March 2013 Case of the Month Answers, Findings and Discussion
Regarding the lesion in the L4 vertebral body, what are its signal characteristics?
- hypointense on T1, hypointense on T2
- hyperintense on T1, hyperintense on T2
- hypointense on T1, hyperintense on T2
- hyperintense on T1, hypointense on T2
These signal characteristics are consisted with which type of tissue?
- Fluid
- Air
- Malignant tumor
- Fat
What is the diagnosis?
- Metastatic tumor
- Metallic implant
- Intraosseous hemangioma
- Solitary plasmacytoma
The lesion disappears on the STIR image because?
- It contains fat
- It is an artifact
- It is a malignant lesion
- It contains fluid
*Note that the
hemangioma (red arrows) in L4 follows
subcutaneous fat (blue arrows) on all 3 sequences; it is hyper on T1, hyper on T2, and drops out on STIR, just like the other fat does
*Incidentally noted are
Schmorl’s nodes (green arrows) that herniate into the superior endplates of L2, L3 and L4; the node at L4 has herniated into the hemangioma and that accounts for the small difference in signal in the middle of the lesion
*Note that the
hemangioma (red arrows) in L4 follows
subcutaneous fat (blue arrows) on all 3 sequences; it is hyper on T1, hyper on T2
*Incidentally noted are
Schmorl’s nodes (green arrows) that herniate into the superior endplates of L2, L3 and L4; the node at L4 has herniated into the hemangioma and that accounts for the small difference in signal in the middle of the lesion
Discussion
- Intraosseous vertebral hemangioma- a solitary, vascular neoplasm composed of vascular channels lined by epithelial cells, as well as varying amounts of adipose tissue
- Most common benign tumor of the spine
- 75% occur in spine or skull
- Peak incidence in fifth decade
- Usually asymptomatic
- Usually require no treatment, but fracture may occur; may also expand causing canal stenosis and neurological symptoms, requiring surgical intervention
- Not always seen on radiographs; frequently a coincidental finding on MRI
- On conventional radiographs, vertebral lesions have thickened vertical trabeculae secondary to erosion of the horizontal trabeculae, which gives a “corduroy cloth” or “striated” appearance
- On MR, fat content causes appearance of hyper T1, hyper T2, and hypo on STIR (because it is a fat suppression technique)
*Note that the lesion will have similar signal to subcutaneous fat on all 3 of these pulse sequences (it follows fat, therefore it must contain fat)
- Axial CT demonstrates a “polka dot” appearance as the vessels are seen in cross section
References