Vertebral Body, T1 Hypointense Signal, Diffuse

Kevin R. Moore, MD

DIFFERENTIAL DIAGNOSIS

Common

Hyperplastic Vertebral Marrow
Normal Variant (Technical)
Neoplasm
- Metastases, Blastic Osseous
- Leukemia
- Lymphoma
- Multiple Myeloma

Less Common

HIV
Sickle Cell
Renal Osteodystrophy

Rare but Important

Myelofibrosis
Osteopetrosis
Fibrous Dysplasia
Extramedullary Hematopoiesis

ESSENTIAL INFORMATION

Key Differential Diagnosis Issues

Determine whether there is diffusely abnormal hypointense vertebral marrow signal intensity or scattered patchy areas of hypointensity within multiple vertebra
Hypointense marrow appearance by itself is relatively nonspecific; look for ancillary clues that may permit a specific diagnosis

Helpful Clues for Common Diagnoses

Hyperplastic Vertebral Marrow
- Physiologic process in which fatty marrow is converted to red marrow in response to systemic stress
- Intervertebral discs are hyperintense compared to vertebral marrow on T1WI
Normal Variant (Technical)
- Marrow demonstrates hypointense signal artifactually due to MR pulse sequence technique
- Commonly observed when T1 FLAIR imaging is used at higher field (> 3T) imaging to reduce patient heating related to specific absorbed radiation (SAR)
- T1 FLAIR produces lower marrow signal intensity in normal bone marrow compared to that observed using spin echo or fast spin echo T1WI MR technique
  - Less likely to produce erroneous diagnosis of marrow infiltration as radiologist gains experience using this technique
Neoplasm
- Metastases, Blastic Osseous
  - Hematogenous systemic dissemination (arterial or venous via Batson plexus) > perineural, lymphatic, CSF spread
  - Marrow initially infiltrated, trabeculae destroyed, then subsequently bone cortex destroyed
  - Blastic rather than lytic presentation occurs when bone production exceeds bone destruction
- Leukemia
  - Acute or chronic, myeloid or lymphoid white blood cell neoplasia with spinal involvement as component of systemic disease burden
  - Single or multiple vertebral involvement
  - Most common (classic) spinal presentation is diffuse osteopenia with multiple vertebral fractures ± lytic spine lesions
- Lymphoma
  - Lymphoreticular neoplasms with wide variety of specific diseases & cellular differentiation
  - Variable imaging manifestations
- Multiple Myeloma
  - Multifocal malignant proliferation of monoclonal plasma cells within bone marrow
  - Multifocal, diffuse, or heterogeneous T1 hypointensity; may be diffusely hypointense in high disease burden, particularly if accompanied by severe anemia