1. Congenital and Acquired Conditions of the Mesial Temporal Lobe: A Pictorial Essay 
Martin Ochoa-Escudero, MD, Diego A. Herrera, MD, Sergio A. Vargas, MD, Arthur B. Dublin, MD, MBA, FACR 
Canadian Association of Radiologists Journal 
Volume 66, Issue 3, Pages (August 2015)
DOI: /j.carj
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

2. Figure 1
Normal radiological anatomy of the mesial temporal lobe. Coronal T2-weighted magnetic resonance image at (A) amygdala, (B) hippocampal head and (C) hippocampal body sections; 1 = Amygdala; 2 = uncus; 3 = parahippocampal gyrus; 4 = collateral sulcus; 5 = hippocampal head; 6 = temporal horn of lateral ventricle; 7 = fusiform gyrus; 8 = temporo-occipital sulcus; 9 = hippocampal fissure; 10 = hippocampal body; 11 = choroid fissure.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

3. Figure 2
Epidermoid cyst. Axial T2-weighted image (A) shows an extra-axial cerebrospinal fluid-like mass compressing left mesial temporal lobe. Diffusion-weighted imaging (B) and apparent diffusion coefficient map (C) show restricted diffusion.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

4. Figure 3
Left choroidal fissure cyst. Coronal T1-weighted (A) and Axial T2 FLAIR images (B) show a cerebrospinal fluid isointense lesion in the left choroid fissure (arrows).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

5. Figure 4
Hippocampal sulcus remnant cyst. Coronal T2-weighted image shows a cerebrospinal fluid signal small cyst along lateral margin of the left hippocampus (arrow).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

6. Figure 5
A 7-year-old boy with refractory temporal lobe epilepsy and dual pathology. Coronal T2-weighted image (A) shows hippocampal sclerosis (arrow). A more anterior coronal section (B) shows gray/white matter blurring (circle) indicating concomitant focal cortical dysplasia.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

7. Figure 6
A 56-year-old woman with hippocampal malrotation and rhombencephalosynapsis. Coronal T2-weighted images show (A) vertically oriented hippocampus (arrows), ventriculomegaly, and (B) fusion of the cerebellar hemispheres.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

8. Figure 7
A 6-year-old girl with abnormal mesotemporal gyral pattern. Coronal T2-weighted image shows abnormally deep temporo-occipital sulci (white arrows). The collateral sulcus is shallow (black arrow).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

9. Figure 8
A 7-year-old boy with learning disability, a speech disorder and an abnormal mesotemporal gyral pattern. Coronal T2-weighted image (A) shows abnormal temporo-occipital sulci (arrows) with mesial temporal cortex thickening. Sagittal T1-weighted image (B) shows a thick corpus callosum (arrow).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

10. Figure 9
A 8-year-old boy with abnormal mesotemporal gyral pattern. Coronal T2-weighted image shows overgyrification of the hippocampal formation, collateral and temporo-occipital sulci (circles).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

11. Figure 10
Craniosynostosis patient with abnormal mesotemporal gyral pattern. Coronal T2-weighted image shows crowding of mesial and basal temporal gyri (circles).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

12. Figure 11
Neurofibromatosis type 1. Coronal T2-weighted image shows mild enlargement and increased signal of both hippocampus (arrows).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

13. Figure 12
Right hippocampal sclerosis. Coronal T2-weighted image (A) shows hippocampal high signal intensity and volume loss (long arrows). Axial T1-weighted image (B) shows atrophy in the hippocampal head, body and tail. Coronal T1-weighted image (C) shows ipsilateral fornix atrophy (short arrow).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

14. Figure 13
A 38-year-old woman with bilateral hippocampal sclerosis. Coronal T2-weighted image shows bilateral hippocampal volume loss with high signal intensity (arrows). There is hippocampal head flattening. The right hippocampus is more atrophic than the left.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

15. Figure 14
A 10-year-old infant with status epilepticus. Diffusion-weighted apparent diffusion coefficient map images (A, B) show restricted water diffusion in the hippocampus.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

16. Figure 15
A 19-year-old woman after right anteromedial temporal lobectomy with amygdalo-hippocampectomy. Axial (A) and coronal (B) T2-weighted images show the anterior and medial temporal resection cavity.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

17. Figure 16
Alzheimer’s disease. Coronal T2-weighted image shows bilateral hippocampal volume loss (arrows).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

18. Figure 17
Frontotemporal lobar degeneration. (A) Coronal and (B) axial T2-weighted image shows left temporal cortical atrophy suggesting a semantic dementia. Mesial temporal atrophy is noted as well.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

19. Figure 18
Glioblastoma multiforme. (A) Coronal T2-weighted image and (B) Coronal post-contrast T1-weighted image show a large, heterogeneous enhancing mass in the left temporal lobe, with necrotic areas and surrounding vasogenic edema. Additionally, there is left uncal herniation.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

20. Figure 19
Meningioma. Axial T2-weighted image (A) and axial postcontrast T1-weighted image (B) show an extra-axial mass compressing the right mesial temporal lobe. There is a small dural tail (arrow) and edema in the adjacent brain parenchyma.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

21. Figure 20
Dysembryoplastic neuroepithelial tumour. (A) Axial T2-weighted image shows a large bubbly cystic intracortical mass (“soap bubble” appearance) in the left temporal lobe. (B) Coronal T2-weighted image in a different patient shows a smaller dysembryoplastic neuroepithelial tumour in the left parahippocampal gyrus (arrow).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

22. Figure 21
Ganglioglioma. There is a solid non-enhancing mass expanding the right hippocampus (arrows) in the post-contrast T1-weighted image (A). High signal intensity on coronal T2-weighted image is noted (B).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

23. Figure 22
Patient with sudden onset of memory loss due to transient global amnesia. Diffusion-weighted imaging shows a small punctate lesion in right hippocampus (arrow).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

24. Figure 23
Acute infarction. Coronal T2-weighted image (A) shows hyperintensity of the right hippocampus (long arrow). Apparent diffusion coefficient map (B) shows low signal (short arrow) due to restricted diffusion. Additionally, there is another infarction in right occipital lobe. Magnetic resonance angiography image (C) shows occlusion of the right posterior cerebral artery (arrowhead).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

25. Figure 24
Aneurysm. Coronal (A) and axial (B) T2-weighted images show a right posterior communicating artery aneurysm (arrows) compressing the right amygdala and hippocampal head.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

26. Figure 25
Arteriovenous malformation. Coronal T2-weighted image shows multiple flow voids with the typical “bag of worms” appearance in the left temporal lobe.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

27. Figure 26
Limbic encephalitis. Axial FLAIR (A) image shows bilateral high signal intensity and mild enlargement of amygdala and hippocampal body. A more superior axial section (B) shows bilateral high signal intensity of hippocampal tail.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

28. Figure 27
Neurocysticercosis. (A) Coronal T2-weighted image shows intraventricular and subarachnoid neurocysticercosis. There are cysts in the body and temporal horn of the left lateral ventricle as well as right hippocampal sulcus involvement (white arrows). (B) Axial post-contrast T1-weighted image demonstrates neurocysticercosis in colloidal-vesicular stage. There are multiple enhancing cysts in both temporal lobes including hippocampi (black arrows).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

29. Figure 28
Cerebral malaria. Axial FLAIR image shows swelling and hyperintensity of both temporal lobes predominantly on the left. Additionally, there is uncal herniation (arrows).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

30. Figure 29
Tuberculoma. (A) Coronal T2-weighted image shows a lesion with hypointense rim and surrounding edema in the left amygdala (long arrow). Additionally, there is right hippocampal volume loss and another tuberculoma in the right temporal lobe. (B) Postcontrast T1-weighted image shows ring enhancement (short arrow).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

31. Figure 30
Herpes encephalitis. Coronal FLAIR image shows bilateral and asymmetric increased signal in temporal lobes, insular cortex, inferior frontal lobes and cingulate gyrus.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

32. Figure 31
Superficial siderosis. Coronal T2-weighted image shows linear low signal in left amygdala and parahippocampal gyrus due to hemosiderin deposition (arrow).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

33. Figure 32
Kernicterus. Coronal T2-weighted image shows bilateral with left predominance (long arrows) high signal and volume loss of hippocampi. Additionally, there is bilateral high signal in globus pallidus (short arrows) and subthalamic nuclei (not shown).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2015 Canadian Association of Radiologists Terms and Conditions