With the growing number of MR installations, clinicians and radiologist are being confronted more and more with visual information they do not feel as confident with as with the more 'mono-form' infor­ mation of conventional radiographs, CT and US. The freedom of parameter choice ofthe MR operator allows the same object to be depicted in various ways and the contrast in the images to be changed and inverted at will. For those not experienced in interpreting MR images, this may cause confusion and uncertainty about their diagnostic content. This will sometimes lead to an unnecessary retreat to other diagnostic modalities. The purpose of this book is to help close the gap between MR operators and readers and clinicians. A variety of cases is presented, together with the MRI considerations. In nearly all these cases, confirma­ tion of diagnosis was obtained by histological examination. Quite deliberately, this book only includes the occasional CT scan or angiography for comparison, to avoid the temptation of falling back on other modalities and of escaping from the often more difficult to interpret, but in the end more rewarding MR images. All the MR images in this book were made with a 'first-generation', unsophisticated Teslacon I, 0.6 T, superconducting magnet system. Hopefully, they will reflect the quality of the machine. Some people will agree with me that it is sad that investments in expensive health care systems are subject to the whims of those who are mainly interested in satisfying their stockholders.

1. Introduction.- 1.1 Introduction.- 1.2 Basic principles of MRI.- 2. Technical Considerations.- 2.1 Pulse sequences.- 5. MRI cisternography.- 6. Tissue differentiation, same slice, different techniques, IR, SE, SE with Gd-DTPA.- 7. Tissue differentiation in complex pathology.- 8. 'Anatomical' sequence, short TR, short TE.- 9. Application of 'anatomical' sequence.- 2.2. Artefacts.- 10. Artefacts (1).- 11. Artefacts (2).- 12. Artefacts (3).- 2.3. Functional studies.- 13. Functional studies on MRI systems.- 2.4. Flow related phenomenons.- 14. Signal void in aqueduct.- 15, 16. Flow-void in aqueduct; NPH.- 17. Flow-void in aqueduct; hydrocephalus in infants.- 18. CSF flow obstruction.- 19. Arteriovenous malformation.- 20. Flow phenomena, carotid artery.- 2.5. Surface coils.- 21, 22, 23. Surface coils (1).- 24. Surface coils (2).- 25. Surface coils (3), coronal and oblique images.- 26. Surface coils (4), orbit, oblique sagittal views.- 3. Special Procedures.- 3.1. Sellar and parasellar regions.- 27. Empty sella.- 28, 29. Pituitary adenomas.- 30. Chromophobe adenoma.- 31. Parasellar lesion.- 32. Parasellar lesion.- 3.2. Mesencephalon, region pineal gland.- 33. Pinealoma.- 3.3. Pontocerebellar cisterns.- 34. Coronal T2W, thin section series.- 35. Pontocerebellar cistern: T2W images; MRI cisternography.- 36, 37. Acustic neurinomas.- 38. Acustic neurinoma.- 4. Intracranial Tumours.- 4.1. Diagnostic problems.- 4.2. Cerebral tumours.- 39. Localization; intraventricular meningeoma.- 40. Cyst or solid?.- 41. Oligodendroglioma; large linear calcifications.- 42. Low grade glioma.- 43. Malignant glioma.- 44. Malignant glioma, patchy enhancement.- 45. Multifocal astrocytoma.- 46. Posterior fossa tumour.- 4.3. Extracerebral tumours.- 47. Medulloblastoma.- 48. Suprasellar lesion, craniopharyngeoma.- 49. Parasellar meningeoma.- 4.4. High SI lesions in pons and mesencephalon.- 50. Intrapontine haematoma; glioma.- 51. Intrapontine haemorrhage, dd. dermoid cyst.- 52. Same patient as in 51; follow-up.- 53. Dermoid cyst.- 54. Same patient as in 53; follow-up.- 4.5. Metastases.- 55. Metastases and Gd-DTPA.- 56. Metastasis of adenocarcinoma with haemorrhage.- 57. Tissue characterization; adenocystic carcinoma, metastasis.- 4.6. Gliomatosis cerebri.- 58. Multifocal astrocytoma or gliomatosis cerebri.- 59. Gliomatosis diffusa.- 60. Gliomatosis diffusa.- 61. Gliomatosis diffusa.- 62. Vasculitis simulating gliomatosis diffusa.- 63. Gliomatosis diffusa.- 64. Gliomatosis diffusa; cerebellar involvement.- 65. Gliomatosis diffusa.- 5. Spinal Lesions.- 5.1. Spondylarthrotic and disc related disease.- 66. Spondylarthrotic and disc related disease.- 67. Spondylarthrotic and disc related disease.- 68, 69. Myelopathy due to compression.- 70. Herniated disc L5-S1.- 71. Postoperative lumbar spine.- 5.2. Orthopedic problems.- 72. Orthopedic problems.- 73. Orthopedic problems.- 5.3. Spinal tumours.- 5.3.1. Intramedullary tumours.- 74. Intramedullary tumour, lipoma/dermoid.- 75. Intramedullary tumour.- 76. Cystic tumour, craniovertebral region.- 77. Intramedullary tumour and syrinx.- 78. Intramedullary tumour (metastasis).- 79. Intramedullary tumour and cysts.- 80. Recurrent intramedullary astrocytoma Gd-DTPA.- 81. Intramedullary tumour, ependymoma with calcifications.- 82. Whole cord spinal tumour, astrocytoma, grade 2, recurrence.- 83. Intramedullary tumour, astrocytoma grade 1.- 84. Intradural dermoid cyst and lipoma.- 85. Cystic ependymoma (post-operative).- 86. Intramedullary tumour without and with Gd-DTPA.- 87. Mutiple lesions; intramedullary tumour.- 5.3.2. Vascular malformations.- 88. Intramedullary lesion. Cryptic angioma?.- 89. Intramedullary arteriovenous malformation.- 5.3.3 Extramedullary and extradural lesions.- 90. Meningeoma at the C1 level.- 91. Osteochondroma of posterior arch.- 92. Extradural expanding lesion, Schwannoma.- 93. Post-laminectomy Th 1-2 for metastasis of adenocarcinoma of the breast.- 94. Metastasis of breast carcinoma.- 95. Giant cell tumour in sacrum.- 96. Extramedullary compression. Non Hodgkin lymphoma.- 97. Extradural lesion with cord compression. Osteoporosis of vertebral column.- 5.3.4. Congenital malformations, Myelodysplasia.- 98. Chiari I+, syrinx.- 99. Chiari I and syringomyelia.- 100. Spondylolysis and listhesis.- 101. Tethered cord, lipoma, syrinx.- 102. Tethered cord, intra-extradural lipoma.- 103. Tethered cord, hydronephrosis.- 104. Myelodysplasia; diastematomyelia.- 105. Myelodysplasia; diastematomyelia.- 106. Sacral cyst.- 6. Contrast Agents.- 107. Virus infection.- 108. Metastatic disease.- 109. Metastatic disease.- 110. Low grade astrocytoma.- 111. Glioma, grade 3; postoperative, postradiotherapy.- 112. Glioblastoma multiforme, distinction between tumour/oedema.- 113. Cystic or solid lesion.- 114. Meningeoma of the foramen magnum.- 115. Tentorium meningeoma.- 116. Intramedullary tumour.- 117. Recurrent spinal meningeoma.- 118. Intramedullary tumour.- 119. Intra- or extramedullary lesion with arachnoiditis.- 120. Intramedullary lesion in Wegener's disease.- 121. Same patient as in 120, follow-up after treatment.- 7. Infections.- 7.1. General.- 122. Neurocysticercosis.- 123. Viral encephalitis.- 124. Tuberculoma with partial epileptic seizures.- 125. Tuberculous meningitis.- 126. Postencephalitic changes; herpes simplex encephalitis.- 127. Empyema, infectious sinus thrombosis, infarctions.- 128. Septicaemia, meningoencephalitis.- 129. Transverse myelitis.- 7.2. AIDS encephalopathy.- 130. AIDS related disease.- 131. AIDS dementia-complex; encephalitis.- 132. AIDS encephalopathy.- 133. AIDS encephalopathy.- 134. AIDS encephalitis.- 135. AIDS dementia-complex.- 8. Vascular Lesions.- 8.1. Cerebral infarctions.- 136. Infarction or astrocytoma.- 137. Middle cerebral artery infarction.- 138. Multiple infarctions.- 139. Anterior cerebral artery infarction; lymphoma; haemorrhage.- 140. Anterior cerebral artery infarction; recurrent artery of Heubner infarction.- 141. Old deep middle cerebral artery infarction.- 142, 143. Border zone infarctions.- 144, 145. Border zone infarction; dd. MS.- 146. Border zone infarction.- 147. Old infarction of middle cerebral artery (MCA); recent infarction of the basilar artery territory.- 8.2. Cryptic angiomas.- 148. Cryptic angiomas.- 149. Cryptic angiomas; multiple echoes.- 150, 151. Cryptic angiomas.- 8.3. AVM's, aneurysms, intracerebral haemorrhage.- 152. Arteriovenous …