. The surface was mostly smooth yet partially irregular with redness, suggesting that the masses were epithelial neoplasms. Histological findings of cholangioscopy-guided targeted biopsies of the mass showed subepithelial spindle cell proliferation with no atypical epithelium. The patient underwent an extrahepatic bile duct resection to confirm the pathological diagnosis. Immunohistochemistry of surgical specimens revealed that the spindle cells were positive for estrogen and progesterone receptors. Finally, the cystic lesion with ovarian-like stroma was diagnosed as a mucinous cystic neoplasm with low-grade intraepithelial neoplasia. This is the first report of cholangioscopic imaging of a biliary mucinous cyctic neoplasm. Cholangioscopic imaging can be helpful in the differential diagnosis of biliary neoplasms and in the determination of treatment strategies.

Focal Lesions of the Liver and Radiomics: What Do We Know?

Despite differences in pathological analysis, focal liver lesions are not always distinguishable in contrast-enhanced magnetic resonance imaging (MRI), contrast-enhanced computed tomography (CT), and positron emission tomography (PET). This issue can cause problems of differential diagnosis, treatment, and follow-up, especially in patients affected by HBV/HCV chronic liver disease or fatty liver disease. Radiomics is an innovative imaging approach that extracts and analyzes non-visible quantitative imaging features, supporting the radiologist in the most challenging differential diagnosis when the best-known methods are not conclusive. The purpose of this review is to evaluate the most significant CT and MRI texture features, which can discriminate between the main benign and malignant focal liver lesions and can be helpful to predict the response to pharmacological or surgical therapy and the patient's prognosis.

Clinicopathological features and management of biliary cystic tumors of the liver: a single-center experience

BACKGROUND

Biliary cystic neoplasms (BCNs) of the liver are rare pathologies encountered in hepatobiliary surgeries. Till now, there is a lack of definitive criteria used to differentiate biliary cystadenoma (BCA) from biliary cystadenocarcinoma (BCAC).

METHODS

In the period between 2005 and 2018, the data of consecutive patients diagnosed with BCA and BCAC were retrospectively reviewed.

RESULTS

A total of 62 patients underwent surgical management for BCNs. BCA was diagnosed in 50 patients while 12 patients had BCAC. Old age, male gender, smoking, and abdominal pain were strongly associated with BCAC. Left lobe location, small size, with the presence of mural nodule, and solid component were significantly noticed with BCAC. A novel pre-operative score was developed to predict the susceptibility for BCAC and help us to identify the optimal surgical strategy. Blood loss, operative time, and complications were comparable between the two study groups.

CONCLUSION

Mural nodules or solid components are suggestive of BCAC. Complete surgical resection of cystic tumors of the liver is mandatory due to malignant potential of the lesion and for prolonged survival.

Cytology as the guiding light: Prompt cytomorphologic diagnosis of cystic metastases from a jejunal neuroendocrine tumor masquerading as hepatic abscesses

Hepatic cystic lesions are commonly seen in radiology and can occur due to infective or neoplastic causes. It is imperative to determine the precise nature of these hepatic cysts owing to significant therapeutic and prognostic differences. Hepatic metastases from gastrointestinal neuroendocrine tumors (NETs) mostly present as solid hypervascular lesions. Cystic presentation of the metastatic NETs is extremely rare. A 64-year-old woman presented with an abdominal lump of 3 months duration and high-grade fever from the last 2 days. An ultrasound abdomen revealed multiple hypoechoic liver lesions suggestive of liver abscesses. An ultrasound-guided fine-needle aspiration (FNA) from the cystic liver lesions revealed a NET confirmed by immunocytochemistry. The Ki-67 index was 5%; hence, a final diagnosis of metastatic NET, grade 2, was given with advice to work up for localizing the primary tumor. Subsequently, a contrast-enhanced computerized tomography of the abdomen revealed a polypoidal lesion in the proximal jejunum, which showed intense expression on the whole-body DOTANOC scan (SUVmax-76.5), indicating it to be the likely primary tumor along with somatostatin receptor-expressing multiple lymph nodes and hypodense liver lesions. Thus, a final diagnosis of a jejunal NET with abdominal lymph node and liver metastases was made. The present report highlights the importance of FNA as a reliable modality in diagnosing metastatic NETs presenting as unusual cystic hepatic metastases masquerading as liver abscesses. Additionally, the cell block helps confirm the cytologic diagnosis and enables upfront tumor grading, thereby helping in prognostication and therapeutic decision-making.

Diagnosis and management of choledochal cysts

BACKGROUND

Choledochal cysts (CCs) are rare cystic dilatations of the intrahepatic and/or extrahepatic bile ducts. We review the pathophysiology, diagnosis, and management of CCs.

METHODS

MEDLINE/PubMed and Web of Science databases were queried for "choledochal cyst", "bile duct cyst", "choledochocele", and "Caroli disease". Data were synthesized and systematically reviewed.

RESULTS

Classified according to the Todani Classification, CCs are generally believed to arise secondary to reflux of pancreatic enzymes into the biliary tree due to anomalous pancreaticobiliary duct union. Complications of CCs include abdominal pain, jaundice, cystolithiasis, cholecystitis, pancreatitis, liver abscess, liver cirrhosis and malignant transformation (3-7.5%). Radiological and endoscopic imaging is the cornerstone of CC diagnosis and full delineation of cyst anatomy is imperative for proper management. Management is generally guided by cyst classification with complete cyst excision necessary for CCs with high potential of malignant transformation such as types I and IV. 5-year overall survival after choledochal cyst excision is 95.5%.

CONCLUSION

Most CCs should undergo surgical intervention to mitigate the risk of cyst related complications such as cholangitis and malignant transformation.

Hepatobiliary mucinous cystic neoplasms and mimics

This review will provide an overview of hepatobiliary mucinous cystic neoplasms and their mimics such as complex appearing benign cysts, intraductal papillary neoplasm of bile ducts, choledochal cysts, infectious cysts, and other cystic neoplasms. Preoperative imaging, particularly abdominal MRI with MRCP, plays a key role in differentiating these entities which differ widely in management. Familiarity with the differentiating imaging features of mucinous cystic neoplasms and their mimics allows radiologists to provide management-guiding reports.

Mucinous cystic neoplasms of the liver with biliary prolapse

Objectives

To describe the prevalence, clinical and radiological findings of biliary prolapse in pathologically proven mucinous cystic neoplasm of the liver (MCN-L).

Methods

Thirty-four patients, all female with median age 50 years (range, 14–82), with histologically confirmed MCN-L were enrolled. Median tumor size was 9 cm (range, 2–21 cm). Fifty-seven examinations (17 ultrasound, 25 CT, and 15 MR) among 34 MCN-Ls were reviewed. Two radiologists retrospectively assessed images for tumor location, size and other morphological features of the tumor, presence of biliary prolapse and upstream bile duct dilatation. Ultrasound, CT, and MR were assessed separately. Clinical features were evaluated. Clinical and radiological characteristics of MCN-L with and without biliary prolapse were compared.

Results

15% (5/34) of MCN-Ls showed biliary prolapse confirmed at pathology. None of MCN-Ls were associated with invasive carcinoma. Patients with biliary prolapse were significantly younger than those without (median 27 years [22–56] vs. median 51 years [14–82], p = 0.03). MCN-Ls with biliary prolapse were significantly smaller than those without (median 6.4 cm [2.2–7.5] vs. median 9.6 cm [3.1–21], p = 0.01). The upstream bile duct was dilated more frequently in MCN-Ls with biliary prolapse (100% vs. 38%, p = 0.02). Jaundice was significantly more common in MCN-Ls with biliary prolapse (80 vs 3%, p = 0.0005). Other clinical or radiological features were not significantly different between two groups.

Conclusions

Biliary prolapse was found in 15% of MCN-Ls. MCN-Ls with biliary prolapse were significantly smaller and were more commonly associated with upstream bile duct dilation and jaundice than those without biliary prolapse.

Benign liver lesions 2022: Guideline for clinical practice of Associazione Italiana Studio del Fegato (AISF), Società Italiana di Radiologia Medica e Interventistica (SIRM), Società Italiana di Chirurgia (SIC), Società Italiana di Ultrasonologia in Medicina e Biologia (SIUMB), Associazione Italiana di Chirurgia Epatobilio-Pancreatica (AICEP), Società Italiana Trapianti d'Organo (SITO), Società Italiana di Anatomia Patologica e Citologia Diagnostica (SIAPEC-IAP) - Part I - Cystic lesions

Benign liver lesions are increasingly diagnosed in daily clinical practice due to the growing use of imaging techniques for the study of the abdomen in patients who have non-specific symptoms and do not have an increased risk of hepatic malignancy. They include simple or parasitic cysts and solid benign tumors which differ widely in terms of prevalence, clinical relevance, symptoms and natural history and often lead to significant clinical problems relating to diagnosis and clinical management. Following the need to have updated guidelines on the management of benign focal liver lesions, the Scientific Societies mainly involved in their management have promoted the drafting of a new dedicated document. This document was drawn up according to the present Italian rules and methodologies necessary to produce clinical, diagnostic, and therapeutic guidelines based on evidence. Here we present the first part of the guideline, concerning the characterization of focal hepatic lesions detected by ultrasound, and the diagnosis and clinical management of simple and parasitic hepatic cysts, and of polycystic liver disease.

Case report: Rare isolated cystic hepatic metastasis of a patient with squamous cell lung carcinoma history and the prognosis

Cystic hepatic metastasis of squamous cell carcinoma usually develops from necrosis due to insufficient blood supply, yet metastasis initially resembling simple liver cyst is rare. Here, we present a case of a patient with squamous cell lung carcinoma history who found an isolated cystic mass in the liver. Historical MR studies indicated that the mass did not exist 12 months ago and emerged as a small cystic lesion 7 months ago. Radiological findings and tumor markers level suggested metastasis, while 18F-Fluorodeoxyglucose (18F-FDG) PET/CT showed moderate tracer uptakes in solid parts of the mass. Pathological study after surgery confirmed metastatic squamous cell carcinoma. Chemotherapy plus recombinant human endostatin and sintilimab therapy was employed after surgery; however, the patient developed remote metastasis of osteolytic lesions in the humerus bone and thoracic vertebra. Our case indicates that metastasis should be taken into consideration in emerging cystic hepatic lesion with malignant history.

EASL Clinical Practice Guidelines on the management of cystic liver diseases

The advent of enhanced radiological imaging techniques has facilitated the diagnosis of cystic liver lesions. Concomitantly, the evidence base supporting the management of these diseases has matured over the last decades. As a result, comprehensive clinical guidance on the subject matter is warranted. These Clinical Practice Guidelines cover the diagnosis and management of hepatic cysts, mucinous cystic neoplasms of the liver, biliary hamartomas, polycystic liver disease, Caroli disease, Caroli syndrome, biliary hamartomas and peribiliary cysts. On the basis of in-depth review of the relevant literature we provide recommendations to navigate clinical dilemmas followed by supporting text. The recommendations are graded according to the Oxford Centre for Evidence-Based Medicine system and categorised as 'weak' or 'strong'. We aim to provide the best available evidence to aid the clinical decision-making process in the management of patients with cystic liver disease.

Mucinous cystic neoplasm of the liver with polypoid nodule prolapsing into the bile duct: a case report and review of literature

Background

Mucinous cystic neoplasm of the liver (MCN-L) is a rare cystic tumor as defined by the 2010 World Health Organization classification. MCN-L usually does not communicate with or grow into the bile duct. Herein, we present a rare case of MCN-L with a polypoid nodule protruding into the bile duct.

Case presentation

A 69-year-old woman was referred to our hospital for elevated serum liver enzyme levels and obstructive jaundice. The patient also complained of abdominal pain in the right hypochondriac region. Abdominal ultrasonography showed a cystic lesion in segment 4 (S4) of the liver. Computed tomography revealed a 4-cm multilocular cystic lesion with a thick wall and multiple septal formations, showing a cyst-in-cyst appearance in S4. Endoscopic retrograde cholangiography showed a contrast defect between the left hepatic duct and the common bile duct, which was suspected to be a nodular lesion in the bile duct. Bile cytology and biopsy of the nodular lesion showed no malignant findings. Based on these findings, the differential diagnosis in this patient included intraductal papillary neoplasm of the bile duct and MCN-L, which had malignant potential. The patient underwent left hemihepatectomy, including caudate lobe excision with bile duct resection and right hepatocholangiojejunostomy. Macroscopic findings showed a 40 × 29 mm multilocular cystic lesion with a polypoid nodule that protruded into the left intrahepatic bile duct. As an ovarian-like stroma was observed in both cystic and polypoid lesions microscopically, the histopathological diagnosis was MCN-L. The postoperative course was uneventful, and the patient was discharged 24 days after surgery. The patient is currently alive without recurrence 22 months after the surgery.

Conclusion

Although MCN-L rarely communicates with the bile duct, it is necessary to consider that MCN-L could grow into the bile duct, occasionally causing obstructive jaundice.

Unique diagnostic challenge in surgery: hepatic abscess versus malignancy

A man in his 30s had presented with a history of abdominal pain, vomiting and high-grade fever. He had tender hepatomegaly with peritonism in the upper abdomen. Investigations revealed a neutrophilic leucocytosis, and contrast-enhanced CT had shown several well-defined peripherally enhancing thick-walled cystic lesions with non-enhancing centres throughout the liver suggestive of pyogenic liver abscess, treated initially with antibiotics. However, ultrasonography-guided fine needle aspiration revealed atypical neoplastic cells, and a trucut biopsy showed squamous cell carcinoma (SCC). He developed acute shortness of breath. CT pulmonary angiogram confirmed pulmonary thromboembolism (PTE). Incidentally, here we saw a solitary nodule in the right middle lobe, probably a neoplastic lesion. His condition deteriorated rapidly secondary to PTE and died. A pathological review was positive for CK7, p40, p63 and CK19 confirming SCC. We concluded the primary was a pulmonary SCC with multiple hepatic metastases. Hepatic metastases can mimic an abscess; trucut biopsy with immunohistochemistry was critical for a definitive diagnosis.

Imaging Features of Premalignant Biliary Lesions and Predisposing Conditions with Pathologic Correlation

Biliary malignancies include those arising from the intrahepatic and extrahepatic bile ducts as well as the gallbladder and hepatopancreatic ampulla of Vater. The majority of intrahepatic and extrahepatic malignancies are cholangiocarcinomas (CCAs). They arise owing to a complex interplay between the patient-specific genetic background and multiple risk factors and may occur in the liver (intrahepatic CCA), hilum (perihilar CCA), or extrahepatic bile ducts (distal CCA). Biliary-type adenocarcinoma constitutes the most common histologic type of ampullary and gallbladder malignancies. Its prognosis is poor and surgical resection is considered curative, so early detection is key, with multimodality imaging playing a central role in making the diagnosis. There are several risk factors for biliary malignancy as well as predisposing conditions that increase the risk; this review highlights the pertinent imaging features of these entities with histopathologic correlation. The predisposing factors are broken down into three major categories: (a) congenital malformations such as choledochal cyst and pancreaticobiliary maljunction; (b) infectious or inflammatory conditions such as parasitic infections, hepatolithiasis, primary sclerosing cholangitis, and porcelain gallbladder; and (c) preinvasive epithelial neoplasms such as biliary intraepithelial neoplasm, intraductal papillary neoplasm of the bile duct, intra-ampullary papillary tubular neoplasm, and intracholecystic papillary neoplasm of the gallbladder. Recognizing the baseline features of these premalignant biliary entities and changes in their appearance over time that indicate the advent of malignancy in high-risk patients can lead to early diagnosis and potentially curative management. An invited commentary by Volpacchio is available online. Online supplemental material is available for this article. ^©RSNA, 2022.

Polycystic Liver Disease: Pathophysiology, Diagnosis and Treatment

Polycystic liver disease (PLD) is a clinical condition characterized by the presence of more than 10 cysts in the liver. It is a rare disease Of genetic etiology that presents as an isolated disease or assoc\iated with polycystic kidney disease. Ductal plate malformation, ciliary dysfunction, and changes in cell signaling are the main factors involved in its pathogenesis. Most patients with PLD are asymptomatic, but in 2–5% of cases the disease has disabling symptoms and a significant reduction in quality of life. The diagnosis is based on family history of hepatic and/or renal polycystic disease, clinical manifestations, patient age, and polycystic liver phenotype shown on imaging examinations. PLD treatment has evolved considerably in the last decades. Somatostatin analogues hold promise in controlling disease progression, but liver transplantation remains a unique curative treatment modality.

Characteristics and outcomes of anterior mediastinal cystic lesions diagnosed on chest MRI: implications for management of cystic lesions

BACKGROUND

Chest MRI is a useful diagnostic modality for the evaluation of anterior mediastinal lesions but the outcomes of anterior mediastinal cystic lesions diagnosed on chest MRI are unclear.

METHODS

In this multicenter retrospective study, patients who underwent contrast-enhanced chest MRI in two tertiary centers to assess anterior mediastinal cystic lesions were included after excluding overt solid tumors and thymic hyperplasia. Anterior mediastinal cystic lesions were classified into two categories: probable (simple) cyst or indeterminate lesion (complex cyst). Size and imaging features of lesions during follow-up were evaluated and clinical outcomes were assessed.

RESULTS

A total of 204 patients (mean age, 59 ± 11 years; M:F = 111:93) were studied; 186 (91.2%) were classified as probable cysts and 18 (8.8%) as indeterminate lesions on MRI. Among patients with probable cysts and more than 2 years of follow-up, lesion size was unchanged in 39.6% (36/91), decreased in 16.5% (15/91), and fluctuated in 8.8% (8/91). All patients who underwent surgery were confirmed cysts. None developed mural nodules or irregular wall thickening, suspicious for malignancy during follow-up. In patients with indeterminate lesions, 16.7% (3/18) had pathologically confirmed thymoma and 44.4% (8/18) had proven cysts. Follow-up numbers and intervals after MRI in patients with probable cysts were variable among physicians and institutions in clinical practice (p < 0.05) but more than half were followed for up to 2 years in two centers.

CONCLUSION

Diagnosing anterior mediastinal cysts using MRI is reliable. MRI-based management of anterior mediastinal lesions may reduce the number of unnecessary follow-ups and surgeries.

Cystic liver lesions: a pictorial review

Hepatic cysts (HC) are sac-like structures mainly filled with liquid and showing a distinct membrane. They are usually found incidentally through imaging. A wide spectrum of imaging patterns may be observed for common and uncommon, neoplastic and non-neoplastic diseases. While simple hepatic cysts occur frequently and do not require any treatment or follow-up, non-typical cysts should be carefully analysed to avoid misdiagnosing a lesion that would require appropriate management. Therefore, adequate knowledge of all the relevant imaging patterns is critical to secure an accurate diagnosis. The aim of this review is to describe the imaging features of the different types of hepatic cysts.

Imaging findings of spontaneous intraabdominal hemorrhage: neoplastic and non-neoplastic causes

Contrary to traumatic and iatrogenic intraabdominal hemorrhages, spontaneous intraabdominal hemorrhage is a challenging clinical situation. A variety of neoplastic and non-neoplastic conditions may cause spontaneous intraabdominal bleeding. Imaging findings vary depending on the source of bleeding and the underlying cause. In this article, we aim to increase the awareness of imagers to the most common causes of spontaneous intraabdominal hemorrhage by using representative cases.

Imaging features of biliary adenofibroma of the liver with malignant transformation: a case report with literature review

Background

Biliary adenofibroma (BAF) is a rare primary hepatic tumor with the potential risk of malignant transformation. Given the extreme rarity of the disease, the imaging features of BAF are unclear. We presented a case of malignant BAF and conducted a systematic literature review. We highlighted the key imaging features in the diagnosis and aggressiveness assessment of BAF, as well as the role of various imaging modalities in evaluating BAF.

Case presentation

We reported a 64-year-old woman with a 5-months history of pain in the right upper quadrant abdomen. US of the liver showed a hypoechoic subcapsular nodule. CT scan revealed a subcapsular solid-cystic mass in segment V of the liver. The mass showed a marked enhancement in the arterial phase followed by wash-out in the venous phase. The patient underwent partial resection of liver’s right lobe. The mass was diagnosed as BAF with malignant transformation by postoperative pathology.

Conclusions

CT and MRI are helpful in recognizing and characterizing BAF. The imaging features of BAF include a solitary, large solid-cystic mass with a well-defined margin, lobulated shape, and internal septa; subcapsular location; no intrahepatic bile duct communication; the presence of von Meyenberg complexes in background liver. The enhancement patterns may have the potential to assess the aggressiveness of BAF, and that marked enhancement in the arterial phase followed by wash-out in the venous phase is suggestive of malignant BAF.

Extensive solitary lymphatic malformation of the liver in a child: a case report and literature review

Intrabdominal lymphatic malformations are rare benign congenital vascular anomalies that account for less than 5% of benign masses in childhood, with an extremely variable clinical presentation. For this reason, although their radiological appearance is usually typical, diagnosis can be challenging and not always immediate. This report describes a unique case of extensive solitary hepatic lymphatic malformation in a 10-year-old boy with both extra- and intraparenchymal development with no associated symptoms. A literature review of reported cases of solitary hepatic lymphatic malformation is also included.

Efficiency of diffusion-weighted MRI for differentiating radiologically similar simple and type I hydatid cysts of the liver

BACKGROUND

Determining the nature of purely cystic hepatic lesions is essential because different kinds have different follow-ups, treatment options, and complications.

PURPOSE

To explore the potential of apparent diffusion coefficient (ADC) values of diffusion-weighted imaging (DWI) for the differentiation of type I hydatid cysts (HC) and simple liver cysts (SLC), which have similar radiological appearances.

MATERIAL AND METHODS

This single-center prospective study was conducted during 2016-2019. Round, homogenous, anechoic liver cysts >1 cm were classified according to at least two years of imaging follow-up, radiological features, serology, as well as puncture aspiration injection reaspiration procedure and pathology results. ADC values of 95 cysts (50 type I HCs and 45 SLCs) were calculated on DWI. The differences in ADC values were analyzed by independent t-test.

RESULTS

Of 51 patients, 28 were female, 23 were male (mean age 32.07 ± 22.95 years; age range 5-82 years). Mean diameter of 45 SLCs was 2.59 ± 1.23 cm (range 1.2-7.6 cm) and ADC_mean value was 3.03 ± 0.47 (range 2.64-5.85) while mean diameter of 50 type I HCs was 7.49 ± 2.95 cm (range 2.8-14 cm) and ADC_mean value was 2.99 ± 0.29 (range 2.36-3.83). There was no statistically significant difference in ADC values between type I HCs and SLCs.

CONCLUSION

Some studies report that ADC values of type I HCs are statistically significantly lower than those of SLCs. Others suggest no significant difference. In our study with a higher number of cases, using ADC parameters similar to those in previous studies, we did not find any statistically significant difference.

Steady-state ferumoxytol-enhanced MRI: early observations in benign abdominal organ masses and clinical implications

INTRODUCTION

The off-label use of ferumoxytol as a vascular MR imaging agent is growing rapidly. However, the properties of ferumoxytol suggest that it may play an important role in the detection and characterization of abdominal mass lesions.

METHODS

Thirty-six patients with benign abdominal mass lesions who underwent MR angiography with ferumoxytol also had T2-weighted HASTE imaging and fat-suppressed 3D T1-weighted imaging. The T1 and T2 enhancement characteristics of the lesions were analyzed and correlated with other imaging modalities and/or surgical findings and/or clinical follow-up.

RESULTS

In all patients with benign masses in the liver (n = 22 patients), spleen (n = 6 patients), kidneys (n = 33 patients), adrenal (n = 2 patients) and pancreas (n = 4 patients), based on the enhancement characteristics with ferumoxytol, readers were confident of the benign nature of the lesions and their conclusions were consistent with correlative imaging, tissue sampling and follow-up. One patient with a suspicious enhancing 2F Bosniak renal cyst had renal cell carcinoma confirmed on biopsy.

CONCLUSION

Ferumoxytol-enhanced MRI can increase diagnostic confidence for benign abdominal masses and can increase the conspicuity of mass lesions, relative to unenhanced MRI.

Stability of Liver Radiomics across Different 3D ROI Sizes-An MRI In Vivo Study

We aimed to evaluate the stability of radiomic features in the liver of healthy individuals across different three-dimensional regions of interest (3D ROI) sizes in T1-weighted (T1w) and T2-weighted (T2w) images from different MR scanners. We retrospectively included 66 examinations of patients without known diseases or pathological imaging findings acquired on three MRI scanners (3 Tesla I: 25 patients, 3 Tesla II: 19 patients, 1.5 Tesla: 22 patients). 3D ROIs of different diameters (10, 20, 30 mm) were drawn on T1w GRE and T2w TSE images into the liver parenchyma (segment V–VIII). We extracted 93 radiomic features from the different ROIs and tested features for significant differences with the Mann–Whitney-U (MWU)-test. The MWU-test revealed significant differences for most second- and higher-order features, indicating a systematic difference dependent on the ROI size. The features mean, median, root mean squared (RMS), 10th percentile, and 90th percentile were not significantly different. We also assessed feature robustness to ROI size variation with overall concordance correlation coefficients (OCCCs). OCCCs across the different ROI-sizes for mean, median, and RMS were excellent (>0.90) in both sequences on all three scanners. These features, therefore, seem robust to ROI-size variation and suitable for radiomic studies of liver MRI.

A rare case of extrahepatic biliary mucinous cystic neoplasm in a middle-aged woman: A case report

Biliary mucinous cystic neoplasms are very rare tumors of the biliary tract with malignant potential. Preoperative diagnosis is challenging, as clinical, biochemical and radiological features are not specific. Surgical resection with negative margins is the gold standard treatment for these uncommon lesions. A 55-year-old woman presented at the Third Department of Surgery (Attikon University Hospital, Athens, Greece) with a history of mild right upper quadrant (RUQ) abdominal pain and jaundice. A 2-cm lesion in the distal common bile was identified by imaging. Following discussion in our multidisciplinary board meeting the patient underwent a pylorus preserving pancreatoduodenectomy, and histopathological examination revealed an ovarian-stromal type intraductal mucinous cystic neoplasm of the extra hepatic biliary. Since biliary mucinous cystic neoplasms are characterized by malignant transformation and high rates of recurrence, surgical resection with negative margins is the treatment of choice for both non-invasive and invasive biliary mucinous cystic neoplasms.

Liver Imaging Reporting and Data System Comprehensive Guide: MR Imaging Edition

The Liver Imaging Reporting and Data System (LI-RADS) is a comprehensive system for standardizing the lexicon, technique, interpretation, reporting, and data collection of liver imaging. Developed specifically for assessment of liver observations in patients at risk for hepatocellular carcinoma (HCC), LI-RADS classifies hepatic observations on the basis of the probability of their being HCC, from LR-1 (definitely benign) to LR-5 (definitely HCC). This article discusses the technical requirements, major features, and ancillary features of and a systematic approach for using the LI-RADS diagnostic algorithm, with special emphasis on MR imaging.

Cystic lesions of the pancreatico-biliary tree: A schematic MRI approach

Although a common occurrence, cystic lesions of the pancreatico-biliary tree (PBT) may pose a diagnostic dilemma because they encompass a large number of neoplastic and benign processes with varied clinical symptoms. Knowledge of lesion classification and characterization are essential in making an accurate prospective diagnosis. This is necessary for identifying clinically significant cystic masses, which at times may require invasive intervention from indolent, nonneoplastic lesions, for which surveillance may suffice. Today, there is an arsenal of modalities for assessing the PBT, however, magnetic resonance imaging (MRI) remains at the forefront for characterizing cystic morphology and fluid content, internal septations, solid component, enhancement patterns, as well as assessing the surrounding normal structures. This pictorial review aims to review the spectrum of MRI features, which will aid in the differential diagnoses of cystic lesions of the PBT and mimickers, enabling the radiologist to reach a more confident diagnosis.

Liver metastasis mimicking an abscess

Hepatic metastases from carcinoid tumours are typically solid, hypervascular lesions on imaging. The cystic form, mimicking an abscess, is extremely rare. We report a case of a 48-year-old female presenting with a large hepatic mass that was diagnosed as a hepatic abscess, but the ultrasound-guided biopsy showed well-differentiated grade 1 neuroendocrine tumour. CT scan of chest, abdomen and pelvis was performed, looking for the primary tumour, it revealed an endobronchial mass of the right inferior lobe. Lung biopsy by rigid bronchoscopy was taken confirming the diagnosis of a typical carcinoid tumour.

Deep-learning-based image reconstruction in dynamic contrast-enhanced abdominal CT: image quality and lesion detection among reconstruction strength levels

AIM

To evaluate the use of deep-learning-based image reconstruction (DLIR) algorithms in dynamic contrast-enhanced computed tomography (CT) of the abdomen, and to compare the image quality and lesion conspicuity among the reconstruction strength levels.

MATERIALS AND METHODS

This prospective study included 59 patients with 373 hepatic lesions who underwent dynamic contrast-enhanced CT of the abdomen. All images were reconstructed using four reconstruction algorithms, including 40% adaptive statistical iterative reconstruction-Veo (ASiR-V) and DLIR at low, medium, and high-strength levels (DLIR-L, DLIR-M, and DLIR-H, respectively). The signal-to-noise ratio (SNR) of the abdominal aorta, portal vein, liver, pancreas, and spleen and the lesion-to-liver contrast-to-noise ratio (CNR) were calculated and compared among the four reconstruction algorithms. The diagnostic acceptability was qualitatively assessed and compared among the four reconstruction algorithms and the conspicuity of hepatic lesions was compared between <5 and ≥5 mm lesions.

RESULTS

The SNR of each anatomical structure (p<0.0001) and CNR (p<0.0001) were significantly higher in DLIR-H than the other reconstruction algorithms. Diagnostic acceptability was significantly better in DLIR-M than the other reconstruction algorithms (p<0.0001). The conspicuity of hepatic lesions was highest when using 40% ASiR-V and tended to lessen as the reconstruction strength level was getting higher in DLIR, especially in <5 mm lesions; however, all hepatic lesions could be detected.

CONCLUSIONS

DLIR improved the SNR, CNR, and image quality compared with 40% ASiR-V, while making it possible to decrease lesion conspicuity using higher reconstruction strength.

MR imaging features of multiple biliary hamartomas (Von Meyenburg Complex): A pictorial review and differential diagnosis

Biliary hamartomas (BHs) are rare malformative cystic/cystic-like lesions of the liver affecting the biliary tree, named after Hanns von Meyenburg who described them for the first time and still known with this eponym to this day. They usually lack clinical symptoms, and abnormalities in liver function tests are unusual; thus, it is typically an incidental finding of liver imaging. Despite being benign lesions, BHs can pose clinical challenges; the first one is differential diagnosis with other more relevant pathological conditions. Therefore, knowledge of MR imaging findings of BHs is helpful for a prompt and correct diagnosis, avoiding unnecessary invasive procedures and/or an excessive number of radiological investigations. This pictorial review is aimed to depict the most typical MR imaging features of multiple biliary hamartomas (von Meyenburg Complex), in order to familiarize the diagnosis and facilitate the differentiation from other hepato-biliary cystic diseases.

Efficacy and Validity of Image-Guided Percutaneous Fine Needle Aspiration and Core Biopsy of Liver Pathologies: Saga of Focal Hepatic Lesions from the Nodule to the Needle to the Slide

Context:

Radiology and pathology are pivotal tools in the investigational artillery for management of wide spectrum of hepatic lesions and early detection is of a paramount importance.

Aims:

The study aimed at analyzing the efficacy, comparative yield and validity of image-guided aspiration cytology (FNA)/core biopsy (CB) in focal hepatic lesions.

Settings and Design:

A retrospective hospital-based study was conducted in departments of Pathology and Radiology and Imaging of a tertiary care center.

Materials and Methods:

Cases of focal hepatic lesions that underwent percutaneous image guided-FNA reported (2011-2018) were analyzed. Cytological-histopathological correlation was performed where available. FNA diagnoses were divided into four categories-positive for malignancy (group 1), atypical (group 2), negative for malignancy (group 3), and non-diagnostic (group 4).

Statistical Analysis Used:

Categorical data was depicted in the form of frequencies and proportions. Validity of percutaneous image-guided FNA diagnosis was collated with the final diagnosis and results were analyzed.

Results:

A total of 338 FNA of focal hepatic lesions were reported in which 217 (68.2%) cases in group 1; 21 (6.2%) in group 2; 58 (17.2%) in group 3 and 42 (12.4%) in group 4. CB correlation was available in 123 cases. Based on clinical, radiological and pathological findings, conclusive final diagnoses were obtained and the cases were regrouped [malignant cases-245, benign lesions-57 and uncertain lesions-36]. Metastasis was the most common malignancy (175/245; 71.4%). Sensitivity, specificity, and overall diagnostic accuracy of FNA to categorize the lesion as benign or malignant were 96.94%, 100% and 97.51%, respectively. However, the cytology-histopathology correlation revealed discordance of subtyping the lesion in 20% of cases and sensitivity and specificity reduced to 80% and 50% respectively in rendering the specific diagnosis.

Conclusions:

Percutaneous image-guided FNA is a sensitive and specific tool with high diagnostic accuracy in evaluating focal hepatic lesions. The study highlights the pre-eminence of interventional radiology and cytology in the care of patients with liver lesions.

CT and MRI features differentiating mucinous cystic neoplasms of the liver from pathologically simple cysts

PURPOSE

The purpose of this study was to determine if CT and MRI features can accurately differentiate mucinous cystic neoplasms (MCNs) from simple liver cysts and to compare accuracy of CT and MRI in detecting these features.

METHODS

Eighty-four surgically treated lesions with pre-operative CT or MRI were evaluated by two abdominal radiologists for upstream biliary dilatation, perfusional change, internal hemorrhage, thin septations, thick septations/nodularity, lobar location, and number of coexistent liver cysts. Odds ratios, sensitivities, specificities, and positive and negative predictive values were calculated for association of each feature with MCNs.

RESULTS

Of 84 liver lesions, 13 (15%) were MCNs, all in women, and 71 (85%) were simple cysts, in 59 women and 12 men. Thick septations/nodularity, upstream biliary dilation, thin septations, internal hemorrhage, perfusional change, and fewer than 3 coexistent liver cysts were more frequent in MCNs than in simple cysts. The combination of thick septations/nodularity and at least one additional associated feature showed high specificity for MCNs (94-98%). MRI detected significant associations of biliary dilation, thin septations, and hemorrhage/debris with MCNs which CT did not.

CONCLUSION

Surgically treated MCNs of the liver with preoperative imaging occurred at our institution only in women. Thick septations or nodularity, biliary dilation, thin septations, internal hemorrhage or debris, perfusional change, and fewer than 3 coexistent liver cysts are features that help differentiate MCNs from simple cysts. MRI has advantages over CT in detecting these features.

Infected hepatic cyst complicating urinary sepsis

Congenital hepatic cysts are a common disorder. Usually they are asymptomatic and do not have to be treated. However, some serious complications can occur. We report here the case of an 86-year old patient who has been treated by a percutaneous drainage for an infected solitary hepatic cyst due to urinary sepsis. She was admitted to the Department of Internal Medicine for epigastric pain with fever and chills. The patient was treated for a urinary tract infection 3 weeks ago by her General Practitioner. On admission, blood tests showed 21 620 neutrophils per microliter with a C-reactive protein level at 443.7 mg/L, procalcitonin > 200 ng/mL, total bilirubin at 1.43 mg/dL, lactate dehydrogenase at 666 U/L and alanine aminotransferase at 227 U/L. Urinalysis and hemocultures highlighted the presence of Escherichia coli and Streptococcus constellatus. The abdominal tomodensitometry indicated the presence of a left hepatic biliary cyst with banal appearance. She was first treated with intravenous amoxicillin clavulanic acid. After a few days, another abdominal tomodensitometry with contrast pinpointed a large abscess of 11 centimeters in diameter extending to liver segments II and IV with a similar small lesion in segments IV and V. clindamycin per os was added to the treatment because of its good diffusion in tissues. Percutaneous drain was inserted under tomodensitometric control and stayed in place until the follow-up at three weeks. Bacteriologic culture on the fluid sample demonstrated the presence of Escherichia coli and Streptococcus constellatus. The abscess completely regressed after 6 weeks of treatment and the biologic abnormalities resolved at the same time.

Huge solitary-infected liver cyst successfully managed by deroofing operation to remove 3.8 l of pus

Simple liver cysts are usually asymptomatic, and complications are uncommon. However, infection of cysts can very occasionally occur, and this troublesome complication requires treatment. An 87-year-old woman admitted for dyspnea, abdominal discomfort, fever, and mild icterus underwent ultrasonographic (US) and computed tomography (CT) examinations, and a huge cystic lesion was identified in the right hepatic lobe. The diagnosis of an infected gigantic liver cyst was made by abdominal CT and percutaneous transhepatic drainage under ultrasonographic guidance. The pus viscosity was so high that pus drainage was ineffective. Bacterial culture was positive for Klebsiella pneumoniae. The cyst diameter was approximately 21 cm, and the total pus discharge was 3.8 l. Emergency operation to fenestrate the cyst wall relieved the patient's critical condition. This report is clinically significant because 3.8 l of pus may be one of the largest reported quantity of drained pus from an infected cyst. We found no reports of > 3.8 l of drained pus in an English literature search. It is also very rare that imaging identified postoperative liver regeneration filling the huge empty space previously occupied by the cyst. Large liver cysts in older people should be carefully followed, preparing for the rare possibility of infection.

Hepatic Hydatid Cyst Misdiagnosed as Simple Cyst: A Case Report

BACKGROUND Hepatic hydatid cysts is a cystic disease of the liver caused by echinococcosis. Echinococcosis usually forms a monolocular cyst and causes space occupying effect, while alveolar echinococcosis often progresses into a polycystic mass that dilates into the adjacent liver parenchyma, with different clinical manifestations. In clinical practice, hepatic hydatid cyst and simple cyst are generally diagnosed clearly, but there are still misdiagnosed cases. CASE REPORT A 40-year-old female patient with no symptoms had a computed tomography and magnetic resonance imaging examination that revealed multiple round-like shadows of varying sizes in her liver. Combined with the laboratory and imaging results, the diagnosis was considered as hepatic hemangioma and hepatic cyst. Therefore, we planned to perform ultrasound guided microwave ablation of hepatic hemangioma and laparoscopic fenestration of hepatic cyst. Considering the possibility of hepatic hydatid cysts during the operation, partial hepatectomy was performed. CONCLUSIONS More attention should be paid to the differential diagnosis of cystic space occupying lesions in the liver. For the treatment of hepatic cyst, if suspected, must change the surgical strategy.

Portal hypertension in a patient with biliary hamartomas: A case report

BACKGROUND

Biliary hamartomas (BH) are a rare benign disease caused by malformation of the intrahepatic bile ducts. BH are occasionally diagnosed, but often lack obvious clinical symptoms. They are usually diagnosed by biopsy and imaging tests in clinical practice. Few studies have reported the association of BH with portal hypertension.

CASE SUMMARY

A 40-year-old man was repeatedly admitted to our hospital due to hematochezia. The source of bleeding was considered to be gastroesophageal varices and portal hypertensive gastropathy by endoscopy. He had no history of hepatitis virus infection, alcohol abuse, drug-induced liver injury, or autoimmune liver disease. He underwent magnetic resonance imaging, which showed rounded, irregular, low-signal-T1 and high-signal-T2 lesions diffusely distributed on the liver, that were not communicated with the biliary system on magnetic resonance cholangiopancreatography. According to the imaging examination, the patient was considered to have a diagnosis of BH with portal hypertension.

CONCLUSION

Based on the present case report, BH may be a potential etiology of portal hypertension.

Fluid-filled Cystic Lesions of the Lungs

A pulmonary cyst usually refers to an air-filled space with a smooth, thin wall. Fluid-filled cystic lesions of the lungs include a range of etiologies such as true cysts, congenital malformations, infections, and benign and malignant neoplasms. With relatively little solid component, these lesions often have similar imaging appearances to one another. This article focuses on key imaging features and clinical characteristics that can be used to narrow the differential diagnosis.

Non-neoplastic hepatopancreatobiliary lesions simulating malignancy: can we differentiate?

Despite the success of cross-sectional imaging in evaluating hepatopancreatobiliary system malignancies, several non-malignant disease processes may closely mimic malignancy. Differentiating these benign diseases from malignancy may be difficult, or even impossible, even in the hands of experienced imagers. In this manuscript, we present benign mimics involving the hepatopancreatobiliary system and try to increase awareness of these potential pitfalls.

Early detection of intrahepatic cholangiocarcinoma

Cholangiocarcinoma (CC) is a malignant tumor which arises from the biliary epithelium and most cases represent adenocarcinoma. CC can be classified into intrahepatic CC (ICC), perihilar CC, and distal CC, based on the site of anatomic origin. The incidence of ICC is increasing in both Western and Eastern countries, while that of extrahepatic cholangiocarcinoma remains fairly stable. ICC infiltrates into adjacent nerves and lymphatic vessels, resulting in progressive disease with a poor prognosis; thus, early detection of ICC is critical for achieving better outcomes and providing better patient care. However, it is difficult for clinicians to detect an ICC, especially in its early stage. Different from hepatocellular carcinoma, the lack of surveillance system for the high-risk group of CC does not allow for a reliable screening examination. In this context, for early detection and diagnosis of ICC, radiologists need to know predisposing conditions that can lead to the development of ICC, such as chronic biliary or hepatic inflammation, primary sclerosing cholangitis, congenital biliary diseases, and other conditions. In this article, we discuss and illustrate the radiologic features of ICC with special attention to early disease stages and of predisposing conditions of ICC.

Biliary mucinous cystic neoplasm mimicking a hydatid cyst: a case report and literature review

Background

Biliary mucinous cystic neoplasms are rare cystic lesions of the liver which carry pre-malignant potential. Given the scarcity of reports in the literature, they pose a considerable challenge to clinical management, particularly with regards to accurate pre-operative diagnosis.

Case presentation

We present the case of a 37-year-old Tunisian woman who presented with subacute right upper quadrant pain and a large multi-loculated cystic lesion, most consistent with a hydatid cyst. She underwent an open right hepatectomy, and pathology surprisingly revealed a biliary mucinous cystadenoma. Herein, we review the current literature on biliary mucinous cystic neoplasms, with a particular emphasis on diagnostic investigations, key radiological features and optimal treatment modalities.

Conclusion

Biliary mucinous cystic neoplasms require a high index of suspicion and should be managed with complete surgical resection, as conservative techniques are associated with high recurrence rates. Considering the potential for malignant transformation, periodical surveillance imaging is recommended in the post-operative period.

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.

Recurrent renal cell carcinoma leading to a misdiagnosis of polycystic liver disease: A case report

BACKGROUND

Polycystic liver disease (PCLD) with a large cystic volume deteriorates the quality of life of patients through substantial effects on the adjacent organs, recurrent cyst infections, cyst rupture, and hemorrhage. Surgical or radiological intervention is usually needed to alleviate these symptoms. We report a rare case of the cystic metastasis of renal cell carcinoma (RCC), which was misdiagnosed as PCLD, as a result of the clinical and radiological similarity between these disorders.

CASE SUMMARY

A 74-year-old female who had undergone nephrectomy for papillary-type RCC (PRCC) was suffering from abdominal pain and the recurrent intracystic hemorrhage of multiple cysts in the liver. Imaging studies and aspiration cytology of the cysts showed no evidence of malignancy. With a diagnosis of autosomal dominant polycystic liver disease, the patient received hepatectomy for the purpose of mass reduction and infectious cyst removal. Surgery was performed without complications, and the patient was discharged on postoperative day 14. Postoperatively, the pathology revealed a diagnosis of recurrent PRCC with cystic formation.

CONCLUSION

This case demonstrates the importance of excluding the cystic metastasis of a cancer when liver cysts are observed.

Morphological and dynamic evaluation of complex cystic focal liver lesions by contrast-enhanced ultrasound: current state of the art

Complex cystic and cystic-like focal liver lesions (FLLs) encompass a spectrum of disorders ranging from non-neoplastic conditions to benign and malignant tumors. In this prospective, the possibility of non-invasive differentiation of these lesions is extremely important, because the clinical implications and therapeutic strategies vary considerably. Because of its advantageous cost/benefit ratio, widespread availability and easy execution, ultrasound (US) is the first-line imaging modality in most countries for the initial liver survey and represents the imaging technique that usually detects a complex liver cyst. However, US showed poor efficacy in the differential diagnosis of complex cystic FLLs. Thus, for years, computed tomography (CT) and magnetic resonance (MR) imaging have been used for further assessment of these lesions. Recently, the development of low mechanical index real-time contrast-enhanced ultrasound (CEUS) technique performed with the second generation of US contrast agents has led to an accurate depiction of macrovasculature and microvasculature. The technique yields information about contrast enhancement of the liver and FLLs almost as CT and MRI do, but in real time and without the use of ionizing radiation. To date, there is only a small amount of evidence about the role of CEUS in the less common setting of complex liver cysts. The aim of this review is to offer an up-to-date overview on the state of the art of CEUS in the study of the most common complex cystic focal liver lesions. To our knowledge, there are no literature comprehensive reviews on this topic.

Diagnostic and Therapeutic Challenges of Intrahepatic Biliary Cystadenoma and Cystadenocarcinoma: A Report of 10 Cases and Review of the Literature

The objective of this study was to present our experience with intrahepatic biliary cystadenomas and cystadenocarcinomas in 10 patients surgically managed in our department. Intrahepatic biliary cystadenomas and cystadenocarcinomas are rare cystic tumors that are often misdiagnosed preoperatively as simple cysts or hydatid cysts. They recur after incomplete resection and entail a risk of malignant transformation to cystadenocarcinoma. A retrospective review was conducted of patients with histologically confirmed intrahepatic biliary cystadenomas and cystadenocarcinomas between August 2004 and February 2013 who were surgically managed in our department. A total of 10 patients, 9 female and 1 male (mean age, 50 years), with cystic liver were reviewed. The size of the cysts ranged between 3.5 and 16 cm (mean, 10.6). Five patients had undergone previous interventions elsewhere and presented with recurrences. Liver resections included 6 hepatectomies, 2 bisegmentectomies, 1 extended right hepatectomy, and 1 enucleation due to the central position and the large size of the lesion. Pathology reports confirmed R0 resections in all cases. All patients were alive after a median follow-up of 6 years (range, 1-10 years), and no recurrence was detected. Intrahepatic biliary cystadenoma and cystadenocarcinoma should be considered in differential diagnosis in patients with liver cystic tumors. Because of the high recurrence rate and difficult accurate preoperative diagnosis, formal liver resection is mandatory. Enucleation with free margins is an option and is indicated where resection is impossible.

CT reconstruction algorithms affect histogram and texture analysis: evidence for liver parenchyma, focal solid liver lesions, and renal cysts

PURPOSE

To determine the effects of different reconstruction algorithms on histogram and texture features in different targets.

MATERIALS AND METHODS

Among 3620 patients, 480 had normal liver parenchyma, 494 had focal solid liver lesions (metastases = 259; hepatocellular carcinoma = 99; hemangioma = 78; abscess = 32; and cholangiocarcinoma = 26), and 488 had renal cysts. CT images were reconstructed with filtered back-projection (FBP), hybrid iterative reconstruction (HIR), and iterative model reconstruction (IMR) algorithms. Computerized histogram and texture analyses were performed by extracting 11 features.

RESULTS

Different reconstruction algorithms had distinct, significant effects. IMR had a greater effect than HIR. For instance, IMR had a significant effect on five features of liver parenchyma, nine features of focal liver lesions, and four features of renal cysts on portal-phase scans and four, eight, and four features, respectively, on precontrast scans (p < 0.05). Meanwhile, different algorithms had a greater effect on focal liver lesions (six in HIR and nine in IMR on portal-phase, three in HIR, and eight in IMR on precontrast scans) than on liver parenchyma or cysts. The mean attenuation and standard deviation were not affected by the reconstruction algorithm (p > .05). Most parameters showed good or excellent intra- and interobserver agreement, with intraclass correlation coefficients ranging from 0.634 to 0.972.

CONCLUSIONS

Different reconstruction algorithms affect histogram and texture features. Reconstruction algorithms showed stronger effects in focal liver lesions than in liver parenchyma or renal cysts.

KEY POINTS

• Imaging heterogeneities influenced the quantification of image features. • Different reconstruction algorithms had a significant effect on histogram and texture features. • Solid liver lesions were more affected than liver parenchyma or cysts.