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Kim D, Woodham BL, Chen K, Kuganathan V, Edye MB. Rapid MRI Abdomen for Assessment of Clinically Suspected Acute Appendicitis in the General Adult Population: a Systematic Review. J Gastrointest Surg 2023; 27:1473-1485. [PMID: 37081221 PMCID: PMC10366263 DOI: 10.1007/s11605-023-05626-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 01/27/2023] [Indexed: 04/22/2023]
Abstract
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.
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Affiliation(s)
- Dongchan Kim
- School of Medicine, Western Sydney University, Campbelltown, N.S.W. Australia
| | - Benjamin Luke Woodham
- School of Medicine, Western Sydney University, Campbelltown, N.S.W. Australia
- Department of General Surgery, Blacktown and Mount Druitt Hospitals, Blacktown Road, Blacktown, N.S.W. Australia
| | - Kathryn Chen
- School of Medicine, Western Sydney University, Campbelltown, N.S.W. Australia
| | - Vinushan Kuganathan
- School of Medicine, Western Sydney University, Campbelltown, N.S.W. Australia
| | - Michael Benjamin Edye
- School of Medicine, Western Sydney University, Campbelltown, N.S.W. Australia
- Department of General Surgery, Blacktown and Mount Druitt Hospitals, Blacktown Road, Blacktown, N.S.W. Australia
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D'Souza N, Hicks G, Beable R, Higginson A, Rud B. Magnetic resonance imaging (MRI) for diagnosis of acute appendicitis. Cochrane Database Syst Rev 2021; 12:CD012028. [PMID: 34905621 PMCID: PMC8670723 DOI: 10.1002/14651858.cd012028.pub2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Appendicitis remains a difficult disease to diagnose, and imaging adjuncts are commonly employed. Magnetic resonance imaging (MRI) is an imaging test that can be used to diagnose appendicitis. It is not commonly regarded as a first-line imaging test for appendicitis, but the reported diagnostic accuracy in some studies is equivalent to computed tomography (CT) scans. As it does not expose patients to radiation, it is an attractive imaging modality, particularly in women and children. OBJECTIVES The primary objective was to determine the diagnostic accuracy of MRI for detecting appendicitis in all patients. Secondary objectives: To investigate the accuracy of MRI in subgroups of pregnant women, children, and adults. To investigate the potential influence of MRI scanning variables such as sequences, slice thickness, or field of view. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase until February 2021. We searched the references of included studies and other systematic reviews to identify further studies. We did not exclude studies that were unpublished, published in another language, or retrospective. SELECTION CRITERIA We included studies that compared the outcome of an MRI scan for suspected appendicitis with a reference standard of histology, intraoperative findings, or clinical follow-up. Three study team members independently filtered search results for eligible studies. DATA COLLECTION AND ANALYSIS We independently extracted study data and assessed study quality using the Quality Assessment of Studies of Diagnostic Accuracy - Revised (QUADAS-2) tool. We used the bivariate model to calculate pooled estimates of sensitivity and specificity. MAIN RESULTS We identified 58 studies with sufficient data for meta-analysis including a total of 7462 participants (1980 with and 5482 without acute appendicitis). Estimates of sensitivity ranged from 0.18 to 1.0; estimates of specificity ranged from 0.4 to 1.0. Summary sensitivity was 0.95 (95% confidence interval (CI) 0.94 to 0.97); summary specificity was 0.96 (95% CI 0.95 to 0.97). Sensitivity and specificity remained high on subgroup analysis for pregnant women (sensitivity 0.96 (95% CI 0.88 to 0.99); specificity 0.97 (95% CI 0.95 to 0.98); 21 studies, 2282 women); children (sensitivity 0.96 (95% CI 0.95 to 0.97); specificity 0.96 (95% CI 0.92 to 0.98); 17 studies, 2794 children); and adults (sensitivity 0.96 (95% CI 0.93 to 0.97); specificity 0.93 (95% CI 0.80 to 0.98); 9 studies, 1088 participants), as well as different scanning techniques. In a hypothetical cohort of 1000 patients, there would be 12 false-positive results and 30 false-negative results. Methodological quality of the included studies was poor, and the risk of bias was high or unclear in 53% to 83% of the QUADAS-2 domains. AUTHORS' CONCLUSIONS MRI appears to be highly accurate in confirming and excluding acute appendicitis in adults, children, and pregnant women regardless of protocol. The methodological quality of the included studies was generally low due to incomplete and low standards of follow-up, so summary estimates of sensitivity and specificity may be biased. We could not assess the impact and direction of potential bias given the very low number of high-quality studies. Studies comparing MRI protocols were few, and although we found no influence of MRI protocol variables on the summary estimates of accuracy, our results do not rule out that some MRI protocols are more accurate than others.
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Affiliation(s)
| | | | | | | | - Bo Rud
- Gastrounit, Copenhagen University Hospital Hvidovre , Hvidovre, Denmark
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Bracken RL, Harringa JB, Markhardt BK, Kim N, Park JK, Kitchin DR, Robbins JB, Ziemlewicz TJ, Birstler J, Ryan MJ, Hoang L, Pickhardt P, Reeder SB, Repplinger MD. Abdominal fellowship-trained versus generalist radiologist accuracy when interpreting MR and CT for the diagnosis of appendicitis. Eur Radiol 2021; 32:533-541. [PMID: 34268596 PMCID: PMC8665009 DOI: 10.1007/s00330-021-08163-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 06/12/2021] [Accepted: 06/24/2021] [Indexed: 01/03/2023]
Abstract
OBJECTIVES To compare the diagnostic accuracy of generalist radiologists working in a community setting against abdominal radiologists working in an academic setting for the interpretation of MR when diagnosing acute appendicitis among emergency department patients. METHODS This observational study examined MR image interpretation (non-contrast MR with diffusion-weighted imaging and intravenous contrast-enhanced MR) from a prospectively enrolled cohort at an academic hospital over 18 months. Eligible patients had an abdominopelvic CT ordered to evaluate for appendicitis and were > 11 years old. The reference standard was a combination of surgery and pathology results, phone follow-up, and chart review. Six radiologists blinded to clinical information, three each from community and academic practices, independently interpreted MR and CT images in random order. We calculated test characteristics for both individual and group (consensus) diagnostic accuracy then performed Chi-square tests to identify any differences between the subgroups. RESULTS Analysis included 198 patients (114 women) with a mean age of 31.6 years and an appendicitis prevalence of 32.3%. For generalist radiologists, the sensitivity and specificity (95% confidence interval) were 93.8% (84.6-98.0%) and 88.8% (82.2-93.2%) for MR and 96.9% (88.7-99.8%) and 91.8% (85.8-95.5%) for CT. For fellowship-trained radiologists, the sensitivity and specificity were 96.9% (88.2-99.5%) and 89.6% (82.8-94%) for MR and 98.4% (90.5-99.9%) and 93.3% (87.3-96.7%) for CT. No statistically significant differences were detected between radiologist groups (p = 1.0, p = 0.53, respectively) or when comparing MR to CT (p = 0.21, p = 0.17, respectively). CONCLUSIONS MR is a reliable, radiation-free imaging alternative to CT for the evaluation of appendicitis in community-based generalist radiology practices. KEY POINTS • There was no significant difference in MR image interpretation accuracy between generalist and abdominal fellowship-trained radiologists when evaluating sensitivity (p = 1.0) and specificity (p = 0.53). • There was no significant difference in accuracy comparing MR to CT imaging for diagnosing appendicitis for either sensitivity (p = 0.21) or specificity (p = 0.17). • With experience, generalist radiologists enhanced their MR interpretation accuracy as demonstrated by improved interpretation sensitivity (OR 2.89 CI 1.44-5.77, p = 0.003) and decreased mean interpretation time (5 to 3.89 min).
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Affiliation(s)
- Rebecca L Bracken
- BerbeeWalsh Department of Emergency Medicine, University of
Wisconsin-Madison, Madison, WI, USA
| | - John B Harringa
- BerbeeWalsh Department of Emergency Medicine, University of
Wisconsin-Madison, Madison, WI, USA
| | - B Keegan Markhardt
- Department of Radiology, University of Wisconsin-Madison,
Madison, WI, USA.,Department of Radiology, UnityPoint Health Meriter,
Madison, WI, USA
| | - Newrhee Kim
- Department of Radiology, University of Wisconsin-Madison,
Madison, WI, USA.,Department of Radiology, UnityPoint Health Meriter,
Madison, WI, USA
| | - John K Park
- Department of Radiology, University of Wisconsin-Madison,
Madison, WI, USA.,Department of Radiology, UnityPoint Health Meriter,
Madison, WI, USA
| | - Douglas R Kitchin
- Department of Radiology, University of Wisconsin-Madison,
Madison, WI, USA.,Madison Radiologists, Madison, WI, USA
| | - Jessica B Robbins
- Department of Radiology, University of Wisconsin-Madison,
Madison, WI, USA
| | | | - Jen Birstler
- Department of Biostatistics & Medical Informatics,
University of Wisconsin-Madison, Madison, WI, USA
| | - Michael J Ryan
- BerbeeWalsh Department of Emergency Medicine, University of
Wisconsin-Madison, Madison, WI, USA
| | - Ly Hoang
- BerbeeWalsh Department of Emergency Medicine, University of
Wisconsin-Madison, Madison, WI, USA
| | - Perry Pickhardt
- Department of Radiology, University of Wisconsin-Madison,
Madison, WI, USA
| | - Scott B Reeder
- BerbeeWalsh Department of Emergency Medicine, University of
Wisconsin-Madison, Madison, WI, USA.,Department of Radiology, University of Wisconsin-Madison,
Madison, WI, USA
| | - Michael D Repplinger
- BerbeeWalsh Department of Emergency Medicine, University of
Wisconsin-Madison, Madison, WI, USA.,Department of Radiology, University of Wisconsin-Madison,
Madison, WI, USA
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