Katsuhiro Uchiyama

Relationship between CT findings of pulmonary tuberculosis and the number of acid-fast bacilli on sputum smears.

PURPOSE To investigate the relationship between computed tomography (CT) findings in patients with active pulmonary tuberculosis (PTB) and the number of acid-fast bacilli (AFB) on sputum smears. METHODS We reviewed CT scans of 173 patients with active PTB. The patients were divided into groups according to the number of AFB on sputum smears as follows: A, negative (n = 40); B, doubtful (n = 21); C, + (n = 34); and D, ++ or greater (n = 78). The presence or absence and the number of lobes that included micronodules, nodules, consolidation and cavitation, the number of cavities and the maximum diameter of the cavity lumen were noted. RESULTS The frequency of micronodules and nodules did not significantly differ among the four groups. In contrast, the frequency of consolidation and cavitation increased with the number of AFB (P < .0001). Differences in the number of lobes involving micronodules, nodules, consolidation and cavitation were significant between Group D and the other groups (P < .0001), but not between Groups A or B and C. The number and maximum size of cavities significantly differed between Group D and the other groups (P < .0001). CONCLUSIONS CT findings correlated with the number of AFB in sputum smears to some extent. However, CT findings do not reliably discriminate between smear-negative patients and those with very few AFB excreting smear-positive patients.

Pancreatic enzyme activity after a pylorus-preserving pancreaticoduodenectomy reconstructed with pancreaticogastrostomy

This study was initiated to clarify whether the main hydrolytic enzymes of the pancreas are activated or inactivated when secreted into the stomach of patients who had undergone a pylorus-preserving pancreaticoduodenectomy (PPPD) and were given a pancreaticogastrostomy (PG) for the reconstruction. Seventeen such patients, 15 cancer patients and two pancreatitis patients, who underwent PPPD-PG reconstruction were postoperatively followed up for 3 or more years to investigate the influence of the gastric acid on the p-type amylase and lipase activity. Results revealed that when the pH was <3.0, both the p-type amylase and the lipase secretion remained inactivated, but when the pH was >3.1, the activity of both enzymes increased proportionately. The pancreatic enzyme activity in the small intestine was also investigated in seven patients, six cancer cases and one case of pancreatitis, given a PPPD-PG reconstruction, and it was found that the pancreatic enzyme activity in the small intestine increased after milk loading. Further, the fecal pancreatic enzyme activity was investigated in 17 patients given a PPPD-PG reconstruction. Results reveal that the fecal p-type amylase, lipase, and chymotrypsin activity amounted to 21, 27, and 31% of the respective values seen in 10 healthy volunteers. However, the fecal pancreatic enzyme activity levels did not differ significantly from the levels seen in 20 pancreaticoduodenectomy patients given a pancreaticojejunostomy reconstruction. In conclusion, it was found that the main hydrolytic enzymes of the pancreas are activated when the gastric acidity is over pH 3.I, which normally occurs after ingestion of a meal.

Effect of the rate of gadolinium injection on magnetic resonance pulmonary perfusion imaging

To determine whether the injection rate of contrast agent affects the dynamics of enhancement of the pulmonary parenchyma on magnetic resonance (MR) pulmonary perfusion imaging.

Detectability of pulmonary perfusion defect and influence of breath holding on contrast-enhanced thick-slice 2D and on 3D MR pulmonary perfusion images †

The present study assesses the detectability of perfusion defect and the influence of breathhold on pulmonary magnetic resonance (MR) perfusion imaging using contrast‐enhanced thick‐slice two‐dimensional (2D) fast gradient‐echo sequence compared with three‐dimensional (3D) fast spoiled gradient‐recalled sequence. Dynamic studies were performed in 16 patients. MR perfusion images were interpreted by two independent observers using perfusion scintigraphy as the reference standard. The patients were divided into two groups according to the duration of holding the breath measured during MR imaging. The sensitivity and specificity of 2D MR perfusion imaging in detecting perfusion defects were 93% and 94%, respectively, while those of 3D MR perfusion imaging were 89% and 85%, respectively. The diagnostic accuracy of 2D MR perfusion imaging was significantly higher than that of 3D MR perfusion imaging (P < 0.05) among those who could not hold their breath. Therefore, 2D MR perfusion imaging offers promise for evaluating pulmonary perfusion even among patients who cannot hold their breath. J. Magn. Reson. Imaging 2001;14:580–585.

A proposed new pancreatic classification system according to segments: Operative procedure for a medial pancreatic segmentectomy

Based on anatomical considerations and our experience in performing segmental resections of the pancreas, we propose here a new pancreatic classification system that divides the pancreas into four segments: posterior, proximal, medial, and distal. We also describe the operative procedures for medial pancreatic segmentectomy, carried out in two patients. Under this new classification system, based on the clinical position of these pancreatic segments, the embryologically termed ventral pancreas is now retermed the posterior segment, while the dorsal pancreas is divided into three segments, termed: the proximal segment (the duodenum-sided segment of the dorsal pancreas that connects with the posterior pancreas), the medial segment (the segment that corresponds with the pancreatic neck), and the distal segment (the area from the left border of the superior mesenteric artery to the hilum of the spleen). Although this division of the pancreas into four segments is a new concept, the development of new and better operative procedures that enable the resection of each pancreatic segment independently has made this concept not only valuable but clinically practical.

Dual-time point scanning of integrated FDG PET/CT for the evaluation of mediastinal and hilar lymph nodes in non-small cell lung cancer diagnosed as operable by contrast-enhanced CT

PURPOSE To evaluate whether dual-time point scanning with integrated fluorine-18 fluorodeoxyglucose ((18)F-FDG) positron emission tomography and computed tomography (PET/CT) is useful for evaluation of mediastinal and hilar lymph nodes in non-small cell lung cancer diagnosed as operable by contrast-enhanced CT. MATERIALS AND METHODS PET/CT data and pathological findings of 560 nodal stations in 129 patients with pathologically proven non-small cell lung cancer diagnosed as operable by contrast-enhanced CT were reviewed retrospectively. Standardized uptake values (SUVs) on early scans (SUVe) 1h, and on delayed scans (SUVd) 2h after FDG injection of each nodal station were measured. Retention index (RI) (%) was calculated by subtracting SUVe from SUVd and dividing by SUVe. Logistic regression analysis was performed with seven kinds of models, consisting of (1) SUVe, (2) SUVd, (3) RI, (4) SUVe and SUVd, (5) SUVe and RI, (6) SUVd and RI, and (7) SUVe, SUVd and RI. The seven derived models were compared by receiver-operating characteristic (ROC) analysis. k-Fold cross-validation was performed with k values of 5 and 10. p<0.05 was considered statistically significant. RESULTS Model (1) including the term of SUVe showed the largest area under the ROC curve among the seven models. The cut-off probability of metastasis of 3.5% with SUVe of 2.5 revealed a sensitivity of 78% and a specificity of 81% on ROC analysis, and approximately 60% and 80% on k-fold cross-validation. CONCLUSION Single scanning of PET/CT is sufficiently useful for evaluating mediastinal and hilar nodes for metastasis.

Temporary Percutaneous Aortic Balloon Occlusion to Enhance Fluid Resuscitation Prior to Definitive Embolization of Post-Traumatic Liver Hemorrhage

We successfully stabilized severe hemorrhagic shock following traumatic liver injury by percutaneous transcarotid supraceliac aortic occlusion with a 5 Fr balloon catheter. Then we were able to perform transfemoral embolization therapy of the hepatic arterial bleeding source. Transient aortic occlusion using a balloon catheter appears to be a useful adjunct in select cases where stabilization of the patient is necessary to allow successful selective embolization of the bleeding source.

Indications for the choledochoscopic removal of intrahepatic stones based on the biliary anatomy

BACKGROUND Choledochoscopic treatment has been used primarily to remove intrahepatic stones. However, failure in removing such stones can occasionally occur, resulting in the need for additional surgery. The aim of this study was to clarify the clinical indications and limitations of choledocoscopic treatment for the removal of intrahepatic stones. METHODS A review of the records of 86 patients treated for intrahepatic stones between April 1974 and December 1993 formed the basis of this study. These patients were evaluated based on their bile-duct findings (no strictures, mild strictures, or severe strictures), the site of the stones (left hepatic lobe, right hepatic lobe, and the bilateral lobes), and the presence of variations in the posterior segmental bile-duct drainage. RESULTS Complete removal of stones was achieved in 59 patients (69%). Further, choledochoscopic removal was mainly successful in patients with no strictures or, to a lesser degree, with mild strictures; whereas stone removal was impossible in all patients (19) with severe strictures (P < 0.0001). As for the site of the stones, no statistical differences were seen among the three groups. Regarding the presence of drainage variations of the segmental bile duct, removal of the stones was more difficult in patients with variations than in those without variations (P < 0.01). With respect to long-term clinical outcomes, of the 59 successful patients, only 2 (3%) developed recurring stones. CONCLUSION Based on these findings, choledochoscopic treatment should be indicated for patients who have no, or only mild, bile-duct strictures and who mainifest normal segmental bile-duct drainage.

Complete duodenum-preserving resection of the head of the pancreas with preservation of the biliary tract

A complete resection of the head of the pancreas, with preservation of the duodenum and biliary tract was performed for 14 patients: 8 with chronic pancreatitis, 3 with mucin-producing cancer of the head of the pancreas, 2 with pancreas divisum, and 1 with cystadenoma of the head of the pancreas. With our technique, duodenal blood flow is maintained, and no pancreatic parenchyma is left on the duodenal side. For these patients, a pancreaticoduodenostomy without resection of the digestive tract was provided; however, for those in whom an anastomosis between the caudal side of the pancreas and the duodenum was too difficult, due to distance, a pancreaticojejunostomy, using a Roux-en-Y jejunal loop, was performed as an alternative method. The digestive tract was reconstructed by a pancreaticoduodenostomy in 8 patients and by a pancreaticojejunostomy in the remaining 6. The operation time for the former procedure was 5h, and for the latter, 5h and 40 min; the mean blood loss in both groups was similar, being 926 and 940 ml, respectively. The successful results in all cases indicate that maintenance of the duodenal blood flow is significantly related to complete resection of the head of the pancreas. Thus, it appears that the use of Kochers maneuver should be avoided and that the preservation of the posterior superior pancreaticoduodenal artery is important.

Choledochoscopy during biliary surgery for reducing the risk of overlooked stones

SummaryAlthough cholangiography is routinely performed during biliary surgery to ensure the removal of all stones, it is not always successful. Some investigators have claimed that intraoperative choledochoscopy is more effective in detecting all stones, although reports on the efficacy of this method have been contradictory. Furthermore, no study has systematically examined either of these procedures in terms of the actual incidence of overlooked stones. Thus, to evaluate the merits of intraoperative cholangiography as opposed to choledochoscopy, we studied the incidence of overlooked bile duct stones after surgery. We investigated 126 patients who had undergone surgery during which choledocholithotomy was performed within the past 10 years; 117 of these cases involved common bile duct stones and 22, intrahepatic stones. After the exclusion of 13 subjects whose stones were deliberately left for postoperative treatment due to severe complications, 126 patients were finally analyzed. Overlooked stones were found postoperatively in 13 (10%) of these 126 subjects, including 11 (14%) of 63 patients who had been inspected by intraoperative cholangiography alone and 2 (3%) of 63 who had undergone both choledochoscopy and cholangiography during surgery. Therefore, the incidence of overlooked stones proved to be significantly lower in those who had undergone choledochoscopy combined with cholangiography (P <0.01). Our results suggest the value of combining choledochoscopy with cholangiography during surgery for reducing the risk of overlooked bile duct stones.