{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2025:AC44KIMACOQRQJT2Q6FBZPTAVW","short_pith_number":"pith:AC44KIMA","canonical_record":{"source":{"id":"2505.21853","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.med-ph","submitted_at":"2025-05-28T00:53:45Z","cross_cats_sorted":["physics.app-ph"],"title_canon_sha256":"9285ab8498594d9856171cdf0b5aa65e1cab434f3d762d02e2e31b6e6f9c9b00","abstract_canon_sha256":"4e66023dc051076118cff6e996201ab01b3a69a918becbdc9102bd26e77f08b0"},"schema_version":"1.0"},"canonical_sha256":"00b9c5218013a118267a878a1cbe60adbe81b187e7fe6a08572735800cdef379","source":{"kind":"arxiv","id":"2505.21853","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2505.21853","created_at":"2026-07-05T11:11:04Z"},{"alias_kind":"arxiv_version","alias_value":"2505.21853v1","created_at":"2026-07-05T11:11:04Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2505.21853","created_at":"2026-07-05T11:11:04Z"},{"alias_kind":"pith_short_12","alias_value":"AC44KIMACOQR","created_at":"2026-07-05T11:11:04Z"},{"alias_kind":"pith_short_16","alias_value":"AC44KIMACOQRQJT2","created_at":"2026-07-05T11:11:04Z"},{"alias_kind":"pith_short_8","alias_value":"AC44KIMA","created_at":"2026-07-05T11:11:04Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2025:AC44KIMACOQRQJT2Q6FBZPTAVW","target":"record","payload":{"canonical_record":{"source":{"id":"2505.21853","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.med-ph","submitted_at":"2025-05-28T00:53:45Z","cross_cats_sorted":["physics.app-ph"],"title_canon_sha256":"9285ab8498594d9856171cdf0b5aa65e1cab434f3d762d02e2e31b6e6f9c9b00","abstract_canon_sha256":"4e66023dc051076118cff6e996201ab01b3a69a918becbdc9102bd26e77f08b0"},"schema_version":"1.0"},"canonical_sha256":"00b9c5218013a118267a878a1cbe60adbe81b187e7fe6a08572735800cdef379","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T11:11:04.847525Z","signature_b64":"MF8rL+plrV7LNVHh8RRegrGpDncZGGtEpdslV28i1zJM+IOnQrY9ySzrrK4k9DkC4DE0jboZo78L7PBWqZadBw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"00b9c5218013a118267a878a1cbe60adbe81b187e7fe6a08572735800cdef379","last_reissued_at":"2026-07-05T11:11:04.847025Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T11:11:04.847025Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2505.21853","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T11:11:04Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"mFUxbE/K3sDyLfkxbtos3cvvACM+BkzcjSstYpg4DlzKLrJ7/LyJRfVMbpDbW+cFJ4tqW+D9WPqNrWkSsi18Dw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-07T22:08:47.277611Z"},"content_sha256":"d708e155e50800955261eafac022c0979f847a393cf41562da0a72bb3cd16303","schema_version":"1.0","event_id":"sha256:d708e155e50800955261eafac022c0979f847a393cf41562da0a72bb3cd16303"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2025:AC44KIMACOQRQJT2Q6FBZPTAVW","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Quantitative Macromolecular Proton Fraction Imaging using Pulsed Spin-Lock","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["physics.app-ph"],"primary_cat":"physics.med-ph","authors_text":"((1) Department of Imaging, 2), Baiyan Jiang (1, Interventional Radiology (2) Illumination Medical Technology Limited (3) Department of Medicine, Jian Hou (1), Qianxue Shan (1), Qiuyi Shen (1), Therapeutics), Vincent WS Wong (3), Weitian Chen (1), Winnie CW Chu (1), Ziqiang Yu (1)","submitted_at":"2025-05-28T00:53:45Z","abstract_excerpt":"Purpose: Recent studies have shown that spin-lock MRI can simplify quantitative magnetization transfer (MT) by eliminating its dependency on water pool parameters, removing the need for a T1 map in macromolecular proton fraction (MPF) quantification. However, its application is often limited by the requirement for long radiofrequency (RF) pulse durations, which are constrained by RF hardware capabilities despite remaining within specific absorption rate (SAR) safety limits.\n  Methods: To address this challenge, we propose a novel method, MPF mapping using pulsed spin-lock (MPF-PSL). MPF-PSL em"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2505.21853","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2505.21853/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T11:11:04Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"VuqbOuWR7LqlEWoXtOy9ndkZRJIngItNRpLjOcBSA3rrFI9OsFl5rd2Ey1BGKC1s/YtbIAiAnl9bXMxeUd/WCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-07T22:08:47.278038Z"},"content_sha256":"1135973f85099a5404c9459f784736999ad75b647f9faaa5af95f7f6b793c5d7","schema_version":"1.0","event_id":"sha256:1135973f85099a5404c9459f784736999ad75b647f9faaa5af95f7f6b793c5d7"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/AC44KIMACOQRQJT2Q6FBZPTAVW/bundle.json","state_url":"https://pith.science/pith/AC44KIMACOQRQJT2Q6FBZPTAVW/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/AC44KIMACOQRQJT2Q6FBZPTAVW/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-08-07T22:08:47Z","links":{"resolver":"https://pith.science/pith/AC44KIMACOQRQJT2Q6FBZPTAVW","bundle":"https://pith.science/pith/AC44KIMACOQRQJT2Q6FBZPTAVW/bundle.json","state":"https://pith.science/pith/AC44KIMACOQRQJT2Q6FBZPTAVW/state.json","well_known_bundle":"https://pith.science/.well-known/pith/AC44KIMACOQRQJT2Q6FBZPTAVW/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2025:AC44KIMACOQRQJT2Q6FBZPTAVW","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"4e66023dc051076118cff6e996201ab01b3a69a918becbdc9102bd26e77f08b0","cross_cats_sorted":["physics.app-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.med-ph","submitted_at":"2025-05-28T00:53:45Z","title_canon_sha256":"9285ab8498594d9856171cdf0b5aa65e1cab434f3d762d02e2e31b6e6f9c9b00"},"schema_version":"1.0","source":{"id":"2505.21853","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2505.21853","created_at":"2026-07-05T11:11:04Z"},{"alias_kind":"arxiv_version","alias_value":"2505.21853v1","created_at":"2026-07-05T11:11:04Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2505.21853","created_at":"2026-07-05T11:11:04Z"},{"alias_kind":"pith_short_12","alias_value":"AC44KIMACOQR","created_at":"2026-07-05T11:11:04Z"},{"alias_kind":"pith_short_16","alias_value":"AC44KIMACOQRQJT2","created_at":"2026-07-05T11:11:04Z"},{"alias_kind":"pith_short_8","alias_value":"AC44KIMA","created_at":"2026-07-05T11:11:04Z"}],"graph_snapshots":[{"event_id":"sha256:1135973f85099a5404c9459f784736999ad75b647f9faaa5af95f7f6b793c5d7","target":"graph","created_at":"2026-07-05T11:11:04Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2505.21853/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Purpose: Recent studies have shown that spin-lock MRI can simplify quantitative magnetization transfer (MT) by eliminating its dependency on water pool parameters, removing the need for a T1 map in macromolecular proton fraction (MPF) quantification. However, its application is often limited by the requirement for long radiofrequency (RF) pulse durations, which are constrained by RF hardware capabilities despite remaining within specific absorption rate (SAR) safety limits.\n  Methods: To address this challenge, we propose a novel method, MPF mapping using pulsed spin-lock (MPF-PSL). MPF-PSL em","authors_text":"((1) Department of Imaging, 2), Baiyan Jiang (1, Interventional Radiology (2) Illumination Medical Technology Limited (3) Department of Medicine, Jian Hou (1), Qianxue Shan (1), Qiuyi Shen (1), Therapeutics), Vincent WS Wong (3), Weitian Chen (1), Winnie CW Chu (1), Ziqiang Yu (1)","cross_cats":["physics.app-ph"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.med-ph","submitted_at":"2025-05-28T00:53:45Z","title":"Quantitative Macromolecular Proton Fraction Imaging using Pulsed Spin-Lock"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2505.21853","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:d708e155e50800955261eafac022c0979f847a393cf41562da0a72bb3cd16303","target":"record","created_at":"2026-07-05T11:11:04Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"4e66023dc051076118cff6e996201ab01b3a69a918becbdc9102bd26e77f08b0","cross_cats_sorted":["physics.app-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.med-ph","submitted_at":"2025-05-28T00:53:45Z","title_canon_sha256":"9285ab8498594d9856171cdf0b5aa65e1cab434f3d762d02e2e31b6e6f9c9b00"},"schema_version":"1.0","source":{"id":"2505.21853","kind":"arxiv","version":1}},"canonical_sha256":"00b9c5218013a118267a878a1cbe60adbe81b187e7fe6a08572735800cdef379","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"00b9c5218013a118267a878a1cbe60adbe81b187e7fe6a08572735800cdef379","first_computed_at":"2026-07-05T11:11:04.847025Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T11:11:04.847025Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"MF8rL+plrV7LNVHh8RRegrGpDncZGGtEpdslV28i1zJM+IOnQrY9ySzrrK4k9DkC4DE0jboZo78L7PBWqZadBw==","signature_status":"signed_v1","signed_at":"2026-07-05T11:11:04.847525Z","signed_message":"canonical_sha256_bytes"},"source_id":"2505.21853","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:d708e155e50800955261eafac022c0979f847a393cf41562da0a72bb3cd16303","sha256:1135973f85099a5404c9459f784736999ad75b647f9faaa5af95f7f6b793c5d7"],"state_sha256":"fe31bc5921496e78b280b58cecca0d1fb0c3192f0166b8c8969c974604a471f5"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"hl82Coxr7Bv3zVxtgSSi8f9f7odweE14jQ8ndMIc5uAyKMe2KCPvbJNM3on6hGdXyShcm7pEsW6NYbQrcCbIAQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-07T22:08:47.280999Z","bundle_sha256":"17191e728d7f179b3bdfcdddb7be3d77b1def0cd9a444f8f229d1c119b8ce9c1"}}