New Imaging Techniques.

The chapter discusses the advancement of new imaging techniques, the role of imaging in CCA diagnosis, anatomical and morphological classification, ultrasound screening of CCA, ultrasound findings of MF-CCA, PI-CCA, ID-CCA, the use of CT in CCA diagnosis, staging and treatment planning, CT volumetry and estimation of future liver remnant, post-treatment follow-up and surveillance, MRI imaging, Positron Emission Tomography (PET)/CT, limitations to contrast studies and resolution, internal receivers for CCA imaging, and in vitro imaging of CCA.

Survival after surgery among patients with cholangiocarcinoma in Northeast Thailand according to anatomical and morphological classification.

BACKGROUND: Cholangiocarcinoma (CCA) has been categorized based on tumor location as intrahepatic (ICCA), perihilar (PCCA) or distal (DCCA), and based on the morphology of the tumor of the bile duct as mass forming (MF), periductal infiltrating (PI) or intraductal (ID). To date, there is limited evidence available regarding the survival of CCA among these different anatomical and morphological classifications. This study aimed to evaluate the survival rate and median survival time after curative surgery among CCA patients according to their anatomical and morphological classifications, and to determine the association between these classifications and survival. METHODS: This study included CCA patients who underwent curative surgery from the Cholangiocarcinoma Screening and Care Program (CASCAP), Northeast Thailand. The anatomical and morphological classifications were based on pathological findings after surgery. Survival rates of CCA and median survival time since the date of CCA surgery and 95% confidence intervals (CI) were calculated. Multiple cox regression was performed to evaluate factors associated with survival which were quantified by hazard ratios (HR) and their 95% CIs. RESULTS: Of the 746 CCA patients, 514 had died at the completion of the study which constituted 15,643.6 person-months of data recordings. The incidence rate was 3.3 per 100 patients per month (95% CI: 3.0-3.6), with median survival time of 17.8 months (95% CI: 15.4-20.2), and 5-year survival rate of 24.6% (95% CI: 20.7-28.6). The longest median survival time was 21.8 months (95% CI: 16.3-27.3) while the highest 5-year survival rate of 34.8% (95% CI: 23.8-46.0) occurred in the DCCA group. A combination of anatomical and morphological classifications, PCCA+ID, was associated with the longest median survival time of 40.5 months (95% CI: 17.9-63.0) and the highest 5-year survival rate of 42.6% (95% CI: 25.4-58.9). The ICCA+MF combination was associated with survival (adjusted HR: 1.45; 95% CI: 1.01-2.09; P = 0.013) compared to ICCA+ID patients. CONCLUSIONS: Among patients receiving surgical treatment, those with PCCA+ID had the highest 5-year survival rate, which was higher than in groups classified by only anatomical characteristics. Additionally, the patients with ICCA+MF tended to have unfavorable surgical outcomes. Showed the highest survival association. Therefore, further investigations into CCA imaging should focus on patients with a combination of anatomical and morphological classifications.

A comparison of the proportion of early stage cholangiocarcinoma found in an ultrasound-screening program compared to walk-in patients.

BACKGROUND: Patients with cholangiocarcinoma (CCA) usually have no specific symptoms until an advance stage of the disease and curative treatment is not possible. Patients with early stage, operable disease can be found using ultrasonography (US). A US-screening program was implemented in Thailand where CCA incidence is the highest worldwide. Here we evaluate the effectiveness of the program by comparing the proportion of individuals with early stage CCA in the screening group with that of the walk-in group presenting at hospitals with clinical symptoms. METHODS: All patients had a pathological diagnosis of CCA. The difference in the proportions and the 95% confidence interval (CI) were obtained using binomial regression. RESULTS: Of the 762 histologically proven CCA cases, 161 were from the screening group and 601 from the walk-in group. The proportion of early stage CCA (stages 0 to II) diagnosed was 84.5% in the screening and 21.6% in the walk-in groups. After adjustment age, gender, and liver fluke infection, there was a significantly higher proportion (P < 0.001) and higher chance (P < 0.001) of having early stage CCA in the screening group than in the walk-in group. CONCLUSIONS: US-screening is an effective tool for detecting early stage, operable CCA in high incidence areas.

Discovery and Qualification of Serum Protein Biomarker Candidates for Cholangiocarcinoma Diagnosis.

Cholangiocarcinoma (CCA) is a major health problem in northeastern Thailand. The majority of CCA cases are clinically silent and difficult to detect at an early stage. Although abdominal ultrasonography (US) can detect premalignant periductal fibrosis (PDF), this method is not suitable for screening populations in remote areas. With the goal of developing a blood test for detecting CCA in the at-risk population, we carried out serum protein biomarker discovery and qualification. Label-free shotgun proteomics was performed on depleted serum samples from 30 participants (n = 10 for US-normal, US-PDF, and CCA groups). Of 40 protein candidates selected using multiple reaction monitoring on 90 additional serum samples (n = 30 per group), 11 discriminatory proteins were obtained using supervised multivariate statistical analysis. We further evaluated 3 candidates using ELISA and immunohistochemistry (IHC). S100A9, thioredoxin (TRX), and cadherin-related family member 2 (CDHR2) were significantly different between CCA and normal, and CCA and PDF groups when measured in an additional 247 serum samples (P < 0.0001). By IHC, TRX and CDHR2 were detected in the cytoplasm and nucleus of CCA and inflammatory cells. S100A9 was detected in the infiltrating tumor stroma immune cells. Proteomics discovery and qualification in depleted sera revealed promising biomarker candidates for CCA diagnosis.

Evaluating a preoperative protocol that includes magnetic resonance imaging for lymph node metastasis in the Cholangiocarcinoma Screening and Care Program (CASCAP) in Thailand.

BACKGROUND: Treatment planning especially liver resection in cholangiocarcinoma (CCA) depends on the extension of tumor and lymph node metastasis which is included as a key criterion for operability. Magnetic resonance imaging (MRI) offers a rapid and powerful tool for the detection of lymph node metastasis (LNM) and in the current manuscript is assessed as a critical tool in the preoperative protocol for liver resection for treatment of CCA. However, the accuracy of MRI to detect LNM from CCA had yet to be comprehensively evaluated. METHODS: The accuracy of MRI to detect LNM was assessed in a cohort of individuals with CCA from the Cholangiocarcinoma Screening and Care Program (CASCAP), a screening program designed to reduce CCA in Northeastern Thailand by community-based ultrasound (US) for CCA. CCA-positive individuals are referred to one of the nine tertiary centers in the study to undergo a preoperative protocol that included enhanced imaging by MRI. Additionally, these individuals also underwent lymph node biopsies for histological confirmation of LNM (the "gold standard") to determine the accuracy of the MRI results. RESULTS: MRI accurately detected the presence or absence of LNM in only 29 out of the 51 CCA cases (56.9%, 95% CI 42.2-70.7), resulting in a sensitivity of 57.1% (95% CI 34.0-78.2) and specificity of 56.7% (95% CI 37.4-74.5), with positive and negative predictive values of 48.0% (95% CI 27.8-68.7) and 65.4% (95% CI 44.3-82.8), respectively. The positive likelihood ratio was 1.32 (95% CI 0.76-2.29), and the negative likelihood ratio was 0.76 (95% CI 0.42-1.36). CONCLUSIONS: MRI showed limited sensitivity and a poor positive predictive value for the diagnosis of LNM for CCA, which is of particular concern in this resource-limited setting, where simpler detection methods could be utilized that are more cost-effective in this region of Thailand. Therefore, the inclusion of MRI, a costly imaging method, should be reconsidered as part of protocol for treatment planning of CCA, given the number of false positives, especially as it is critical in determining the operability for CCA subjects.

Cohort profile: cholangiocarcinoma screening and care program (CASCAP).

BACKGROUND: Cholangiocarcinoma (CCA) is an extremely aggressive cancer that is usually fatal. Although globally morbidity and mortality are increasing, knowledge of the disease remains limited. The Mekong region of Southeast Asia, and particularly the northeast of Thailand, has by far the highest incidence of CCA worldwide with 135.4 per 100,000 among males and 43.0 per 100,000 among females being reported in Khon Kaen Province. Most patients are first seen during late stage disease with 5-year survival being less than 10%. Starting in 1984, control and prevention strategies have been focused on health education. Although early detection can substantially increase 5-year survival, there are currently no strategies to increase early diagnosis. METHODS/DESIGN: The Cholangiocarcinoma Screening and Care Program (CASCAP) is a prospective cohort study comprising two cohorts- the screening and the patient cohorts. For the screening cohort, ultrasound examination will be carried out regularly at least annually to determine whether there is current bile duct and/or liver pathology so that the optimal screening program for early diagnosis can be established. This cohort is expected to include at least 150,000 individuals coming from high-risk areas for CCA. For the patient cohort, it is estimated that about 25,000 CCA patients will be included during the 5-year recruitment period. All CCA patients will be treated according to routine clinical care and followed so that effective surgical treatment can be formulated. This cohort is indeed a conventional cancer registry. Thus, CASCAP is an ongoing project in which the number of participants changes dynamically. DISCUSSIONS: This is the first project on CCA that involves screening the at risk population at the community level. At the time of preparing this report, a total of 85,927 individuals have been enrolled in the screening cohort, 55.0% of whom have already undergone ultrasound screening, and 2661 CCA cases have been enrolled in the patient cohort. Among the participants of the screening, whose mean age was 53.8±9.8 years, 55.6% were female, 77.5% attained primary school as the highest level of education, 79.9% were farmers, 29.9%, reported having relatives with CCA, 89.1% had eaten uncooked fish, and 42.2% of those who had been tested for liver fluke were found to be infected.

Intraductal magnetic resonance imaging of cholangiocarcinoma - a practical possibility.

Intraductal T2 mapping based on a catheter receiver is proposed as a method of visualizing the extent of intraductal and periductal cholangiocarcinoma (CCA). Compared to external receivers, internal receivers provide locally enhanced signal-to-noise ratios by virtue of their lower field-of-view for body noise, allowing smaller voxels and higher resolution. However, inherent radial sensitivity variation and segmentation for patient safety both distort image brightness. We discuss simulated T2 weighted images and T2 maps, and in vitro images obtained using a thin film catheter receiver of a freshly resected liver specimen containing a polypoid intraductal tumor from a patient with CCA. T2 mapping provides a simple method of compensating non-uniform signal reception patterns of catheter receivers, allowing the visualization of tumor extent without contrast enhancement and potentially quantitative tissue characterization. Potential advantages and disadvantages of in vivo intraductal imaging are considered.

Sonographic findings of hepatocellular carcinoma detected in ultrasound surveillance of cirrhotic patients.

BACKGROUND: Hepatocellular carcinoma (HCC) is associated with high mortality. Patients with hepatitis B or C viral cirrhosis have an increased risk of developing HCC. Ultrasound is the most widely used screening method, and is recommended by many guidelines. OBJECTIVE: To study the sonographic findings ofHCC detected in ultrasound surveillance of cirrhotic patients. MATERIAL AND METHOD: Retrospective assessment of ultrasoundfindings of all nodules that were diagnosed HCC by either dynamic imaging (CTor MRI) or biopsy between October 2008 and July 2011. Nodules were classified based on echogenicity and other sonographic characteristics. RESULTS: Of 92 nodules, 42 (45.7%) were hyperechoic, 29 (31.5%) hypoechoic, 20 (21.7%) heterogeneous echoic and 1 (1.1%) isoechoic. Heteroechoic nodules were more common among nodules over 3.0 cm (p = 0.0037) while hypoechoic nodules tended to be the smaller ones. About half (48/92) of the nodules had a hypoechoic halo and occurred significantly more commonly among hyperechoic and heteroechoic nodules (p< 0. 001). Posterior enhancement was found in 54 nodules (58. 7%0), also more common in nodules >3.0 cm (p = 018). Lateral shadowing occurred in 40 nodules (43.5%). CONCLUSION: The sonographic findings of HCC nodules in the present studies varied, but the prevalence of hyperechoic nodules was higher than in most of other studies. The authors emphasize the necessity of performing dynamic imaging for any nodule detected in a cirrhotic liver in order to exclude their neoplastic nature, no matter what it may look like.

Association of Cholangiocarcinoma among People with Periductal Fibrosis.

BACKGROUND: Cholangiocarcinoma (CCA) is a highly fatal tumor, and the most favorable chance for long-term survival lies in curative resection. Periductal fibrosis (PDF), a precancerous condition associated with chronic inflammation of the bile ducts, can serve as a screening marker for CCA using hepatobiliary ultrasonography (US). However, limited studies have explored the relationship between PDF and CCA. This study aimed to investigate the association between PDF and CCA in a population at risk in Northeast Thailand. METHODS: The study included participants enrolled in the Cholangiocarcinoma Screening and Care Program (CASCAP) between 2013 and 2021 who underwent US. Histological evaluations were conducted following the standard protocol of the tertiary hospital at Khon Kaen University, Thailand. PDF was defined as the presence of fibrosis in the peripheral (PDF1), segmental (PDF2), or main bile duct (PDF3), diagnosed by well-trained general practitioners or radiologists. The association between PDF and CCA was assessed using multiple logistic regression, calculating adjusted odds ratios (AORs) and 95% confidence intervals (CIs). RESULTS: Out of 751,061 participants, the overall prevalence of PDF was 115,267 (15.35%), with an overall CCA rate of 0.11%. The rates of CCA were 0.1%, 0.15%, and 0.27% in participants with PDF1, PDF2, and PDF3, respectively. After adjusting for gender, age at enrollment, education levels, history of O. viverrini infection, smoking, and alcohol consumption, the AORs for CCA were 0.94 (95% CI: 0.74 - 1.20), 1.4 (95% CI: 1.03 - 1.91), and 2.52 (95% CI: 1.38 - 4.58) for participants with PDF1, PDF2, and PDF3, respectively. CONCLUSION: Our findings demonstrate a significant association between fibrosis of the segmental and main bile ducts (PDF2 and PDF3) and CCA, with the strongest association observed in participants with PDF3. Hepatobiliary US screening could serve as a valuable tool for early detection of CCA, enabling timely curative treatment.

BiTNet: Hybrid deep convolutional model for ultrasound image analysis of human biliary tract and its applications.

Certain life-threatening abnormalities, such as cholangiocarcinoma, in the human biliary tract are curable if detected at an early stage, and ultrasonography has been proven to be an effective tool for identifying them. However, the diagnosis often requires a second opinion from experienced radiologists, who are usually overwhelmed by many cases. Therefore, we propose a deep convolutional neural network model, named biliary tract network (BiTNet), developed to solve problems in the current screening system and to avoid overconfidence issues of traditional deep convolutional neural networks. Additionally, we present an ultrasound image dataset for the human biliary tract and demonstrate two artificial intelligence (AI) applications: auto-prescreening and assisting tools. The proposed model is the first AI model to automatically screen and diagnose upper-abdominal abnormalities from ultrasound images in real-world healthcare scenarios. Our experiments suggest that prediction probability has an impact on both applications, and our modifications to EfficientNet solve the overconfidence problem, thereby improving the performance of both applications and of healthcare professionals. The proposed BiTNet can reduce the workload of radiologists by 35% while keeping the false negatives to as low as 1 out of every 455 images. Our experiments involving 11 healthcare professionals with four different levels of experience reveal that BiTNet improves the diagnostic performance of participants of all levels. The mean accuracy and precision of the participants with BiTNet as an assisting tool (0.74 and 0.61, respectively) are statistically higher than those of participants without the assisting tool (0.50 and 0.46, respectively (p<0.001)). These experimental results demonstrate the high potential of BiTNet for use in clinical settings.

1H NMR fecal metabolic phenotyping of periductal fibrosis- and cholangiocarcinoma-specific metabotypes defining perturbation in gut microbial-host co-metabolism.

Background: The liver fluke Opisthorchis viverrini (OV), which subsequently inhabits the biliary system and results in periductal fibrosis (PDF), is one of the primarily causes of cholangiocarcinoma (CCA), a bile duct cancer with an exceptionally high incidence in the northeast of Thailand and other Greater Mekong Subregion (GMS) countries. Insights in fecal metabolic changes associated with PDF and CCA are required for further molecular research related to gut health and potential diagnostic biological marker development. Methods: In this study, nuclear magnetic resonance (NMR) metabolomics was applied for fecal metabolic phenotyping from 55 fecal water samples across different study groups including normal bile duct, PDF and CCA groups. Results: By using NMR spectroscopy-based metabolomics, fecal metabolic profiles of patients with CCA or PDF and of individuals with normal bile duct have been established with a total of 40 identified metabolites. Further multivariate statistical analysis and hierarchical clustering heat map have demonstrated the PDF- and CCA-specific metabotypes through various altered metabolite groups including amino acids, alcohols, amines, anaerobic glycolytic metabolites, fatty acids, microbial metabolites, sugar, TCA cycle intermediates, tryptophan catabolism substrates, and pyrimidine metabolites. Compared to the normal bile duct group, PDF individuals showed the significantly elevated relative concentrations of fecal ethanol, glycine, tyrosine, and N-acetylglucosamine whereas CCA patients exhibited the remarkable fecal metabolic changes that can be evident through the increased relative concentrations of fecal uracil, succinate, and 5-aminopentanoate. The prominent fecal metabolic alterations between CCA and PDF were displayed by the reduction of relative concentration of methanol observed in CCA. The metabolic alterations associated with PDF and CCA progression have been proposed with the involvement of various metabolic pathways including TCA cycle, ethanol biogenesis, hexamine pathway, methanol biogenesis, pyrimidine metabolism, and lysine metabolism. Among them, ethanol, methanol, and lysine metabolism strongly reflect the association of gut-microbial host metabolic crosstalk in PDF and/or CCA patients. Conclusion: The PDF- and CCA-associated metabotypes have been investigated displaying their distinct fecal metabolic patterns compared to that of normal bile duct group. Our study also demonstrated that the perturbation in co-metabolism of host and gut bacteria has been involved from the early step since OV infection to CCA tumorigenesis.

Associations between ultrasound screening findings and cholangiocarcinoma diagnosis in an at-risk population.

The rate of cholangiocarcinoma (CCA) is increasing every year, especially in northeastern Thailand. Screening for CCA using ultrasonography (US) is the fastest technique to identify patients in early stage of CCA development. Currently, few studies have examined patterns of hepatobiliary abnormalities identified using US, which can be indicative of CCA. We aim to evaluate the rate of CCA and its relations to history of US findings. Our study included participants who underwent US and pathological diagnosis of CCA from the Cholangiocarcinoma Screening and Care Program, Northeast Thailand between 2013 and 2020. Data on histological findings were based on the standard protocol of the tertiary hospital at Khon Kaen University. CCA data is categorized into two groups (yes/no) to find the relationship with history of US findings. The adjusted odds ratio (AOR) and their 95% confidence intervals (CI) were used to evaluate the relationship obtained by multiple logistic regression. Of 1880 subjects who underwent US and a pathological diagnosis of CCA, the overall rate of CCA was 35.74%. CCA rate among those with liver mass (LM) was 54.85% and with dilated bile duct (DBD) was 62.01%. The relationship between DBD and CCA was highly significant (AOR = 3.46; 95% CI 2.74-4.36) followed by LM (AOR = 2.28; 95% CI 1.81-2.86) P value < 0.001. Our study reveals that US findings history have a strong association with CCA, especially in people diagnosed with DBD and LM. Therefore, these abnormalities can be indicators for suspected CCA diagnosis through US.

Association between the Number of Repeated Praziquantel Treatments and Kidney Parenchymal Change in Northeast Thailand.

BACKGROUND: In Northeast Thailand, Praziquantel (PZQ) is used to treat infection with the Opisthorchis viverrnini (OV). OV has highly prevalence in this area due to the traditional consumption of uncooked cyprinid fish. The nephrotoxic effects of PZQ metabolite excretion through the kidney have not been assessed yet. This study investigated the relationship between number of Praziquantel treatments and kidney parenchymal change. METHODS: A study was carried out on participants from the Cholangiocarcinoma Screening and Care Program (CASCAP) between 2013 - 2018. The frequency of PZQ use was reported using a standardized questionnaire. Kidney parenchymal change (KPC) was defined as having a kidney abnormality based on ultrasonography diagnosed by well-trained general practitioners. Adjusted odds ratios (ORs) measured associations between PZQ frequency and KPC controlling for the effects of other extraneous factors using multiple logistic regression. RESULTS: A total of 490,969 subjects with mean age of 55.2 (SD = 9.15) years were enrolled among them 62.1% were female. Prevalence of KPC was 1.2% while prevalence of KPC were 1.2%, 1.3%, 1.4%, and 1.5% for participants with one, two, three, and more than 3 PZQ treatment occasions respectively. Those dose-response relationship was statistically significant based on chi-square test for trend (p-value <0.001). After controlling for possible confounders, compared to non-treatment, subjects with more than 3 treatment occasions were 25% more likely to have a KPC positive result (OR = 1.25; 95% CI: 1.02 - 1.52; p-value = 0.028). CONCLUSION: The number of repeated PZQ treatments is statistically significantly related to KPC. This relationship could be included in health messaging for those who continue eating uncooked fish with an understanding that the OV infection can easily be cured by PZQ without any other health concerns. For positive OV cases, however, the known efficacy of PZQ could over-ride the small magnitude of the adverse effect.

Computed tomographic features of adenocarcinoma compared to malignant lymphoma of the stomach.

OBJECTIVE: To compare the CT findings of adenocarcinoma and malignant lymphoma of the stomach. MATERIAL AND METHOD: The authors retrospectively reviewed the computed tomographic images of 21 patients who received a definite pathologic diagnosis of adenocarcinoma or malignant lymphoma of the stomach. The images were taken at Srinagarind Hospital between January 2006 and February 2009. Seventeen patients with gastric adenocarcinoma and four with malignant gastric lymphoma were included in the present study. The pattern of involvement, the location of lesion, the perigastric fat plane, the perigastric lymphadenopathy and the extension of disease on CT images were evaluated and analyzed by Chi-square and Fisher exact tests. RESULTS: There was a statistically significant difference between gastric adenocarcinoma and malignant gastric lymphoma in the pattern of involvement of disease (p = 0.010), the perigastric fat plane (p = 0.002) and the location of disease (p = 0.008). By contrast, there was no respective statistically significant difference in the perigastric lymphadenopathy (p = 0.950) and the extension of disease (p = 0.175) in between gastric adenocarcinoma and malignant gastric lymphoma. CONCLUSION: The CT findings helpful for differentiating gastric adenocarcinoma from malignant gastric lymphoma are the pattern of involvement, the perigastric fat plane, and the location of lesion. Localized involvement of the lesion, abnormal perigastric fat plane and location involving one region of the stomach tend to indicate gastric adenocarcinoma; while diffused involvement of the lesion, preserved perigastric fat plane and location involving more than one region of the stomach tend to indicate malignant gastric lymphoma.

Computed tomographic appearances of colorectal liver metastases.

BACKGROUND: There are various computed tomographic appearances of liver metastases from colorectal cancer, but there is little data in Thailand. MATERIAL AND METHOD: This was a retrospective, descriptive study of the CT appearances of 21 patients diagnosed with liver metastasis from colorectal cancer in Srinagarind Hospital, Khon Kaen, between January 2003 and December 2007. All of the patients were examined in the portovenous phases. RESULTS: Rim-enhancement was seen in 20 patients (95.2%). Irregular rim-enhancement was seen in 19 patients (90.5%) and smooth rim-enhancement in one (4.8%). Thin rim was seen in 16 patients (76.2%) and thick rim in four (19%). Internal heterogeneous enhancement was seen in 15 patients (71.4%). Irregular, thin rim-enhancement with internal heterogeneous enhancement was the most common combination seen in 12 patients (57.1%). CONCLUSION: An enhancing rim could be seen in 95.2% of patients. Internal heterogeneous enhancement was shown in 71.4% of patients. Familiarity with the various CT appearances may help to facilitate the diagnosis of colorectal liver metastases.

Accuracy of Nonenhanced CT vs Contrast-Enhanced CT for Diagnosis of Acute Appendicitis in Adults.

BACKGROUND: Acute appendicitis is one of the most common causes of acute abdominal pain requiring emergency intervention. It is often difficult for the clinician to make an accurate diagnosis due to nonspecific and overlapping clinical symptoms. Computed tomography (CT) has become the imaging modality of choice for the evaluation of suspected acute appendicitis. The main purpose of our study was to compare nonenhanced CT (NECT) with contrast-enhanced CT (CECT) for the diagnosis of acute appendicitis. MATERIAL AND METHODS: A total of 140 patients were enrolled in the study. Two abdominal radiologists-masked to both the clinical information and the final diagnosis-retrospectively reviewed the computed tomographic findings and made an imaging diagnosis based on (1) NECT only, (2) CECT only, and (3) both NECT and CECT. With the final diagnosis as the reference standard, the accuracy of each CT technique was estimated. RESULTS: The respective sensitivity, specificity, and accuracy for NECT, CECT, and NECT + CECT for the diagnosis of acute appendicitis were 80.7%, 86.7%, and 84.3%; 86.0%, 81.9%, and 83.6%; and, 87.7%, 80.7%, and 83.6%. There was no significant difference in the diagnosis of acute appendicitis among the 3 techniques. In order to make a correct diagnosis, the presence of at least 3 imaging findings for NECT or at least 4 for CECT had the best diagnostic accuracy. We also found that 9.25 mm was the optimal cut-off threshold for the detection of patients with acute appendicitis. CONCLUSION: Our study allowed direct comparison between NECT, CECT, and NECT + CECT combined. There was no difference in the ability of each CT technique for diagnosing patients with acute appendicitis. For a patient whom iodinated contrast media is contraindicated or a patient who has an increased risk of severe adverse reaction, we would encourage the use of NECT because it provides comparable diagnostic accuracy without further exposing such patient to the contrast media.

Computerized tomographic findings of hepatic fascioliasis compared with melioidosis-caused liver abscesses.

OBJECTIVE: To compare the computerized tomographic (CT) findings of hepatic fascioliasis (HF) vs. melioidosis-caused liver (ML) abscesses. MATERIAL AND METHOD: CT images of 15 patients with hepatic fascioliasis (HF) and 16 patients with melioidosis-caused liver (ML) abscesses were retrospectively reviewed. The authors evaluated and compared HF and ML abscesses (by chi2 and Fisher exact tests) vis-a-vis their location of liver involvement, size, shape, number margins, enhancement patterns, subcapsular lesions, internal architecture, dilatation of intrahepatic bile duct and combination with splenic abscesses. RESULTS: Fourteen HF patients had only liver abscesses and 1 had combined liver and splenic abscesses. Four ML patients had liver abscesses alone while 12 had combined liver and splenic abscesses (p = 0.000). Eight of the 15 HF (53.3%) and 2 of the 16 ML (12.5%) patients had subcapsular lesions (p = 0.019). The liver abscesses were round or oval with linear tracts in 8 of the 15 HF (53.3%) and none of the ML patients (p = 0.001). Between the respective HF and ML patients, there was a significant difference in those with round shaped in ML (p = 0.008), multiple and conglomerately distributed in HF (p = 0.050), multiple and discretely distributed in ML (p = 0.001) no (or minimal) peripheral contrast enhancement in HF (p = 0.011) and moderate or mark peripheral enhancement in ML (p = 0.011). CONCLUSION: The CT findings of liver abscesses that helped to differentiate hepatic fascioliasis from melioidosis liver abscesses were: their number shape, enhancement pattern, presence of subcapsular lesion (s) and co-occurrence with splenic abscesses. The diagnosis of hepatic fascioliasis by CT is suggested when the following characteristics were seen: (1) multiple, small round or oval (with linear tracts) conglomerates presenting as hypodense lesions; (2) no (or minimal) peripheral contrast enhancement; (3) subcapsular lesions; or (4) less frequent co-occurrence with splenic abscesses.

Comparison of computed tomographic finding of the intraductal and periductal cholangiocarcinoma.

OBJECTIVE: To compare the CT findings of the intraductal and periductal cholangiocarcinoma (CCA) in Srinagarind Hospital. MATERIAL AND METHOD: The authors retrospectively reviewed the abdominal CT images (taken between January 2004 and December 2005) of 60 patients with pathologicalproof of CCA. There were 34 and 26 cases of the intraductal and periductal CCA, respectively. The bile duct dilatation, size and location of the intraductal and infiltrative extraductal masses, ductal wall enhancement and other associated findings (i.e., biliary stones, ascites, intra-abdominal lymphadenopathy and distant metastases) were compared and analyzed using the chi2 and Fisher exact tests. RESULTS: All cases of the intraductal and periductal CCA showed bile duct dilatation. The intraductal mass was seen in all cases of the intraductal CCA but none in the periductal CCA (p = 0.00). All intraductal mass sizes were >1 cm. Most (77%, n = 20/26) cases of the periductal CCA had an infiltrative extraductal mass, whereas none were found in the intraductal CCA (p = 0.00). Ductal wall enhancement was found in 73% (n = 19/26) of the periductal CCA and 26% (n = 9/34) of the intraductal CCA cases (p = 0.01). Only one case in each group presented with biliary stones. Half (50%, n = 13/26) and 12% (n = 3/26) of the periductal CCA cases demonstrated with intra-abdominal lymphadenopathy and ascites, respectively, vs. none in the intraductal CCA (p = 0.00 and 0.07, respectively). No distant metastasis was found in either group. CONCLUSION: The CT findings that helped to diferentiate the intraductal from periductal CCA include: the intraductal mass, an infiltrative extraductal mass, ductal wall enhancement and other associated findings such as intra-abdominal lymphadenopathy. Features of the intraductal CCA included the intraductal mass without intra-abdominal lymphadenopathy and ductal wall enhancement about 26% (9/34 cases).

Spatial analysis of hepatobiliary abnormalities in a population at high-risk of cholangiocarcinoma in Thailand.

Cholangiocarcinoma (CCA) is a serious health challenge with low survival prognosis. The liver fluke, Opisthorchis viverrini, plays a role in the aetiology of CCA, through hepatobiliary abnormalities: liver mass (LM), bile duct dilation, and periductal fibrosis (PDF). A population-based CCA screening program, the Cholangiocarcinoma Screening and Care Program, operates in Northeast Thailand. Hepatobiliary abnormalities were identified through ultrasonography. A multivariate zero-inflated, Poisson regression model measured associations between hepatobiliary abnormalities and covariates including age, sex, distance to water resource, and history of O. viverrini infection. Geographic distribution was described using Bayesian spatial analysis methods. Hepatobiliary abnormality prevalence was 38.7%; highest in males aged > 60 years (39.8%). PDF was most prevalent (20.1% of males). The Standardized Morbidity Ratio (SMR) for hepatobiliary abnormalities was highest in the lower and upper parts of the Northeast region. Hepatobiliary abnormalities specifically associated with CCA were also more common in males and those aged over 60 years and distributed along the Chi, Mun, and Songkram Rivers. Our findings demonstrated a high risk of hepatobiliary disorders in Northeast Thailand, likely associated with infection caused by O. viverrini. Screening for CCA and improvement of healthcare facilities to provide better treatment for CCA patients should be prioritized in these high-risk areas.

In Vitro Intraductal MRI and T2 Mapping of Cholangiocarcinoma Using Catheter Coils.

AIM: Diagnostic imaging of early-stage cholangiocarcinoma is challenging. A previous in vitro study of fixed-tissue liver resection specimens investigated T2 mapping as a method of exploiting the locally increased signal-to-noise ratio (SNR) of duodenoscope coils for improved quantitative magnetic resonance imaging (MRI), despite their non-uniform sensitivity. This work applies similar methods to unfixed liver specimens using catheter-based receivers. METHODS: Ex vivo intraductal MRI and T2 mapping were carried out at 3T on unfixed resection specimens obtained from cholangiocarcinoma patients immediately after surgery using a catheter coil based on a thin-film magneto-inductive waveguide, inserted directly into an intrahepatic duct. RESULTS: Polypoid intraductal cholangiocarcinoma was imaged using fast spin-echo sequences. High-resolution T2 maps were extracted by fitting of data obtained at different echo times to mono-exponential models, and disease-induced changes were correlated with histopathology. An increase in T2 was found compared with fixed specimens and differences in T2 allowed the resolution of tumour tissue and malignant features such as polypoid morphology. CONCLUSION: Despite their limited field of view, useful data can be obtained using catheter coils, and T2 mapping offers an effective method of exploiting their local SNR advantage without the need for image correction.