Improvement in imaging time and quality of 3D negative-contrast computed tomography cholangiography with minimum intensity projections: application of vari-slice manual cut and erosion functions

doi:10.1016/j.clinimag.2008.09.010

Clinical Imaging

Volume 33, Issue 3, May–June 2009, Pages 213-220

https://doi.org/10.1016/j.clinimag.2008.09.010 Get rights and content

Abstract

Objective

To investigate the improvement in postprocessing time and image quality of 3D negative-contrast CT cholangiography (nCTC) with minimum intensity projection (minIP).

Methods

Thirty-eight patients with suspected biliary obstruction who underwent portal phase helical CT were retrospectively studied. Three-dimensional nCTC was generated using 3D tools with manual cut function in three methods: one-slice, two-slice, and vari-slice cut slab, respectively. After adjusting the threshold level to about −20 HU, the erosion function with a value of one voxel was employed each time for further cleaning up hypodense interfering voxels such as fat and air that remained and the procedure was stopped before the biliary and pancreatic ducts were overeroded.

Results

Mean values of the total postprocessing time of the three manual cut methods for 3D nCTC were 57.8, 29.9, and 20.6 min, respectively. After the first erosion, interfering voxels were removed in more than half of the cases and they could be primarily eliminated following the second erosion. Meanwhile, the pancreaticobiliary ducts showed obvious erosion findings at the third erosion.

Conclusions

The vari-slice manual cut method was shown to be the most timesaving postprocessing method and the image quality for 3D nCTC can be improved when one to two frequencies of erosion are applied.

Introduction

Direct cholangiography procedures, such as percutaneous transpheptic cholangiography (PTC), endoscopic retrograde cholangiography (ERC), or intraoperative cholangiography, have been regarded as gold standard examinations for patients with suspected biliary obstruction. However, they are invasive investigations [1], [2], [3]. Although magnetic resonance cholangiography (MRC) offers cholangiographic-like images nonivasively, some contraindications and prolonged examination time have limited its use [4]. Helical CT cholangiography without biliary contrast agent has been reported as a useful tool for the assessment of biliary obstruction [4], [5], [6], [7], [8], [9], [10], [11], [12]. In contrast to CT cholangiography with positive cholangiographic contrast agent, it creates a negative contrast CT cholangiography (nCTC) [11], [13]. However, to show the entire biliary tract using 3D nCTC with minimum intensity projection (minIP), manual cut-off is required for the interfering voxels (gas, fat, etc.) surrounding the regions of intra- and extrahepatic biliary systems. This postprocessing method is a time-consuming procedure [7]. Nevertheless, during our experience, those hypodense components were difficult to be removed completely even after performing the manual cut. The purpose of this study was to investigate the improvement in imaging time and quality of 3D nCTC with minIP using the vari-slice manual cut and erosion methods.

Section snippets

Patients

Thirty-eight patients whose ultrasound examination had suggested biliary obstructive disorders accompanied by elevated total serum bilirubin and/or alkaline phosphatase level underwent retrospective CT studies. It included 18 men and 20 women ranging in age from 24 to 87 years old (mean 57.7 years). Among them, 25 patients also underwent ERC (n=10), PTC (n=3), intraoperative cholangiogram (n=5), and MRC (n=7) within 48 h to 1 week after CT examination. Final clinical diagnoses were made by

Results

The presence of biliary obstruction was correctly diagnosed using 3D nCTC with minIP after the first or second erosion in all patients. According to the Baron et al. [14] classification, seven in 38 had extrahepatic ductal obstruction at the porta hepatis, six at the suprapancreatic level, and 25 at the intrapancreatic level (including the ampulla of Vater). The whole cutting width was 157.7±18.1 mm (125–198 mm) and the mean values of the total postprocessing time were shortest with the

Discussion

The terminology of CT cholangiography using conventional intravenous contrast agent has not been uniform. Some researchers described this method as “CT cholangiography without biliary contrast agent” [4] or “CT cholangiography with minimum intensity projection” [7], [8]. Since its imaging principle is opposite to that of CT cholangiography using positive cholangiographic agent, it is also called as “CT cholangiography using a negative contrast” [11], [13] and because the pancreatic and bile

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Comparison of three-dimensional negative-contrast CT cholangiopancreatography with three-dimensional MR cholangiopancreatography for the diagnosis of obstructive biliary diseases
2012, European Journal of Radiology
Citation Excerpt :
Several years ago, Park and Rao et al. reported the 3D-nCTCP with MinIP techniques, which permits to cover the whole pancreatobiliary systems in one image similar to that of 3D-MRCP, outlines clear anatomy, and provides excellent overview information for clinical diagnoses as well as no need of additional examination time or radiation exposure, but it needs to segment the liver and pancreas from the surrounding low dense tissues (gas, fat, etc.) that interferes the bile and pancreatic ducts, so a time-consuming postprocedures about 40–60 min is inevitable according to their reports [12,18]. Recently, Zhang et al. [20] have introduced a newly improved method for 3D-nCTCP with vari-slice manual cut and erosion functions in segmentation, the total postprocessing time was shorten to about 20 min, which might make this technique clinically practicable. In our study, both methods correctly identified the presence and location of biliary obstruction in all patients, especially 3D-nCTCP depicting the obstructive morphology and whole pancreatobiliary system was consistent with 3D-MRCP regardless the obstructive location occurred, so it is favorable to those patients who are unsuitable for both PTC and ERCP or failed PTC or ERCP.
The purpose of our study was to compare three-dimensional (3D) negative-contrast CT cholangiopancreatography (3D-nCTCP) with 3D MR cholangiopancreatography (3D-MRCP) for the diagnosis of obstructive biliary diseases.
3D-nCTCP and 3D-MRCP were performed on seventy clinically documented obstructive biliary diseases patients. The accuracy of each technique in determining the location and cause of biliary obstruction was evaluated compared with the final clinical diagnoses.
Both methods achieved 100% of accuracy in the diagnosis of the presence and location of biliary obstruction, and had a similar sensitivity, specificity, accuracy in differentiating benign from malignant biliary obstruction or calculous from noncalculous biliary obstruction (p > 0.05). At 3D-nCTCP, six patients with stones were misinterpreted as cholangitis (N = 2), papillitis (N = 3), or bile duct adenocarcinoma (N = 1); two metastases were mistaken as acute pancreatitis or pancreatic head carcinomas, and one intrahepatic cholangiocarcinoma was misled as bile duct adenoma. At 3D-MRCP, one small stone, one ampullary adenoma, and one intrahepatic cholangiocarcinoma were mistaken as cholangitis, ampullary stone, and intrahepatic bile duct stone, respectively, and three gallbladder carcinomas and another intrahepatic cholangiocarcinoma were misdiagnosed as hilar cholangiocarcinoma (N = 3) or common hepatic duct stone (N = 1); four metastases were mistaken as pancreatic head carcinomas (N = 3) or distal cholangiocarcinoma (N = 1). The overall accuracy in making specific diagnosis of the cause of biliary obstruction was 87.1% for 3D-nCTCP and 84.3% for 3D-MRCP, respectively, (p > 0.05).
3D-nCTCP has the similar effects as 3D-MRCP for the diagnosis of biliary obstruction and, the location and the cause of biliary obstruction. In view of selected cases contraindications for MRI, 3D-nCTCP is a potential substitute.
Prediction of vascular invasion using a 3-point scale computed tomography grading systemin pancreatic ductal adenocarcinoma: Correlation with surgery
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Presurgical evaluation of pancreatic cancer: A comprehensive imaging comparison of CT versus MRI
2016, American Journal of Roentgenology
Preoperative evaluation of malignant perihilar biliary obstruction: Negative-contrast CT cholangiopancreatography and CT angiography versus MRCP and MR angiography
2015, American Journal of Roentgenology
Differentiation of noncalculous periampullary obstruction: comparison of CT with negative-contrast CT cholangiopancreatography versus MRI with MR cholangiopancreatography
2015, European Radiology
Differential diagnosis of periampullary carcinomas: Comparison of CT with negative-contrast CT cholangiopancreatography versus MRI with MR cholangiopancreatography
2014, Abdominal Imaging

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Original articleImprovement in imaging time and quality of 3D negative-contrast computed tomography cholangiography with minimum intensity projections: application of vari-slice manual cut and erosion functions

Abstract

Objective

Methods

Results

Conclusions

Introduction

Section snippets

Patients

Results

Discussion

Clin Imaging

Radiol Clin N Am

Semi Roentgenol

Fine-needle transhepatic cholangiography: reflections after 450 cases

AJR Am J Roentgenol

Complications of diagnostic and therapeutic ERCP

Abdom Imaging

MRCP and ERCP in the diagnosis of common bile duct stones

Gastrointest Endosc

Multislice CT cholangiography without biliary contrast agent: technique and initial clinical result in the assessment of patients with biliary obstruction

Eur Radiol

Biliary tract: three-dimensional helical CT without cholangiographic contrast material

Radiology

Multiplanar CT pancreatography and distal cholangiography with minimum intensity projections

Radiology

Three-dimensional spiral CT cholangiography with minimum intensity projection in patients with suspected obstructive biliary disease: comparison with percutaneous transhepatic cholangiography

Abdom Imaging

Three-dimensional helical computed tomography cholangiography with minimum intensity projection in gallbladder carcinoma patients with obstructive jaundice: comparison with magnetic resonance cholangiography and percutaneous transhepatic cholangiography

J Gastroenterol Hepatol

MR versus multislice CT cholangiography in evaluating patients with obstruction of the biliary tract

Abdom Imaging

Minimum intensity projections of the biliary system using 16-channel multidetector computed tomography in patients with biliary obstruction: comparison with MRCP

Eur Radiol

Original article
Improvement in imaging time and quality of 3D negative-contrast computed tomography cholangiography with minimum intensity projections: application of vari-slice manual cut and erosion functions