1. Pictorial Essay: Tumours and Pseudotumours of Sacrum
Keh Oon Ong, MBBS, MRCS (Glasg), MRCSEd, FRCR, David A. Ritchie, MBChB, FRCR 
Canadian Association of Radiologists Journal 
Volume 65, Issue 2, Pages (May 2014)
DOI: /j.carj
Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

2. Figure 1
A 30-year-old woman with giant cell tumour. Coronal T1-weighted magnetic resonance image, showing a large hypointense expansile lesion in left sacral ala (arrow), which extends across the left sacroiliac joint to involve the iliac bone (arrowheads).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

3. Figure 2
A 12-year-old girl with aneurysmal bone cyst. Axial T2-weighted magnetic resonance image, showing large heterogeneous expansile lesion centred at the posterior aspect of the upper sacrum, with multiple fluid-fluid levels (arrows), which represent sedimentation of static blood.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

4. Figure 3
A 16-year-old boy with constant low back pain that was worse at night. Bone scintigraphy (A), showing focal increased radionuclide uptake (black arrow) in the left S1 vertebrae, and axial, bone window, computed tomography image (B), showing a small mineralized nidus (black arrow) in the left S1 posterior arch with surrounding sclerosis (white arrowheads). Histology-confirmed osteoid osteoma.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

5. Figure 4
A 54-year-old man with chordoma. Frontal (A) and lateral (B) radiographs, showing a large expansile lytic lesion arising from the lower sacral segments (black arrows). Sagittal, soft-tissue window (C) computed tomography image, showing large midline destructive lesion in lower sacral segments, with anterior (white arrowheads) and posterior extraosseous extension into the spinal canal (black arrowheads) and internal punctuate calcification (black arrow). Axial T1 (D) and sagittal fat-saturation T2-weighted (E) magnetic resonance images, showing a large midline mass arising from the lower sacral segments with anterior and posterior extraosseous extension and infiltration of the spinal canal (arrowheads).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

6. Figure 5
A 47-year-old woman with plasmacytoma. Axial soft-tissue window (A) and bone window (B) computed tomography images, axial T1 (C), and fat-saturation T2-weighted (D) magnetic resonance images, showing an expansile lytic lesion without sclerotic margin in the body of the sacrum that extends to the right sacral ala (A-D, arrows).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

7. Figure 6
A 78-year-old man with lymphoma. (A) Axial bone window computed tomography image, showing a permeative sclerotic lesion in the sacral body (arrowheads) extending to right ala (arrows). Axial T1 (B) and sagittal fat-saturation T2-weighted (C) magnetic resonance images, showing a heterogeneous lesion in the sacrum (arrows) that extends into the spinal canal (arrowheads) with intact cortex.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

8. Figure 7
A 16-year-old girl with Ewing sarcoma. Axial T1-weighted magnetic resonance image, showing a large heterogeneous lesion in the lower sacrum with soft-tissue extension anteriorly (white arrowhead) and hyperintense foci (black arrows) consistent with subacute hemorrhage.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

9. Figure 8
A 39-year-old man with osteosarcoma. (A) Axial soft-tissue window computed tomography image, showing bone-forming lesion arising from the sacrum (black arrows). (B) Sagittal T1-weighted magnetic resonance image, showing hypointense lesion arising from the sacrum, with a large prevertebral extraosseous component (white arrow).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

10. Figure 9
A 27-year-old woman with chondrosarcoma. (A) Axial soft-tissue window computed tomography image, showing a soft-tissue lesion with faint mineralization (black arrows) arising from the left sacral ala. Axial T1-weighted (B) and T2-weighted (C) magnetic resonance images, showing a heterogeneous lesion arising from the left sacral ala (white arrows), with extraosseous extension into the spinal canal (black arrows). The high signal on T2 is suggestive of low-grade, unmineralized cartilaginous tumour.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

11. Figure 10
A 76-year-old man with sclerotic metastasis from prostate carcinoma. Axial bone window computed tomography, showing a sclerotic lesion in the right sacral ala (white arrow).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

12. Figure 11
A 69-year-old man with lytic metastasis from renal carcinoma. (A) Frontal radiograph, showing lytic lesion in the right sacral ala (black arrows). (B) Axial bone window computed tomography image, showing an expansile lytic lesion in the body and right sacral ala (black arrows), with an anterior extraosseous component (white arrows) and extension into the right sacral foramen (black star). (C) Sagittal fat-saturation T2-weighted magnetic resonance image, showing expansile lesion in the sacral body (black arrows) that extends into the spinal canal (white arrowheads).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

13. Figure 12
A 62-year-old woman with an incidental meningeal cyst. (A) Axial bone window computed tomography image, showing lobulated expansion of spinal canal with well-defined sclerotic margin (black arrows). Axial T1 (B) and T2-weighted (C) magnetic resonance images, showing lobulated expansion of spinal canal of cerebrospinal fluid signal intensity (black arrows).
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

14. Figure 13
A 25-year-old woman with tuberculosis. (A) Axial T2-weighted magnetic resonance image, showing presacral-iliopsoas abscess (black arrowheads), and a rectangular hypointense lesion (white arrow) with a thin rim of fluid (black arrow) in the first sacral vertebral body. (B) Axial bone window computed tomography image, showing mineralization of the hypointense lesion (white arrow) consistent with a sequestrum.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
Copyright © 2014 Canadian Association of Radiologists Terms and Conditions