Appendiceal Visualization on 2-mSv CT vs. Conventional-Dose CT in Adolescents and Young Adults with Suspected Appendicitis: An Analysis of Large Pragmatic Randomized Trial Data

Abstract

Objective We compared appendiceal visualization on 2-mSv CT vs. conventional-dose CT (median 7 mSv) in adolescents and young adults and analyzed the undesirable clinical and diagnostic outcomes that followed appendiceal nonvisualization. Materials and Methods A total of 3074 patients aged 15–44 years (mean ± standard deviation, 28 ± 9 years; 1672 female) from 20 hospitals were randomized to the 2-mSv CT or conventional-dose CT group (1535 vs. 1539) from December 2013 through August 2016. A total of 161 radiologists from 20 institutions prospectively rated appendiceal visualization (grade 0, not identified; grade 1, unsure or partly visualized; and grade 2, clearly and entirely visualized) and the presence of appendicitis in these patients. The final diagnosis was based on CT imaging and surgical, pathologic, and clinical findings. We analyzed undesirable clinical or diagnostic outcomes, such as negative appendectomy, perforated appendicitis, more extensive than simple appendectomy, delay in patient management, or incorrect CT diagnosis, which followed appendiceal nonvisualization (defined as grade 0 or 1) and compared the outcomes between the two groups. Results In the 2-mSv CT and conventional-dose CT groups, appendiceal visualization was rated as grade 0 in 41 (2.7%) and 18 (1.2%) patients, respectively; grade 1 in 181 (11.8%) and 81 (5.3%) patients, respectively; and grade 2 in 1304 (85.0%) and 1421 (92.3%) patients, respectively ( p < 0.001). Overall, undesirable outcomes were rare in both groups. Compared to the conventional-dose CT group, the 2-mSv CT group had slightly higher rates of perforated appendicitis (1.1% [17] vs. 0.5% [7], p = 0.06) and false-negative diagnoses (0.4% [6] vs. 0.0% [0], p = 0.01) following appendiceal nonvisualization. Otherwise, these two groups were comparable. Conclusion The use of 2-mSv CT instead of conventional-dose CT impairs appendiceal visualization in more patients. However, appendiceal nonvisualization on 2-mSv CT rarely leads to undesirable clinical or diagnostic outcomes.

Diagnostic performance and image quality of an image-based denoising algorithm applied to radiation dose-reduced CT in diagnosing acute appendicitis

“…The appendix was well visualized in most patients on both the ULDCT and D-ULDCT images, with a range of 77.8–91.7% for ULDCT and 79.4–92.2% for D-ULDCT, respectively. Considering that a previous study achieved good visualization in more than 85% of cases with 2-mSv CT [ 34 ], appendiceal visualization might be slightly compromised, although the formal statistical comparison is limited. However, regardless of the degree of appendix visualization, radiologists achieved a good diagnostic performance (AUC, 0.94–0.97) for appendicitis in D-ULDCT, which aligns with the previous study’s findings [ 34 ].…”

“…Considering that a previous study achieved good visualization in more than 85% of cases with 2-mSv CT [ 34 ], appendiceal visualization might be slightly compromised, although the formal statistical comparison is limited. However, regardless of the degree of appendix visualization, radiologists achieved a good diagnostic performance (AUC, 0.94–0.97) for appendicitis in D-ULDCT, which aligns with the previous study’s findings [ 34 ]. Intriguingly, radiologists could accurately diagnose or rule out appendicitis in most cases, even if the appendix was not visualized.…”

Radiology Residents’ Independent Diagnosis of Appendicitis Using 2-mSv Computed Tomography: A Secondary Analysis of a Large Pragmatic Randomized Trial

“…SNUBH B-2108-705-104, CAUH 2108-030-19386, GMC 2021-343, DSMC 2021-08-132, JNUH 2021-08-010, SCHSH 2021-08-013, HUKNHH 2021-08-032, YUHS 4-2021-1133, SNUH J-2109-122-1257, KNUH 2021-09-024-001, WKUH 2021-08-027-002, KUAH 2021AS0266, KBSMC 2021-09-024, CNUH 2021-381, WMCSB 202202-11, CMC KC14EIMI0655, KUGH 2021GR0441, HUSHH HALLYM 2021-08-029-001, SCHBC 2021-08-034-002, DMC 2021-09-009). Our patients have been included in previous studies [ 19 20 ], including the main report of the trial [ 2 ]. Compared to the main trial that aimed to prove the non-inferiority of 2-mSv CT over CDCT with respect to the negative appendectomy rate, this study analyzed the diagnostic performance and clinical outcomes following radiology residents’ CT readings.…”