Collision Tumor of the Ovary: Adult Granulosa Cell Tumor and Mesonephric-like Adenocarcinoma.

Collision tumors of the ovaries are rare, with only a few reports in the literature. Adult granulosa cell tumors are a relatively common primary tumor component of previously reported collision tumors. The combination of serous and mucinous tumors with adult granulosa cell tumors has been reported in several cases. On the other hand, mesonephric-like adenocarcinomas are rare neoplasms that commonly arise in the uterine corpus and ovaries. In this report, we present the case of a collision tumor composed of an adult granulosa cell tumor and mesonephric-like adenocarcinoma of the ovary in a 63-year-old woman. The initial magnetic resonance imaging findings showed a cystic mass with an internal hemorrhage, which suggested an adult granulosa cell tumor, and a solid mass with different enhancements. Microscopically, the tumor had two distinct components: An adult granulosa cell tumor and a mesonephric-like adenocarcinoma. Recognizing collision tumors consisting of slow-growing and aggressive tumors may prove beneficial in future diagnostic and treatment strategies.

Immunoglobulin G4-related disease mimicking an appendiceal neoplasm: a case report.

Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory condition characterized by chronic activation of the immune system and a tendency to form tumorous lesions. IgG4-RD is frequently characterized by the presence of tumor-like masses affecting multiple organs and is easily mistaken for a malignant neoplasm. However, IgG4-RD affecting the appendix is extremely rare, with only seven cases reported previously. We report the case of a woman in her early 60s who presented with insidious abdominal pain and radiological findings mimicking appendiceal neoplasms. After diagnosing appendiceal neoplasms, surgery was performed. The patient had a serum IgG4 concentration of <1.35 g/L, which did not satisfy one of the three revised comprehensive diagnostic criteria for IgG4-RD. A pathological examination was conducted, and the patient was diagnosed with appendiceal IgG4-RD. To the best of our knowledge, there have been no previously reported cases of IgG4-RD affecting the appendix in patients with low serum IgG4 concentrations. This report may prove beneficial for the future understanding of IgG4-RD and for the revision of diagnostic and treatment strategies.

Comparison of non-contrast abbreviated MRI and ultrasound as surveillance modalities for HCC.

BACKGROUND & AIMS: Ultrasonography (US) is recommended for HCC surveillance in high-risk patients but has limited performance in detecting early-stage HCC. We aimed to compare the diagnostic performance of biannual US and annual non-contrast abbreviated magnetic resonance imaging (NC-AMRI) as HCC surveillance modalities in high-risk patients. METHODS: This prospective, multicenter cohort study enrolled participants with an estimated annual risk of HCC greater than 5% between October 2015 and April 2017. Participants underwent six rounds of HCC surveillance at 6-month intervals, with both US and NC-AMRI at rounds 1, 3, and 5, and only US at rounds 2, 4, and 6. The sensitivity, diagnostic yield (DY), and false referral rate (FRR) for HCC detection by US and NC-AMRI were compared. RESULTS: In total, 208 participants underwent 980 US and 516 NC-AMRI examinations during 30 months of follow-up. Among them, 34 HCCs were diagnosed in 31 participants, with 20 (64.5%) classified as very early-stage and 11 (35.5%) as early-stage HCC. The sensitivity of annual NC-AMRI (71.0%, 22/31) was marginally higher than that of biannual US (45.2%, 14/31; p = 0.077). NC-AMRI showed a significantly higher DY than US (4.26% vs. 1.43%, p <0.001), with a similar FRR (2.91% vs. 3.06%, p = 0.885). A simulation of alternating US and NC-AMRI at 6-month intervals yielded a sensitivity of 83.9% (26/31), significantly exceeding that of biannual US (p = 0.006). CONCLUSIONS: Annual NC-AMRI showed a marginally higher sensitivity than biannual US for HCC detection in high-risk patients. The DY of annual NC-AMRI was significantly higher than that of biannual US, without increasing the FRR. Thus, alternating US and NC-AMRI at 6-month intervals could be an optimal surveillance strategy for high-risk patients. IMPACT AND IMPLICATIONS: Current guidelines permit the use of magnetic resonance imaging (MRI) as a surveillance tool for hepatocellular carcinoma in patients in whom ultrasonography (US) is inadequate. However, the specific indications, imaging sequences, and intervals for MRI surveillance remain unclear. In our study, we found that annual non-contrast abbreviated MRI exhibited marginally higher sensitivity and significantly better diagnostic yield than biannual US in patients at high risk of hepatocellular carcinoma. Alternating US and non-contrast abbreviated MRI at 6-month intervals led to significantly improved sensitivity compared to biannual US, making it a potentially optimal surveillance strategy for high-risk patients. GOV IDENTIFIER: NCT02551250.

Differentiating Uterine Sarcoma From Atypical Leiomyoma on Preoperative Magnetic Resonance Imaging Using Logistic Regression Classifier: Added Value of Diffusion-Weighted Imaging-Based Quantitative Parameters.

OBJECTIVE: To evaluate the added value of diffusion-weighted imaging (DWI)-based quantitative parameters to distinguish uterine sarcomas from atypical leiomyomas on preoperative magnetic resonance imaging (MRI). MATERIALS AND METHODS: A total of 138 patients (age, 43.7 ± 10.3 years) with uterine sarcoma (n = 44) and atypical leiomyoma (n = 94) were retrospectively collected from four institutions. The cohort was randomly divided into training (84/138, 60.0%) and validation (54/138, 40.0%) sets. Two independent readers evaluated six qualitative MRI features and two DWI-based quantitative parameters for each index tumor. Multivariable logistic regression was used to identify the relevant qualitative MRI features. Diagnostic classifiers based on qualitative MRI features alone and in combination with DWI-based quantitative parameters were developed using a logistic regression algorithm. The diagnostic performance of the classifiers was evaluated using a cross-table analysis and calculation of the area under the receiver operating characteristic curve (AUC). RESULTS: Mean apparent diffusion coefficient value of uterine sarcoma was lower than that of atypical leiomyoma (mean ± standard deviation, 0.94 ± 0.30 10-3 mm²/s vs. 1.23 ± 0.25 10-3 mm²/s; P < 0.001), and the relative contrast ratio was higher in the uterine sarcoma (8.16 ± 2.94 vs. 4.19 ± 2.66; P < 0.001). Selected qualitative MRI features included ill-defined margin (adjusted odds ratio [aOR], 17.9; 95% confidence interval [CI], 1.41-503, P = 0.040), intratumoral hemorrhage (aOR, 27.3; 95% CI, 3.74-596, P = 0.006), and absence of T2 dark area (aOR, 83.5; 95% CI, 12.4-1916, P < 0.001). The classifier that combined qualitative MRI features and DWI-based quantitative parameters showed significantly better performance than without DWI-based parameters in the validation set (AUC, 0.92 vs. 0.78; P < 0.001). CONCLUSION: The addition of DWI-based quantitative parameters to qualitative MRI features improved the diagnostic performance of the logistic regression classifier in differentiating uterine sarcomas from atypical leiomyomas on preoperative MRI.

[Multi-Detector CT Findings of Typical and Atypical Appendicitis: A Pictorial Essay]. / ì „í˜•ì  및 ë¹„ì „í˜•ì  충수염의 다중검출기컴퓨터단층촬영 소견: 임상화보.

Multi-detector CT (MDCT) is a highly accurate diagnostic tool that is commonly used to evaluate appendicitis and its complications. The diagnosis of appendicitis based on MDCT findings can be difficult and challenging when the observed findings are inconsistent with the typical features. Atypical appendicitis includes a wide spectrum of features, such as variable positions of the appendix and cecum, complications, and unusual pathological findings of secondary appendicitis that mimic or induce appendicitis. Our pictorial essay describes the diverse spectrum of atypical appendicitis and appendicitis-like conditions in terms of location abnormalities, complications, and uncommon pathologies, including related tumors, reactive appendicitis, appendiceal diverticulitis, and IgG4-related disease. Through this essay, the readers can become more familiar with MDCT findings of atypical appendicitis.

Predicting resection margin status of pancreatic neuroendocrine tumors on CT: performance of NCCN resectability criteria.

OBJECTIVE: To test the performance of the National Comprehensive Cancer Network (NCCN) CT resectability criteria for predicting the surgical margin status of pancreatic neuroendocrine tumor (PNET) and to identify factors associated with margin-positive resection. METHODS: Eighty patients with pre-operative CT and upfront surgery were retrospectively enrolled. Two radiologists assessed the CT resectability (resectable [R], borderline resectable [BR], unresectable [UR]) of the PNET according to NCCN criteria. Logistic regression was used to identify factors associated with resection margin status. κ statistics were used to evaluate interreader agreements. Kaplan-Meier method with log-rank test was used to estimate and compare recurrence-free survival (RFS). RESULTS: Forty-five patients (56.2%) received R0 resection and 35 (43.8%) received R1 or R2 resection. R0 resection rates were 63.6-64.2%, 20.0-33.3%, and 0% for R, BR, and UR diseases, respectively (all p ≤ 0.002), with a good interreader agreement (κ, 0.74). Tumor size (<2 cm, 2-4 cm, and >4 cm; odds ratio (OR), 9.042-18.110; all p ≤ 0.007) and NCCN BR/UR diseases (OR, 5.918; p = 0.032) were predictors for R1 or R2 resection. The R0 resection rate was 91.7% for R disease <2 cm and decreased for larger R disease. R0 resection and smaller tumor size in R disease improved RFS. CONCLUSION: NCCN resectability criteria can stratify patients with PNET into distinct groups of R0 resectability. Adding tumor size to R disease substantially improves the prediction of R0 resection, especially for PNETs <2 cm. ADVANCES IN KNOWLEDGE: Tumor size and radiologic resectability independently predicted margin status of PNETs.

Uterine Cervical Angioleiomyoma Mimicking Squamous Cell Carcinoma.

Angioleiomyoma, a rare variant of leiomyoma, is a benign tumor of mesenchymal origin. Angioleiomyomas of the female urogenital tract are extremely rare, with only six cases of uterine cervical angioleiomyoma previously reported in the literature. In this case study, we report on a 49-year-old female patient who presented with menorrhagia whose initial magnetic resonance imaging (MRI) findings suggested cervical squamous cell carcinoma (SCC). However, following the hysterectomy, histological examination confirmed the lesion to be angioleiomyoma. To the best of our knowledge, there have been no previously reported cases of angioleiomyomas presenting with MRI findings that are suggestive of uterine SCC. Recognizing that angioleiomyomas can mimic uterine malignancies on MRI may prove beneficial for future diagnostic and treatment strategies.

Unusual Duodenal Ulcer: Metastatic Urothelial Carcinoma of the Renal Pelvis.

Metastatic urothelial carcinoma of the renal pelvis (MUCP), a type of metastatic upper tract urothelial carcinoma (MUTUC), is a rare malignancy, and some patients with MUCP present with distant metastasis at the time of diagnosis. MUCP in the gastrointestinal tract is even rarer. Herein, we report a 78-year-old man with MUCP that presented as a duodenal ulcer. He complained of anorexia, dizziness, and melena for one month. Endoscopic examination at a local clinic revealed a duodenal hemorrhagic and ulcerative lesion, and the patient was referred. He noted dark-colored stools with increasing frequency, but he denied hematochezia, coffee ground emesis, weight changes, or abdominal pain. Gastroduodenoscopic examination at our hospital demonstrated an ulcerofungating lesion of the second portion of the duodenum. Colonoscopic findings showed no abnormality. Computed tomography showed a 6.7 cm sized mass abutting the inferior vena cava, second portion of the duodenum, lower pole of the right kidney, and right iliopsoas. The mass showed heterogeneous enhancement and internal hemorrhagic necrosis and infiltrated the perinephric soft tissues, the second portion of the duodenum, the right psoas muscle, the right renal vein, and the right adrenal gland. Duodenal biopsy showed moderately differentiated squamous cell carcinoma. Immunohistochemistry (IHC) showed diffuse and strong positivity for CK5/6. Tissue from the liver biopsy showed similar histopathologic features and showed GATA3 positivity on IHC. The imprint cytology smears of the liver tissue showed "cercariform" cell features. We confirmed the diagnosis as MUCP. This case illustrated a rare cause of a secondary duodenal tumor, MUCP.

Association between Posttreatment Serum Platelet-to-Lymphocyte Ratio and Distant Metastases in Patients with Hepatocellular Carcinoma Receiving Curative Radiation Therapy.

BACKGROUND: We sought to investigate whether serum immune and inflammatory parameters can help to predict distant metastasis (DM) in patients with unresectable hepatocellular carcinoma (HCC) undergoing curative radiation therapy (RT). METHODS: A total of 76 RT courses were analyzed. The following variables were included in the analysis: systemic inflammation index, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio (PLR), prognostic nutritional index (PNI), absolute lymphocyte count, lymphocyte-to-monocyte ratio, albumin, albumin-to-alkaline phosphatase ratio, RT-related parameters, and levels of total protein, hemoglobin, α-fetoprotein, and PIVKA-II. Distant control (DC) and overall survival (OS) rates were calculated and compared. RESULTS: The mean age was 61.4 years, and most patients were men (n = 62, 81.6%). The median RT fraction number and fractional doses were 12 (range, 4-30) and 5 (range, 2-12) Gy, respectively. With a median follow-up of 12 (range, 3.1-56.7) months, the 1-year DC and OS rates were 64.4% and 55.2%, respectively. The development of DM significantly deteriorated OS (p = 0.013). In the multivariate analysis, significant independent prognostic indicators for DC and OS rates were the highest posttreatment PLR (≤235.7 vs. >235.7, p = 0.006) and the lowest posttreatment PNI (≤25.4 vs. >25.4, p < 0.001), respectively. CONCLUSIONS: Posttreatment serum PLR might be helpfully used as a predictive biomarker of DM in unresectable HCC patients undergoing RT. Future research is necessary to confirm our findings.

Association between Vascular Calcification and Esophagojejunal Anastomotic Complications after Total Gastrectomy for Gastric Cancer: A Propensity-Matched Study.

Esophagojejunal anastomosis (EJA) complications after total gastrectomy are related to significant morbidity and mortality. The aim of this study was to evaluate the association between arterial calcifications and EJA complications such as leak and stricture for gastric cancer. Between January 2014 and October 2019, 30 patients with EJA complications after total gastrectomy were enrolled and matched to 30 patients without complications through retrospective data review. Arterial calcification grade on preoperative computed tomography (CT) was reported in the abdominal aorta and superior mesenteric artery (SMA) as "absent", "minor", or "major", and in the jejunal vascular arcade (JVA) and left inferior phrenic artery (LIPA) as "absent" or "present". A Chi-square test was used to compare the variables between the two groups. p-Value < 0.050 was considered statistically significant. Among 30 patients, the numbers of patients with leak and stricture were 23 and seven, respectively. Aortic calcifications were not associated with EJA complications regardless of their grade (p = 0.440). Only major SMA calcifications were associated with EJA complications, as they were present in five patients (16.7%) in the complication group and absent in the non-complication group (p = 0.020). Major SMA calcifications were more related to anastomotic stricture than leak. Three (13.0%) out of 23 patients with leak and two (28.6%) out of seven with stricture had major SMA calcifications (p = 0.028). No calcifications were detected in the JVA or LIPA in any of the 60 patients. Major SMA calcifications were found to be associated with EJA complications, especially in stricture.

Prognostic value of noggin protein expression in patients with resected gastric cancer.

BACKGROUND: Noggin and RNA-binding protein for multiple splicing 2 (RBPMS2) are known to regulate the expression of smooth muscle cells, endothelial cells, and osteoblasts. However, the prognostic role of combined Noggin and RBPMS2 expression in resected gastric cancer (GC) is unclear. METHODS: A total of 163 patients with GC who underwent gastrectomy were included in this study. The expression of Noggin and RBPMS2 proteins in tumor cells at the tumor center and invasive front of resected GC was evaluated by immunohistochemistry, and in conjunction with clinicopathological parameters the patient survival was analyzed. RESULTS: RBPMS2 protein expression was high at the tumor center (n = 86, 52.8%) and low at the invasive front (n = 69, 42.3%), while Noggin protein expression was high in both tumor center (n = 91, 55.8%) and the invasive front (n = 90, 55.2%). Noggin expression at the invasive front and tumor center was significantly decreased in advanced T stage, non-intestinal-type (invasive front, P = 0.008 and P <  0.001; tumor center lesion, P = 0.013 and P = 0.001). RBPMS2 expression at the invasive front was significantly decreased in non-intestinal-type and positive lymphatic invasion (P <  0.001 and P = 0.013). Multivariate analysis revealed that high Noggin protein expression of the invasive front was an independent prognostic factor for overall survival (hazard ratio [HR], 0.58; 95% confidence interval [CI]; 0.35-0.97, P <  0.036), but not at the tumor center (HR, 1.35; 95% CI; 0.81-2.26, P = 0.251). CONCLUSIONS: Our study indicates that high Noggin expression is a crucial prognostic factor for favorable outcomes in patients with resected GC.

Exploration of the potential capacity of fly ash and bottom ash derived from wood pellet-based thermal power plant for heavy metal removal.

This study was conducted to explore the potential capacity for the removal of heavy metals from the fly ash (FA) and bottom ash (BA) emitted by wood pellet thermal power plants. Fly ash consists of inorganic compounds such as CaSiO3, P2O5, and K2O, whereas BA shows properties very similar to the biochar derived from organic biomass. The adsorption properties of both FA and BA for Cd were described well by the Langmuir and pseudo-second-order models, and the maximum adsorption capacity of FA for Cd was 4.2 times higher than that of BA. The results indicate that FA can be applied to the treatment of wastewater that contains heavy metals over pH range from 2-6; however, BA is considered to be most effective for application with wastewater that contains heavy metals at a pH of 5-6. Study of the mechanism concluded that the adsorption of Cd by FA is dominated by the formation of Cd2SiO4 complexes by chemical reactions between CaSiO3 and Cd ions as well as via the precipitation of Cd(OH)2 in the neutral and alkaline solutions that is caused by the dissolution of K. It was found that the adsorption of Cd by BA was influenced by the binding of functional groups (CC and COH), coupled CaCO3 dissolution-CdCO3 precipitation reaction and ion exchange between some minerals with Si and Cd ions in weakly acidic conditions. Results indicate that the FA and BA emitted from wood pellet thermal power plants have high potential for heavy metal removal, and their practical use in the purification and restoration of heavy metals could be an effective way to reduce the waste produced by power plants and clean the environment.

Imprint cytology of histiocytic sarcoma manifesting as a retroperitoneal mass: A valuable aid for frozen section diagnosis.

Histiocytic sarcoma (HS) is a comparatively rare hematolymphoid neoplasm. Differential diagnosis of this entity has generally been proven to be so difficult that extensive immunohistochemical staining is required to confirm its presence. We herein present a case of HS manifesting as a retroperitoneal mass in which imprint cytology (IC) contributed to the diagnosis. A 77-year-old man was referred for the evaluation of a colonic tubulovillous polypoid lesion. Preoperative imaging revealed a 3 cm-sized polypoid lesion in the transverse colon. Incidentally, a retroperitoneal mass of 8 cm in the left para-aortic region was also detected. Diff-Quik stained IC slides were prepared as an adjunct to intraoperative pathology consultation. The smear exhibited moderate cellularity involving loosely cohesive cell clusters with intervening delicate vasculature. Most of the tumor cells consisted of large single cells with abundant eosinophilic cytoplasm that was vacuolated and foamy. The nuclei were predominantly large and eccentrically located. Mitotic figures were minimal in number and finely granular brown pigments were occasionally observed. A frozen section diagnosis was reported as a malignant neoplasm, and a histologic diagnosis of HS was confirmed by conducting a battery of immunohistochemical stains: negative for pan-cytokeratin, EMA, CD117, HMB45, Melan A, CD30, PAX5, CD20, S-100, and CD23 but strong positive for vimentin and CD68. This entity is rarely described in terms of cytopathologic features. This case study highlights how cytopathologists should be aware of HS as a retroperitoneal lesion and should become familiar with cytomorphologic features.

The added value of pelvic surveillance by MRI during postoperative follow-up of rectal cancer, with a focus on abbreviated MRI.

OBJECTIVES: To assess the added value of MRI over CT for the detection of pelvic recurrence during postoperative surveillance after rectal cancer surgery and to compare the diagnostic accuracy for pelvic recurrence achieved with abbreviated MRI (aMRI) with that of conventional enhanced MRI (cMRI). METHODS: Patients who underwent rectal cancer surgery followed by MRI in addition to the standard CT follow-up protocol were evaluated retrospectively. Two readers independently scored images from CT, cMRI, and aMRI, which consisted of T2-weighted and diffusion-weighted imaging, to rate the likelihood of recurrence. Diagnostic accuracy and ROC curves were calculated. The patients were divided into two groups for risk-adapted surveillance according to risk of recurrence: high-risk (n = 157) and low-risk (n = 169) groups. RESULTS: In total, 579 MRIs from 326 patients were assessed. A total of 48 pelvic recurrences occurred in 33 patients. The AUC in cMRI, aMRI, and CT were 0.98, 0.99, and 0.84, respectively. The difference in performance between CT and cMRI or aMRI for identifying recurrence was statistically significant (p < 0.001). Both cMRI and aMRI showed superior performance compared with CT in the high-risk group (p < 0.001), but this was not the case in the low-risk group (p = 0.13). Furthermore, the diagnostic accuracy of aMRI was similar to that of cMRI. CONCLUSIONS: The addition of MRI to the postoperative surveillance protocol may result in an improvement in the detection of pelvic recurrence after rectal cancer surgery. For patients at high risk of recurrence, an aMRI surveillance may be justified to improve the diagnostic yield. KEY POINTS: • The addition of MRI to the postoperative surveillance protocol improved the diagnostic yield in patients at a high risk of recurrence. • Abbreviated non-enhanced MRI with DWI allows detection of pelvic recurrence with a diagnostic accuracy that is similar to that of contrast-enhanced MRI (AUC, 0.99 and 0.98, respectively; p = 0.12). • Abbreviated MRI that is restricted to high spatial resolution structural imaging and diffusion-weighted imaging takes less time and can be carried out without the need for injection of a contrast agent.

[Multidetector CT Findings of Solid Organ Injury Based on 2018 Updated American Association for the Surgery of Trauma Organ Injury Scaling System]. / 2018 ê°œì • ë¯¸êµ­ì™¸ìƒìˆ˜ìˆ í˜‘íšŒ ë³µë¶€ê³ í˜•ìž¥ê¸° 손상척도에 따른 다중검출 CT 소견.

The newly revised 2018 Organ Injury Scale (OIS) has a similar format to the previous American Association for Surgery and Trauma (AAST) Emergency General Surgery Grading System, dividing the criteria for grading solid organ damage into three groups; imaging, operation, and pathology. The most significant alteration in the OIS system 2018 revision is the incorporation of multidetector CT (MDCT) findings of vascular injury including pseudoaneurysm and arteriovenous fistula. Similar to the previous OIS, the highest of the three criteria is assigned the final grade. In addition, if multiple grade I or II injuries are present, one grade is advanced for multiple injuries up to grade III. This pictorial essay demonstrates the MDCT findings of solid organ injury grades based on the 2018 OIS system.

Lipiodol Pneumonitis Following Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma.

Transcatheter arterial chemoembolization (TACE) is a useful palliative therapeutic modality for hepatocellular carcinoma (HCC). Postembolization syndromes, such as fever, abdominal pain, and elevated liver enzyme levels are commonly known complications of TACE. One post-TACE pulmonary complication, lipiodol pneumonitis, is rarely reported. Lipiodol pneumonitis after TACE appears to be associated with chemical injury due to accidental perfusion of lipiodol to the lung vasculature, promoted by arteriovenous shunts within the hypervascular HCC. Here, we report a 42-year-old man with unresectable HCC and hepatic vein thrombosis. The patient was initially treated with TACE. The following day after TACE, acute respiratory symptoms such as dyspnea and cough developed with decreased oxygen saturation. Chest X-ray and computed tomography showed multiple patches and diffuse ground-glass opacities in both lung fields, suggesting of lipiodol pneumonitis. The patient's condition and radiologic abnormalities subsequently improved after 2 weeks of conservative treatment alone.

Diagnostic value of magnetic resonance cholangiopancreatography to detect bile duct stones in acute biliary pancreatitis.

OBJECTIVES: This study aims to evaluate the diagnostic value of magnetic resonance cholangiopancreatography (MRCP) in detecting common bile duct (CBD) stones in acute biliary pancreatitis (ABP). METHODS: The medical records of patients presenting with ABP from January 2008 to July 2013 were reviewed to assess the value of MRCP in detecting CBD stones in ABP. Endoscopic retrograde cholangiopancreatography (ERCP) was used as the reference standard to assess the diagnostic yield of MRCP in detecting choledocholithiasis. When ERCP was unavailable, intraoperative cholangiography or clinical follow-up was used as the reference standard. RESULTS: Seventy-eight patients who underwent MRCP were diagnosed with ABP, and thirty of the 78 patients (38%) were confirmed to have CBD stones per the study protocol. The sensitivity of MRCP in detecting CBD stones in ABP was 93.3% compared to 66.7% for abdominal CT (P < 0.008). The overall accuracy of MRCP in detecting choledocholithiasis was 85.9% compared to 74.0% for abdominal CT (P < 0.041). The area under the receiver operating characteristic curve (AUC) of MRCP in detecting CBD stones was 0.882, which was more accurate than the AUC of 0.727 for abdominal CT (P = 0.039). In 38 patients who underwent ERCP, the sensitivity and negative predictive value of MRCP in detecting CBD stones were both 100% regardless of the dilatation of the bile duct (≥7 mm versus < 7 mm). CONCLUSION: MRCP is an effective, noninvasive modality to detect CBD stones in ABP and can help identify patients who require ERCP.