Optimized scan delay for late hepatic arterial or pancreatic parenchymal phase in dynamic contrast-enhanced computed tomography with bolus-tracking method

Objectives:To determine the optimal scan delay corresponding to individual hemodynamic status for pancreatic parenchymal phase in dynamic contrast-enhanced CT of the abdomen.Methods:One hundred and fourteen patients were included in this retrospective study (69 males and 45 females; mean age, 67.9 ± 12.1 years; range, 39–87 years). These patients underwent abdominal dynamic contrast-enhanced CT between November 2019 and May 2020. We calculated and recorded the time from contrast material injection to the bolus-tracking trigger of 100 Hounsfield unit (HU) at the abdominal aorta (s) (Time_TRIG) and scan delay from the bolus-tracking trigger to the initiation of pancreatic parenchymal phase scanning (s) (Time_SD). The scan delay ratio (SDR) was defined by dividing the Time_SD by Time_TRIG. Non-linear regression analysis was conducted to assess the association between CT number of the pancreas and SDR and to reveal the optimal SDR, which was ≥120 HU in pancreatic parenchyma.Results:The non-linear regression analysis showed a significant association between CT number of the pancreas and the SDR (p < 0.001). The mean Time_TRIG and Time_SD were 16.1 s and 16.8 s, respectively. The SDR to peak enhancement of the pancreas (123.5 HU) was 1.00. An SDR between 0.89 and 1.18 shows an appropriate enhancement of the pancreas (≥120 HU).Conclusion:The CT number of the pancreas peaked at an SDR of 1.00, which means Time_SD should be approximately the same as Time_TRIG to obtain appropriate pancreatic parenchymal phase images in dynamic contrast-enhanced CT with bolus-tracking method.Advances in knowledge:The hemodynamic state is different in each patient; therefore, scan delay from the bolus-tracking trigger should also vary based on the time from contrast material injection to the bolus-tracking trigger. This is necessary to obtain appropriate late hepatic arterial or pancreatic parenchymal phase images in dynamic contrast-enhanced CT of the abdomen.     

A randomized controlled trial of radiofrequency ablation with ethanol injection for small hepatocellular carcinoma

BACKGROUND & AIMS: Percutaneous radiofrequency ablation is a recently introduced treatment for hepatocellular carcinoma, whereas ethanol injection is now a standard therapy. We compared their long-term outcomes. METHODS: Two hundred thirty-two patients with hepatocellular carcinoma who had 3 or fewer lesions, each 3 cm or less in diameter, and liver function of Child-Pugh class A or B were entered onto a randomized controlled trial. The primary end point was survival, and the secondary end points were overall recurrence and local tumor progression. RESULTS: One hundred eighteen patients were assigned to radiofrequency ablation and 114 to ethanol injection. The number of treatment sessions was smaller (2.1 times vs 6.4 times, respectively, P < .0001) and the length of hospitalization was shorter (10.8 days vs 26.1 days, respectively, P < .0001) in radiofrequency ablation than in ethanol injection. Four-year survival rate was 74% (95% CI: 65%-84%) in radiofrequency ablation and 57% (95% CI: 45%-71%) in ethanol injection. Radiofrequency ablation had a 46% smaller risk of death (adjusted relative risk, 0.54 [95% CI: 0.33-0.89], P = .02), a 43% smaller risk of overall recurrence (adjusted relative risk 0.57 [95% CI: 0.41-0.80], P = .0009), and an 88% smaller risk of local tumor progression (relative risk, 0.12 [95% CI: 0.03-0.55], P = .006) than ethanol injection. The incidence of adverse events was not different between the 2 therapies. CONCLUSIONS: Judging from higher survival but similar adverse events, radiofrequency ablation is superior to ethanol injection for small hepatocellular carcinoma.     

Chronic active hepatitis with hepatitis B virus DNA and antibody against e antigen in the serum. Disturbed synthesis and secretion of e antigen from hepatocytes due to a point mutation in the precore region

Some patients with type B chronic active hepatitis have a high titer of hepatitis B virus DNA despite antibody against e antigen in the serum. Clones of hepatitis B virus were propagated from the sera of seven patients with this disease, and the precore region was sequenced. Essentially all clones (128/131 or 98%) showed a point mutation from guanine to adenine at nucleotide 83, converting codon 28 for tryptophan (TGG) to a stop codon (TAG); the second guanine-to-adenine point mutation at nucleotide 86 was identified in only 29 clones from two patients. In patients followed up since they had hepatitis B e antigen, a shift from guanine to adenine was observed at nucleotide 83 along with the seroconversion to the antibody to e antigen. The precore-region product is required for the synthesis and secretion of e antigen from hepatocytes. A point mutation from guanine to adenine at nucleotide 83 observed in the seven patients, therefore, would be responsible for disturbed secretion of e antigen.     

Primary leiomyosarcoma of the pulmonary artery: a case of a 20-month survivor after incomplete surgical resection

We report a 53-year-old man who presented with dyspnea and low-grade fever. Cardiac ultrasound showed pulmonary hypertension and an ill-defined echogenic mass within the pulmonary trunk. Computed tomography scan revealed an inhomogeneous mass which filled the main pulmonary trunk with near-total occlusion, and extended into both pulmonary arteries. Anticoagulant therapy was administered based on a presumptive diagnosis of pulmonary thromboembolism. Positron-emission tomography scan was useful for differentiating the mass, which was determined as a pulmonary artery sarcoma by surgical resection. Although complete resection was impossible, the patient survived for 20 months with adjuvant chemotherapy and medical treatment.