MRI evaluation of acute appendicitis in pregnancy

CAR/CETARS/CSAR Practice Guideline on Imaging the Adult Patient With Right Lower Quadrant Pain

In 2023, the Canadian Society of Abdominal Radiology (CSAR) and Canadian Emergency, Trauma, and Acute Care Radiology Society (CETARS) received Canadian Association of Radiologists (CAR) member feedback that there was an unmet educational need for guidance in the imaging investigation of right lower quadrant (RLQ) pain. Members requested specific guidance on how to handle controversial scenarios including which test to order when, specifics of imaging protocols, and managing pregnant patients who have RLQ pain-all from a Canadian perspective. After conducting an exhaustive literature review, the working group agreed that a Canadian-specific set of guidelines was warranted. The management recommendations presented in this guideline were discussed as a group to achieve expert consensus. As the workup for RLQ pain can vary considerably in the paediatric population, the scope of this paper was restricted to adults (18 years of age or older). Whenever possible, the best evidence was used to inform the clinical guidance, and where gaps existed, the guidelines reflect consensus among experts in the field. The result is a framework to aid in this process of managing patients with RLQ pain across various clinical scenarios while addressing current questions and controversies, particularly those most relevant to the Canadian healthcare system.

Analysis of risk factors for complicated appendicitis during pregnancy and evaluation of clinical prediction model: A prospective cohort study

OBJECTIVE

To investigate the risk factors and the value of clinical prediction model for complicated appendicitis (CA) during pregnancy.

METHODS

Prospective analysis of pregnant patients who underwent appendectomy at a single tertiary care center between February 2020 and February 2023 and who ultimately had pathologically confirmed acute appendicitis (AA). According to intraoperative conditions and postoperative pathology, they were divided into the CA group and the uncomplicated appendicitis (UA) group. The two groups of patients were then compared in terms of demographic characteristics, disease features, ancillary tests and predictive models of acute appendicitis.

RESULTS

A total of 90 patients with AA in pregnancy were included, 21 of whom had CA in pregnancy and 69 had UA in pregnancy. Multivariate regression analysis showed that gestational week, neutrophil ratio and C-reactive protein (CRP) were independent risk factors for CA during pregnancy. Relative to the first trimester, the third trimesters had an increased risk of complicated appendicitis (OR = 12.48, 95% CI: 1.56-99.57, P = 0.017). Neutrophil ratio ≥85.30% (OR = 24.54, 95% CI: 2.59-232.72, P = 0.005) and CRP ≥34.26 mg/L (OR = 7.86, 95% CI: 2.18-28.38, P = 0.002) had a significantly increased risk of CA. The AIR and AAS score models were statistically different between the two groups, but with a lower sensitivity of 52.38% and 42.86%, respectively.

CONCLUSION

The third trimesters, neutrophil ratio ≥85.30% and CRP ≥34.26 mg/L may be key predictors of CA in pregnancy. The current scoring model is inadequate to identify complex appendicitis in pregnancy and further research is needed.

Concomitant Paratubal Cyst and Isolated Fallopian Tube Torsion Masquerading as Acute Appendicitis in a Pregnant Female

Abdominal pain in pregnant individuals presents diagnostic challenges, especially when appendicitis is suspected. We report a rare case of a 26-year-old pregnant female with recurrent right lower quadrant (RLQ) abdominal pain initially misdiagnosed as a urinary tract infection. Diagnostic uncertainty led to a magnetic resonance imaging (MRI) scan, which revealed a right adnexal cystic structure and a thickened tubular structure adjacent to the cecal pole, raising concerns of complicated appendicitis. Subsequent diagnostic laparoscopy revealed a right-sided fallopian tube paratubal cyst with 360-degree torsion and associated fallopian tube torsion without the involvement of the ovary. The cyst was successfully excised, and the patient subsequently delivered a healthy baby via emergency lower section caesarean section. Abdominal pain during pregnancy has various causes. Diagnosing appendicitis during pregnancy is challenging due to anatomical and physiological changes. Ultrasound (US) is commonly used but has limited accuracy. Computed tomography (CT) is avoided due to radiation risks, while MRI is increasingly used and shows high diagnostic accuracy or aids in alternative diagnoses. Regardless of the diagnosis, the prompt recognition of intraabdominal pathology is crucial to prevent fetal morbidity. This case highlights the challenges in the accurate diagnosis of abdominal pain during pregnancy and emphasizes the importance of considering alternative pathologies to prevent delays in treatment and complications. Clinicians should consider diagnostic laparoscopy for pregnant patients with equivocal investigations and lower abdominal pain. The differential diagnosis may include both common and rare causes such as concomitant paratubal cyst and isolated fallopian tube torsion (IFTT), emphasizing a high index of suspicion and collaboration with obstetric colleagues to ensure optimal care.

Development of a nomogram for the prediction of complicated appendicitis during pregnancy

BACKGROUND

Complicated appendicitis during pregnancy directly affects the clinical prognosis of both mother and fetus. However, accurate identification of complicated appendicitis in pregnancy is fraught with various challenges. The purpose of this study was to identify the risk factors and to develop a useful nomogram to predict complicated appendicitis during pregnancy.

METHODS

This retrospective study involved pregnant women who underwent appendectomy at the Maternal and Child Health Hospital of Hubei Provincial from May 2016 to May 2022 and who ultimately had histopathological confirmed acute appendicitis. Univariate and multivariate logistic regression were applied to analyze clinical parameters and imaging features as a way to identify risk factors. Then, nomogram and scoring systems predicting complicated appendicitis in pregnancy were constructed and evaluated. Finally, the potential non-linear association between risk factors and complicated appendicitis was analyzed using restricted cubic splines.

RESULTS

Three indicators were finally identified for the construction of the nomogram: gestational weeks, C-reactive protein (CRP), and neutrophil percentage (NEUT%). To improve the clinical utility, the gestational weeks were divided into three periods (first trimesters, second trimesters, and third trimesters), while the optimal cut-offs for CRP level and NEUT% were found to be 34.82 mg/L and 85.35%, respectively. Multivariate regression analysis showed that third trimesters (P = 0.013, OR = 16.81), CRP level ≥ 34.82 mg/L (P = 0.007, OR = 6.24) and NEUT% ≥85.35% (P = 0.011, OR = 18.05) were independent risk factors for complicated appendicitis. The area under the ROC curve (AUC) of the nomogram predicting complicated appendicitis in pregnancy was 0.872 (95% CI: 0.803-0.942). In addition, the model was shown to have excellent predictive performance by plotting calibration plots, Decision Curve Analysis (DCA), and clinical impact curves. When the optimal cut-off point of the scoring system was set at 12, the corresponding AUC, sensitivity, specificity, Positive Likelihood Ratio (PLR), Negative Likelihood Ratio (NLR), Positive Predictive Value (PPV), and Negative Predictive Value (NPV) values were AUC: 0.869(95% CI: 0.799-0.939),100%, 58.60%, 2.41, 0, 42%, and 100%, respectively. The restricted cubic splines revealed a linear relationship between these predictors and complicated appendicitis during pregnancy.

CONCLUSIONS

The nomogram utilizes a minimum number of variables to develop an optimal predictive model. Using this model, the risk of developing complicated appendicitis in individual patients can be determined so that reasonable treatment choices can be made.

Rapid MRI Abdomen for Assessment of Clinically Suspected Acute Appendicitis in the General Adult Population: a Systematic Review

OBJECTIVES

To perform a systematic review on the use of magnetic resonance imaging (MRI) of the abdomen to evaluate clinically suspected appendicitis in the general adult population. We examined the diagnostic accuracy, the reported trends of MRI use, and the factors that affect the utility of MRI abdomen, including study duration and cost-benefits.

METHODS

We conducted a systematic literature search on PubMed, MEDLINE, Embase, Web of Science, and Cochrane Library databases. We enrolled primary studies investigating the use of MRI in diagnosing appendicitis in the general adult population, excluding studies that predominantly reported on populations not representative of typical adult appendicitis presentations, such as those focusing on paediatric or pregnant populations.

RESULTS

Twenty-seven eligible primary studies and 6 secondary studies were included, totaling 2,044 patients from eight countries. The sensitivity and specificity of MRI for diagnosing appendicitis were 96% (95% CI: 93-97%) and 93% (95% CI: 80-98%), respectively. MRI can identify complicated appendicitis and accurately propose alternative diagnoses. The duration of MRI protocols in each primary study ranged between 2.26 and 30 minutes, and only one study used intravenous contrast agents in addition to the non-contrast sequences. Decision analysis suggests significant benefits for replacing computed tomography (CT) with MRI and a potential for cost reduction. Reported trends in MRI usage showed minimal utilisation in diagnostic settings even when MRI was available.

CONCLUSIONS

MRI accurately diagnoses appendicitis in the general adult population and improves the identification of complicated appendicitis or alternative diagnoses compared to other modalities using a single, rapid investigation.

A Review of Radiological Investigations in Cases of Acute Appendicitis in a Tertiary Care Hospital

INTRODUCTION

Acute appendicitis is the most common non-traumatic surgical emergency and early diagnosis and management are crucial to decrease morbidity and mortality. There is a variety of scoring systems and radiological investigations that have been used in the diagnosis of acute appendicitis. Hence, the aim of this study is to assess the diagnostic approach in patients with suspected appendicitis in a tertiary care hospital, focusing on the radiological burden.

METHODS

This is a cross-sectional study reviewing the electronic and manual medical records of all adult patients admitted with the diagnosis of acute appendicitis between January 2018 and December 2018 in Salmaniya Medical Complex, Manama, Bahrain. A review of the method of diagnosis (clinical, ultrasound, computed tomography, or others) was done, with a comparison to histopathological results in those that underwent surgical intervention to determine sensitivity and specificity.

RESULTS

In the study period, 488 patients were admitted with acute appendicitis; out of these, 461 underwent surgical intervention. A total of 66 CT scans and 148 ultrasounds were conducted for these patients, out of which 57% of ultrasounds and 86% of CT scans accurately diagnosed acute appendicitis based on histopathological diagnosis, resulting in a sensitivity of 65% and 92%, respectively, and a specificity of 56% and 25%, respectively.

CONCLUSION

The most accurate method of diagnosis of acute appendicitis (highest sensitivity) is CT scanning. However, a prospective study with a detailed assessment of complications of appendicitis is recommended.

Accuracy of Point-of-care Ultrasound in Diagnosing Acute Appendicitis During Pregnancy

Introduction: Acute appendicitis is the most common non-obstetrical surgical emergency in pregnancy. Ultrasound is the imaging tool of choice, but its use is complicated due to anatomical changes during pregnancy and depends on the clinician’s expertise. In this study, our aim was to investigate the diagnostic accuracy of point-of-care ultrasound (POCUS) in suspected appendicitis in pregnant women. Methods: We conducted a retrospective analysis of all pregnant women undergoing POCUS for suspected appendicitis between June 2010–June 2020 in a tertiary emergency department. The primary outcome was to establish sensitivity, specificity, and likelihood ratios of POCUS in diagnosing acute appendicitis, overall and for each trimester. We used histology of the appendix as the reference standard in case of surgery. If appendectomy was not performed, the clinical course until childbirth was used to rule out appendicitis. If the patients underwent magnetic resonance imaging (MRI), we compared readings to POCUS. Results: A total of 61 women were included in the study, of whom 34 (55.7%) underwent appendectomy and in 30 (49.2%) an acute appendicitis was histopathologically confirmed. Sensitivity of POCUS was 66.7% (confidence interval [CI] 95% 47.1-82.7), specificity 96.8% (CI 95% 83.3-99.9), and positive likelihood ratio 20.7. Performance of POCUS was comparable in all trimesters, with highest sensitivity in the first trimester (72.7%). The MRI reading showed a sensitivity of 84.6% and a specificity of 100%. In the four negative appendectomies a MRI was not performed. Conclusion: Point-of-care ultrasound showed a high specificity and positive likelihood ratio in diagnosing acute appendicitis in pregnant women in all trimesters with suspected appendicitis. In negative (or inconclusive) cases further imaging as MRI could be helpful to avoid negative appendectomy.

MRI as First Line Imaging for Suspected Acute Appendicitis during Pregnancy: Diagnostic Accuracy and level of Inter-Radiologist Agreement

OBJECTIVE

Evaluation of acute appendicitis (AA) in pregnancy is supported with diagnostic imaging. Typically, ultrasound (US) is performed first, and then often followed by magnetic resonance imaging (MRI) due to continued diagnostic uncertainty. The purpose of our study was to evaluate the sensitivity, specificity, and accuracy of US as compared to MRI and to evaluate the inter-radiologist agreement amongst body Radiologists with varying levels of expertise.

MATERIALS AND METHODS

We performed a retrospective study of 364 consecutive pregnant patients with clinical suspicion of AA at a single center over a 6-year period. Sensitivity, Specificity, accuracy, positive and negative predictive values were calculated for US and MRI. Inter Radiologist agreement was determined using Cohen's Kappa analysis between original interpreting Radiologist and retrospective review by expert Radiologist.

RESULTS

Thirty-one of 364 patients (8.5%) underwent appendectomy based on preoperative diagnosis, with confirmation of acute appendicitis (AA) by pathology in 19. US was able to visualize the appendix in only 6 (1.65%), 5 of whom had appendicitis. 141 patients underwent MRI, and correctly diagnosed appendicitis in 9. No patient with a negative MRI diagnosis had AA. The sensitivity, and negative predictive value for diagnosing AA with MRI was 100%. The MRI inter-reader agreement for appendix visualization and overall accuracy were 87.9 and 98% with Cohen Kappa of 0.7 and 0.56 respectively.

CONCLUSIONS

Our data suggests that MRI should be considered the first line imaging modality in pregnant patients suspected of having AA. Body Radiologists with varied levels of experience in MRI readouts had substantial agreement.

MRI in Pregnancy and Precision Medicine: A Review from Literature

Magnetic resonance imaging (MRI) offers excellent spatial and contrast resolution for evaluating a wide variety of pathologies, without exposing patients to ionizing radiations. Additionally, MRI offers reproducible diagnostic imaging results that are not operator-dependent, a major advantage over ultrasound. MRI is commonly used in pregnant women to evaluate, most frequently, acute abdominal and pelvic pain or placental abnormalities, as well as neurological or fetal abnormalities, infections, or neoplasms. However, to date, our knowledge about MRI safety during pregnancy, especially about the administration of gadolinium-based contrast agents, which are able to cross the placental barrier, is still limited, raising concerns about possible negative effects on both the mother and the health of the fetus. Contrast agents that are unable to cross the placenta in a way that is safe for the fetus are desirable. In recent years, some preclinical studies, carried out in rodent models, have evaluated the role of long circulating liposomal nanoparticle-based blood-pool gadolinium contrast agents that do not penetrate the placental barrier due to their size and therefore do not expose the fetus to the contrast agent during pregnancy, preserving it from any hypothetical risks. Hence, we performed a literature review focusing on contrast and non-contrast MRI use during pregnancy.

Acute appendicitis–advances and controversies

Being one of the most common causes of the acute abdomen, acute appendicitis (AA) forms the bread and butter of any general surgeon’s practice. With the recent advancements in AA’s management, much controversy in diagnostic algorithms, possible differential diagnoses, and weighing the management options has been generated, with no absolute consensus in the literature. Since Alvarado described his eponymous clinical scoring system in 1986 to stratify AA risk, there has been a burgeoning of additional scores for guiding downstream management and mortality assessment. Furthermore, advancing literature on the role of antibiotics, variations in appendicectomy, and its adjuncts have expanded the surgeon’s repertoire of management options. Owing to the varied presentation, diagnostic tools, and management of AA have also been proposed in special groups such as pregnant patients, the elderly, and the immunocompromised. This article seeks to raise the critical debates about what is currently known about the above aspects of AA and explore the latest controversies in the field. Considering the ever-evolving coronavirus disease 2019 situation worldwide, we also discuss the pandemic’s repercussions on patients and how surgeons’ practices have evolved in the context of AA.

The diagnostic role of hemogram parameters in pregnant appendicitis

Background: Acute appendicitis is the most frequently encountered non-obstetric disease requiring surgical intervention during pregnancy. Early diagnosis reduces maternal and fetal morbidity / mortality rates. Aim: This study aims to investigate hemogram parameters in the diagnosis of acute appendicitis in pregnant women. Material and Methods: A retrospective case-controlled study was conducted in three groups. Thirty-nine pregnant patients with acute appendicitis (Group A), 39 fertile nonpregnant patients with acute appendicitis (Group B), and 39 healthy pregnant women (Group C) were included in the study. WBC, neutrophil count, lymphocyte count, NLR, PLR, MPV and RDW values were compared. Results: The mean NLR values in group A, group B and group C were 7.39 (1.58–46.6), 5.66 (1–20) and 4.23 (1.54–10.77) respectively, and there was a significant difference in NLR values between the groups (P= 0.002). The mean PLR values in group A, group B and group C were 159.09 (69.1–574), 134.28 (21.5-360) and 120 (68.7–334) and difference was statistically significant (P= 0.019). Cutoff points for WBC count was 14155 106/μL (51,3% sensitivity, 82,1% specificity), for neutrophil count is 10955 106/μL (53,8% sensitivity, 84,6% specificity), for NLR is 9.23 (46,2% sensitivity, 92,3% specificity) and PLR is 157,6 (51,3% sensitivity and 82,1% specificity) NLR had largest area under the curve with 0.667 NLR. Conclusion: Neutrophil count, WBC and PLR were found to be the most valuable inflammatory parameters however, RDW, Lymphocyte count, and MPV levels are not found valuable markers in terms of sensitivity and specificity in the diagnosis of acute appendicitis in pregnant patients by this study.

Appendicitis with concurrent COVID-19 infection in a patient during the third trimester of pregnancy

This article presents an unusual case of appendicitis in pregnancy complicated by the novel coronavirus (SARS-CoV-2). The novel coronavirus has affected the way medicine is practised across most parts of the world with over 160 000 000 global cases to date. Tackling management of these cases is more complex when other pathological processes are ongoing. Appendicitis is a common occurrence in pregnancy, with most obstetric centres seeing about one or two cases a year. Though maternal morbidity and mortality are relatively unimpacted by this event, fetal loss and preterm labour are common sequelae. This case involves a 35-year-old woman presenting in her third trimester with abdominal pain and who went on to be diagnosed with concurrent appendicitis and SARS-CoV-2 infection. Although spinal anaesthesia would be most appropriate as it avoids aerosol generation, general anaesthetic techniques were indicated due to thrombocytopenia in this case. She underwent a successful appendicectomy, although preterm delivery was indicated as a result of maternal and fetal concerns.

Magnetic resonance imaging reduces the rate of unnecessary operations in pregnant patients with suspected acute appendicitis: a retrospective study

Purpose

This is a retrospective single-institution study performed to compare the rate of unnecessary operations in pregnant women with suspected acute appendicitis with and without the use of MRI.

Methods

The study subjects were all pregnant women with suspected acute appendicitis admitted to a tertiary institution from January 2012 to December 2019. If acute appendicitis was not excluded clinically and by ultrasound (US), laparoscopies were performed until May 2017 (US-only group). MRI was added as a diagnostic tool when US was inconclusive from May 2017 (US + MRI group). Surgery was considered unnecessary when no inflamed appendix was found. The rate of unnecessary surgery, postoperative complications, length of stay were analyzed.

Results

Seventy-six women were included in the study; 38 women in the US-only group and 38 women in the US + MRI group. There were no differences in admission characteristics between the groups. One of 38 women (2.6%) underwent unnecessary surgery in the US + MRI group vs. 10 of 38 (26.3%) in the US-only group (P = 0.007). The patients in the US + MRI group were significantly less likely to undergo a diagnostic operation than in the US-only group (5.26% vs. 55.3%, respectively; P < 0.001) and their hospital stay was significantly shorter (0.74 ± 1.64 days vs. 3.7 ± 3.0 days, respectively; P < 0.001). The obstetric outcomes were not different between the groups. MRI had a sensitivity of 83.3% and specificity of 100% in the series.

Conclusion

The rate of unnecessary surgery was significantly reduced in pregnant women, who underwent MRI after inconclusive transabdominal US.

Pregnancy and appendicitis: a systematic review and meta-analysis on the clinical use of MRI in diagnosis of appendicitis in pregnant women

Background

The aim of this systematic review and meta-analysis was to evaluate the clinical use of MRI for the evaluation of acute appendicitis during pregnancy.

Methods

The searches were conducted by two independent researchers (MK, MS) to find the relevant studies published from 1/1/2009 until end of 30/12/2018. We searched for published literature in the English language in MEDLINE via PubMed, EMBASETM via Ovid, The Cochrane Library, and Trip database. For literature published in other languages, we searched national databases (Magiran and SID), KoreaMed, and LILACS. The keywords used in the search strategy are Pregnancy [MeSH], Pregnant [MeSH] OR-Magnetic resonance imaging [MeSH] OR-Appendicitis [MeSH] OR-Ultrasound, [MeSH] OR, imaging, MRI [MeSH] OR"،" and Right lower quadrant pain [MeSH]. The risk of bias of every article was evaluated by using QUADAS-2. On the basis of the results from the 2 × 2 tables, pooled measures for sensitivity, specificity, diagnostic odds ratio (DOR), and area under the curves (AUC) along with their 95% confidence intervals (CIs) were calculated using the DerSimonian Lair methodology.

Results

As many as 1164 studies were selected. After analyzing the correspondence of the studies with the required criteria, 19 studies were selected for the final review. For appendicitis in pregnancy, the MRI sensitivity was 91.8% at the 95% confidence interval of (95% CI 87.7-94.9%). At the confidence interval of 95%, the specificity was 97.9% (95% CI 0.97.2-100%). The risk of bias in the studies conducted was measured using the QUADAS-2 tool.

Conclusion

MRI has high sensitivity and specificity (91.8%, 97.9% respectively) for the diagnosis of acute appendicitis in pregnant patients with clinically suspected appendicitis. It is an excellent imaging technique in many instances, which does not expose a fetus, or the mother, to ionizing radiation, making it an excellent option for pregnant patients with suspected acute appendicitis.

Management of acute abdomen in pregnancy: current perspectives

Acute abdomen in pregnancy represents a unique diagnostic and therapeutic challenge. Acute abdominal pain in pregnancy can occur due to obstetric factors as well for reasons that are unrelated to pregnancy. The diagnostic approach of acute abdomen during pregnancy can be tricky owing to the altered clinical presentations brought about by the anatomical and physiological changes of gestation along with the reluctance to use certain radiological investigations for fear of harming the fetus. Delay in diagnosis and treatment can lead to adverse outcomes for both the mother and fetus. In this article, we attempt to review and discuss the various etiologies, the current concepts of diagnosis, and treatment, with a view to developing a strategy for timely diagnosis and management of pregnant women presenting with acute abdominal pain.

MRI in pregnancy: Indications and practical considerations

There is a constantly evolving knowledgebase regarding the safety of MRI in pregnant patients, as well as the safety of gadolinium administration, given potential fetal risks. This review provides an overview of national and international recommendations for patient screening and safety by trimester, evaluates the most recent literature regarding administration of gadolinium in pregnant patients, and discusses technical requirements when imaging pregnant patients. A protocol for imaging pregnant patients is provided, and multiple common indications for MRI in pregnancy are discussed. Level of Evidence 5. Technical Efficacy Stage 5. J. Magn. Reson. Imaging 2019;49:621-631.

MRI of the Nontraumatic Acute Abdomen: Description of Findings and Multimodality Correlation

Obtaining a specific diagnosis in the nontraumatic acute abdomen can be clinically challenging, because a wide range of disease processes affecting a number of different organ systems may have very similar presentations. Although computed tomography and ultrasound examination are the imaging tests most commonly used to evaluate the acute abdomen, MRI can often offer comparable diagnostic performance, and may be considered when other modalities are equivocal, suboptimal, or contraindicated. In some circumstances, MRI is emerging as an appropriate first-line imaging test.

Clinical use of MRI for the evaluation of acute appendicitis during pregnancy

PURPOSE

The purpose of this study was to determine the diagnostic accuracy of MRI for detecting acute appendicitis in pregnancy in a multi-institution study involving general body MR readers with no specific expertise in MR imaging of the pregnant patient.

METHODS

Retrospective review of MRI examinations on PACS in 42 pregnant patients was evaluated for acute right lower quadrant pain. Three fellowship-trained general body radiologists analyzed the MRI examinations in consensus and attempted to localize the appendix, assess for features of appendicitis, and exclude alternative etiologies for the right lower quadrant pain.

RESULTS

Of the 42 MRI examinations, the readers noted 6 cases of acute appendicitis, 16 cases of a normal appendix, and 20 cases involving non-visualization of the appendix but where there were no secondary features of acute appendicitis. Based on the surgical data and clinical follow-up, there were 3 true-positive cases, 3 false-positive cases, 34 true-negative cases, and 2 false-negative cases of acute appendicitis on MRI. This yielded an accuracy of 88.1%, sensitivity of 60%, specificity of 91.9%, positive predictive value of 50%, and negative predictive value of 94.4% for the detection of acute appendicitis in the pregnant patient on MRI. Alternative etiologies for the right lower quadrant pain on MRI included torsion of an ovarian dermoid in 1 case and pyelonephritis in 1 case.

CONCLUSION

MRI is an excellent modality for excluding acute appendicitis in pregnant patients presenting with right lower quadrant pain.

T1 bright appendix sign to exclude acute appendicitis in pregnant women

OBJECTIVE

To evaluate the diagnostic value of the T1 bright appendix sign for the diagnosis of acute appendicitis in pregnant women.

MATERIAL AND METHODS

This retrospective study included 125 pregnant women with suspected appendicitis who underwent magnetic resonance (MR) imaging. The T1 bright appendix sign was defined as a high intensity signal filling more than half length of the appendix on T1-weighted imaging. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the T1 bright appendix sign for normal appendix identification were calculated in all patients and in those with borderline-sized appendices (6-7 mm).

RESULTS

The T1 bright appendix sign was seen in 51% of patients with normal appendices, but only in 4.5% of patients with acute appendicitis. The overall sensitivity, specificity, PPV, and NPV of the T1 bright appendix sign for normal appendix diagnosis were 44.9%, 95.5%, 97.6%, and 30.0%, respectively. All four patients with borderline sized appendix with appendicitis showed negative T1 bright appendix sign.

CONCLUSION

The T1 bright appendix sign is a specific finding for the diagnosis of a normal appendix in pregnant women with suspected acute appendicitis.

KEY POINTS

• Magnetic resonance imaging is increasingly used in emergency settings. • Acute appendicitis is the most common cause of acute abdomen. • Magnetic resonance imaging is widely used in pregnant population. • T1 bright appendix sign can be a specific sign representing normal appendix.

Endoluminal contrast for abdomen and pelvis magnetic resonance imaging

Magnetic resonance (MR) imaging of the abdomen and pelvis can be limited for assessment of different conditions when imaging inadequately distended hollow organs. Endoluminal contrast agents may provide improved anatomic definition and detection of subtle pathology in such scenarios. The available routes of administration for endoluminal contrast agents include oral, endorectal, endovaginal, intravesicular, and through non-physiologic accesses. Appropriate use of endoluminal contrast agents requires a thorough understanding of the clinical indications, available contrast agents, patient preparation, and interaction of the contrast agent with the desired MR imaging protocol. For example, biphasic oral enteric contrast agents are preferred in MR enterography as their signal properties on T1- and T2-weighted imaging allow for evaluation of both intraluminal and bowel wall pathology. In specific situations such as with MR enterography, MR defecography, and accurate local staging of certain pelvic tumors, the use of an endoluminal contrast agent is imperative in providing adequate diagnostic imaging. In other clinical scenarios, the use of an endoluminal contrast agent may serve as an indispensable problem-solving tool.

Contrast-Enhanced Abdominal MRI for Suspected Appendicitis: How We Do It

OBJECTIVE

The purpose of this article is to describe our approach to contrast-enhanced abdominal MRI in patients with nontraumatic abdominal pain and suspected appendicitis. We aim to share our experience on the advantages, pearls, and pitfalls of MRI in this clinical setting, in comparison with CT and ultrasound.

CONCLUSION

We present some typical cases of appendicitis and alternative diagnoses in patients presenting with acute nontraumatic abdominal pain.

Magnetic Resonance Imaging of Abdominal and Pelvic Pain in the Pregnant Patient

The utility of MR imaging in evaluating abdominal and pelvic pain in the pregnant patient is discussed. Details regarding the indications, technical aspects, and imaging findings of various common abdominal and pelvic abnormalities in pregnancy are reviewed.

Magnetic resonance imaging of acute appendicitis in pregnancy: a 5-year multiinstitutional study

OBJECTIVE

The purpose of this study was to determine the diagnostic performance of magnetic resonance imaging (MRI) in the diagnosis of acute appendicitis during pregnancy in a multiinstitutional study.

STUDY DESIGN

In this multicenter retrospective study, the cases of pregnant women who underwent MRI evaluation of abdominal or pelvic pain and who had clinical suspicion of acute appendicitis between June 1, 2009, and July 31, 2014, were reviewed. All MRI examinations with positive findings for acute appendicitis were confirmed with surgical pathologic information. Sensitivity, specificity, negative predictive values, and positive predictive values were calculated. Receiver operating characteristic curves were generated, and area under the curve analysis was performed for each participating institution.

RESULTS

Of the cases that were evaluated, 9.3% (66/709) had MRI findings of acute appendicitis. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive values were 96.8%, 99.2%, 99.0%, 92.4%, and 99.7%, respectively. There was no statistically significant difference between centers that were included in the study (pair-wise probability values ranged from 0.12-0.99).

CONCLUSION

MRI is useful and reproducible in the diagnosis of suspected acute appendicitis during pregnancy.

Adult pancreatic hemangioma in pregnancy--concerns and considerations of a rare case

BACKGROUND

Pancreatic tumors in pregnancy are rare but clinically challenging. Careful diagnostic workup, including appropriate imaging examinations, should be performed to evaluate surgery indications and timing . In the present case a diagnosis of an adult pancreatic hemangioma was made. We were not able to identify a similar case in the very sparse literature on this rare disease.

CASE PRESENTATION

A 30-year-old woman at 12 weeks of gestation was diagnosed with a large pancreatic tumor having a cystic pattern based on imaging. Although the preoperative diagnosis was uncertain, patient preference and clinical symptoms and signs suggested surgery. Open distal pancreatic resection including splenectomy was performed, and complete resection of the large cystic tumor was successfully achieved, with no postoperative complications. Although a solid pseudopapillary epithelial neoplasm (SPEN) was suspected, specimen morphology, including immunohistochemistry, supported the diagnosis of an adult benign pancreatic hemangioma.

CONCLUSION

Although mucinous cystic neoplasm (MCN) and adenocarcinoma are the most common pancreatic tumors during pregnancy, various other malignant and benign lesions can be encountered. This report adds to the very small number of pancreatic hemangiomas reported in the literature and involves the first patient diagnosed with this rare condition during pregnancy. Careful clinical considerations regarding diagnostic workup and treatments are required to ensure that mother and child receive the best possible care.

Challenges in magnetic resonance imaging for suspected acute appendicitis in pregnant patients

The assessment of a gravid patient with abdominal pain is a clinical challenge, as one must consider not only the common etiologies for abdominal pain but also etiologies resulting from the pregnancy. Further complicating the assessment is the altered anatomy and physiology that result from the enlarged uterus displacing and compressing normal anatomical structures. This alteration of anatomy makes the symptoms of appendicitis more variable and thus the diagnosis more difficult. Appropriate and timely imaging can result in better patient outcomes, and when appendicitis is suspected, imaging investigation should not be delayed. This article reviews some of the challenges of magnetic resonance imaging in gravid patients with suspected appendicitis and presents strategies for imaging this population.

Magnetic resonance imaging of acute abdominal and pelvic pain in pregnancy

Evaluation of acute abdominal and pelvic pain in pregnancy presents a diagnostic challenge for clinicians and radiologists alike. The differential diagnosis includes obstetric and nonobstetric conditions unique to pregnancy, in addition to causes of acute abdominal and pelvic pain unrelated to the pregnancy. The clinical presentation and course of disease may be altered in pregnancy, and several pathologies are exacerbated by pregnancy. Discriminating clinical features in the diagnosis of abdominal and pelvic pain are often confounded by expected anatomic and physiologic changes in pregnancy. Moreover, while diagnostic pathways may be altered in pregnancy, the necessity for a timely and accurate diagnosis must be underscored, as delay in treatment may result in an undesirable increase in morbidity and/or mortality for both the patient and fetus. Advances in magnetic resonance imaging (MRI) through faster acquisition and motion-insensitive techniques, coupled with increased awareness and education regarding the value of MRI in diagnosing a wide range of pathology, have established MRI as a valuable strategy in the investigation of acute abdominal and pelvic pain in the pregnant patient. This review presents a practical approach to common obstetric and nonobstetric causes of acute abdominal and pelvic pain during pregnancy, as well as safety considerations for performing MRI in this patient population.

Utility of magnetic resonance imaging for suspected appendicitis in pregnant women

OBJECTIVE

The purpose of this study was to estimate the rate and risk of appendix nonvisualization and alternative diagnoses made with magnetic resonance imaging (MRI) for suspected appendicitis in pregnant women.

STUDY DESIGN

We performed a retrospective cohort study of consecutive pregnant women who underwent MRI for suspected appendicitis at a single center from 2007-2012. Data on clinical presentation, imaging, and surgical pathologic evidence were extracted from electronic medical records. Odds ratios estimated risk factors for nondiagnosis. Radiologic diagnoses were identified, and rates of diagnoses were calculated. Subgroup analysis was performed among women who underwent initial imaging with ultrasound scanning.

RESULTS

Over the 5-year period, 171 pregnant women underwent MRI for suspected appendicitis. The rate of nonvisualization was 30.9% (n = 53). Of the remaining 118 women with a visualized appendix, 18 women had imaging findings that were consistent with appendicitis and underwent appendectomy. Twelve cases of appendicitis were confirmed on pathologic evaluation (66.7%). Women with nonvisualization of the appendix on MRI were more likely to be beyond the first trimester (odds ratio, 2.1; 95% confidence interval, 1.0-4.5). Seventy-four women had disease diagnosed on MRI (43.3%). In the group of 43 women who had a nondiagnostic ultrasound scanning before the MRI, the rate of subsequent diagnostic MRI was 65% (n = 28).

CONCLUSION

MRI yields a high diagnostic rate and accuracy in pregnant women with suspected appendicitis and provides alternative diagnoses to guide further management. Given the high rate of appendix nonvisualization on ultrasound scanning that has been reported in the literature, we recommend MRI as the imaging modality of choice for this population in settings in which MRI is readily available.

Diagnostic performance of contrast-enhanced MR for acute appendicitis and alternative causes of abdominal pain in children

OBJECTIVE

Unenhanced MRI has emerged as a useful tool for diagnosing pediatric acute appendicitis. The use of contrast-enhanced MRI for diagnosing pediatric appendicitis has not been documented. The purpose of this study is to examine the diagnostic performance of contrast-enhanced MRI for acute appendicitis and alternative entities in the pediatric population presenting with acute abdominal pain.

MATERIALS AND METHODS

A retrospective review was conducted of 364 consecutive pediatric patients undergoing contrast-enhanced MRI for the evaluation of possible appendicitis at a single institution between November 2012 and September 2013.

RESULTS

There were 132 cases of pathologically confirmed appendicitis out of 364 pediatric patients (36.3%) included in the study. Overall sensitivity and specificity were 96.2% (95% CI [91.4-98.4%]) and 95.7% (95% CI [92.3-97.6%]), respectively. Positive predictive value and negative predictive value were 92.7% (95% CI [86.6-96.3%]) and 97.8% (95% CI [94.7-99.1%]), respectively. The appendix was visualized in 243 cases (66.8%). Imaging confirmed alternative diagnoses in 75 patients, including most commonly colitis, enteritis or terminal ileitis (n = 25, 6.9%), adnexal cysts (n = 25, 6.9%) and mesenteric adenitis (n = 7, 1.9%).

CONCLUSION

Contrast-enhanced MRI is capable of accurately diagnosing acute appendicitis while detecting many alternative entities of abdominal pain, and it allows good visualization of the appendix. Further evaluation is needed to determine whether contrast-enhanced MRI provides an advantage over non-enhanced MRI for imaging evaluation of acute abdominal pain in the pediatric population.