Feasibility of Ultra-Low Volume Contrast-Saline Mixture Injection With Dual-Flow Technique in a Pre-TAVI Computed Tomography Angiography.

BACKGROUND: To explore the feasibility and image quality of ultra-low volume contrast-saline mixture injection with dual-flow injection technique in a computed tomography angiography (CTA) protocol in patients scheduled for transcatheter aortic valve implantation (TAVI). METHODS: Forty (40) TAVI candidates underwent investigation with CTA using a third-generation dual-source CT scanner between September and November 2020. Different volumes of a monophasic contrast-saline mixture at an 80:20 ratio were administered at an infusion rate of 3 mL/s in 20 patients (group A). The injected volume was based on patient body mass index (BMI): 50 mL if BMI <29 kg/m2 and 63 mL if BMI >29 kg/m2. The other 20 patients (group B)-the control cases-received a total of 65 mL of contrast medium (CM), in multiphasic injections at different flow rates, followed by 10 mL of saline. The images that were obtained were prospectively evaluated for image quality, vessel attenuation (HU), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and estimated radiation dose. RESULTS: Image quality of the aortic root and ilio-femoral vessels was diagnostic in all patients. Vascular attenuation was >200 HU and CNR >3 at any vessel level. CONCLUSIONS: Data from this study suggest that a monophasic ultra-low volume contrast-saline mixture injection with a dual-flow technique can provide clear visualisation of the aortic root and ilio-femoral vessels in pre-TAVI CTA, which is comparable with a standard multiphasic volume injection protocol.

Case 305.

HISTORY: A 27-year-old man was admitted to the emergency department with fever and thoracic pain. In the previous 6 months, the patient lost a substantial amount of weight (12 kg). His family history was negative for cardiac disease. Electrocardiography revealed sinus rhythm, and diffuse T-wave inversion. Two-dimensional echocardiography was performed (Fig 1) and revealed normal left systolic function (ejection fraction, 60%). Laboratory tests showed elevated levels of high-sensitivity cardiac troponin (1.07 ng/mL; normal value, <0.015 ng/mL), high levels of C-reactive protein (16 mg/dL; normal range, 0-5 mg/dL), and leukocytosis with an eosinophilia level of 8710/µL (normal level, <400/µL). Parasitic and infectious diseases (Toxocara canis, strongyloides, filariasis, cysticercosis, fasciola, trichinella, echinococcosis) were excluded based on blood and fecal test results. Corticosteroid therapy was started, and the patient was dismissed. A few days later, he was readmitted to the emergency department with a headache and suddenly blurred vision. Neurologic and ophthalmologic findings were normal, and MRI of the brain was performed (Fig 2). Cardiac MRI (Fig 3) was performed 2 days later and revealed the following quantitative results: (a) left ventricular end-diastolic volume (LVDV) of 165 mL (LVDV/body surface area [BSA], 89 mL/m2; normal range, 64-100 mL/m2), left ventricular end-systolic volume (LVSV) of 80 mL (LVSV/BSA, 43 mL/m2; normal range, 17-39 mL/m2); stroke volume (SV) of 85 mL (SV/BSA, 46 mL/m2; normal range, 43-67 mL/m2); and ejection fraction of 52% and (b) right ventricular end-diastolic volume (RVDV) of 163 mL (RVDV/BSA, 88 mL/m2; normal range, 63-111 mL/m2), right ventricular end-systolic volume (RVSV) of 81 mL (RVSV/BSA, 44 mL/m2; normal range, 32-92 mL/m2); stroke volume (SV) of 82 mL (SV/BSA, 44 mL/m2; normal range, 39-71 mL/m2); and ejection fraction of 50%.

Case 305: Loeffler Endocarditis.

HISTORY: A 27-year-old man was admitted to the emergency department with fever and thoracic pain. In the previous 6 months, the patient lost a substantial amount of weight (12 kg). His family history was negative for cardiac disease. Electrocardiography revealed sinus rhythm and diffuse T-wave inversion. Two-dimensional echocardiography was performed and revealed normal left systolic function (ejection fraction, 60%). Laboratory tests showed elevated levels of high-sensitivity cardiac troponin (1.07 ng/mL; normal value, <0.015 ng/mL), high levels of C-reactive protein (16 mg/dL; normal range, 0-5 mg/dL), and leukocytosis with an eosinophilia level of 8710/µL (normal level, <400/µL). Parasitic and infectious diseases (Toxocara canis, strongyloides, filariasis, cysticercosis, fasciola, trichinella, echinococcosis) were excluded based on blood and fecal test results. Corticosteroid therapy was started, and the patient was dismissed. A few days later, he was readmitted to the emergency department with a headache and suddenly blurred vision. Neurologic and ophthalmologic findings were normal, and MRI of the brain was performed. Cardiac MRI was performed 2 days later and revealed the following quantitative results: (a) left ventricular end-diastolic volume (LVDV) of 165 mL (LVDV/body surface area [BSA], 89 mL/m2; normal range, 64-100 mL/m2), left ventricular end-systolic volume (LVSV) of 80 mL (LVSV/BSA, 43 mL/m2; normal range, 17-39 mL/m2), stroke volume (SV) of 85 mL (SV/BSA, 46 mL/m2; normal range, 43-67 mL/m2), and ejection fraction of 52% and (b) right ventricular end-diastolic volume (RVDV) of 163 mL (RVDV/BSA, 88 mL/m2; normal range, 63-111 mL/m2), right ventricular end-systolic volume (RVSV) of 81 mL (RVSV/BSA, 44 mL/m2; normal range, 32-92 mL/m2), stroke volume (SV) of 82 mL (SV/BSA, 44 mL/m2; normal range, 39-71 mL/m2), and ejection fraction of 50%.

Recurrent graft failure secondary to portal vein steal syndrome: a case report with an unusual indication for a third liver transplant.

BACKGROUND: Portal vein shunt is common in chronic hepatic diseases and after a liver transplant. Ensuring a satisfactory portal flow is essential to support a rapid liver recovery, of paramount importance to meet the recipient's metabolic needs. CASE PRESENTATION: We report the case of a 32-year-old female undergoing a third liver transplant due to recurrence of graft failure secondary to portosystemic shunting. The patient, affected with biliary atresia, was first transplanted in 2009 with a right split liver graft. The clinical course was complicated by biliary stenosis of the Roux-en-Y anastomosis and multiple episodes of acute rejection treated with steroid boluses, plastic dilation of the biliary anastomosis, and biliary catheter placement. Unfortunately, in 2017 a liver biopsy showed an autoimmunity with histological evidence of ANA 1:80 (granular and nucleolar pattern). This was a contributing factor of liver function impairment, leading to the need to perform a second liver transplant, complicated by an acute rejection, with only a partial response to steroid therapy. Due to the further worsening of the liver function (MELD: 40, Child-Pugh: C11), the patient was relisted for a liver transplant. After five days, she received her third liver transplant, with an entire graft of an AB0 identical group. Intraoperative exploration revealed multiple collaterals and large splenocaval shunts, with a significant alteration of the portal flow and hypertension, isolated and closed with a vascular stapler to restore the graft's regular portal vein flow. CONCLUSIONS: In patients listed for a liver transplant, portal steal syndrome should be identified prior to the transplant. Our recommendation is to consider intraoperative or perioperative closure of the portal collateral varices.

Acute rejection after lung transplantation: association between histopathological and CT findings.

PURPOSE: To evaluate the predictive role of computed tomography (CT) on acute rejection in patients who underwent lung transplantation (LT). MATERIALS AND METHODS: Seventy-eight patients who underwent LT were evaluated in our study. The CT scans were reviewed by three different radiologists, who evaluated the findings potentially associated with acute rejection such as air trapping, tree-in-bud, consolidations, crazy paving, ground-glass opacity, bronchiectasis, thickening of intralobular or interlobular septa and presence of pleural effusion. The association between a tissue diagnosis of acute rejection and the above-mentioned CT findings was assessed using a multivariate model of logistic regression. RESULTS: Based on our results, none of the CT findings included in the study, alone or in combination, showed significant statistical association with the diagnosis of acute rejection. CONCLUSION: CT is a very useful technique for the assessment of lung transplant recipients although it has limited accuracy for the assessment of acute rejection. None of the radiological findings considered in our study was significantly associated with histologically proven acute rejection.

Intrahepatic mass-forming cholangiocarcinoma: enhancement pattern on Gd-BOPTA-MRI with emphasis of hepatobiliary phase.

PURPOSE: To describe the Gd-BOPTA MRI findings of intrahepatic mass-forming type cholangiocarcinomas (IMCs), with emphasis on the hepatobiliary phase (HBP). METHODS: We reviewed retrospectively 29 IMC patients who underwent Gd-BOPTA-MRI between June, 2004 and June, 2014. Images were acquired prior to, and after, administration of 15-20 mL of Gd-BOPTA in the dynamic phase (arterial phase, portal venous phase, and 3-5 min phase), 10-15-min late phase, and 2-3 h HBP phase. RESULTS: In the dynamic phase, 27 (93%) lesions showed a peripheral rim-like enhancement in the arterial and portal venous phases, followed by progressive filling-in on the delayed images. In 14 (56%) cases, a hypointense peripheral rim was identified in the 10-15-min late phase, delineating a target pattern. In the HBP, the cholangiocarcinoma showed a diffuse, mainly central and inhomogeneous enhancement (cloud of enhancement) in 28 (96%) patients; in 23 (79%) cases, there was an association between cloud appearance and a hypointense peripheral rim, showing a target pattern. CONCLUSIONS: Gd-BOPTA MRI pattern of IMC on dynamic study is similar to that of conventional extracellular agents, that is peripheral enhancement with progressive and concentric filling of contrast material on delayed phases. At 10-15 min delayed phases, IMC shows often a peripheral hypointense rim consistent with a target appearance. In the HBP, due to progressive central enhancement (cloud) and peripheral hypointense rim, an higher number of tumors show a target appearance; this pattern is not specific and would also be expected to be seen in metastases from adenocarcinoma.

Minimally invasive endovascular and biliary treatments of children with acute hepatic artery thrombosis following liver transplantation.

Hepatic artery thrombosis is a major problem after pediatric liver transplantation. Ischemia caused by hepatic artery thrombosis results in severe biliary and parenchymal damage and is associated with high rates of graft loss and mortality. We present a case-based pictorial essay to illustrate the role of minimally invasive treatment in the prompt management of acute hepatic artery thrombosis, and the associated biliary complications.

Imaging of hepatocellular carcinoma recurrence after liver transplantation.

Liver transplantation (LT) provides the highest survival benefit to patients with unresectable hepatocellular carcinoma (HCC). The Milan criteria have been developed for the selection of LT candidates with the goal of improving survival and maintaining an acceptable risk of HCC recurrence. Despite this, recurrence of HCC after LT occurs in up to 20% of cases and represents a major concern due to the poor prognosis of these patients. Furthermore, several extended criteria for the selection of LT candidates have been proposed to account for the growing demand for organs and the resultant increase in the risk of HCC recurrence. Radiologists should be aware that HCC can recur after LT with multiple organ involvement. Knowledge of the location and radiologic appearance of recurrent HCC is necessary to ensure the choice of the most appropriate therapy. This paper aims to comprehensively summarize the spectrum of HCC recurrence after LT and to examine and discuss the imaging features of these lesions. CRITICAL RELEVANCE STATEMENT: This paper aims to share a review of imaging findings of HCC recurrence after LT and to make radiologists familiar with the spectrum of this disease.

Natural course of extrahepatic nonmalignant partial portal vein thrombosis in patients with cirrhosis.

PURPOSE: To define the natural course of extrahepatic nonmalignant partial portal vein thrombosis (PVT), including the progression from partial to complete PVT, in patients with cirrhosis who had undergone multidetector computed tomography (CT). MATERIALS AND METHODS: This study was institutional review board and ethics committee approved. Written informed consent was obtained for each procedure. Forty-two consecutive patients with cirrhosis and untreated extrahepatic, nonmalignant partial PVT were followed up until the final clinical evaluation, liver transplantation, or death. Multidetector CT was used to evaluate the thrombus lumen occlusion, patent lumen area, thrombus area, total lumen area, and diameter of main portal vein, superior mesenteric vein, and splenic vein. Statistical analysis was performed with the Wilcoxon Mann-Whitney U test, χ2 test, Wilcoxon matched-pairs signed-rank test, life-table analysis, Kaplan-Meier method, and log-rank test, as appropriate. RESULTS: After a mean follow-up period of 27 months, partial PVT worsened in 20 (48%) patients, improved in 19 (45%), and was stable in three (7%). The Kaplan-Meier probability of episodes of hepatic decompensation at 1 and 2 years was 41% and 57%; probability of hospital admission for hepatic decompensation, 37% and 54%; and survival rates, 77% and 57%, respectively. There was no clear association between progression or regression of partial PVT and clinical outcome. Multivariate analysis showed that the Child-Pugh score at diagnosis was the only independent predictor of survival (hazard ratio, 1.97; 95% confidence interval: 1.19, 3.23; P=.007) and hepatic decompensation (hazard ratio, 1.51; 95% confidence interval: 1.18, 1.19; P=.001). CONCLUSION: Extrahepatic nonmalignant partial PVT improved spontaneously in 45% of patients with cirrhosis, and the progression of partial PVT was not associated with clinical outcome, which appeared to be dependent on the severity of cirrhosis.

Transjugular intrahepatic portosystemic shunt (TIPS) complications: what diagnostic radiologists should know.

Transjugular intrahepatic portosystemic shunt (TIPS) is an effective therapy for portal hypertension complications and can successfully treat variceal bleeding and refractory ascites. Although TIPS is relatively safe, procedural- or shunt-related morbidity can reach 20%, and procedural complications have a fatality rate of 2%. Delayed recognition and treatment of TIPS complications can lead to life-threatening clinical scenarios. Complications can vary from stent migration or malpositioning to nontarget organ injury, TIPS dysfunction, encephalopathy, or liver failure. This review aims to outline the role of diagnostic radiology in assessing post-TIPS complications.

Changing picture of central nervous system complications in liver transplant recipients.

Central nervous system (CNS) complications are common after liver transplantation (LT). According to the literature, the most common causes are infections and the neurotoxicity of immunosuppressive drugs (cyclosporine and tacrolimus). The aim of this study was to evaluate the incidence, clinical presentations, etiologies, and outcomes of CNS complications in a series of 395 consecutive LT recipients whose immunosuppression regimen was designed for low tacrolimus blood levels. An analysis of the 12-hour trough concentrations of tacrolimus in the study population showed that the target drug levels, which were designed to maintain minimal immunosuppression, were usually achieved. In all, 64 patients (16.2%) developed major neurological symptoms (37 within 30 days of LT). None of the observed CNS complications were caused by infections (viral, bacterial, or fungal), and only 3 of the 395 patients (0.8%) received a diagnosis of tacrolimus-related leukoencephalopathy. Cerebrovascular disease was identified in 15 patients (3.8%; 8 had cerebral hemorrhages, 5 had ischemic strokes, and 2 had subdural hemorrhages). Pontine myelinolysis was found in 2 patients (0.5%). Notably, no clear cause was identified for the remaining 44 cases (11.1%): brain imaging was negative for 22 cases, and diffuse hypoxic changes were present for the other 22. CNS complications were significantly associated with a reduction in 3-month patient survival (88.8% versus 95.4%) and 5-year patient survival (57.3% versus 84.1%). Among the pretransplant variables that were analyzed, the incidence of portosystemic encephalopathy, the peak serum bilirubin levels, and the lowest serum total cholesterol levels were significantly different between the 64-patient group with CNS complications and the asymptomatic group of 331 patients.

Thoracic complications following lung transplantation: 64-MDCT findings.

The aim of this review is to present the wide spectrum of common and uncommon thoracic complications that can affect the lung after transplantation. These complications were analyzed using 64 multi-detector row helical CT (MDCT). Sixty-four MDCT techniques and parameters are illustrated. Correlations of imaging findings and pathologic and histologic specimens obtained by transbronchial biopsy and broncoalveolar lavage are illustrated in representative cases.

Biliary cystadenoma with bile duct communication depicted on liver-specific contrast agent-enhanced MRI in a child.

Biliary cystadenoma is a benign, but potentially malignant, cystic neoplasm of the biliary ducts occurring most commonly in middle-aged females and very rarely in children. We present a 9-year-old boy with biliary cystadenoma, diagnosed by MRI using a new liver-specific contrast agent (gadoxetic acid) that is eliminated by the biliary system. The images clearly demonstrate the communication between the multiloculated cystic mass and the biliary tree, suggesting the possibility of biliary cystadenoma. Due to the malignant potential of a cystadenoma, the lesion was resected. The resection was complete and the postoperative course was uneventful.

Imaging of calcified hepatic lesions: spectrum of diseases.

Hepatic calcifications have been increasingly identified over the past decade due to the widespread use of high-resolution Computed Tomography (CT) imaging. Calcifications can be seen in a vast spectrum of common and uncommon diseases, from benign to malignant, including cystic lesions, solid neoplastic masses, and inflammatory focal lesions. The purpose of this paper is to present an updated review of CT imaging findings of a wide range of calcified hepatic focal lesions, which can help radiologists to narrow the differential diagnosis.

Multidetector-row computed tomography (MDCT) for the diagnosis of hepatocellular carcinoma in cirrhotic candidates for liver transplantation: prevalence of radiological vascular patterns and histological correlation with liver explants.

AIM: To define the prevalence of different multidetector-row computed tomography (MDCT) vascular patterns and their histopathological correlation with liver explants, and to evaluate the accuracy of MDCT for the diagnosis of hepatocellular carcinoma (HCC). METHODS: We retrospectively reviewed 125 cirrhotic patients imaged by MDCT before liver transplantation. Three main vascular patterns were identified: hypervascular lesion with washout (Hyper-L-Wo), hypervascular lesion without washout (Hyper-L) and non-hypervascular lesion (Hypo-L). Radiological findings were matched with histopathology of explants. RESULTS: Positive predictive value (PPV) and likelihood ratio (LR) were 95% and 18.66, respectively, for Hyper-L-Wo; 45% and 0.82 for Hyper-L; and 75% and 3 for Hypo-L of 20 mm or larger. Overall accuracy of MDCT for detection and characterisation of HCC was 89% and 43%, respectively. Sensitivity of MDCT for detection and characterisation was related to the lesion size, ranging from 78% (lesion smaller than 10 mm) to 98% (larger than 20 mm) and from 9% to 64%, respectively. MDCT established the accurate stage of disease in 46% of the patients, underestimated in 52% and overestimated in 2%. CONCLUSION: In cirrhotic patients, any Hyper-L-Wo detected by MDCT can be confidently considered to be HCC. Hyper-L larger than 10 mm and Hypo-L of 20 mm or larger are at high risk of HCC. However, even using MDCT and the newest imaging protocols, imaging underestimated the diagnosis of small HCC.

Diffuse liver diseases in neonatal and pediatric liver transplant candidates: a pictorial essay.

A wide spectrum of common and uncommon diffuse liver diseases affecting neonatal and pediatric liver transplant candidates is presented and analyzed using 16 and 64 multi-detector row helical CT (MDCT) and 1.5 T MRI fast imaging. Correlation of imaging findings and explanted liver or histology is illustrated in representative cases. Associated uncommon congenital anomalies are shown. In conclusion, in pediatric liver transplant candidates, 16-MDCT and 1.5 T fast MRI are useful for diagnosis and staging of liver disease, as well as for the evaluation of associated congenital anomalies.

Focal liver diseases in neonatal and pediatric liver transplant candidates: a pictorial essay.

The aim of this review is to present the wide spectrum of common and uncommon focal liver diseases affecting neonatal and pediatric liver transplant candidates, analyzed using ultrasonography (US), 16- or 64-multidetector row helical CT (MDCT) and 1.5-T magnetic resonance (MR) fast imaging. Correlation of imaging findings and explanted liver or histology is illustrated in representative cases. Associated uncommon congenital anomalies are shown.