{"doi":"10.1002/mrm.30530","title":"When CEST meets diffusion: Multi‐echo diffusion‐encoded <scp>CEST</scp> (<scp>dCEST</scp>) <scp>MRI</scp> to measure intracellular and extracellular <scp>CEST</scp> signal distributions","abstract":"Abstract Purpose To develop a multi‐echo, diffusion‐encoded chemical exchange saturation transfer (dCEST) imaging technique for estimating the intracellular and extracellular/intravascular contributions to the conventional CEST signal. Methods A dCEST pulse sequence was developed to quantify the signal fractions, transverse relaxation times (T 2 ), and apparent diffusion coefficient (ADC) of the intracellular and extracellular/intravascular water compartments. dCEST images were acquired across a wide range of TE, b‐values, RF saturation strengths, and frequency offsets. The data were analyzed using a two‐compartment model with distinct diffusivities and T 2 values. Intracellular and extracellular fractions of conventional water‐saturation spectra (Z‐spectra) and corresponding amide proton transfer (APT) signals were estimated from human brain scans of healthy volunteers at 3 T. Results The multi‐echo diffusion results showed that the intracellular water fractions were significantly higher than the extracellular water fractions, whereas the intracellular T 2 values were shorter than those of the extracellular/intravascular compartments. The ADC for the intracellular compartment was significantly lower than that of the extracellular compartment. The dCEST analysis showed that the average intracellular and extracellular fractions of the Z‐spectra were 85 ± 7% and 15 ± 4%, respectively. The overall intracellular APT‐weighted values were higher than the total (i.e., intracellular + extracellular) APT‐weighted values. Conclusions The dCEST imaging technique provides valuable insight into the source of signals in conventional CEST MRI, offering potential utility for clinical applications.","journal":"Magnetic Resonance in Medicine","year":2025,"id":552355,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.951,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":686908,"name":"Hye‐Young Heo","orcid":"0000-0002-7297-2015","position":1,"is_corresponding":false},{"id":1151472,"name":"Sultan Z. Mahmud","orcid":"0000-0002-0670-0716","position":0,"is_corresponding":true}],"reference_count":45,"raw_metadata":null,"created_at":"2026-07-19T02:54:33.203144Z","pmid":"40228073","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}