{"artifact_id":"L1-044","layer":"L1","title":"Magnetic Resonance Spectroscopy (MRS)","domain":"Medical Imaging","sub_domain":"Proton chemical-shift tissue metabolite spectroscopy","physics_fingerprint":{"L_DAG":3.5,"title":"Magnetic Resonance Spectroscopy (MRS)","domain":"Medical Imaging","carrier":"radio_wave","primitives":["L.rf_excitation","L.chemical_shift_encode","D.fid_acquisition","int.spectral"],"sub_domain":"Proton chemical-shift tissue metabolite spectroscopy","noise_model":"gaussian","problem_class":"linear_inverse","solution_space":"1D_metabolite_spectrum","difficulty_delta":5,"integration_axis":"spectral","sensing_mechanism":"mrs_chemical_shift"},"observable_profile":{"metric":"PSNR_dB","regime":"Existence of the recovered 1D metabolite spectrum is guaranteed within the declared Omega bounds. Uniqueness holds on the measurement-supported subspace; out-of-support modes are controlled by the declared priors. Stability is moderately conditioned (kappa_eff ~= 15); B0_shim dominates the stability cliff; water_suppression_imperfection and the remaining mismatch parameters contribute higher-order bias terms. Additive gaussian thermal/electronic noise sets the irreducible data-fidelity floor, while mild Tikhonov or analytic inversion is sufficient at the nominal Omega point.","secondary":"SSIM"},"size_tiers":{"center_spec":{"omega":{"N_avg":128,"TE_ms":30,"TR_ms":2000,"SNR_dB":10,"B0_shim":0.0,"N_samples":2048,"lipid_contamination":0.0,"water_suppression_imperfection":0.0},"input_format":"measurement_only","problem_class":"mrs","forward_operator":"mrs_forward","epsilon_fn_center":"18.0"},"omega_bounds":{"N_avg":[16,2048],"TE_ms":[10,500],"TR_ms":[500,10000],"SNR_dB":[0.0,30.0],"B0_shim":[0.0,0.2],"N_samples":[512,8192],"short_T2_signals":[0.0,0.3],"lipid_contamination":[0.0,0.5],"water_suppression_imperfection":[0.0,0.3]},"epsilon_bounds":{"psnr_db":[5.0,45.0]},"allowed_problem_classes":["mrs"],"allowed_omega_dimensions":["N_samples","TR_ms","TE_ms","N_avg","SNR_dB","B0_shim","water_suppression_imperfection","lipid_contamination","B0_shim","water_suppression_imperfection","lipid_contamination","short_T2_signals"],"allowed_forward_operators":["mrs_forward"]},"hardness_fn":{"type":"epsilon_fn","delta":5,"kappa":300,"metric":"PSNR_dB"},"initiator_dataset":[{"name":"primary","weight":1.0,"ipfs_cid":null,"license_hash":null}],"status":"testnet","staked_pwm":0.0,"chain_hash":"0x506214b0a18b9f43f347ba6be778bb17c7785b21a7713d1f5000414d866d8a05","chain_tx_hash":"0x1067900ea6b77824cf468127217f947d62d5cea6c28c50e527ea15391a09ab7f","chain_block":41553385}