Evidence map›Paper›PMID 41817635›Full record

SynthesisBrain imaging and behavior2026

The correlation between olfactory bulb volume and T&T odor threshold: a systematic review and meta-analysis.

Zhuoying Luo, Yuqin Zhong, Canfeng Zhao, Chong Ouyang, Jiaping Ren, Hua Peng

Abstract readSystematic ReviewMeta-AnalysisReview
PubMed Publisher
In one paragraph

Synthesis in Brain imaging and behavior, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Zhuoying Luo *Department of Otolaryngology Head and Neck Surgery, General Hospital of Southern Theater Command, 111 Liuhua Rd, Guangzhou, CT, 510180, China.
Yuqin Zhong *Department of Otolaryngology Head and Neck Surgery, General Hospital of Southern Theater Command, 111 Liuhua Rd, Guangzhou, CT, 510180, China.
Canfeng Zhao *Department of Otolaryngology Head and Neck Surgery, General Hospital of Southern Theater Command, 111 Liuhua Rd, Guangzhou, CT, 510180, China.
Chong OuyangDepartment of Otolaryngology Head and Neck Surgery, General Hospital of Southern Theater Command, 111 Liuhua Rd, Guangzhou, CT, 510180, China.
Jiaping RenDepartment of Otolaryngology Head and Neck Surgery, General Hospital of Southern Theater Command, 111 Liuhua Rd, Guangzhou, CT, 510180, China.
Hua PengDepartment of Otolaryngology Head and Neck Surgery, General Hospital of Southern Theater Command, 111 Liuhua Rd, Guangzhou, CT, 510180, China. doctorpeng2006@hotmail.com.

Funding

Natural Science Foundation of Guangdong Province 2023A1515010268
6 · The paper itself

Abstract

This meta-analysis aims to quantitatively assess the correlation between olfactory bulb (OB) volume measured by magnetic resonance imaging (MRI) and the T&T olfactometer identification threshold, with subgroup analyses conducted in patients with neurodegenerative disorders and healthy individuals. We searched PubMed, Web of Science, Embase, Cochrane Library, China Biology Medicine Disc (CBM), China National Knowledge Infrastructure (CNKI), Wanfang, and VIP databases for relevant studies. The procedure was under the guidance of the Preferred Systematic Reviews and Meta-Analyses Reporting Items (PRISMA) checklist. English or Chinese cross-sectional studies concerned with OB volume and olfactory function published before January 31, 2025, were searched in the data sources mentioned above. After study selection, data extraction, and the assessment of study quality, this meta-analysis was performed independently performed by two reviewers. Correlation coefficients were pooled using Fisher’s z transformation. Random- or fixed-effects models were applied according to heterogeneity. Subgroup analyses were conducted for neurodegenerative disorder patients and healthy controls. Fifteen studies concerning 1289 subjects were qualified for the study, including 824 patients who suffered from olfactory deficiency and 465 healthy individuals. Fourteen studies were of high quality, and one study was of medium quality. An overall correlation between OB volume and T&T olfactory test score (r=-0.64, P= 0.01) was detected. Further subgroup analysis showed significant correlations among cognitive syndrome patients (mild cognitive impairment (MCI) and Alzheimer’s disease (AD)) (r=-0.84,P=0.82), Parkinson’s disease patients (PD) (r=-0.70,P=0.01), healthy subjects (r=-0.61,P=0.97). According to meta-regression analysis, age was not a source of heterogeneity. The result supported a significant correlation between OB volume and T&T odor identification threshold. OB volume measurement may be a potential alternative for the T&T odor identification test, especially in neurodegenerative individuals.

Indexed as

Olfactory BulbSensory ThresholdsSmellHumansMagnetic Resonance ImagingNeurodegenerative DiseasesOdorantsOlfaction DisordersOrgan SizeCorrelationMagnetic resonance imaging (MRI)Meta-analysisNeurodegenerative disordersOlfactory bulb volume (OB volume)T&T olfactory test

Identifiers

What Socratic holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.