Osteosarcoma MRI

Revision as of 17:08, 29 May 2018 by Damola (talk | contribs) (→‎MRI)
Jump to navigation Jump to search


Editor-In-Chief: C. Michael Gibson, M.S., M.D. [2];Associate Editor(s)-in-Chief: Suveenkrishna Pothuru, M.B,B.S. [3]

Osteosarcoma Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Osteosarcoma from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Staging

History and Symptoms

Physical Examination

Laboratory Findings

Biopsy

X Ray

CT

MRI

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Osteosarcoma MRI On the Web

Most recent articles

cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Osteosarcoma MRI

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Osteosarcoma MRI

CDC on Osteosarcoma MRI

Osteosarcoma MRI in the news

Blogs on Osteosarcoma MRI

Directions to Hospitals Treating Osteosarcoma

Risk calculators and risk factors for Osteosarcoma MRI

Overview

On MRI, osteosarcoma is characterized by intermediate intensity of soft tissue and low signal intensity of ossified components on T1. High signal intensity of soft tissue and low signal intensity of ossified components on T2. Considerable contrast enhancement of solid components on T1 contrast.

MRI

  • MRI is proving essential in accurate local staging and assessment for limb sparing resection, particularly for evaluation of intraosseous tumor extension and soft-tissue involvement.
  • Assessment of the growth plate is also essential as up to 75-88% of metaphyseal tumors do cross the growth plate into the epiphysis.
  • MRI is used to:
  • Show how far a bone tumor has grown inside a bone.
  • Show how much a bone tumor has grown outside the bone.
  • Observe if a tumor has grown into blood vessels, nerves, bone marrow or other nearby tissues or structures.
  • Determine if the tumor has developed in one or more sites within the same bone (skip metastases).
  • Plan for possible surgery.

On MRI, signal characteristics of osteosarcoma include:[1]

  • T1:
  • Soft tissue, non-mineralized component: intermediate signal intensity.
  • Mineralized/ossified components: low signal intensity.
  • Peri-tumoral edema: intermediate signal intensity.
  • Scattered regions of hemorrhage will have variable signal.
  • T2:
  • Soft tissue non-mineralised component: high signal intensity.
  • Mineralised/ossified components: low signal intensity.
  • peri-tumoral edema: high signal intensity.
  • T1 C+ (Gd):
  • Solid components show considerable enhancement.
  • The following table illustrates the findings on MRI for the subtypes of osteosarcoma:[1]
Subtype MRI findings
Intracortical osteosarcoma
  • It was believed that intracortical osteosarcoma was confined to the cortex of bone and does not show intramedullary or superficial involvement but it may involve medullary canal as well as surrounding soft tissue.
  • It shows peripheral enhancement after intravenous contrast administration.
  • T1 - hypointense.
  • T2 - intermediate to high signal intensity.
Parosteal osteosarcoma
  • It exhibits predominantly low signal intensity both on T1 and T2 weighted imaging. High signal intensity on T2 is suggestive of high grade tumor.
Periosteal osteosarcoma
  • Typically hypointense on both T1 and T2 sequences: may see bony spicules radiating from surface lesion (sunburst pattern).
  • It may appear hyperintense on T2 sequence which represents its chondroid matrix.
  • Reactive marrow changes are commonly observed, but true marrow invasion is rare.
  • It is difficult to differentiate periosteal osteosarcoma from the conventional high grade osteosarcoma at imaging, however conventional osteosarcomas involve entire circumference of cortex and show intramedullary extension.
Telangiectatic osteosarcoma
  • Commonly shows fluid-fluid levels within the lesion (~90% of cases) with variable signal intensity.
  • Allows appreciation of surrounding soft tissue components.
  • Signal characteristics are often heterogeneous.
  • Enhancement of septations as well as the soft tissue component may be observed.
  • Hemorrhage appears as hyperintense on T1 and variable signal intensity on T2.
Extra skeletal osteosarcoma
  • Well circumscribed heterogeneous mass lesion with presence of haemorrhage and necrotic areas.
  • T1: isointense to muscles.
  • T2: hyperintense.
  • Hyperintense foci on both T1 and T2 sequences (due to methaemoglobin) or hypointense foci on T2 (due to haemosiderin).
  • In extreme cases of hemorrhage it can mimic hematoma.

References

  1. 1.0 1.1 Osteosarcoma. Dr Amir Rezaee ◉ and Dr Frank Gaillard ◉ et al. Radiopaedia.org 2015. http://radiopaedia.org/articles/osteosarcoma
  2. 2.0 2.1 2.2 Image courtesy of Dr Frank Gaillard. Radiopaedia (original file [1]). http://radiopaedia.org/licence Creative Commons BY-SA-NC

Template:WH Template:WS