Yasuo Naitoh

Intraductal ultrasonography in diagnosing tumor extension of cancer of the papilla of Vater

BACKGROUND Intraductal ultrasonography is clinically useful in assessing various pancreatobiliary diseases. This study was carried out to evaluate the usefulness of intraductal ultrasonography in diagnosing tumor extension of cancer of the papilla of Vater. METHODS Thirty-two patients with cancer underwent intraductal ultrasonography. According to the spatial relationship between the tumor echo and the hypoechoic layers representing Oddis muscle layer or the duodenal muscularis propria layer, the images were classified into four grades. We attempted to diagnose tumor extension using this grading system. Lymph nodes measuring over 10 mm were evaluated as involved. Findings were compared with postoperative histopathologic findings classified as follows: d0, tumor limited to Oddis muscle layer; d1, tumor invading the duodenal submucosal layer; d2, tumor invading the duodenal muscularis propria layer; and panc(+), tumor invading the pancreas. RESULTS Diagnostic accuracy rate was 100% (6 of 6) in d0 cases, 92.3% (12 of 13) in d1 cases, 100% (1 of 1) in a d2 case, and 75% (9 of 12) in panc(+) cases. Overall accuracy rate was 87.5% (28 of 32). In assessing lymph node metastases, sensitivity was 66.7% (6 of 9) and specificity was 91.3% (21 of 23). CONCLUSION Intraductal ultrasonography examination is useful in diagnosing tumor extension of cancer of the papilla of Vater.

New technique using intraductal ultrasonography for the diagnosis of bile duct cancer

We investigated the extent to which BDca can be visualized and diagnosed via a percutaneous fistula using IDUS. IDUS was performed in 42 cases, including 15 of normal bile ducts; 12 of choledocholithiasis, and 15 of BDca. The depth of invasion of the BDca was diagnosed with a 93% accuracy rate by visualizing the EP or MA or both. The infiltration of BDca into the surrounding organs was clearly visualized and diagnosed with an accuracy of 100% in the RHA, 93% in the PV, and 93% in the pancreas. These accuracy rates were higher than those obtained by computed tomography or angiography. We believe, therefore, that IDUS should be further studied as a diagnostic modality for staging malignancy in the biliary field.

New technique using intraductal ultrasonography for the diagnosis of diseases of the pancreatobiliary system.

Intraductal ultrasonography (IDUS), a new technique for visualizing arterial structures, operates at an ultrasound frequency of 30 MHz to produce high resolution, cross‐sectional images in real time. The purpose of this study was to provide a basis for interpreting IDUS images in vitro. We also attempted to determine the clinical usefulness of the IDUS system in diagnosing pancreatobiliary diseases in vivo. IDUS echograms of both the bile duct (BD) and main pancreatic duct (MPD) from autopsy specimens of 15 patients demonstrated three distinct layers with a fine reticular pattern in the pancreas in vitro. In clinical cases, the MPD and BD of four patients could be scanned by inserting the IDUS catheter via the major papilla without requiring endoscopic sphincterotomy. We hope that IDUS will become routine in scanning the BD and MPD to achieve early and accurate diagnoses of pancreatobiliary diseases.

Endoscopic ultrasonography in diagnosis of the extent of gallbladder carcinoma.

Endoscopic ultrasonography (EUS) was performed preoperatively in 39 patients with gallbladder carcinoma. Diagnosis of the anatomical extent of gallbladder carcinoma was compared with histologic analysis, and staging accuracy was evaluated according to the TNM classification. Carcinoma considered to be at an early stage with no lymph node metastasis was correctly diagnosed in 87.5%. Differential diagnosis between early and advanced staged tumors was possible in 79.5%. Overall accuracy for depth of tumor invasion (T) was 76.9%. Limitations were due to many stones in the gallbladder and microinfiltration of carcinoma. Assessment of regional lymph node metastasis (N) was at a sensitivity of 81.8% and specificity of 92.9%, for an overall accuracy of 89.7%. We believe endoscopic ultrasonography is useful in the clinical staging of gallbladder carcinoma.

Contrast-enhanced endoscopic ultrasonography in gallbladder diseases

BACKGROUND The purpose of this study was to investigate the usefulness of contrast-enhanced endoscopic ultrasonography in gallbladder diseases. METHODS Subjects were 38 patients including 12 with adenocarcinoma, 2 adenosquamous carcinoma, 6 cholesterol polyp, 10 cholecystitis, and 8 adenomyomatosis. After endoscopic ultrasonography, sonicated albumin was intravenously injected and the enhanced effect on images of these lesions was determined. For malignancies we compared diagnostic accuracy (T factor, TNM classification) of endoscopic ultrasonography and contrast-enhanced endoscopic ultrasonography. Vascularity as shown by contrast-enhanced endoscopic ultrasonography and angiograms was compared. RESULTS Enhancement was observed in 11 patients with adenocarcinoma but not of those with adenosquamous carcinoma or cholesterol polyp. Angiography provided hypervascular images for all cases of adenocarcinoma, but all other lesions were hypovascular. In one case of adenocarcinoma, 3 cases of adenomyomatosis, and 8 cases of cholecystitis, there was a discrepancy between contrast-enhanced endoscopic ultrasonography images and angiograms with regard to vascularity. The accuracy of depth of tumor invasion for endoscopic ultrasonography was 78.6% (11 of 14) versus 92.9% (13 of 14) for contrast-enhanced endoscopic ultrasonography. CONCLUSION Contrast-enhanced endoscopic ultrasonography is useful in the diagnosis of gallbladder lesions.

Differential diagnosis of pancreatic diseases with an intraductal ultrasound system

Forty patients with pancreatic diseases (11 cancer, 1 islet cell tumor, 12 mucin-producing tumor, 1 teratoma, and 15 chronic pancreatitis) were studied in vivo with ERP and were also scanned with an intraductal ultrasound (IDUS) probe at a frequency of 30 MHz inserted into the main pancreatic duct. The usefulness of in vivo IDUS was evaluated by comparison of images with the ERP findings. IDUS was of diagnostic value in 18 of the 40 patients; it distinguished between 4 malignant and 6 benign causes of localized stenosis revealed by ERP, provided parenchymal information in 2 cases with only displacement revealed by ERP (1 islet cell tumor and 1 teratoma), and determined the extent of tumor in 6 cases with main-duct-type mucin-producing tumor. Ten of 11 cancer, 4 of 12 mucin-producing tumor, 1 islet cell tumor, and 11 of 15 chronic pancreatitis (previously scanned in vivo), and 2 islet cell tumor (not scanned in vivo), were resected and scanned in vitro. Fifteen normal pancreases from autopsy subjects were also scanned in vitro. The IDUS images were then compared with corresponding histopathological sections from the 15 normal pancreases and 28 post-operative pancreatic specimens. Differential diagnosis of the pancreatic diseases by echo patterns was possible in all cases except those with intraductal papillary adenocarcinoma and adenoma.

Endoscopic ultrasonography in the diagnosis of depth invasion and lymph node metastasis of carcinoma of the papilla of Vater.

To evaluate diagnostic accuracy of endoscopic ultrasonography (EUS) on the extent of carcinoma of the papilla of Vater, 28 patients were preoperatively evaluated using our EUS grading system. EUS was accurate in diagnosing carcinoma infiltration into the duodenal proper muscle layer (100%) and into the pancreas (75%). When compared with postoperative histologic findings, the overall accuracy of EUS in assessing local infiltration was 89.3%. Misdiagnoses occurred in three cases due to microinfiltration of the carcinoma. Lymph node metastasis around the pancreatic head was accurately diagnosed in nine cases; however, mesenteric lymph node metastasis could not be detected in four cases because the tumor was far from the scanning site.

Diagnosis of mucin-producing tumor of the pancreas with an intraductal ultrasonographic system

The purpose of this study is to examine the usefulness of intraductal ultrasonography at a frequency of 20 or 30 MHz in the diagnosis of mucin‐producing tumor. The subjects were 66 patients with mucin‐producing tumor (10 with main pancreatic duct type tumor and 56 with branch type tumor) who had also undergone endoscopic ultrasonography. In main pancreatic duct type tumors, we could diagnose the extent of the tumor and evaluate the invasion of the tumor into the pancreatic parenchyma in all seven patients who had undergone resection (three invasive tumors, four noninvasive tumors). Sixteen of 32 resected branch type tumors showing mural nodules with intraductal sonography were carcinoma or adenoma. On comparing intraductal and endoscopic ultrasonography in the rate of detecting nodules, in five tumors (one carcinoma and four adenomas), nodules were detected only with intraductal ultrasonography. In conclusion, intraductal ultrasonography is very useful for the diagnosis in the main pancreatic duct type tumor and in the detection of mural nodules in the branch type tumor.

Intraductal ultrasonography for the examination of duodenal papillary region.

The purpose of this study was to provide basic criteria for interpreting images of the normal duodenal papillary region obtained by intraductal ultrasonography at the frequency of 20 MHz. Our in vitro examination of autopsy specimens from 15 patients revealed that the images could be classified into three patterns according to the spatial relationships between the duodenal muscularis propria and the bile duct, or the common duct. Oddis muscle was clearly demonstrated surrounding the mucosa of the bile duct or the common duct, which was visualized as a hypoechoic layer. The images obtained using in vivo examination of 60 patients with pancreato‐biliary disease via either the percutaneous or the peroral approach were similar to the images obtained in vitro. In eight patients with cancer of the papilla of Vater, the tumor was demonstrated clearly on intraductal sonograms. The intraductal imaging features of the normal papillary region were clarified, and the clinical usefulness of this technique in the evaluation of the tumor extent in patients with cancer of the papilla of Vater is suggested.

Differential diagnosis of gall-bladder masses using colour Doppler ultrasonography

To evaluate the diagnostic accuracy of colour Doppler ultrasonography in the differential diagnosis of gall‐bladder lesions, we studied colour Doppler flow imaging of gall‐bladder masses in 75 patients with gall‐bladder masses, including 26 patients with cancer, 18 with benign polyps, 10 with adenomyomatosis and 21 with pseudo‐tumorous sludge and 28 healthy subjects as controls. The presence of a colour signal, pattern of the colour signal, blood flow velocity and resistive index (RI) within lesions were assessed using colour Doppler ultrasonography. In cancerous lesions, the colour signal pattern was diffuse or arborizing (sensitivity 90.5% (19/21); specificity 62.5% (10/16)) and the velocity and RI were (mean ± s.d.) 39.0 ± 12.4 cm/s and 0.62 ± 0.12, respectively, which was significantly different (P< 0.01) compared with controls (11.4 ± 2.5 and 0.75 ± 0.03, respectively). The colour signal pattern obtained from polyps was linear at their base in 62.5% (10/16) of cases, but the velocity (13.6 ± 5.5) and RI (0.74 ± 0.08) did not differ from those of the controls. Lesions other than cancer and polyp had no colour signal. There were overlaps in the values of velocity and RI between malignant and benign lesions. When 20 cm/s for velocity and 0.65 for RI were used as the respective cut‐off values, the sensitivity and specificity of this method in the diagnosis of malignant lesions was 95.2% (20/21) and 87.5% (14/16) for velocity and 66.7% (14/21) and 87.5% (14/16) for RI, respectively. In a prospective study consisting of 10 patients with cancer and 21 patients with polyps, the sensitivity and specificity were 90 and 66.7% for the colour signal, 100 and 100% for velocity and 80 and 90.4% for RI, respectively. In conclusion, colour Doppler ultrasonography can be useful in the diagnosis of gallbladder masses in combination with conventional ultrasonographic findings of gall‐bladder masses, especially in the differentiation of cancers from benign lesions.