1. Yukunori Korogi, Shingo Kakeda, Tetsuya Yoneda Department of Radiology, University of Occupational and Environmental Health, Japan. Department of course of Radiological Sciences, Kumamoto University School of Health Sciences Neuroanatomy of Visual Pathway and Brain stem: Demonstration with Modern MR Technology

2. Contents 1.Optic radiation on conventional MRI 2.Phase-weighted MR imaging 1.Optic radiation and calcarine area 2.Brain stem 3.Contrast-enhanced FIESTA image 1.Optic nerve and suprasellar tumors

3. Contents 1.Optic radiation on conventional MRI 2.Phase-weighted MR imaging 1.Optic radiation and calcarine area 2.Brain stem 3.Contrast-enhanced FIESTA image 1.Optic nerve and suprasellar tumors

4. MR signal intensity of the optic radiation 11 brain specimens and MR images from 43 healthy volunteers. To determine which layer adjacent to the lateral ventricle on MRI represents the optic radiation. Kitajima, Korogi, et al. AJNR 1996;17:1379 external sagittal stratum=optic radiation internal sagittal stratum tapetum from the outside

5. Optic radiation: histologic specimens Bodian KB ESSISS Bodian x200 AJNR 1996;17:1379 ESS: external sagittal stratum ISS: internal sagittal stratum

6. MR signal intensity of the optic radiation AJNR 1996;17:1379 measuring the distance from the ventricular wall related to their lower axonal density?

7. MR signal intensity of the optic radiation The hyperintense layer on T2-weighted images represents the external sagittal stratum, or optic radiation. The signal intensity of the external sagittal stratum seems to reflect histologic characteristics of low axonal density. Kitajima, Korogi, et al. AJNR 1996;17:1379 Signal intensity of tissues on conv MRI still not always understood.

8. Contents 1.Optic radiation on conventional MRI 2.Phase-weighted MR imaging 1.Optic radiation and calcarine area 2.Brain stem 3.contrast-enhanced FIESTA image 1.Optic nerve and suprasellar tumors

9. Phase-weighted MR imaging SWI is one of existing techniques for phase- weighted MR imaging; with SWI, however, phase difference is fixed and cannot be selected. We have developed new phase-weighted MR imaging, “ Phase Difference Enhanced Imaging (PADRE*) ”, in which phase difference between objective and surrounding tissue is selected in order to enhance the contrast of objective tissue. *Yoneda, et al. Proc. Intl. Soc. Mag. Reson. Med., vol.17 p2764, 2009

10. PADRE technique surrounding tissue object phase PADRE selects the phase difference between the object and surrounding tissue, and enhances them selectively. Source imge PADRE phase By choosing appropriate phase differences, we are able to create various contrasts of tissues.

11. PADRE Images 3T MR system (Signa EXCITE 3T; GE Healthcare)  three-dimensional fast spoiled gradient-echo (3D fast SPGR) sequence  TR=45 msec, TE=/28 msec, imaging time= 12 minutes, 22 cm field of view, 512 x 512 matrix, and 1.4-mm thick sections. High spatial resolution (voxel size of 0.4 x 0.4 x 1.4 mm 3 )

12. Delineation of optic radiation and stria of Gennari We tried to delineate the optic radiation and primary visual cortex (stria of Gennari) with the high-spatial-resolution PADRE at 3T. These structures might have specific phase differences than others.

13. Visualization of optic radiation PADRE Three layers are clearly identified on PADRE. phase difference caused by myelin content? KB stain

14. PADRE Visualization of calcarine area (striated cortex) The stria of Gennari is clearly identified on PADRE as a continuous black line. bright line coronal

15. Delineation of optic radiation and stria of Gennari Phase-weighted MRI, or PADRE, offers a different contrast of tissues than conventional MRI. Phase-weighted MRI can constantly delineate the stria of Gennari and three layers of optic radiation. Phase differences of these structures seem caused by the myelin content, at least, in part.

16. Contents 1.Optic radiation on conventional MRI 2.Phase-weighted MR imaging 1.Optic radiation and calcarine area 2.Brain stem 3.contrast-enhanced FIESTA image 1.Optic nerve and suprasellar tumors Moriya, et al. Parallel session: Encephalopathies 2 Tuesday, 5 Oct. White hall 2

17. Brain stem Brain stem concentrates structures of vital importance. Many structures of the brain stem cannot be delineated on conventional MRI. With DTI, the superior, middle, and inferior cerebellar peduncles and corticospinal tract can be identified. However, the medial lemniscus, central tegmental tract, and medial and dorsal longitudinal fasciculi have not been defined using DTI.

18. Brain stem Normal anatomy and MSA Using Phase-weighted MRI (PADRE), Visualize the small fiber tracts of the brain stem. Detect the pathological changes in a multiple system atrophy (MSA).

19. Normal Anatomic Analysis  6 healthy volunteers  Brain stem anatomy on the PADRE images was assessed on the basis of anatomic knowledge.

20. Medial lemniscus Corticospinal fibers Spinothalamic tract Marjorie A. England, Jennifer Wakely: Color Atlas of the BRAIN & SPINAL CORD p194 Normal Anatomic Analysis: Midbrain PADRE

21. Normal Anatomic Analysis: Pons and medulla Medial longitudinal fasciculus Superior cerebellar peduncle Central tegmental tract PADRE Transverse pontine fibers inferior cerebellar peduncle PADRE

22. Investigation of the 3D configuration Spinothalamic tract c Medial lemniscus medial longitudinal fasciculus superior cerebellar peduncle coronal image sagittal image

23. SPGR T2WI PADRE vs SWI, T2WI, SPGR SWI vs

24. Analysis of the patients with MSA  MSA-C (n=3), MSA-P (n=2), spinocerebellar ataxia (SCA) type 6 (n=2), SCA type 8 (n=1), and cortical cerebellar atrophy (CCA) (n=1).  Comparison of PADRE images between healthy volunteers and patients.  PADRE images were evaluated on the basis of the existing anatomical postmortem data regarding MSA.

25. * * * * Healthy volunteer MSA-C CCA Pathology of MSA-C Evaluation at the level of the pons (*)superior cerebellar peduncles (←) medial longitudinal fasciculus ( ▼ ) transverse pontine fibers disappearance of the transverse pontine fibers in MSA-C

26. Healthy volunteer MSA-C CCA Pathology of MSA-C (←) inferior cerebellar peduncles Evaluation at the level of medulla atrophy of inferior cerebellar peduncle in MSA-C

27. T2WI Early stage MSA-C PADRE 59y. m. Duration of symptoms (10 months) (←) inferior cerebellar peduncles ( ▼ ) transverse pontine fibers PADRE T2WI absence of so-called hot cross bun sign

28. Analysis of the patients with MSA Phase-weighted MRI, or PADRE, can offer a new tract imaging of the brain stem and may have a potential to reinforce the clinical utility of MRI in differentiating MSA from other conditions.

29. Contents 1.Optic radiation on conventional MRI 2.Phase-weighted MR imaging 1.Optic radiation and calcarine area 2.Brain stem 3.Contrast-enhanced FIESTA image 1.Optic nerve and suprasellar tumors

30. “ Missing ” optic nerve in large suprasellar tumors In large suprasellar tumors, a preoperative understanding of the anatomical relationship between the anterior optic pathways and tumors is an important factor in determining surgical approaches. Conventional MRI often fails to depict the optic nerves and tracts because of their marked thinning due to long-term compression.

31. “ Missing ” optic nerve in large suprasellar tumors detection with contrast-enhanced FIESTA image Fast imaging employing steady-state acquisition (FIESTA) sequence –high spatial resolution –increased contrast as concentration of contrast agent increases. CE FIESTA for the detectability of the anterior optic pathways in patients with large suprasellar tumors.

32. Shigematsu, Korogi, et al. Contrast-enhanced CISS MRI of vestibular schwannomas: Phantom and clinical studies. JCAT 23 : 224, 1999 Contrast-enhanced CISS vestibular schwannomas facial nerve, cochlear nerve, vestibular nerve compressed or involved by the tumor Both CISS and FIESTA sequences have T2/T1 contrast.

33. contrast enhancement on CISS CISS-3DFT 3D-T2-TSE T2-TSE Gd-DTPA 濃度 (mmol) -100 -50 0 50 100 150 200 250 300 350 400 450 1E-2.1110 T2 R Shigematsu, Korogi, et al. JCAT 1999 signal intensity Gd concentration

34. Vestibular schwannomas Shigematsu, Korogi, et al. JCAT 1999

35. Optic nerve in suprasellar tumors: CE FIESTA 28 pts with suprasellar tumor –pituitary adenoma in 19, meningioma in 7 and others in 3. Two radiologists –visibility of 5 segments of anterior optic pathway –5 point quality rating Conventional MRI (3 mm-thick coronal T2WI, CE 3D SPGR) vs CE FIESTA MR findings also correlated with surgical findings (12 pts)

36. Meningioma clearly visible invisible CE FIESTAT2WI

38. Pituitary adenoma clearly visible CE FIESTA CE SPGR invisible

39. Optic nerve in suprasellar tumors: CE FIESTA Of all 140 segments of the anterior optic pathway, 22% were invisible with conventional MRI, while 99% could be identified with CE FIESTA. All preoperative CE FIESTA were compatible with operative findings.

40. Optic nerve in suprasellar tumors: CE FIESTA CE FIESTA is useful in determining the location of the anterior optic pathways in patients with large suprasellar tumor. This information is useful in predicting surgical anatomy and selecting a proper surgical approach.

41. Conclusion Modern MR technology offers us novel method to evaluate fine brain anatomy, which cannot be evaluated with conventional imaging techniques. Kokura Castle in Kitakyushu city