Split-Bolus Multidetector-Row Computed Tomography Technique for Characterization of Focal Liver Lesions in Oncologic Patients.

BACKGROUND: In oncologic patients, the liver is the most common target for metastases. An accurate detection and characterization of focal liver lesions in patients with known primary extrahepatic malignancy are essential to define management and prognosis. OBJECTIVES: To assess the diagnostic accuracy of the split-bolus multidetector-row computed tomography (MDCT) protocol in the characterization of focal liver lesions in oncologic patients. PATIENTS AND METHODS: We retrospectively analyzed the follow-up split-bolus 64-detector row CT protocol in 36 oncologic patients to characterize focal liver lesions. The split-bolus MDCT protocol by intravenous injection of two boluses of contrast medium combines the hepatic arterial phase (HAP) and hepatic enhancement during the portal venous phase (PVP) in a single-pass. RESULTS: The split-bolus MDCT protocol detected 208 lesions and characterized 186 (89.4%) of them: typical hemangiomas (n = 9), atypical hemangiomas (n = 3), cysts (n = 78), hypovascular (n = 93) and hypervascular (n = 3) metastases. Twenty two (10.6%) hypodense lesions were categorized as indeterminate (≤5 mm). The mean radiation dose was 24.5±6.5 millisieverts (mSv). CONCLUSION: The designed split-bolus MDCT technique can be proposed alternatively to triphasic MDCT and in a single-pass to PVP in the initial staging and in the follow-up respectively in oncologic patients.

Pancreatic tumors imaging: An update.

Currently, ultrasound (US), computed tomography (CT) and Magnetic Resonance imaging (MRI) represent the mainstay in the evaluation of pancreatic solid and cystic tumors affecting pancreas in 80-85% and 10-15% of the cases respectively. Integration of US, CT or MR imaging is essential for an accurate assessment of pancreatic parenchyma, ducts and adjacent soft tissues in order to detect and to stage the tumor, to differentiate solid from cystic lesions and to establish an appropriate treatment. The purpose of this review is to provide an overview of pancreatic tumors and the role of imaging in their diagnosis and management. In order to a prompt and accurate diagnosis and appropriate management of pancreatic lesions, it is crucial for radiologists to know the key findings of the most frequent tumors of the pancreas and the current role of imaging modalities. A multimodality approach is often helpful. If multidetector-row CT (MDCT) is the preferred initial imaging modality in patients with clinical suspicion for pancreatic cancer, multiparametric MRI provides essential information for the detection and characterization of a wide variety of pancreatic lesions and can be used as a problem-solving tool at diagnosis and during follow-up.

FDG PET and Split-Bolus Multi-Detector Row CT Fusion Imaging in Oncologic Patients: Preliminary Results.

PURPOSE: To assess the incremental value of split-bolus multidetector computed tomography (CT) combined with fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) for follow-up of oncologic patients. MATERIALS AND METHODS: The institutional ethics committee approved the use of this protocol. Thirty-eight oncologic patients who underwent FDG PET/unenhanced multidetector CT and split-bolus multidetector CT for restaging were investigated retrospectively. The split-bolus CT protocol included imaging during the hepatic arterial and portal venous phases in one scan. Software was used for fusion of the independently acquired FDG PET and split-bolus CT data, and fused datasets were compared with FDG PET/unenhanced CT data. The standard of reference for diagnosis of lesions in all patients was a combination of histologic results (if available), clinical results (medical history, physical examination, and laboratory test results), and the results of follow-up imaging (conventional CT, magnetic resonance imaging, and/or ultrasonography) for at least 6 months. Descriptive statistics were used. RESULTS: Fifty-nine true-positive lesions were identified with fused FDG PET/split-bolus CT; 41 were concordant and detected with both split-bolus CT and PET/unenhanced CT, 16 with split-bolus CT only, and two with PET/unenhanced CT. Two different false-positive lesions were identified with PET/unenhanced CT and PET/split-bolus CT. Furthermore, in 20 of 38 (53%) patients, FDG PET/split-bolus CT allowed detection of important additional findings (n = 40) not detected at FDG PET/unenhanced CT. Both the tumor-related findings (n = 13, 32.5%) and the non-tumor-related findings (n = 27, 67.5%) were important to the clinical treatment of these patients. CONCLUSION: Fused FDG PET/split-bolus multidetector CT provides additional information compared with FDG PET/unenhanced multidetector CT in oncologic patients.

Single-phase Whole-body 64-MDCT Split-bolus Protocol for Pediatric Oncology: Diagnostic Efficacy and Dose Radiation.

PURPOSE: To evaluate the image quality and the diagnostic efficacy by single-phase whole-body 64-slice multidetector CT (MDCT) for pediatric oncology. PATIENTS AND METHODS: Chest-abdomen-pelvis CT examinations with single-phase split-bolus technique were evaluated for T: detection and delineation of primary tumor (assessment of the extent of the lesion to neighboring tissues), N: regional lymph nodes and M: distant metastasis. Quality scores (5-point scale) were assessed by two radiologists on parenchymal and vascular enhancement. RESULTS: Accurate TNM staging in term of detection and delineation of primary tumor, regional lymph nodes and distant metastasis was obtained in all cases. On the image quality and severity artifact, the Kappa value for the interobserver agreement measure obtained from the analysis was 0.754, (p<0.001), characterizing a very good agreement between observers. CONCLUSION: Single-pass total body CT split-bolus technique reached the highest overall image quality and an accurate TNM staging in pediatric patients with cancer.

Split-bolus versus triphasic multidetector-row computed tomography technique in the diagnosis of hepatic focal nodular hyperplasia: a case report.

INTRODUCTION: Computed tomography and magnetic resonance imaging are able to demonstrate and to diagnose hepatic focal nodular hyperplasia when a typical pattern of a well-circumscribed lesion with a central scar is present.Our aim is to propose the split-bolus multidetector-row computed tomography technique as an alternative to the conventional triphasic technique in the detection and characterization of focal nodular hyperplasia to reduce the radiation dose to the patient.To the best of our knowledge, this is the first report regarding the application of the split-bolus computed tomography technique in the evaluation of hepatic focal nodular hyperplasia. CASE PRESENTATION: We describe a case of focal nodular hyperplasia of the liver in a 53-year-old Caucasian woman (weight 75Kg) with a colorectal adenocarcinoma histologically confirmed. An innovative split-bolus multidetector-row computed tomography technique was used that, by splitting intravenous contrast material in two boli, combined two phases (hepatic arterial phase and portal venous phase) in a single pass; a delayed (5 minutes) phase was obtained to compare the findings with that of triphasic multidetector-row computed tomography. CONCLUSIONS: Split-bolus multidetector-row computed tomography was able to show the same appearance of the lesion as the triphasic multidetector-row computed tomography technique.This is the first case demonstrating the effectiveness of the split-bolus multidetector-row computed tomography technique in the detection and characterization of focal nodular hyperplasia with a significant reduction in radiation dose to the patient with respect to triphasic multidetector-row computed tomography technique.

Detection and characterization of focal liver lesions by split-bolus multidetector-row CT: diagnostic accuracy and radiation dose in oncologic patients.

AIM: To assess the diagnostic accuracy and radiation dose of split-bolus multidetector-row computed tomography (MDCT) protocol in the detection and characterization of focal liver lesions in oncologic patients. PATIENTS AND METHODS: We retrospectively analyzed triphasic CT at initial diagnosis and follow-up split-bolus 64-detector row CT protocol in 48 oncologic patients with focal liver lesions. Split-bolus MDCT protocol by i.v. injection of two boli of contrast medium combines hepatic arterial phase (HAP) and hepatic enhancement during portal venous phase (PVP) in a single pass. First bolus: 75-90 mL at 2.0 mL/sec to obtain adequate hepatic enhancement during the PVP; second bolus: 60 mL/sec at 3.5 mL/sec to ensure HAP. Each bolus is followed by 20 mL of saline solution at the same flow rate. Sensitivity, specificity, positive predictive value and negative predictive value of split-bolus MDCT protocol were calculated for detection and characterization of liver lesions. The effective radiation dose (ED) was calculated using dose-length product (DLP) values in mSv determined using a conversion factor. RESULTS: compared to triphasic-MDCT, split-bolus MDCT protocol confirmed all the 210 lesions identified and characterized by triphasic-MDCT technique, unchanged during the follow-up. The mean ED was 27.8 ± 6 mSv for chest-abdomen-pelvis biphasic split-bolus MDCT and 45.7 ± 13.6 mSv for triphasic-MDCT. CONCLUSION: The diagnostic efficacy of split-bolus protocol is comparable to that of triphasic protocol at MDCT with a reduction in radiation dose of approximately 35-40%.