Air microbubbles as MR susceptibility contrast agent at 1.5 Tesla.

Air microbubbles have been investigated recently at high magnetic field strength (2 Tesla or greater) as potential MR susceptibility contrast agents. We used a phantom to measure their susceptibility at 1.5 T to clarify their usefulness for this purpose. The phantom, filled with fresh Levovist suspension at 4 different doses (67 to 125 mg/mL), was continuously scanned with a gradient-echo technique at a temporal resolution of 10 s. The transverse relaxation increase (R2*) by microbubbles demonstrated a time course of exponential decay at each dose (time-constant, 39 to 57 s). The dependency of R2* on microbubble volume fraction was linear, with a slope of 89 s-1 per percentage microbubble volume fraction. Our study represents the first step towards applying microbubbles as susceptibility contrast agents at 1.5 T.     

Utility of high-resolution computed tomography for predicting risk of sputum smear-negative pulmonary tuberculosis

Background

To diagnose sputum smear-negative pulmonary tuberculosis (PTB) is difficult and the ability of high-resolution computed tomography (HRCT) for diagnosing PTB has remained unclear in the sputum smear-negative setting. We retrospectively investigated whether or not this imaging modality can predict risk for sputum smear-negative PTB.

Methods

We used HRCT to examine the findings of 116 patients with suspected PTB despite negative sputum smears for acid-fast bacilli (AFB). We investigated their clinical features and HRCT-findings to predict the risk for PTB by multivariate analysis and a combination of HRCT findings by stepwise regression analysis. We then designed provisional HRCT diagnostic criteria based on these results to rank the risk of PTB and blinded observers assessed the validity and reliability of these criteria.

Results

A positive tuberculin skin test alone among clinical laboratory findings was significantly associated with an increase of risk of PTB. Multivariate regression analysis showed that large nodules, tree-in-bud appearance, lobular consolidation and the main lesion being located in S1, S2, and S6 were significantly associated with an increased risk of PTB. Stepwise regression analysis showed that coexistence of the above 4 factors was most significantly associated with an increase in the risk for PTB. Ranking of the results using our HRCT diagnostic criteria by blinded observers revealed good utility and agreement for predicting PTB risk.

Conclusions

Even in the sputum smear-negative setting, HRCT can predict the risk of PTB with good reproducibility and can select patients having a high probability of PTB.     

Indications for curative resection of advanced gallbladder cancer with hepatoduodenal ligament invasion

Abstract. Purpose: Hepatoduodenal ligament invasion (HLI) is an inhibiting factor for the curative resection of advanced gallbladder cancer. The aim of this study was to clarify the indications for surgical resection in patients with advanced gallbladder cancer with and without HLI by analyzing outcomes. Methods: The subjects were 58 patients with advanced gallbladder cancer who underwent aggressive resection, and 20 nonresected patients diagnosed as haring HLI. The presence of stromal cancerous infiltration at six sites in the hepatoduodenal ligament was investigated. The extent of cancer spread was classified into two grades by the number of sites where cancer cells detected: low grade, one or two invasion sites; high grade, three or more sites. Results: Pancreatoduodenectomy, vascular reconstruction, and extensive hepatectomy were frequently performed in the patients with HLI. The cumulative 5-year-survival rate of the HLI patients was 10.9%, significantly worse than that of the resected patients without HLI (46.6%; P < 0.01). Patients with paraaortic lymph node metastasis died within 1 year. The cumulative 5-year-survival rate after curative resection was 38.1%, significantly better than that after noncurative resection (0%; P < 0.05). The survival was significantly worse in patients with high-grade invasion than in these with low-grade invasion (P < 0.05), being equivalent to that in the nonresection patients. Of four factors, operative curability, hepatic lobectomy, HLI grade, and paraaortic lymph node metastasis, the HLI grade and hepatic lobectomy were considered to be significant prognostic factors by Cox's multivariate analysis (backward stepwise method). Conclusions: Aggressive surgical resection for curative purposes should be limited to patients with low-grade HLI and metastasis-negative paraaortic lymph nodes. Received: January 9, 2001 / Accepted: May 11, 2001     

Negative Impact of Blood Transfusion on Recurrence and Prognosis of Hepatocellular Carcinoma After Hepatic Resection

Background  In perioperative management of hepatic resection for hepatocellular carcinoma, excessive blood loss and blood transfusion greatly influence postoperative complications and prognosis of the patients. We evaluated the influence of blood products use on postoperative recurrence and prognosis of patients with hepatocellular carcinoma. Methods  The subjects were 66 patients who underwent elective hepatic resection for hepatocellular carcinoma without concomitant microwave or radiofrequency ablation therapy nor other malignancies between January 2001 and June 2006. We retrospectively investigated the influence of the use of blood products including red cell concentration and fresh frozen plasma on recurrence of hepatocellular carcinoma and overall survival. Results  In multivariate analysis, the dose of blood products transfusion was a significant predictor of disease-free and overall survival. Both disease-free and overall survival rates of those who were given blood products were significantly worse than those who did not receive. On the other hand, in univariate analysis of disease-free and overall survival after hepatic resection and clinical variables, the amount of blood loss was not a significant predictor of recurrence or death. Conclusion  Transfusion of blood products is associated with increased recurrence rate and worse survival after elective hepatic resection for patients with hepatocellular carcinoma.     

Totally laparoscopic colectomy with intracorporeal anastomosis achieved using a laparoscopic linear stapler: experience of a single institute

Purpose  

Laparoscopic colonic surgery is now widely accepted. We assessed the safety and effectiveness of using a total intracorporeal surgical strategy to perform intracorporeal functional end-to-end anastomosis with an endoscopic linear stapler to treat colon cancer.