Abdominal Radiology最新文献

Choledochal cysts are congenital anomalies of the bile ducts that are most often diagnosed in the pediatric population but are increasingly being detected in adults presenting with complications related to an underlying cyst burden and biliary malignancy. The Modified Todani Classification is commonly used to subdivide choledochal cysts into five groups based on anatomical locations and morphological characteristics. Magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP) demonstrate high diagnostic performance for choledochal malformations and early detection of cyst complications. MRI and MRCP are crucial for preoperative planning to delineate anatomy and exclude malignant transformation. This pictorial review will illustrate the spectrum of MR imaging for Todani classification of bile duct cysts and describe the various complications of choledochal cysts in adults.

Cystic lesions of the genitourinary (GU) tract in the pelvis represent a diverse group of entities that can be challenging to characterize due to overlapping anatomy and variable imaging appearances. While most lesions are benign, accurate identification is critical to guide appropriate clinical management and avoid misdiagnosis. This review presents a comprehensive, image-rich overview of cystic pelvic lesions, focusing on the anterior and middle compartments in both male and female patients. Imaging modalities such as ultrasound, CT, and MRI each provide distinct advantages depending on the clinical context and lesion characteristics. Key entities include bladder, urethral, and ureteral diverticula; urachal anomalies; prostatic utricle and Müllerian duct cysts; seminal vesicle and ejaculatory duct cysts; Gartner duct and Bartholin gland cysts; and infectious processes. Less common pathologies, such as lymphangiomas, benign cystic tumors, and mimics of cystic lesions, including bulking agents, hydrogel spacers, hernias, and cystic degeneration of solid tumors, are also addressed. This manuscript offers practical pearls and highlights potential pitfalls in the evaluation of cystic GU lesions. Familiarity with typical imaging features and potential mimics is essential to ensure diagnostic accuracy and improve patient outcomes.

Oncological imaging in the abdomen and pelvis can be complex. Several imaging pitfalls and mimics of oncology can create diagnostic uncertainty. A pitfall is a malignancy that is missed, either not visualized or misdiagnosed as a benign finding. A mimic is a benign entity that is misinterpreted as malignancy. This article will provide a case-based review with teaching tips to avoid various oncologic pitfalls and mimics in the abdomen and pelvis. The categories of pitfalls to be reviewed include spontaneous regression of primary malignancy, neoplasms resembling benign entities, eye-catching benign pathology with superimposed malignancy, false negative tumor markers, infiltrative malignancy, nuances with disease progression, and concomitant complications. The categories of mimics to be reviewed include benign neoplasms with aggressive growth pattern, benign entities with malignancy appearing enhancement patterns, infectious/inflammatory conditions, iatrogenic/foreign body reactions, and anatomic structures. Insight regarding certain pitfalls and mimics can help the radiologist improve diagnostic precision.

Purpose

To localize PSMA-avid lesions identified by PSMA PET-CT on separately performed prostate MRI and evaluate imaging findings on fused PET-CT/MRI.

Methods

Patients without prior history of clinically significant prostate cancer (csPCa: Gleason score [GS] 3 + 4 or higher) who had (1) PI-RADS 3 on prostate MRI between 2021 and 2023, (2) MRI/US fusion targeted biopsy for PI-RADS 3 lesion(s) and systemic biopsy, and (3) subsequent PSMA PET-CT were identified. PSMA PET-CT images were fused onto prostate MRI. PI-RADS 3 lesions were categorized by PRIMARY score. Discordant PSMA-avid lesions with PRIMARY scores 2–5 outside of PI-RADS 3 lesions were identified. Fisher’s exact test was used to compare the proportion of csPCa on targeted biopsy between PSMA-positive (PRIMARY score 3 or more) and PSMA-negative (PRIMARY score 1 or 2) PI-RADS 3 lesions. P < 0.05 was considered statistically significant.

Results

30 patients (mean age 67 years) with 38 PI-RADS 3 lesions were identified. 29 patients had csPCa, and one patient had GS 6. 22 PI-RADS 3 lesions were PSMA-positive (PRIMARY score 3 or more), of which 18 (81.8%) were csPCa on targeted biopsy; 16 PI-RADS 3 lesions were PSMA-negative, of which 4 (25.0%) were csPCa on targeted biopsy (p < 0.001). Sensitivity and specificity for the presence of csPCa on targeted biopsy was 81.8% and 75.0%. Out of 30 patients, 12 (40.0%) had 16 discordant PSMA-avid (PRIMARY score 2 or more) lesions and 10 patients had 10 discordant PSMA-positive lesions outside PI-RADS 3 lesions In 5 of those 12 (41.7%), discordant PSMA-avid lesions had higher PRIMARY score than PI-RADS 3 lesions. In 4 of those 5 (80%), systemic biopsy showed higher GS than targeted biopsy.

Conclusion

Lesion-level analysis showed PSMA-positive PI-RADS 3 lesions had higher probability of csPCa than PSMA-negative PI-RADS 3 lesions. Discordant PSMA-avid lesions with higher PRIMARY score than that of PI-RADS 3 lesions often represented another more aggressive focus not initially identified on MRI.

Purpose

To compare the clinical, MRI, and prognostic features of intrahepatic cholangiocarcinoma (ICCA) between patients with and without hepatitis B virus (HBV) infection.

Methods

We retrospectively analyzed 211 patients with ICCA who underwent preoperative MRI and curative-intent surgical resection between 2015 and 2018. Two radiologists independently reviewed MRI features. Clinicopathologic and MRI characteristics were compared according to HBV status. Recurrence-free survival (RFS) and overall survival (OS) were assessed using the Kaplan-Meier method and log-rank test. Recurrence rates were compared according to tumor site, and logistic regression analysis was used to identify independent predictors of intrahepatic recurrence.

Results

Among the 211 patients (mean age, 63.4 ± 10.5 years; 126 men), 81 (38.4%) were HBV-positive and 130 (61.6%) were HBV-negative. The purely mass-forming type of ICCA was more common in the HBV-positive group (91.4% vs. 76.9%; p = 0.007), whereas combined types were more frequent in the HBV-negative group. On MRI, peripheral tumor location was more frequent in the HBV-positive group (55.5% vs. 34.6%; p = 0.011), while bile duct invasion/dilatation (p < 0.001), secondary confluence involvement (p = 0.005), and periductal tumor infiltration (p = 0.030) were less common. Rim or non-rim arterial-phase enhancement (85.2% vs. 68.5%; p = 0.024) and radiologically-evident cirrhosis (19.8% vs. 8.5%; p = 0.017) were more frequent in HBV-positive patients. Although RFS and OS did not significantly differ between the groups (p ≥ 0.327), the intrahepatic recurrence rate was significantly higher in the HBV-positive group (37.0% vs. 23.1%; p = 0.029). HBV positivity was also identified as an independent predictor of intrahepatic recurrence (odds ratio, 1.93; p = 0.047).

Conclusion

HBV-associated ICCA demonstrates distinct MRI features and is associated with a higher rate of intrahepatic recurrence following curative resection.

The field of radiology education is undergoing a paradigm shift due to technological advancements and the increasing complexity of medical imaging. Traditional didactic teaching methods are progressively being supplemented or replaced by innovative pedagogical approaches that enhance engagement, competency, and clinical preparedness. This review examines the evolution of radiology education, highlighting novel teaching methodologies such as simulation-based training, artificial intelligence assisted learning, virtual and augmented reality, flipped classrooms, and case-based learning. Furthermore, this manuscript discusses the challenges of integrating these methodologies into radiology curricula and explores potential future directions in radiology education.

Background

Intrahepatic cholestasis of pregnancy (ICP) is a liver disorder that occurs during pregnancy, typically in the third trimester, and is associated with adverse fetal outcomes. Despite being well-recognized, the exact pathogenesis of ICP remains incompletely understood, with impaired hepatobiliary function hypothesized to play a significant role in its development.

Purpose

The study aims to evaluate the relationship between altered gallbladder motility and hepatobiliary dysfunction in pregnancies complicated by ICP.

Materials and methods

This was a prospective hospital-based study involving 90 participants: 30 non-pregnant controls and 60 pregnant women (30 with intrahepatic cholestasis of pregnancy (ICP), and 30 pregnant controls). The cholestasis group was further subdivided into an icteric group (elevated serum bilirubin levels) and an anicteric group (abnormal liver function tests but normal bilirubin levels). Gallbladder volume (GBV) was initially measured after an overnight fast (12–14 h). Following a standardized meal (75 g of bread and butter or 100 g of groundnut), GBV and ejection fraction were re-measured at multiple postprandial time points (15, 30, 45, 60, 75, and 90 min).

Results

The study enrolled 60 pregnant women in their third trimester (gestational weeks 28–40) and 30 non-pregnant controls. Among the pregnant women, 30 were diagnosed with ICP, which was further divided into an icteric group (n = 6) and an anicteric group (n = 24). The ICP group demonstrated consistently higher GB volumes and lower ejection fraction (EF) compared to non-pregnant and pregnant controls, with statistically significant differences across all time intervals. Within the ICP patients, the icteric group consistently exhibited higher GB volumes and lower EF values compared to anicteric group. Receiver operating characteristic (ROC) curve analysis revealed that the best post-prandial 15-min GB ejection fraction cutoff for predicting ICP was 53% and postprandial 15-min GB volume cutoff for predicting ICP was 9.5 ml,

Conclusion

Impaired gallbladder motility, characterized by increased GB volume and decreased EF, is a key feature of obstetric cholestasis. Gallbladder ultrasound measurements, particularly postprandial GB volume and EF, can serve as useful diagnostic tools for distinguishing between cholestasis of pregnancy and healthy pregnancies, with high sensitivity and specificity for identifying ICP in late pregnancy.

The kidney plays a crucial role in regulating the acid-base balance of the body. The development of kidney diseases is often accompanied by changes in the renal PH, protein, glucose, urea, and other metabolites. Chemical exchange saturation transfer (CEST) imaging is a new magnetic resonance imaging (MRI) technique based on the chemical exchange between solute and water protons. The potential of CEST imaging in renal metabolic imaging stems from its ability to provide image contrast based on specific molecular compositions at relevant millimolar physiological concentrations. In this article, we briefly introduce the fundamental principles of CEST imaging and its applications in various renal disorders, including acute kidney injury, chronic kidney disease, renal tumors, and renal allograft rejection. Finally, we discuss the challenges and prospects of CEST imaging in the field of kidney diseases.

Purpose

To evaluate the frequency and independent risk factors associated with transient severe motion artifact (TSM) during the arterial phase of gadoxetic acid–enhanced liver MRI in a Southeast Asian population.

Materials and methods

This retrospective study included 836 consecutive studies who underwent gadoxetic acid–enhanced MRI between October 2022 and October 2024 at a tertiary academic hospital. Two abdominal radiologists reviewed arterial phase images and graded motion artifacts using a validated 5-point scale; grades 4 and 5 were classified as TSM. Clinical and laboratory data were extracted from the electronic medical record. Univariable and multivariable logistic regression analyses were performed to identify predictors of TSM. Subgroup analyses were conducted based on age and body mass index (BMI).

Results

TSM artifacts were observed in 43 of 836 studies (5.14%). In multivariable analysis, older age (> 65 years) (adjusted OR 4.59; 95% CI 1.268–16.710; p = 0.021) and lower serum albumin (adjusted OR 0.33; 95% CI 0.143–0.761; p = 0.009) were independent predictors of TSM. Subgroup analyses demonstrated higher TSM incidence in patients aged ≥ 65 years (7.07% vs. 3.41%; p = 0.019) and in those with BMI > 30 kg/m² (11.11% vs. 4.73%; p = 0.052). Other variables, including sex, comorbidities, liver disease etiology, and fluid overload, were not significantly associated with TSM.

Conclusion

TSM during gadoxetic acid–enhanced liver MRI occurs in approximately 5% of patients and is independently associated with older age and lower serum albumin. Awareness of these risk factors can guide protocol optimization and personalized imaging strategies to improve arterial phase image quality.

Purpose

To explore the value of ultrasound (US) and contrast-enhanced ultrasound (CEUS) in differentiating mass-forming Pancreatitis (MFP) and pancreatic ductal adenocarcinoma (PDAC).

Methods

This retrospective study analyzed clinical and imaging data from 281 patients who underwent pancreatic CEUS between January 2018 and December 2023. Patients were randomly divided into training (n = 196) and validation (n = 85) sets. Logistic regression analyses were conducted to identify independent predictive imaging features for differentiating PDAC from MFP in the training set. Based on the identified predictors, two nomogram models were constructed: the US model and the US + CEUS model. The diagnostic performance of both models was assessed via the area under the receiver operating characteristic curve (AUC), calibration plots, Hosmer-Lemeshow test, and decision-curve analysis (DCA).

Results

Multivariate logistic regression analysis based on these factors identified taller-than-wide shape (P = 0.002, OR = 0.12), calcification (P = 0.003, OR = 13.76), and washout pattern (P = 0.002, OR = 0.13) as independent predictive factors for distinguishing PDAC from MFP. Compared to the US model, the US + CEUS model demonstrated better performance with AUC values 0.930 (95% CI: 0.895–0.965) in the training set and 0.914 (95% CI: 0.853–0.976) in the validation set. Calibration curve plots and the Hosmer-Lemeshow test (P > 0.05) confirmed that the model has good calibration, and DAC showed significant clinical benefit.

Conclusion

The nomogram model constructed using taller-than-wide shape, calcification, and washout pattern demonstrated excellent discriminative ability, accuracy, and clinical utility in differentiating PDAC from MFP.