Common and uncommon pitfalls in pancreatic imaging: it is not always cancer.

Despite advances in multimodality imaging of pancreas, there is still overlap between imaging findings of several pancreatic/peripancreatic disease processes. Pancreatic and peripancreatic non-neoplastic entities may mimic primary pancreatic neoplasms on ultrasound, CT, and MRI. On the other hand, primary pancreatic cancer may be overlooked on imaging because of technical and inherent factors. The purpose of this pictorial review is to describe and illustrate pancreatic imaging pitfalls and highlight the basic radiological features for proper differential diagnosis.

ESGAR consensus statement on liver MR imaging and clinical use of liver-specific contrast agents.

OBJECTIVES: To develop a consensus and provide updated recommendations on liver MR imaging and the clinical use of liver-specific contrast agents. METHODS: The European Society of Gastrointestinal and Abdominal Radiology (ESGAR) formed a multinational European panel of experts, selected on the basis of a literature review and their leadership in the field of liver MR imaging. A modified Delphi process was adopted to draft a list of statements. Descriptive and Cronbach's statistics were used to rate levels of agreement and internal reliability of the consensus. RESULTS: Three Delphi rounds were conducted and 76 statements composed on MR technique (n = 17), clinical application of liver-specific contrast agents in benign, focal liver lesions (n = 7), malignant liver lesions in non-cirrhotic (n = 9) and in cirrhotic patients (n = 18), diffuse and vascular liver diseases (n = 12), and bile ducts (n = 13). The overall mean score of agreement was 4.84 (SD ±0.17). Full consensus was reached in 22 % of all statements in all working groups, with no full consensus reached on diffuse and vascular diseases. CONCLUSIONS: The consensus provided updated recommendations on the methodology, and clinical indications, of MRI with liver specific contrast agents in the study of liver diseases. KEY POINTS: • Liver-specific contrast agents are recommended in MRI of the liver. • The hepatobiliary phase improves the detection and characterization of hepatocellular lesions. • Liver-specific contrast agents can improve the detection of HCC.

[Modern diagnostics of cystic liver lesions and hemangiomas]. / Moderne Diagnostik zystischer Leberläsionen und Hämangiome.

CLINICAL ISSUE: Cystic liver lesions incorporate a broad heterogeneous group of mostly benign but also malignant abnormalities. The radiological aim is the non-invasive diagnosis with the use of different imaging modalities to determine the type of lesion. STANDARD RADIOLOGICAL METHODS: The common generally asymptomatic incidental findings of cystic lesions on ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) must be classified on the basis of specific imaging features. Such a differentiation is essential because the clinical consequences and the appropriate therapy can vary depending on the underlying pathology. Due to the morphological overlap of many cystic lesions, conventional radiological methods are often insufficient. METHODICAL INNOVATIONS: The huge advances in cross-sectional imaging (multidetector CT, MRI with special sequences and different contrast agents and MR cholangiopancreatography) in combination with the clinical history usually enable a non-invasive diagnosis. Pathognomonic morphological and hemodynamic lesion features, as well as a knowledge of the pathomechanisms, help to differentiate this broad spectrum of entities. ACHIEVEMENTS: In this article the different entities of cystic liver lesions, together with the appropriate diagnostic method for detection and distinction and including their strengths and limitations, are demonstrated. PRACTICAL RECOMMENDATIONS: A well-founded knowledge about the development of various cystic liver lesions and the suitable choice of imaging method facilitate a non-invasive diagnosis.

Chronic atrial fibrillation in presence of aortic stenosis in a patient with polysplenia syndrome.

We report a rare case of "situs viscerum ambiguous" with polysplenia syndrome, in a 69 year old female patient with aortic stenosis and chronic atrial fibrillation. The presenting symptom was dyspnoea on moderate exertion and an ECG showed supra ventricular arrhythmia. Patients trans-thoracic echocardiogram revealed a dilated left atrium, reduced ejection fraction, mild tricuspid regurgitation, moderate-severe pulmonary hypertension and severe aortic stenosis. The patient was successfully treated with a replacement of her aortic valve and ascending aorta.

Predicting survival in patients with hepatocellular carcinoma treated by transarterial chemoembolisation.

BACKGROUND: Transarterial chemoembolisation (TACE) is first-line treatment in unresectable hepatocellular carcinoma (HCC) and rescue treatment after failure of radical treatments in early stage HCC. Prognostic tools for HCC using time-fixed Cox models may be unreliable in patients treated with TACE because time-varying predictors interact. AIM: To explore time-dependent variables as survival predictors in patients with HCC receiving TACE as first-line or second-line treatment. METHODS: Eighty four consecutive patients with HCC (mean age 68; male gender 62%; Child-Pugh class: A n=73, B n=11; Barcelona Clinic Liver Cancer class: A n=44, B n=24, C n=16) treated with TACE were enrolled. Clinical, laboratory and radiological follow-up data were collected from the time of first treatment. Time-fixed and time-dependent Cox analyses were done. RESULTS: Overall survival rates were 89.6% (95% CI 82.5-97.2) at 12months, 58.8% (95% CI 46.2-74.9) at 24, 35.4% (95% CI 22.3-56.1) at 36 and 17.2% (95% CI 7.0-41.7) at 48months. Performance status (P<0.001), number of nodules (P<0.016) and prior therapy (P=0.017) were the only variables strongly linked to survival by time-fixed Cox model. Performance status (P<0.001), prior therapy (P=0.005), number of treatments (P=0.013), complete response after TACE (P=0.005) and bilirubin level (P<0.001) were associated with survival using a time-dependent Cox model. CONCLUSIONS: Survival after TACE is influenced most by performance status, complete response and bilirubin. Compared with the time-fixed models, a time-dependent Cox model has the potential to estimate a more precise prognosis in HCC patients treated with TACE.

Hepatocellular carcinoma in cirrhotic patients at multidetector CT: hepatic venous phase versus delayed phase for the detection of tumour washout.

OBJECTIVES: Our aim was to compare retrospectively hepatic venous and delayed phase images for the detection of tumour washout during multiphasic multidetector row CT (MDCT) of the liver in patients with hepatocellular carcinoma (HCC). METHODS: 30 cirrhotic patients underwent multiphasic MDCT in the 90 days before liver transplantation. MDCT was performed before contrast medium administration and during hepatic arterial hepatic venous and delayed phases, images were obtained at 12, 55 and 120 s after trigger threshold. Two radiologists qualitatively evaluated images for lesion attenuation. Tumour washout was evaluated subjectively and objectively. Tumour-to-liver contrast (TLC) was measured for all pathologically proven HCCs. RESULTS: 48 HCCs were detected at MDCT. 46 of the 48 tumours (96%) appeared as either hyper- or isoattenuating during the hepatic arterial phase subjective washout was present in 15 HCCs (33%) during the hepatic venous phase and in 35 (76%) during the delayed phase (p<0.001, McNemar's test). Objective washout was present in 30 of the 46 HCCs (65%) during the hepatic venous phase and in 42 of the HCCs (91%) during the delayed phase (p=0.001). The delayed phase yielded significantly higher mean TLC absolute values compared with the hepatic venous phase (-16.1±10.8 HU vs -10.5±10.2 HU; p<0.001). CONCLUSIONS: The delayed phase is superior to the hepatic venous phase for detection of tumour washout of pathologically proven HCC in cirrhotic patients.

Are pancreatic calcifications specific for the diagnosis of chronic pancreatitis? A multidetector-row CT analysis.

AIM: To retrospectively establish the most frequently encountered diagnoses in patients with pancreatic calcifications and to investigate whether the association of certain findings could be helpful for diagnosis. MATERIALS AND METHODS: One hundred and three patients were included in the study. The location and distribution of calcifications; presence, nature, and enhancement pattern of pancreatic lesions; pancreatic atrophy and ductal dilatation were recorded. Differences between patients with chronic pancreatitis and patients with other entities were compared by using Fisher's exact test. RESULTS: Patients had chronic pancreatitis (n=70), neuroendocrine tumours (n=14), intraductal papillary mucinous neoplasm (n=11), pancreatic adenocarcinoma (n=4), serous cystadenoma (n=4). Four CT findings had a specificity of over 60% for the diagnosis of chronic pancreatitis: parenchymal calcifications, intraductal calcifications, parenchymal atrophy, and cystic lesions. When at least two of these four criteria were used in combination, 54 of 70 (77%) patients with chronic pancreatitis could be identified, but only 17 of 33 (51%) patients with other diseases. When at least three of these four criteria were present, a specificity of 79% for the diagnosis of chronic pancreatitis was achieved. CONCLUSION: Certain findings are noted more often in chronic pancreatitis than in other pancreatic diseases. The presence of a combination of CT findings can suggest chronic pancreatitis and be helpful in diagnosis.

Focal nodular hyperplasia: typical and atypical MRI findings with emphasis on the use of contrast media.

Focal nodular hyperplasia is a benign hypervascular hepatic tumour, frequently detected in asymptomatic patients undergoing imaging studies for unrelated reasons. Magnetic resonance imaging (MRI) generally allows a confident differential diagnosis with other hypervascular liver lesions, either benign or malignant. In addition, due to the recent development of hepatospecific MRI contrast agents, MRI concomitantly enables functional and morphological information to be obtained, thus providing important clues for the detection and characterization of focal nodular hyperplasia lesions.

Hepatic capsular retraction: spectrum of benign and malignant etiologies.

Retraction of the liver capsule may be associated with a diverse spectrum of benign and malignant hepatic abnormalities. These include primary malignant neoplasms (epithelioid hemangioendothelioma, hepatocellular carcinoma, cholangiocarcinoma), secondary malignant neoplasms before and after treatment, and hepatic hemangioma, especially in cirrhotic livers. Other etiologies include confluent fibrosis in cirrhotic livers, chronic biliary obstruction (as can be seen in primary sclerosing cholangitis), and traumatic hepatic injury (iatrogenic and noniatrogenic). Because several recent studies have incorrectly reported hepatic capsular retraction as a specific sign of hepatic malignancy, it is important to understand the imaging appearances of the various etiologies associated with this sign to avoid misdiagnosis that may adversely affect the therapeutic approach.

Acute fulminant hepatic infection causing fatal "emphysematous hepatitis": case report.

We describe a case of fatal fulminant hepatic infection with gas replacement of the hepatic parenchyma and no evidence of a liquified abscess in a diabetic patient: a case of "emphysematous hepatitis," the hepatic equivalent of emphysematous pyelonephritis. Computed tomography and clinical findings are described.

Radiologist performance in the diagnosis of internal hernia by using specific CT findings with emphasis on transmesenteric hernia.

PURPOSE: To evaluate the performance of radiologists in the diagnosis of internal hernia with specific computed tomographic (CT) findings. MATERIALS AND METHODS: Abdominal CT scans obtained in 42 patients were retrospectively reviewed by three radiologists. The case group consisted of 18 patients with internal hernias (two paraduodenal, 16 transmesenteric); the comparison group was 24 patients with no internal hernia. Images were reviewed in a random and blinded fashion. Individual and group performance was evaluated with receiver operating characteristic (ROC) analysis, and interobserver agreement was measured with Cronbach coefficient alpha. Individual CT signs relevant as predictors of transmesenteric hernia were identified with logistic regression analysis and ranked by their odds ratio and P values. RESULTS: Both paraduodenal hernias were diagnosed by all readers on the basis of CT signs, including a retrogastric saclike mass of small-bowel loops. Diagnosis of transmesenteric hernia was more difficult and variable, with an average accuracy of area under the ROC curve (A(z)) of 77%, sensitivity of 63%, and specificity of 76%. CT signs of transmesenteric hernia were recognized consistently (Cronbach coefficient alpha >or= 0.80) and included a cluster of dilated small-bowel segments and stretching and displacement of mesenteric vessels. Coexisting volvulus and ischemia were diagnosed with low sensitivity (46% and 43%, respectively) but high specificity (96% and 98%, respectively). CONCLUSION: Diagnosis of internal hernia with CT remains difficult. Special attention should be given to the clustering of bowel loops, the mesenteric vessels, and signs of small-bowel obstruction.

Focal nodular hyperplasia: morphologic and functional information from MR imaging with gadobenate dimeglumine.

PURPOSE: To determine whether gadobenate dimeglumine (Gd-BOPTA) is able to provide morphologic and functional information for characterization of focal nodular hyperplasia (FNH). MATERIALS AND METHODS: Sixty-three consecutive patients with proved FNH were retrospectively examined. Magnetic resonance (MR) imaging with T2-weighted turbo spin-echo and T1-weighted gradient-echo sequences was performed. Images were acquired prior to and during the dynamic phase of contrast-material enhancement and 1-3 hours after administration of 0.1 mmol/kg Gd-BOPTA. Qualitative analysis of signal intensity and homogeneity on images in the various phases of the MR study and examination for the presence of central scar or atypical features were performed. On the basis of features observed in the precontrast and dynamic phases, lesions were defined as typical or atypical. Intensity and enhancement patterns of the lesions and scars were also evaluated in the delayed phase. RESULTS: One hundred FNHs were depicted on MR images. Seventy-nine of 100 lesions demonstrated typical morphologic and enhancement characteristics. On delayed phase images, 72% of 100 FNHs appeared hyperintense; 21%, isointense; and 7%, slightly hypointense. The delayed pattern of enhancement was homogeneous, heterogeneous, and peripheral in 58%, 22%, and 20% of 100 FNHs, respectively. Atypical morphologic features and lesion and/or scar enhancement were observed in 21 of 100 FNHs. On delayed phase images, 76% of 100 atypical FNHs appeared hyperintense, 14% isointense, and 10% slightly hypointense. Hyperintensity and isointensity allowed the correct characterization in 90% of atypical FNHs. CONCLUSION: Gd-BOPTA during both dynamic and delayed phases provides morphologic and functional information for the characterization of FNH.

Portal venous thrombosis or sclerosis in liver transplantation candidates: preoperative CT findings and correlation with surgical procedure.

PURPOSE: To review computed tomographic (CT) findings in patients with surgically proved portal venous (PV) thrombosis or sclerosis and to correlate these findings with the surgical procedure used at orthotopic liver transplantation (OLT). MATERIALS AND METHODS: Among 379 OLTs, PV thrombosis or sclerosis was found at surgery in 39 patients (10.3%). Before OLT, surgical records and CT images were retrospectively reviewed in 35 patients with available CT studies. Diameter of the extrahepatic PV and patency of the PV system were evaluated. Cavernous transformation, calcifications of the venous wall or thrombus, lesions suggestive of tumor, mesenteric varices, edema, or splenorenal shunt were recorded. A nonpaired Student t test and the Fisher exact test were used to analyze the results. RESULTS: Of 35 patients, 23 (66%) underwent thrombectomy with direct PV-to-PV anastomosis and 12 (34%) had placement of venous grafts or other anastomoses. The extrahepatic PV was 8.2 mm, but it significantly (P < or = .05) decreased in patients with splenorenal shunt. In 30 patients, CT depicted thrombosis, PV calcification, or other abnormalities. The thrombus extended to or beyond the confluence of the splenic and superior mesenteric veins in 21 (60%) and 11 (31%) patients, respectively. Eleven patients (31%) had cavernous transformation of the PV; eight (23%), a cordlike sclerotic PV; 19 (54%), a splenorenal shunt; 11 (31%), PV calcification; 17 (49%), mesenteric edema; 14 (40%), mesenteric varices. Patients with a cordlike or calcified PV were significantly (P < or = .05) more likely to require modification of the surgical technique. CONCLUSION: Before OLT, CT can aid in assessment of PV and associated findings and in surgical management.

Primary biliary cirrhosis: clinical, pathologic, and helical CT findings in 53 patients.

PURPOSE: To evaluate and compare clinical, pathologic, and helical computed tomographic (CT) findings of primary biliary cirrhosis (PBC). MATERIALS AND METHODS: The authors reviewed the medical records and CT scans of 53 patients who underwent evaluation, treatment, and orthotopic liver transplantation (OLT) at their institution. All patients underwent helical multiphase CT (total, 98 abdominal CT scans; range, one to five scans per patient). Multiple epidemiologic, clinical, and morphologic criteria were evaluated. Advanced disease was defined as hepatic insufficiency leading to OLT within the subsequent 2 years. Clinical and morphologic features were evaluated and compared in the advanced and less advanced cases of PBC. RESULTS: Common and characteristic findings included the following: 45 (85%) of the 53 patients were women with the onset of disease (diagnosis) in middle age (mean, 50.7 years; range, 26-71 years). The average time from diagnosis to OLT was 6.1 years (range, 1.5-20.0 years). CT findings in advanced PBC often resembled those seen in other forms of cirrhosis, with a small heterogeneously attenuating liver, varices, and splenomegaly. The liver in less advanced disease was usually enlarged or normal in size, with a smooth contour, little atrophy, and lacelike fibrosis and regenerative nodules in nearly one-third of the livers. Patients with less advanced disease frequently had varices (n = 33 [62%]) and ascites (n = 13 [24%]). Lymphadenopathy was seen in 47 (88%) patients. Hepatocellular carcinoma was found in four (8%) patients, two of whom also had chronic hepatitis C. During a follow-up period of 5-72 months (median, 46 months; mean, 42 months) after OLT, only two patients experienced recurrence of PBC. CONCLUSION: PBC is an important cause of liver failure, with distinctive clinical and CT findings that may assist diagnosis and allow adequate treatment. CT can demonstrate varices and ascites before frank cirrhosis is evident and can help evaluate the progression of the disease.

Imaging of benign hepatic masses.

Using helical CT and rapid i.v. injection of contrast material, benign hepatic masses are discovered in at least 20% of subjects. To minimize expensive and invasive evaluation, an orderly approach to the interpretation of these lesions is necessary. Many benign lesions have a near pathognomonic appearance on a properly performed and interpreted CT scan. Others can have the diagnosis confirmed by a specific and well-chosen follow-up study, such as contrast-enhanced MR. In this article we present the most common types of benign hepatic masses and our approach to their diagnosis.

[Thrombolytic therapy in myocardial infarction. Computerized tomography of encephalic complications]. / Terapia trombolitica nell'infarto del miocardio. Aspetti con Tomografia Computerizzata della complicanze encefaliche.

PURPOSE: To evaluate the CT findings of intracerebral hemorrhage in patients undergoing thrombolytic therapy for acute myocardial infarction and to correlate the type of intracerebral hemorrhage with clinical outcome. MATERIAL AND METHODS: We retrospectively reviewed the clinical records and CT scans of intracerebral hemorrhage on a total of 302 patients who underwent thrombolytic therapy for acute myocardial infarction at our institution from January 1996 to September 1999. In each patient we evaluated: the number, sites and size of hemorrhage, and the presence and severity of mass effect. The site of the hemorrhage was classified as intraparenchymal, intraventricular, subdural and subarachnoid. RESULTS: Six patients (2%, mean age 74, range 66-80) developed intracerebral hemorrhage. There was a total of 22 hemorrhages: 1 subdural hemorrhage, 6 subarachnoid, 11 intraparenchymal and 4 intraventricular. Excluding intraventricular hemorrhage, 14/18 hemorr-hages were located supratentorially. In five patients there was a fluid-blood level. Three patients had severe mass effect with midline shift. Symptoms presented within 24 hours from the administration of thrombolytic therapy in all patients. All the patients who died had a large hematoma with a severe mass effect and a severe midline shift at CT scan. In the remaining patients, the hematoma was of medium size and no mass effect was seen. CONCLUSIONS: The most common site of hemorrhage was supratentorial and intraparenchymal. Large volume intracerebral hemorrhage, multiple hemorrhages and mass effect with midline shift were associated with increased mortality. The most commonly observed finding was a fluid-blood level hematoma.

Hepatic adenomas: imaging and pathologic findings.

Hepatocellular adenoma is a rare benign lesion that is most often seen in young women with a history of oral contraceptive use. It is typically solitary, although multiple lesions have been reported, particularly in patients with glycogen storage disease and liver adenomatosis. Because of the risk of hemorrhage and malignant transformation, hepatocellular adenomas must be identified and treated promptly. At pathologic analysis, hepatocellular adenoma is usually a well-circumscribed, nonlobulated lesion, and at gross examination, resected adenomas frequently demonstrate areas of hemorrhage and infarction. Most adenomas are not specifically diagnosed at ultrasonography (US) and are usually further evaluated with computed tomography (CT) or other imaging modalities. Color Doppler US may help differentiate hepatocellular adenoma from focal nodular hyperplasia. Multiphasic helical CT allows more accurate detection and characterization of focal hepatic lesions. Hepatocellular adenomas are typically bright on T1-weighted magnetic resonance images and predominantly hyperintense relative to liver on T2-weighted images. The prognosis of hepatic adenoma is not well established. Criteria that guide treatment include the number and size of the lesions, the presence of symptoms, and the surgical risk incurred by the patient. Understanding the imaging appearance of hepatocellular adenoma can help avoid misdiagnosis and facilitate prompt, effective treatment.

Focal nodular hyperplasia: CT findings with emphasis on multiphasic helical CT in 78 patients.

PURPOSE: To evaluate features of focal nodular hyperplasia (FNH) at multiphasic helical computed tomography (CT). MATERIALS AND METHODS: Clinical, pathologic, and preoperative imaging findings were retrospectively reviewed in 78 patients. Conventional liver CT was performed in nine patients; helical multiphasic CT, in 69. Diagnosis was based on complete resection (n = 20), biopsy (n = 42), or clinical and imaging follow-up for a minimum of 6 months (n = 16). Number, size, location, margins, surface, homogeneity of enhancement, and presence of a central scar, mass effect, exophytic growth, calcification, pseudocapsule, or vessels feeding or draining the lesion were evaluated. RESULTS: CT depicted 124 tumors (mean diameter, 4.1 cm; range, 1-11 cm); 62 were small (< or =3 cm). FNHs were hypervascular and hyperattenuating to liver on 106 of 106 arterial phase scans and were isoattenuating to liver on 82 of 89 delayed scans. Of the 124 tumors, 111 enhanced homogeneously, 109 had a smooth surface, 101 were subcapsular, 89 had ill-defined margins, and 62 had a central scar that was observed more often in large lesions (40 of 62 lesions) than in small lesions (22 of 62 lesions). FNHs less frequently exerted a mass effect (43 lesions), had vessels around or within the lesion (42 lesions), demonstrated exophytic growth (40 lesions), or showed a pseudocapsule (10 lesions). Only one FNH had calcification. CONCLUSION: Helical CT demonstrates characteristic features that may allow confident diagnosis of FNH. In typical cases, neither biopsy nor further imaging is necessary.