TABLE IV.
Individual Case Compilation of Radiological Outcomes in Olfactory Structures in 297 Patients.
| Individual Patients (n = 297) | ||||||
|---|---|---|---|---|---|---|
| COVID Patients With Olfactory Dysfunction (n = 208) | Controls (n = 89; 10 COVID‐19 Without OD, 79 Healthy) | |||||
| With Abnormalities | Without Abnormalities | With Abnormalities | Without Abnormalities | |||
| Radiological Feature | No. of Patients | Specific Abnormalities | No. of Patients | No. of Patients | Specific Abnormalities | No. of Patients |
| Olfactory bulb volume | 12/20 (60%) |
Severe enlargement with bilateral olfactory bulb edema (n = 1) 41 Smaller right olfactory bulb (n = 1) 40 Olfactory bulb atrophy and/or volume loss (n = 10) 15 , 25 , 33 |
8/20 (40%) 25 , 28 , 30 , 34 , 39 , 44 , 46 | 0/5 (0%) | 5/5 (100%) 30 , 33 | |
| Olfactory bulb morphology | 18/39 (46.2%) |
Olfactory bulb asymmetry (n = 3) 36 Mild irregularity with preserved J‐shape (n = 2) 13 Contour lobulations (n = 5) 13 Rectangular shape (n = 8) 13 |
21/39 (53.8%) 13 , 25 , 36 , 39 | 0/8 (0%) | 8/8 (100%) 25 | |
| Olfactory bulb signal intensity | 42/50 (84%) |
Bilateral olfactory bulb hyperintensity (n = 8) 14 , 29 , 30 Unilateral olfactory bulb hyperintensity (n = 1) 29 Hyperintensity, not stated if unilateral or bilateral (n = 14) 24 , 32 , 41 , 42 Diffusely increased signal (n = 9) 13 Hyperintense foci without halo (n = 11) 13 Hyperintense foci with halo (n = 5) 13 Microhemorrhages (n = 4) 13 |
8/50 (16%) 39 , 44 , 45 , 46 | 15/16 (93.4%) |
Bilateral olfactory bulb hyperintensity (n = 3) (COVID‐19 without OD) 30 Unilateral olfactory bulb hyperintensity (n = 1) (COVID‐19 without OD) 29 Hyperintensity, not stated if unilateral or bilateral (n = 11) (10 healthy, 1 COVID‐19 without OD) 24 , 32 |
1/16 (6.6%) 29 |
| Olfactory cleft swelling | 1/1 (100%) | Mild olfactory cleft edema (n = 1) 41 | ||||
| Olfactory cleft volumes | 0/2 (0%) | 2/2 (100%) 41 , 46 | ||||
| Olfactory cleft opacification | 66/115 (57.4%) |
Bilateral olfactory cleft obstruction (n = 49) 13 , 22 , 23 , 36 Unilateral signs of inflammation or olfactory cleft obstruction (n = 4) 13 , 36 Not stated if unilateral or bilateral olfactory cleft opacification (n = 13) 27 |
49/115 (42.6%) 22 , 23 , 27 , 30 , 36 | 3/67 (4.5%) |
Bilateral olfactory cleft opacification (n = 1) (COVID‐19 without OD) 23 Not stated if unilateral or bilateral olfactory cleft opacification (n = 2) (healthy) 27 |
64/67 (55.5%) 22 , 23 , 27 , 30 |
| Olfactory cleft signal intensity | 0/1 (0%) | 1/1 (100%) 46 | ||||
| Olfactory sulcus depth | 0/1 (0%) | 1/1 (100%) 39 | ||||
| Olfactory sulcus signal intensity | 0/1 (0%) | 1/1 (100%) 39 | ||||
| Olfactory mucosa | 4/58 (6.9%) |
Olfactory mucosa thickening (n = 3) 25 Olfactory mucosa thickening with enhancement of olfactory mucosa compared to nasal mucosa (n = 1) 25 |
44/58 (93.1%) 14 , 25 , 34 | 0/8 (0%) | 8/8 (100%) 25 | |
| Olfactory gyrus | 3/3 (100%) |
Hypometabolism of bilateral olfactory–rectal gyrus (n = 1) 37 Hyperintensity in posterior portion of right rectal gyrus (n = 1) 42 Bilateral cortical hyperintensity predominantly involving the rectus gyrus overlying the olfactory tract and olfactory bulb on MRI 47 |
1/1 (100%) | · Hypometabolism of bilateral olfactory–rectal gyrus (n = 1) (COVID‐19 without OD) 37 | ||
| Olfactory nerve morphology–filia architecture | 10/23 (43.5%) |
Evident clumping of olfactory filia (n = 8) 13 Thinning with scarcity of filia (n = 2) 13 |
13/23 (56.5%) 13 | |||
| Olfactory nerve signal intensity | 1/1 (100%) | Linear hyperintensities in bilateral olfactory nerves (n = 1) 40 | ||||
OD = olfactory dysfunction.