Table 2.
MRI Characteristics and diagnostic outcomes reported by included primary studies
| First author | MRI Sequences | MRI duration (min) | Number of histopatho-logically proven appendicitis | Number of cases of alternative diagnoses from pre-treatment MRI | Number of cases of alternative diagnoses after definitive treatment | TP | FP | FN | TN | Sensitivity (%) | Specificity (%) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| S Serinsoz30 | DWI ssEPI + FS, T2 TSE, T2 STIR/TIRM | 7 | 37 (52.9%) | Not reported | Not reported | 37 | 3 | 0 | 30 | 100 | 90.9 |
| G Islam31 | T2 and DWI | 14 | 34 (50.7%) | 6 (9.0%) | 6 (9.0%) | 42 | 3 | 3 | 19 | 93.3 | 86.4 |
| A Inoue32 | T2 HASTE and DWI | Not reported | 25 (49.0%) | Not reported | 16 (31.4%) | 31 | 6 | 4 | 10 | 88.6 | 62.5 |
|
M Repplinger (J Harringa)33 |
T2-SS FSE, T1 3D spoiled GRE, DWI | 30 | Not reported | 51 (25.8%) | 54 (27.3%) | 62 | 14 | 2 | 120 | 96.9 | 89.6 |
| S Byott34 a | HASTE | 15 | 36 (7.7%) | 82 (17.5%) | 82 (17.5%) | 34 | 3 | 3 | 428 | 91.9 | 99.3 |
| I Petkovska35 b | multiplanar single-shot T2 ± SPAIR FS | 14 (mean) | Not reported | Not reported | Not reported | 34 | 1 | 1 | 217 | 97.1 | 99.5 |
| H Gielkens36 c | T2 TSE, T1 GRE | 22 | 29 (28.2%) | 22 (21.4%) | Not reported | 25 | 0 | 3 | 75 | 89.3 | 100 |
| M Leeuwenburgh37 | T2 FSE ± FS, DWI | 15 | 114 (51.1%) | 27 (12.1%) | Not reported | 113 | 7 | 4 | 99 | 96.6 | 93.4 |
| S Avcu38 | DWI, bSSFP, STIR | 2.26 | 40 (72.7%) | 0 (0%) | 0 (0%) | 39 | 0 | 1 | 15 | 97.5 | 100 |
| B Zhu39 | T2 FSE, bSSFP + FS | 2.7 | 36 (87.8%) | 5 (12.2%) | 5 (12.2%) | 33 | 0 | 3 | 5 | 91.7 | 100 |
| E Inci40 | T1 FSE, T2 FSE ± FS, DWI | 4 | 79 (66.4%) | Not reported | 7 (5.9%) | 78 | 0 | 1 | 40 | 98.7 | 100 |
| E Chabanova41 d | T1 SE, T2 FSE, STIR | 20 | 30 (62.5%) | 15 (31.3%) | 14 (29.2%) | 25 | 3 | 5 | 15 | 83.3 | 83.3 |
| L Cobben42 | T1 SGRE, T2 FSE, T2 FSE + FS | 20 | 62 (44.9%) | 41 (29.7%) | 42 (30.4%) | 62 | 1 | 0 | 75 | 100 | 98.7 |
| A Singh43 e | T2 SSFSE + FS, T2 FSE + FS, STIR, pre-GAD T1, post-GAD T1 | <25 | 12 (30.0%) | 36 (90.0%) | 37 (92.5%) | 12 | 1 | 0 | 27 | 100 | 96.4 |
| N Nitta44 | T1 SE, T2 FSE, T2 + FS | 20 | 29 (78.4%) | 1 (2.7%) | 8 (21.6%) | 29 | 1 | 0 | 7 | 100 | 87.5 |
| L Incesu46 | T1 SE, T1 CE FS, T2 FS FSE | 25 | 34 (56.7%) | 9 (15.0%) | 11 (18.3%) | 33 | 2 | 1 | 24 | 97.1 | 92.3 |
ssEPI, single-shot echo-planar imaging; bSSFP, balanced steady-state free precession; RARE, rapid acquisition with relaxation enhancement; SPAIR, spectral selection attenuated inversion recovery; SENSE, sequence, sensitivity encoding; BTFE, balanced turbo field echo; SPIR, spectral pre-saturation and inversion recovery; SS-FSE, single shot fast spin echo; FSE, fast spin echo; STIR, short tau inversion recovery; SE, spin echo; DWI, diffusion-weighted imaging; True-FISP, T2-weighted true-fast imaging with steady-state precession; TIRM, turbo inversion-recovery in magnitude; TSE, turbo spin echo; HF, half Fourier; GRE, gradient echo; FLASH, fast low-angle shot; FS, fat-suppressed; HASTE, half-Fourier acquisition single-shot turbo spin echo; GAD, gadolinium
aThe values for sensitivity and specificity were calculated based on the TP, FP, FN, and TN, and are different to the values reported by the study that were calculated with a restriction to the 90 operative patients
bResults restricted to adults aged over 18
cThis study had nine patients with equivocal MRI results, which were excluded from this table
dThe values of sensitivity and specificity for this study are based on MRI interpretations by a surgeon who had 3 years of experience with abdominal MRI
eResults restricted to patients clinically suspected of appendicitis