| Inbound Relationships | Type | Active | Source | Characteristic | Refinability | Group | 
| Entire fourth ventricle | Is a | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier |  | 
| Structure of ependyma of fourth ventricle | Is a | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier |  | 
| Structure of median eminence of pons | Is a | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier |  | 
| Structure of inferior medullary velum | Is a | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier |  | 
| Median aperture of fourth ventricle | Is a | False | Fourth ventricle structure | Inferred relationship | Existential restriction modifier |  | 
| Structure of tela choroidea of fourth ventricle | Is a | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier |  | 
| Structure of tegmen of fourth ventricle | Is a | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier |  | 
| Structure of lateral aperture of fourth ventricle | Is a | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier |  | 
| Structure of lateral recess of fourth ventricle | Is a | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier |  | 
| Rhomboid fossa structure | Is a | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier |  | 
| Isolated fourth ventricle hydrocephalus | Finding site | False | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 2 | 
| Structure of foramen of Magendie | Is a | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier |  | 
| Compression of the fourth ventricle - technique | Procedure site | False | Fourth ventricle structure | Inferred relationship | Existential restriction modifier |  | 
| Compression of the fourth ventricle - technique | Procedure site - Direct | False | Fourth ventricle structure | Inferred relationship | Existential restriction modifier |  | 
| Hydrocephalus with cleft palate and joint contracture syndrome | Finding site | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 7 | 
| Craniosynostosis with Dandy-Walker malformation and hydrocephalus syndrome | Finding site | False | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 6 | 
| Facial dysmorphism, macrocephaly, myopia, Dandy-Walker malformation syndrome | Finding site | False | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 6 | 
| Dandy-Walker syndrome | Finding site | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 2 | 
| Dandy-Walker malformation with postaxial polydactyly syndrome | Finding site | False | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 4 | 
| X-linked Dandy-Walker malformation with intellectual disability, basal ganglia disease and seizure syndrome | Finding site | False | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 5 | 
| Dandy-Walker syndrome with spina bifida | Finding site | False | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 6 | 
| Macrocephaly, short stature, paraplegia syndrome | Finding site | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 5 | 
| Spinal muscular atrophy, Dandy-Walker malformation, cataract syndrome | Finding site | False | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 4 | 
| Facial dysmorphism, macrocephaly, myopia, Dandy-Walker malformation syndrome | Finding site | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 7 | 
| Craniosynostosis with Dandy-Walker malformation and hydrocephalus syndrome | Finding site | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 7 | 
| Dandy-Walker syndrome with spina bifida | Finding site | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 4 | 
| Spinal muscular atrophy, Dandy-Walker malformation, cataract syndrome | Finding site | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 5 | 
| X-linked Dandy-Walker malformation with intellectual disability, basal ganglia disease and seizure syndrome | Finding site | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 6 | 
| Dandy-Walker malformation with postaxial polydactyly syndrome | Finding site | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 5 | 
| Isolated fourth ventricle hydrocephalus | Finding site | True | Fourth ventricle structure | Inferred relationship | Existential restriction modifier | 1 |