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| ORIGINAL ARTICLE |
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| Year : 2020 | Volume
: 9
| Issue : 4 | Page : 217-221 |
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To study diagnostic efficacy of ultrasound and magnetic resonance cholangiopancreatography in obstructive jaundice
Satyanarayana Goud, B Vijayalakshmi Devi, Pavan Kumar G. Kale, AY Lakshmi, V Venkata Rami Reddy
Department of Radiology and Surgical gastroenterology, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhrapradesh, India
| Date of Submission | 27-Mar-2020 |
| Date of Decision | 30-May-2020 |
| Date of Acceptance | 24-Aug-2020 |
| Date of Web Publication | 6-Jan-2021 |
Correspondence Address:
Dr. B Vijayalakshmi Devi
Professor, Depatment of Radiology, Sri venkateswara institute of Medical Sciences, Tirupati, Andhrapradesh
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/JDRNTRUHS.JDRNTRUHS_43_20
Background and Objective: Ultrasonography (??USG) and magnetic resonance cholangiopancreatography (??MRCP) are noninvasive modalities for evaluation of patients with obstructive jaundice. USG is widely available and less expensive compared to MRCP. But the value of USG is limited in obese patients and distal CBD evaluation due to poor window caused by bowel gas. With this knowledge, we planned to assess the diagnostic efficacy of USG and MRCP in detecting the level and cause of obstructive jaundice considering the gold standard being the final diagnosis made at surgery/Endoscopic retrograde cholangiopancreatography (ERCP).
Settings and Design: Prospective observational study.
Material and Methods: The study was conducted in the department of Radio Diagnosis, SVIMS, over a period of 18 ?months from March 2018–July 2019. This study includes thirty-seven consecutive patients who were referred to the department of Radiodiagnosis with the clinical suspicion of obstructive jaundice and elevated serum bilirubin levels. USG followed by MRCP were done in all the patients.
Results: Of the thirty-seven patients with obstructive jaundice, twenty-nine patients had benign while eight patients had malignant etiology. For diagnosing the cause of obstructive jaundice, MRCP has a diagnostic accuracy of 97.2% and USG has a diagnostic accuracy of 86.4%. The sensitivity of MRCP is greater than USG in diagnosing the cause of obstructive jaundice. In diagnosing the level of obstruction, MRCP had an accuracy of 100%, while USG 81%.
Conclusion: As MRCP has more diagnostic accuracy compared to ultrasound in detecting the level and cause of obstruction in cases of obstructive jaundice, USG may be considered as an initial screening test and MRCP for definitive treatment planning. The limitation of the study is the small sample size.
Keywords: Magnetic resonance cholangiopancreatography, Ultrasonography, Obstructive jaundice
How to cite this article:
Goud S, Devi B V, Kale PK, Lakshmi A Y, Reddy V V. To study diagnostic efficacy of ultrasound and magnetic resonance cholangiopancreatography in obstructive jaundice. J NTR Univ Health Sci 2020;9:217-21 |
How to cite this URL:
Goud S, Devi B V, Kale PK, Lakshmi A Y, Reddy V V. To study diagnostic efficacy of ultrasound and magnetic resonance cholangiopancreatography in obstructive jaundice. J NTR Univ Health Sci [serial online] 2020 [cited 2023 Apr 1];9:217-21. Available from: https://www.jdrntruhs.org/text.asp?2020/9/4/217/306123 |
| Introduction | |  |
Obstructive Jaundice has been documented as one of the leading causes of increased morbidity. ?Any blockage in the hepatobiliary pathway obstructs the flow of bile into the intestine, As a result passage of bile into the circulation occurs which leads to symptoms like jaundice and pruritis.[1] Laboratory investigations like increased serum conjugated bilirubin (>3 mg/?dL) and alkaline phosphatase (ALP) help in the diagnosis of obstructive jaundice.
Information about the level and cause of the obstruction can be known by various anatomic imaging modalities. ERCP is considered as Gold standard in the evaluation of biliary tree, but it is an invasive technique and is associated with complications like pancreatitis. Ultrasonography (USG) and contrast-enhanced computed tomography (CT) are initial modalities of investigations. Though USG is very useful to visualize the common hepatic duct and proximal common bile duct, its major limitation is the difficulty in the visualization of distal common bile duct and pancreas due to obscuration by overlying bowel gas in 30%–50% of cases and obesity can degrade the image quality. CT is more accurate than USG but it uses ionizing radiation. Recently magnetic resonance cholangiopancreatography (MRCP) is emerging as noninvasive means of visualization of the biliary tree and pancreatic duct without injection of contrast material.[2],[3] The quality of images obtained is comparable with that of direct cholangiography procedures like ERCP. The main objective of the study is to assess the diagnostic efficacy of USG and MRCP in detecting the level and cause of obstruction in patients with jaundice with the gold standard being final diagnosis made on surgery or ERCP.
| Materials and Methods | | |
The study was conducted in the department of Radio Diagnosis, SVIMS, over a period of 18 months from March 2018–July 2019. Thirty-seven consecutive patients who were referred to the department of Radiodiagnosis with the clinical suspicion of obstructive jaundice and elevated serum bilirubin levels were included in the study. USG followed by MRCP were done in all the patients. Contrast MRI was not done in any of our patients. Resectability of malignant lesion was assessed based on CECT abdomen findings. One of the two radiologists who was not aware of USG findings reviewed the MRI scan and evaluated the level and cause obstruction in these patients.
Statistical analysis
Continuous variables were summarized as mean and standard deviation. Categorical variables were summarized as numbers and percentages. Sensitivity, specificity, Positive predictive value, negative predictive value, diagnostic accuracy were calculated with the gold standard being final diagnosis made after surgery/ERCP and Histopathology.
Ethical Clearance
Ethical approval for this study (Ethical Committee IEC NO.747) was provided by the Institutional Ethical Committee SVIMS University, Tirupati, Andhra Pradesh, India on 13 March 20018.
| Results | | |
Thirty-seven consecutive patients with clinical suspicion of obstructive jaundice were included in our study. The youngest patient was 21 years of age, with Caseating granulomatous abdominal and retroperitoneal lymphadenopathy. The oldest patient was 73 years of age with cholangiocarcinoma.
USG could identify the level of obstruction in 34/37 cases, whereas MRCP identified the level of obstruction in all cases accurately. Thus, MRCP had an accuracy of 100% while USG 81% in diagnosing the level of obstruction as shown in [Table 1]. | Table 1: Level of Obstruction Diagnosed by USG, MRCP, And Final Diagnosis
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Of the thirty-seven patients with obstructive jaundice, twenty-nine patients had benign lesions while eight patients had malignant lesion on final diagnosis. Causes of obstruction diagnosed by USG, MRCP, and Final diagnosis are shown in [Table 2]. | Table 2: Causes of Obstructive Jaundice Diagnosed by USG, MRCP, and Final Diagnosis
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MRCP identified all the benign causes correctly expect 1 case. USG identified correctly the benign cause of obstruction in 17 out of 29 cases. One case of Caseating granuloma was diagnosed as a pancreatic malignancy on both USG and MRCP. USG and MRCP were able to detect gall bladder calculi in all cases with 100% accuracy. USG showed difficulty in picking up distal CBD calculus in 9 patients, which was diagnosed clearly with MRCP with 100% accuracy. In malignant lesion, MRCP identified all the malignant lesions correctly, whereas USG identified only 4 cases as malignant lesions. One case of pancreatic malignancy and 3 cases of periampullary carcinoma were not diagnosed with USG.
For diagnosing the cause of obstructive jaundice, MRCP has a diagnostic accuracy of 97.2% and USG has a diagnostic accuracy of 86.4%. The sensitivity, specificity, PPV, and NPV of MRCP are 100%, 96.5%, 88.8%, and 100% and USG are 50%, 96.4%, 80.5%, and 87.5% respectively.
| Discussion | | |
Early diagnosis of level and cause of obstruction in patients with obstructive jaundice is imperative for the selection of proper treatment. Knowledge about the advantages and disadvantages of various noninvasive modalities such as USG, CT, and MRCP is needed for workup of patients with obstructive jaundice. USG is widely available, no need for contrast injection and no radiation risk. CT is more accurate than USG, but requires IV Iodinated contrast injection and uses ionizing radiation. MRCP has the advantage of being modality which does not use ionizing radiation or iodinated contrast. The quality of images obtained is comparable with that of direct cholangiography procedures like ERCP. In the present study, we compared the diagnostic efficacy of two noninvasive and nonradiation modalities, USG and MRI in detecting the level and cause of obstruction.
Majority of the study population (32.4%) were adults in the age group of 51–60 years. However, in the study by Al-?Obaidi et al.,[4] most of the patients were in 60–69 years age group. Our study showed male preponderance with 68% male population. But in a similar study by Singh et al.,[5] majority were females (56%).
In diagnosing the level of obstruction, USG could not identify the level of obstruction in 3 cases, whereas MRCP identified the level of obstruction in all cases accurately. Our study is in concordance with the study of Vaishali et al.[6] In their study, the diagnostic accuracy of MRCP in identifying the level of obstruction was 96.4%.
USG and MRCP were able to detect gall bladder calculi in all cases with 100% accuracy. USG showed difficulty in picking up distal CBD calculus in 9 patients, which was diagnosed clearly with MRCP with 100% accuracy. This shows that MRCP is superior to USG in detecting CBD calculi. CBD and GB calculi are shown in [Figure 1]. The present study is in concordance with Guidbaud et al.[7]; in their study, they found an accuracy of 100% in detecting CBD calculi on MRCP in cases with equivocal sonographic and CT results. Our study is also in concordance with Soto et al.[8]; in their study, they reported a sensitivity of 94% and specificity of 100% for detecting biliary calculi in MRCP. The study of Stephan et al.[9] found that the sensitivity of MRCP/USG in diagnosing CBD calculus was 87%. Singh et al.[5] in their study found that sensitivity and diagnostic accuracy in diagnosing CBD calculi by USG were 93.3% and 96%. In our study, we found USG has 43.2% sensitivity in diagnosing CBD calculi. | Figure 1: An 34-year-old female patientfs ultrasound image showing hyperechoic focus with acoustic shadowing in CBD suggestive of calculus (blue arrow) and MRCP image showing hypointense filling defect in GB and CBD suggestive of GB calculus (orange arrow) and CBD calculus (blue arrow)
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CBD stricture was diagnosed in two patients by MRCP clearly with 100% accuracy. MRCP showed clearly the length of the stricture segment very well but USG could not identify these lesions. Our study is in concordance with Bhatt et al.[10]; in their study, they found 100% accuracy for MRCP in diagnosing benign CBD strictures.
One case of choledochal cyst as shown in [Figure 2] was diagnosed with MRCP and USG. Our study is in concordance with Bhatt et al.[10]; in their study, they found 100% accuracy for MRCP in diagnosing anatomical variants. | Figure 2: A 30-year-old female patientfs USG and Coronal T2 W HASTE MRCP image showing fusiform dilatation of CBD suggestive of type 1 choledochal cyst
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In our study of 37 patients, 8 (21.6%) were malignant which include periampullary (n = 3), hilar cholangiocarcinoma (n = 3), and pancreatic cancer (n = 2). In all 3 patients with periampullary growth, MRCP clearly visualized the growth as shown in [Figure 3]. However, USG could not identify the growth in the periampullary region because of the poor window due to bowel gas and obese patients. Diagnostic accuracy of MRCP in detecting periampullary malignancy was 100% and USG was 0%. Our study is in concordance with Andersson et al. 2005[11]; in their study, they found 90% accuracy for MRCP in diagnosing periampullary growth. | Figure 3: A 68-year-old male patientfs coronal T 2 HASTE and 3D MRCP image showing heterogenous signal intense lesion in periampullary region. USG abdomen could not visualize the periampullary lesion
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In 3 patients with cholangiocarcinoma as shown in [Figure 4], MRCP diagnosed all 3 cases with a 100% diagnostic accuracy, while USG showed growth in 2 cases and with suspicion in remaining 1 case, thus approaching 100% accuracy for MR with MRCP compared to 88%–90% diagnostic accuracy in USG. Our study is in concordance with Andersson et al. 2005[11]; in their study, they found that MRCP was more accurate than USG. | Figure 4: A 73-year-old male patientfs ultrasound image showing illdefined hypoechoic mass involving hilum (blue arrow) and Axial T 2 HASTE image showing hypointense mass lesion involving hilum suggestive of hilar cholangiocarcinoma
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Out of 3 cases diagnosed as a malignant mass lesion in the pancreas as shown in [Figure 5] by MRCP, 2 cases were malignant confirmed by histopathology and 1 case turned out to be benign etiology, i.e., caseating granuloma. While USG diagnosed 2 cases as malignant mass lesion in the pancreas, 1 case was found to have benign etiology, i.e., caseating granuloma. USG could not diagnose 1 pancreatic malignant lesion due to poor window. One case of pancreatic head carcinoma had liver metastasis, which is identified in MRCP. | Figure 5: A 57-year-old male patientfs ultrasound image showing hypoechoic mass lesion in pancreas (blue arrow) and Axial T 2 HASTE and MRCP image showing hypointense mass lesion in head of pancreas
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In our study, diagnostic accuracy, sensitivity, and specificity of USG in benign and malignant lesions were 86.4%, 50%, and 96.4%. Diagnostic accuracy, sensitivity, and specificity of MRCP in benign and malignant lesions were 97.2%, 100%, and 96.5%.
In the study conducted by Singh et al., overall diagnostic accuracy, sensitivity, and specificity of USG in benign causes are 88%, 80.7%, and 95.8%, and malignant causes are 88%, 79%, and 96%. Diagnostic accuracy, sensitivity, and specificity of MRCP in benign causes are 98%, 100%, and 95% and malignant causes are 98%, 95%, and 100%.
| Conclusion | | |
- MRCP has high diagnostic accuracy compared to USG in detecting the level of obstruction and diagnosing CBD calculi and strictures of distal CBD.
- MRCP has high sensitivity, specificity,? PPV, NPV, and diagnostic accuracy than USG in diagnosing benign and malignant causes of obstructive jaundice.
Therefore, USG may be considered as an initial screening test and MRCP for? definitive treatment planning.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
| References | | |
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2]
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