1 / 75

University of Rochester, NY

Diffusion-weighted imaging findings of intracranial tumors relationship between T2 and diffusibility. Hiwatashi A, Moritani T. University of Rochester, NY. Introduction.

kevinbrennan
Download Presentation

University of Rochester, NY

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Diffusion-weighted imaging findings of intracranial tumorsrelationship between T2 and diffusibility Hiwatashi A, Moritani T University of Rochester, NY

  2. Introduction • Routine magnetic resonance (MR) imaging is sensitive method of detecting tumors of the brain. Diffusion-weighted imaging (DWI) can differentiate between tumor and infection (1-51) and can help the characterization and grading of brain tumors. This exhibit demonstrates DWI characteristics of intracranial tumors.

  3. Gliomas (Figs 1-6) • The signal intensity of gliomas on DWI is variable and depends mainly on their T2 and apparent diffusion coefficient (ADC) values (1-22). Thus, some gliomas are hyperintense on DWI with decreased ADC, which reflects reduced volume of extracellular space. Other gliomas have normal or increased ADC which causes T2 shine-through effect.

  4. High Grade Tumors • It has been reported that high-grade gliomas tends to show high signal on DWI with decreased ADC (3, 8-10, 12, 13, 19). High tumor cellularity is probably the major cause (3, 8, 12, 18). There are still controversies regarding how well DWI can differentiate between high grade primary brain tumor and metastasis (6, 18, 46). In lymphoma, ADC have been reported to be lower than in high grade gliomas (16), but in the clinical situation there is often overlap between lymphoma and high-grade glioma.

  5. Peritumoral infiltration • The value of DW imaging for the delineation of peritumoral invasion in primary brain tumors is controversial (3, 4, 10-12, 18, 19). The poor delineation is probably due to conjoined effects of T2 and ADC. Diffusion tensor imaging may add more information about tumor infiltration.

  6. Fig 1A. GBM69-year-old female with left side weakness • Postcontrast T1WI shows heterogeneous enhancement (arrow).

  7. Fig 1B. GBM69-year-old female with left side weakness • DWI shows hyperintensity in enhancing (arrow) and hyperintensity in cystic/necrotic portions (arrowhead).

  8. Fig 1C. GBM69-year-old female with left side weakness • ADC map shows heterogeneous hyperintensity (0.74-0.85 x 10-3 mm2/s; arrow) in enhancing portion compared to surrounding vasogenic edema. Cystic/necrotic portion (arrowhead) is hyperintense. These findings may correspond to high cellularity of enhancing tumor and increased diffusibility of cystic/necrotic portion.

  9. Fig 2A. GBM51-year-old male with right side weakness • T2WI shows hyperintense mass in left basal ganglia and thalamus (arrow).

  10. Fig 2B. GBM51-year-old male with right side weakness • T1WI shows hyperintensity (arrow).

  11. Fig 2C. GBM51-year-old male with right side weakness • Postcontrast T1WI shows heterogeneous enhancement posteriorly (arrow).

  12. Fig 2D. GBM51-year-old male with right side weakness • DWI shows hyperintensities (arrows). Areas of marked hyperintensity on DWI does not show contrast enhancement in this patient.

  13. Fig 2E. GBM51-year-old male with right side weakness • ADC map shows heterogeneous hyperintensity (0.58-0.89 x 10-3 mm2/s; arrows).

  14. Fig 3A. GBM80-year-old female with personality change • T2WI shows hyperintense mass which involves genu of corpus callosum (butterfly tumor).

  15. Fig 3B. GBM80-year-old female with personality change • Postcontrast T1WI shows irregular ring-like enhancement.

  16. Fig 3C. GBM80-year-old female with personality change • DWI shows hyperintensity (arrow).

  17. Fig 3D. GBM80-year-old female with personality change • ADC map shows heterogeneous intensity. • Note hyperintensity in center of lesion (arrow). These findings may correspond to the cellularity.

  18. Fig 4A. JPA14-year-old male with headache • T2WI shows hyperintense mass in cerebellum (arrow). Mural nodule is seen (arrowhead).

  19. Fig 4B. JPA14-year-old male with headache • Postcontrast T1WI shows enhancement in nodule (arrowhead).

  20. Fig 4C. JPA14-year-old male with headache • DWI shows hyperintensity in cystic component (arrow) and mild hyperintensity in nodule (arrowhead).

  21. Fig 4D. JPA14-year-old male with headache • ADC map shows hyperintensity in cyst (arrow) and mild hyperintensity in nodule (1.18 x 10-3 mm2/s; arrowhead).

  22. Fig 5A. Brain stem glioma8-year-old female with headache • T2WI shows hyperintense lesion (arrow) with surrounding edema in pons.

  23. Fig 5B. Brain stem glioma8-year-old female with headache • Postcontrast T1WI shows no significant enhancement.

  24. Fig 5C. Brain stem glioma8-year-old female with headache • DWI shows iso-intensity in the lesion (arrow).

  25. Fig 5D. Brain stem glioma8-year-old female with headache • ADC map shows hyperintensity (arrow). • Iso-intensity on DWI is caused by a balance between increased T2 and ADC.

  26. Fig 6A. Low-grade oligoastrocytoma48-year-old female with seizures • T2WI shows a hyperintense lesion in the right temporal lobe (arrow).

  27. Fig 6B. Low-grade oligoastrocytoma48-year-old female with seizures • Postcontrast T1WI shows slightly hyperintense lesion and no enhancement (arrow).

  28. Fig 6C. Low-grade oligoastrocytoma48-year-old female with seizures • DWI shows hyperintensity (arrow).

  29. Fig 6D. Low-grade oligoastrocytoma48-year-old female with seizures • ADC map shows hyperintensity • (0.98-1.19 x 10-3 mm2/s;arrow).

  30. Epidermoid tumor(Fig 7) • Epidermoid tumors are benign neoplasms of ectodermal origin with stratified squamous epithelium and keratinaceous debris (13, 24-31). They are hyperintense on DWI with decreased ADC. The ADC of epidermoid tumors has been reported to be lower than cerebrospinal fluid and equal or higher than brain parenchyma (24-26, 28, 29, 31). Therefore, the hyperintensity of epidermoid tumors on DWI is primarily caused by T2 shine-through effect.

  31. Fig 7A. Epidermoid9-year-old asymptomatic female • T2WI shows hyperintense mass near in midline (arrow).

  32. Fig 7B. Epidermoid9-year-old asymptomatic female • T1WI shows hyperintensity (arrow).

  33. Fig 7C. Epidermoid9-year-old asymptomatic female • DWI shows hyperintensity (arrow).

  34. Fig 7D. Epidermoid9-year-old asymptomatic female • ADC map shows heterogeneous hyperintensity.

  35. Arachnoid cysts (Fig 8) • Arachnoid cysts have a similar appearance on routine MR imaging as epidermoid tumors, but it is well-known that DWI can distinguish the two (24-31). Arachnoid cysts are hyperintense on DWI and their MR signal characteristics are similar to cerebrospinal fluid.

  36. Fig 8A. Arachnoid cyst9-year-old female with developmental delay • T2WI shows large hyperintense lesion in right cerebellopontine angle (arrow).

  37. Fig 8B. Arachnoid cyst9-year-old female with developmental delay • T1WI shows hyperintensity (arrow).

  38. Fig 8C. Arachnoid cyst9-year-old female with developmental delay • DWI shows hyperintensity (arrow).

  39. Fig 8D. Arachnoid cyst9-year-old female with developmental delay • ADC map shows hyperintensity due to increased diffusibility • (3.07-3.12 x 10-3 mm2/s;arrow).

  40. Primitive neuroectodermal tumor (PNET) (Fig. 9) • PNET is a group of histologically similar tumors that occur mostly in children. They include embryonal, largely undifferentiated tumors, such as medulloblastoma, neuroblastoma, pineoblastoma, ependymoblastoma and medulloepithelioma. These tumors have a high cellular density and are typically hyperintensity on DWI with decreased ADC (32-35).

  41. Fig 9A. PNET20-month-old female with lethargy and nausea • T2WI shows a well demarcated and heterogeneous intense mass in right frontal lobe.

  42. Fig 9B. PNET20-month-old female with lethargy and nausea • T1WI shows heterogeneous hyperintensity.

  43. Fig 9C. PNET20-month-old female with lethargy and nausea • DWI shows hyperintensity.

  44. Fig 9D. PNET20-month-old female with lethargy and nausea • ADC map shows heterogeneous hyperintensity (0.54-0.74 x 10-3 mm2/s) representing hypercellularity.

  45. Meningiomas (Figs 10, 11) • Most benign meningiomas are iso-intense on DWI and ADC maps, but some are slightly hyperintense on both DWI and ADC maps. Malignant or atypical meningiomas have markedly increased signal intensity on DWI and decreased ADC due to a high tumor cellularity (12, 18, 36). However, other factors, such as multifocal areas of necrosis, numerous abnormal mitoses and cytologic pleomorphism may also cause the high DWI signal (11, 12, 18, 36,37).

  46. Fig 10A. Benign meningioma72-year-old female with visual disturbance • T2WI shows hyperintense mass near frontal falx.

  47. Fig 10B. Benign meningioma72-year-old female with visual disturbance • Postcontrast T1WI shows homogeneous enhancement.

  48. Fig 10C. Benign meningioma72-year-old female with visual disturbance • DWI shows hyperintensity.

  49. Fig 10D. Benign meningioma72-year-old female with visual disturbance • ADC map shows mild hyperintensity • (0.73-0.78 x 10-3 mm2/s).

  50. Fig 11A. Atypical meningioma45-year-old female with headache • T2WI shows heterogeneous intense mass in left temporal lobe (arrow).

More Related