Merge pull request #424 from lauramble/neuroimaging_instances

Add neuroimaging instances

Author: lzehl

instances/latest/terminologies/MRIFatSuppressionTechnique/DixonWater-fatSeparationTechnique.jsonld

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+{
+  "@context": {
+    "@vocab": "https://openminds.om-i.org/props/"
+  },
+  "@id": "https://openminds.om-i.org/instances/MRIFatSuppressionTechnique/DixonWater-fatSeparationTechnique",
+  "@type": "https://openminds.om-i.org/types/MRIFatSuppressionTechnique",
+  "definition": "A water-fat separation technique that acquires images at different echo times to mathematically decompose water and fat signals based on their phase differences.",
+  "description": "The Dixon water-fat separation technique exploits the phase shift between water and fat signals that occurs at specific echo times due to their chemical shift difference. Images are acquired at in-phase and out-of-phase echo times, allowing computational separation of water and fat components. Multi-echo implementations improve robustness by modeling field inhomogeneities and signal complexity. The technique provides uniform fat suppression even in regions with magnetic field variation. Modern implementations form the basis of many contemporary clinical fat-water imaging protocols.",
+  "interlexIdentifier": null,
+  "knowledgeSpaceLink": null,
+  "name": "Dixon water-fat separation technique",
+  "preferredOntologyIdentifier": null,
+  "synonym": [
+    "Dixon method",
+    "Dixon technique"
+  ]
+}

instances/latest/terminologies/MRIFatSuppressionTechnique/chemicalShiftSelectiveSuppression.jsonld

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+{
+  "@context": {
+    "@vocab": "https://openminds.om-i.org/props/"
+  },
+  "@id": "https://openminds.om-i.org/instances/MRIFatSuppressionTechnique/chemicalShiftSelectiveSuppression",
+  "@type": "https://openminds.om-i.org/types/MRIFatSuppressionTechnique",
+  "definition": "A classical frequency-selective fat saturation technique that suppresses fat signal by applying a narrowband radiofrequency pulse tuned to the fat resonance frequency prior to image acquisition.",
+  "description": "Chemical shift selective suppression, short CHESS, exploits the chemical shift difference between water and fat to selectively target fat protons. A spectrally selective RF pulse is applied at the fat resonance frequency, followed by a spoiler gradient to eliminate transverse magnetization. This preparation reduces fat signal intensity during subsequent imaging readout. The method is fast and straightforward to implement within most pulse sequences. However, it is sensitive to B₀ and B₁ field inhomogeneities, which can lead to incomplete or uneven fat suppression.",
+  "interlexIdentifier": null,
+  "knowledgeSpaceLink": null,
+  "name": "chemical shift selective suppression",
+  "preferredOntologyIdentifier": null,
+  "synonym": [
+    "chemical shift selective saturation",
+    "CHESS"
+  ]
+}

instances/latest/terminologies/MRIParallelAcquisitionTechnique/generalizedAutocalibratingPartiallyParallelAcquisition.jsonld

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+{
+  "@context": {
+    "@vocab": "https://openminds.om-i.org/props/"
+  },
+  "@id": "https://openminds.om-i.org/instances/MRIParallelAcquisitionTechnique/generalizedAutocalibratingPartiallyParallelAcquisition",
+  "@type": "https://openminds.om-i.org/types/MRIParallelAcquisitionTechnique",
+  "definition": "A parallel MRI reconstruction technique that accelerates imaging by undersampling k-space and reconstructing missing data using calibration-derived interpolation kernels in k-space.",
+  "description": "A generalized autocalibrating partially parallel acquisition, short GRAPPA, acquires undersampled k-space data along with additional autocalibration lines. The method determines reconstruction weights directly from acquired calibration data without requiring explicit coil sensitivity maps. Missing k-space lines are synthesized by linear combinations of neighboring acquired data across multiple coils. Reconstruction occurs in k-space prior to final Fourier transformation. The technique is robust to coil sensitivity estimation errors and widely implemented in clinical MRI systems.",
+  "interlexIdentifier": null,
+  "knowledgeSpaceLink": null,
+  "name": "generalized autocalibrating partially parallel acquisition",
+  "preferredOntologyIdentifier": null,
+  "synonym": [
+    "GRAPPA"
+  ]
+}

instances/latest/terminologies/MRIParallelAcquisitionTechnique/sensitivityEncoding.jsonld

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+{
+  "@context": {
+    "@vocab": "https://openminds.om-i.org/props/"
+  },
+  "@id": "https://openminds.om-i.org/instances/MRIParallelAcquisitionTechnique/sensitivityEncoding",
+  "@type": "https://openminds.om-i.org/types/MRIParallelAcquisitionTechnique",
+  "definition": "A parallel MRI reconstruction technique that accelerates imaging by undersampling k-space and using coil sensitivity profiles to reconstruct full-resolution images in the image domain.",
+  "description": "Sensitivity encoding, short SENSE, reduces acquisition time by undersampling phase-encoding steps during data acquisition. The method relies on prior estimation of spatial sensitivity maps for each coil element in a multi-array coil system. Aliased images resulting from undersampling are mathematically unfolded using these sensitivity profiles. Reconstruction is performed in the image domain after Fourier transformation. The technique directly links achievable acceleration to coil geometry and signal-to-noise characteristics.",
+  "interlexIdentifier": null,
+  "knowledgeSpaceLink": null,
+  "name": "sensitivity encoding",
+  "preferredOntologyIdentifier": null,
+  "synonym": [
+    "SENSE"
+  ]
+}

instances/latest/terminologies/MRISpoilingTechnique/combinedSpoiling.jsonld

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+{
+  "@context": {
+    "@vocab": "https://openminds.om-i.org/props/"
+  },
+  "@id": "https://openminds.om-i.org/instances/MRISpoilingTechnique/combinedSpoiling",
+  "@type": "https://openminds.om-i.org/types/MRISpoilingTechnique",
+  "definition": "A spoiling technique that suppresses residual transverse magnetization by combining radiofrequency phase cycling with gradient-induced spatial dephasing.",
+  "description": "Combined spoiling applies radiofrequency (RF) phase cycling together with spoiler gradients within the same pulse sequence. This dual approach disrupts transverse coherence both temporally and spatially. RF spoiling controls phase evolution across repetitions. Gradient spoiling further enforces dephasing within each repetition. The combination provides robust suppression of steady-state transverse magnetization in modern gradient-echo imaging.",
+  "interlexIdentifier": null,
+  "knowledgeSpaceLink": null,
+  "name": "combined spoiling",
+  "preferredOntologyIdentifier": null,
+  "synonym": [
+    "combined radiofrequency–gradient spoiling",
+    "combined RF–gradient spoiling"
+  ]
+}

instances/latest/terminologies/MRISpoilingTechnique/gradientSpoiling.jsonld

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+{
+  "@context": {
+    "@vocab": "https://openminds.om-i.org/props/"
+  },
+  "@id": "https://openminds.om-i.org/instances/MRISpoilingTechnique/gradientSpoiling",
+  "@type": "https://openminds.om-i.org/types/MRISpoilingTechnique",
+  "definition": "A spoiling technique that suppresses residual transverse magnetization by applying additional gradient moments to induce spatial dephasing.",
+  "description": "Gradient spoiling applies crusher or spoiler gradients after signal acquisition. These gradients introduce position-dependent phase shifts in transverse magnetization. The resulting spatial dephasing reduces coherent signal contributions in subsequent repetitions. The effectiveness depends on gradient strength and duration. Gradient spoiling is widely used in gradient-echo and spin-echo sequences to control unwanted coherence pathways.",
+  "interlexIdentifier": null,
+  "knowledgeSpaceLink": null,
+  "name": "gradient spoiling",
+  "preferredOntologyIdentifier": null,
+  "synonym": [
+    "gradient crusher spoiling",
+    "gradient dephasing"
+  ]
+}

instances/latest/terminologies/MRISpoilingTechnique/radiofrequencySpoiling.jsonld

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+{
+  "@context": {
+    "@vocab": "https://openminds.om-i.org/props/"
+  },
+  "@id": "https://openminds.om-i.org/instances/MRISpoilingTechnique/radiofrequencySpoiling",
+  "@type": "https://openminds.om-i.org/types/MRISpoilingTechnique",
+  "definition": "A spoiling technique that suppresses residual transverse magnetization by applying controlled phase cycling to successive radiofrequency excitation pulses.",
+  "description": "Radiofrequency (RF) spoiling introduces systematic phase increments between consecutive RF pulses to disrupt coherent transverse magnetization. This phase cycling prevents the formation of stable transverse steady states. The method enforces incoherence of residual magnetization across repetitions. Reconstruction relies on predictable phase behavior imposed by the RF scheme. RF spoiling is commonly used in spoiled gradient-echo sequences for T1-weighted imaging.",
+  "interlexIdentifier": null,
+  "knowledgeSpaceLink": null,
+  "name": "radiofrequency spoiling",
+  "preferredOntologyIdentifier": null,
+  "synonym": [
+    "RF phase spoiling",
+    "RF spoiling"
+  ]
+}