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.

Split-Bolus Single-Pass Multidetector-Row CT Protocol for Diagnosis of Acute Pulmonary Embolism.

BACKGROUND: Currently computed tomography pulmonary angiography (CTPA) has become a widely accepted clinical tool in the diagnosis of acute pulmonary embolism (PE). OBJECTIVES: To report split-bolus single-pass 64-multidetector-row CT (MDCT) protocol for diagnosis of PE. PATIENTS AND METHODS: MDCT split-bolus results in 40 patients suspicious of PE were analyzed in terms of image quality of target pulmonary vessels (TPVs) and occurrence and severity of flow-related artifact, flow-related artifact, false filling defect of the pulmonary veins and beam hardening streak artifacts. Dose radiation to patients was calculated. RESULTS: MDCT split-bolus protocol allowed diagnostic images of high quality in all cases. Diagnosis of PE was obtained in 22 of 40 patients. Mean attenuation for target vessels was higher than 250 HU all cases: 361 ± 98 HU in pulmonary artery trunk (PAT); 339 ± 93 HU in right pulmonary artery (RPA); 334 ± 100 HU in left pulmonary artery (LPA). Adequate enhancement was obtained in the right atrium (RA):292 ± 83 HU; right pulmonary vein (RPV): 302 ± 91 HU, and left pulmonary vein (LPV): 291 ± 83 HU. The flow related artifacts and the beam hardening streak artifacts have been detected respectively in 4 and 25 patients. No false filling defect of the pulmonary veins was revealed. CONCLUSION: MDCT split-bolus technique by simultaneous opacification of pulmonary arteries and veins represents an accurate technique for diagnosis of acute PE, removes the false filling defects of the pulmonary veins, and reduces flow related artifacts.

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%.

Detection of small (≤ 2 cm) pancreatic adenocarcinoma and surrounding parenchyma: correlations between enhancement patterns at triphasic MDCT and histologic features.

BACKGROUND: The aim is to assess the time-density curves (TDCs) and correlate the histologic results for small (≤ 2 cm) PDA and surrounding parenchyma at triphasic Multidetector-row CT (MDCT). METHODS: Triphasic MDCT scans of 38 consecutive patients who underwent surgery for a small PDA were retrospectively reviewed. The TDCs were analyzed and compared with histologic examination of the PDA and pancreas upstream/downstream in all cases. Three enhancement patterns were identified: 1) enhancement peak during pancreatic parenchymal phase (PPP) followed by a rapid decline on portal venous phase (PVP) and delayed phase (DP) at 5 minutes (type 1 pattern: normal pancreas); 2) maximum enhancement in PVP that gradually decreases in DP (type 2 pattern: mild chronic pancreatitis or PDA with mild fibrous stroma); 3) progressive enhancement with maximum peak in DP (type 3 pattern: severe chronic pancreatitis or PDA with severe fibrous stroma). A p value less than 0.05 was considered statistically significant. Sensitivity was calculated for PDA detection and an attenuation difference with the surrounding tissue of at least 10 HU was considered. RESULTS: PDA showed type 2 pattern in 5/38 cases (13.2%) and type 3 pattern in 33/38 cases (86,8%). Pancreas upstream to the tumor had type 2 pattern in 20/38 cases (52,6%) and type 3 pattern in 18/38 cases (47,4%). Pancreas downstream to the tumor had type 1 pattern in 19/25 cases (76%) and type 2 pattern in 6/25 cases (24%). Attenuation difference between tumor and parenchyma upstream was higher of 10 UH on PPP in 31/38 patients (sensitivity = 81.6%), on PVP in 29/38 (sensitivity = 76.3%) and on DP in 17/38 (sensitivity = 44.7%). Attenuation difference between tumor and parenchyma downstream was higher of 10 UH on PPP in 25/25 patients (sensitivity = 100%), on PVP in 22/25 (sensitivity = 88%) and on DP in 20/25 (sensitivity = 80%). Small PDAs were isodense to the pancreas upstream to the tumor, and therefore unrecognizable, in 8 cases (8/38; 21%) at qualitative analysis and in 4 cases (4/38; 10,5%) at quantitative analysis. CONCLUSIONS: The quantitative analysis increases the sensitivity for detection of small PDA at triphasic MDCT.

Middle ear metastasis from dormant breast cancer as the initial sign of disseminated disease 20 years after quadrantectomy.

We describe an unusual case of breast cancer metastatic to the middle ear in a 71-year-old woman. The metastasis was the initial sign of disseminated disease 20 years after the patient had undergone a quadrantectomy for her primary disease. Computed tomography (CT) demonstrated the presence of an intratympanic mass with a soft-tissue density that was suggestive of chronic inflammation. The patient underwent a canal-wall-down tympanoplasty. When a brownish mass was found around the ossicles, a mastoidectomy with posterior tympanotomy was carried out. However, exposure of the tumor was insufficient, and therefore the posterior wall of the ear canal had to be removed en bloc. Some tumor was left on the round window membrane so that we would not leave the patient with a total hearing loss. Our case highlights the limitations of CT and magnetic resonance imaging in differentiating inflammatory and neoplastic lesions.

Synchronous primary lung cancer. Critical review of diagnostic criteria.

QUESTION OF THE STUDY: Synchronous primary lung cancers (SPLCs) may pose a radiologic-pathologic and therapeutic dilemma in according to recent WHO classification. PATIENTS AND METHODS: Two cases of surgically treated SPLCs are reported. RESULTS: In the first case two nodules were detected by Computed Tomography (CT) in the upper right lobe. The patient underwent lobectomy and histological diagnosis was adenocarcinoma and squamous cell carcinoma. The second patient presented at CT one nodule in the upper left lobe and another nodule in the upper right lobe. Sternotomic access was chosen for bilateral removal of the lesions. The diagnosis was sarcomatoid carcinoma and large cell neuroendocrine adenocarcinoma. DISCUSSION: The criteria of Martini and Melamed are inadequate for the diagnosis of SPLCs. The use of TTF-1 (thyroid transcription factor-1) is necessary to establish the diagnosis of SPLC in patients with adenocarcinoma of other sites. Bronchioloalveolar carcinomas must be excluded because of their multicentricity. When histology of two tumors found in the same lobe is identical and histotype is adenocarcinoma, large cell carcinoma or sarcomatoid carcinoma, the diagnosis of SPLCs must be excluded and those lesions must be considered as metastatic disease. The prognosis and treatment of SPLCs are discussed after critical review of the literature.