CT differentiation between tubo-ovarian and appendiceal origin of right lower quadrant abscess: CT, clinical, and laboratory correlation

ACR Appropriateness Criteria® Acute Pelvic Pain in the Reproductive Age Group: 2023 Update

This review focuses on the initial imaging in the reproductive age adult population with acute pelvic pain, including patients with positive and negative beta-human chorionic gonadotropin (β-hCG) levels with suspected gynecological and nongynecological etiology. For all patients, a combination of transabdominal and transvaginal pelvic ultrasound with Doppler is usually appropriate as an initial imaging study. If nongynecological etiology in patients with negative β-hCG is suspected, then CT of the abdomen and pelvis with or without contrast is also usually appropriate. In patients with positive β-hCG and suspected nongynecological etiology, CT of the abdomen and pelvis with contrast and MRI of the abdomen and pelvis without contrast may be appropriate. In patients with negative β-hCG and suspected gynecological etiology, CT of the abdomen and pelvis with contrast, MRI of pelvis without contrast, or MRI of pelvis with and without contrast may be appropriate. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Comparison of risk prediction models for the progression of pelvic inflammatory disease patients to sepsis: Cox regression model and machine learning model

Introduction

The present study presents the development and validation of a clinical prediction model using random survival forest (RSF) and stepwise Cox regression, aiming to predict the probability of pelvic inflammatory disease (PID) progressing to sepsis.

Methods

A retrospective cohort study was conducted, gathering clinical data of patients diagnosed with PID between 2008 and 2019 from the Medical Information Mart for Intensive Care (MIMIC)-IV database. Patients who met the Sepsis 3.0 diagnostic criteria were selected, with sepsis as the outcome. Univariate Cox regression and stepwise Cox regression were used to screen variables for constructing a nomogram. Moreover, an RSF model was created using machine learning algorithms. To verify the model's performance, a calibration curve, decision curve analysis (DCA), and receiver operating characteristic (ROC) curve were utilized. Furthermore, the capabilities of the two models for estimating the incidence of sepsis in PID patients within 3 and 7 days were compared.

Results

A total of 1064 PID patients were included, of whom 54 had progressed to sepsis. The established nomogram highlighted dialysis, reduced platelet (PLT) counts, history of pneumonia, medication of glucocorticoids, and increased leukocyte counts as significant predictive factors. The areas under the curve (AUCs) of the nomogram for prediction of PID progression to sepsis at 3-day and 7-day (3-/7-day) in the training set and the validation set were 0.886/0.863 and 0.824/0.726, respectively, and the C-index of the model was 0.8905. The RSF displayed excellent performance, with AUCs of 0.939/0.919 and 0.712/0.571 for 3-/7-day risk prediction in the training set and validation set, respectively.

Conclusion

The nomogram accurately predicted the incidence of sepsis in PID patients, and relevant risk factors were identified. While the RSF model outperformed the Cox regression models in predicting sepsis incidence, its performance exhibited some instability. On the other hand, the Cox regression-based nomogram displayed stable performance and improved interpretability, thereby supporting clinical decision-making in PID treatment.

Approach to Abdominal Imaging in 2022

Abdominal pain represents 5% to 7% of all emergency department presentations. Many patients require imaging for diagnosis, and choosing the appropriate imaging modality is a crucial decision point. Modern medicine offers a fantastic array of options including abdominal radiograph, computed tomography, MRI, and ultrasonography, but the plethora of alternatives can be paralyzing. This article introduces the commonly available modalities, discusses the advantages and disadvantages, and presents current recommendations for commonly diagnosed conditions.

Low-grade appendiceal mucinous neoplasms confined to the appendix: clinical manifestations and CT findings

The clinical findings and CT images are investigated in order to fulfill an early preoperative diagnosis and increase awareness of low-grade appendiceal mucinous neoplasm (LAMN) confined to the appendix. 17 cases with histologically proven LAMNs confined to the appendix were included in this study. All patients had received multiphase CT examinations before the surgery. The imaging criteria included shape, size, margin, attenuation, secondary degeneration and internal mass enhancement pattern. In CT images, all cases appeared as oval or tubular cystic masses (average attenuation 20.4±3.6 Hounsfield units), with the longest dimensions ranging from approximately 38 to 106 mm (mean 66.3 mm), and the ratio of length against width was 1.83 in average. The cystic wall was unevenly thickened, with a mean maximal wall thickness of 5.7 mm (>10 mm in 3 cases). The inner capsule wall was rough, and calcification was observed in 3 cases. A few amounts of periappendiceal fat stranding were noted in 2 cases. Mild ring mural enhancement of the cystic wall was seen during the arterial phase, with progressive enhancement during the portal venous phase. In addition, mini enhancing mural nodules was observed in 5 cases. Although preoperative diagnosis of LAMNs confined to the appendix remains challenging, it should be considered when a focal well-defined cystic mass with slightly higher than water attenuation, thickened cystic wall with ring mural enhancement and a characteristic progressive contrast enhancement in CT imaging, especially in older females with non-specific symptoms similar to appendicitis.

Clinical value of early laparoscopic therapy in the management of tubo-ovarian or pelvic abscess

Broad-spectrum antibiotics are the conservative treatment for tubo-ovarian abscess (TOA) or pelvic abscess, but the failure rate of antibiotic therapy remains higher in patients with a larger abscess. The present study aimed to evaluate the clinical value of early laparoscopic therapy in the management of TOA or pelvic abscess. A total of 100 patients were enrolled and their medical records were retrospectively analyzed after excluding 6 patients with malignant diseases. Based on the treatment they had received, the patients were divided into a conservative treatment group (n=41) and an early laparoscopic treatment group (n=53). In the conservative treatment group, 21 patients (51.2%) finally received laparoscopic exploration (late laparoscopic treatment group), and 20 patients (48.8%) achieved a success of antibiotic therapy (successful antibiotic therapy group). The cut-off value of abscess size for predicting antibiotic treatment failure was determined using receiver operating characteristic curve analysis. Multivariate logistic regression analyses were used to explore the association between the clinical variables and antibiotic therapy failure in conservative treatment group. The durations of elevated temperature >38.0°C and hospitalization were significantly longer in the conservative treatment group than those in the early laparoscopic treatment group (all P<0.001). The patients in the late laparoscopic treatment group had a larger abscess size than those in the successful antibiotic therapy group (6.2±1.8 cm vs. 4.8±1.4 cm, P=0.008). An abscess diameter of 5.5 cm was obtained as the cut-off of antibiotic failure, and the sensitivity and specificity were 81.0 and 85.0%, respectively. An abscess diameter of ≥5.5 cm was independently associated with antibiotic failure (odds ratio=5.724; 95%CI: 2.025–16.182; P=0.001). In conclusion, early laparoscopic treatment was associated with a better clinical prognosis than conservative treatment and late laparoscopic therapy for TOA or pelvic abscess patients.

Core curriculum case illustration: tubo-ovarian abscess

This is the 47th installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for Study online at: http://www.erad.org/page/CCIP_TOC.

How to differentiate acute pelvic inflammatory disease from acute appendicitis ? A decision tree based on CT findings

PURPOSE

To construct a decision tree based on CT findings to differentiate acute pelvic inflammatory disease (PID) from acute appendicitis (AA) in women with lower abdominal pain and inflammatory syndrome.

MATERIALS AND METHODS

This retrospective study was approved by our institutional review board and informed consent was waived. Contrast-enhanced CT studies of 109 women with acute PID and 218 age-matched women with AA were retrospectively and independently reviewed by two radiologists to identify CT findings predictive of PID or AA. Surgical and laboratory data were used for the PID and AA reference standard. Appropriate tests were performed to compare PID and AA and a CT decision tree using the classification and regression tree (CART) algorithm was generated.

RESULTS

The median patient age was 28 years (interquartile range, 22-39 years). According to the decision tree, an appendiceal diameter ≥ 7 mm was the most discriminating criterion for differentiating acute PID and AA, followed by a left tubal diameter ≥ 10 mm, with a global accuracy of 98.2 % (95 % CI: 96-99.4).

CONCLUSION

Appendiceal diameter and left tubal thickening are the most discriminating CT criteria for differentiating acute PID from AA.

KEY POINTS

• Appendiceal diameter and marked left tubal thickening allow differentiating PID from AA. • PID should be considered if appendiceal diameter is < 7 mm. • Marked left tubal diameter indicates PID rather than AA when enlarged appendix. • No pathological CT findings were identified in 5 % of PID patients.