This document discusses hematogenous osteomyelitis in infants and children. It defines osteomyelitis as an infection of bone and marrow. Common causative organisms include Staphylococcus aureus and gram-negative bacteria in neonates. In infants and young children, infections typically start in the metaphysis due to its rich blood supply and can spread to the epiphysis or nearby joints. MRI is the recommended imaging modality as it can detect bone marrow inflammation, periosteal reactions, and extraosseous complications. Other modalities like radiography, CT, scintigraphy, ultrasound are also used to diagnose and monitor osteomyelitis at different stages of the disease.

1. Hematogenous Osteomyelitis in Infants and
Children: Imaging of a Changing Disease
By Dr Girish Gunari [PG]
Moderator : Dr Madan Mohan[professor MD
Radiology ]

2. Definition
Osteomyelitis : implies an infection of bone and marrow.
Types

3. Most common organism that infects the
bones
1}Staphylococcus aureus,
2}Kingella kingae,
3]Streptococcus pyogenes,
4]Streptococcus pneumoniae
5}Gram-negative organisms such as
6] E- coli and group B streptococci are more common in –
Neonates
7] Pseudomonas aeruginosa infectionoccurs in association with
puncture wounds through sports shoes,

4. Pertinent Anatomic Concepts
Metaphysis is the primary site of infections
Metaphyseal spongiosa contains abundant
blood vessels with leaky endothelium
and sluggish flow that end in capillary
Loops
bacteria lodge in them causing
Inflammatory changes and infraction of bone

5. First 18 months of life there is communication between the epiphyseal
and metaphysical vessels throw trans physical vessels
communication
results in direct extension of
metaphysical infections into the epiphysis
Epiphyseal extension can cause
Destruction of the epiphyseal cartilage
Extension Joint lead to septic arthritis

6. In child
Epiphyseal plate blocks extension of infection
closer of trasphyseal vessels
Metaphysical vessels loop back towards metaphysis
Infection spread
1]Laterally Sub periosteal
2]Joint with synovial reflction beyond epiphysis

7. Subperiosteal abscess. (a) Diagram demonstrates how a subperiosteal
abscess (∗) separates the periosteum (arrowhead) from the cortex. These
two structures come together at the perichondrium, forming a “V” (arrow).
(STIR)

8. In adult
Fusion of epiphyseal plate
No barrier to spread of infection from
Metaphysis to adjacent joint
Septic arthritis

9. Imaging:
Conventional radiograph : First step
MR imaging : has become the recommended modality for evaluation
of a child with suspected osteomyelitis
Scintigraphy :to detect osseous involvement
Sonography : to depict extra osseous findings such as sub periosteal or soft-tissue
abscess, joint effusion, and deep venous thrombosis

10. Conventional radiographs and CT
1-10 day
1]Premature metpyseal ostiolysis
2]localized soft tissue swelling adjacent o metaphysis
3]oblitration of fat plane
10-14 day
Intracortical fissuring
Elevation of periosteam
Endosteal erosions
3-6 week
Layerd new bone formation peristeal rection Involcurum [20day]
Dead bone : sequetrum > 30 day
Cloaca : space in the new bone formed

11. 1]Premature ill defined
metpyseal ostiolysis in
feumur
2]localized soft tissue swelling
adjacent o metaphysis

12. Infection at the fracture site has delayed
union in the humerus. Note the
extensive
periosteal reaction.

14. Scintigraphy
Findings within 3 days some times within 24 hr
Tc99m: effective dose of approximately 2.8 mSv for a 1-year-old
Triple phase :
blood flow
Blood pool inflammatory region
Bone uptake
Hot in all three phases
False positive result can occur in;
1]degenerative disease,
2]healing fracture
3]loose prosthesis

16. Scintigraphy
2] Gallium 67: 100% sensitive
Ostiomylities :
Gallium 67 uptake positive Tumors : negative
Tc99m uptake positive Tumor :positive
Other :
Wbc scan
Tc99m labeled leukocyte scan

17. MRI:
Bone marrow appears
1]Hypo on T1W
2] Hyper On T2W/FsT2W/STIR
3] Post contrast enhancement
Ischemia within infected marrow, seen as areas that
enhance less than normal or not at all on contrast-
enhanced
Sub periosteal infection
Hyper halo around cortex on T2
Abscess
Hypo T2 T1+c : hyper rim enhancement
Adjacent soft tissue increased signal intensity

18. Coronal T1-weighted image of
the distal femur shows an ill-
defined area of low signal
intensity in the medial distal
femoral metaphysis

19. Sagittal STIR image shows high
signal intensity in the distal
femur (∗). There is also high
signal intensity in the
subperiosteal space (arrow) and
in the adjacent soft tissues

20. Coronal fat-suppressed
gadolinium-enhanced T1-weighted
image shows enhancement in the
distal medial femoral metaphysis
(∗) and adjacent periosteal
cambium (arrow). The normal
marrow of the proximal tibial
metaphysis also is enhanced,
although to a lesser degree.

21. Sagittal non–fat-suppressed T1-
weighted image obtained after
intravenous administration of
gadolinium-based contrast agent
shows an area of enhancement in
the proximal tibia (black arrow)
that extends to the epiphysis.
There is also an area of
nonenhancement (white arrow) in
the calf with an enhanced rim,
consistent with a soft-tissue
abscess.

22. Axial fat-suppressed T2weighted
image of the right knee shows
abundant hyperintense signal
intensity within the soft tissues
around the anterior portion of the
knee and thickened synovium of
the suprapatellar bursa (white
arrow). There is discontinuity of
the anterolateral epiphyseal border
(black arrow) with a subtle focal
area of abnormal signal intensity
within the epiphyseal cartilage (∗).

23. Subperiosteal abscess with fat
globules in a 7-year-old boy with a
left distal fibular osteomyelitis.
Coronal T1-weighted MR image
shows the low signal intensity
periosteum (black arrow)
converging with the bone at the
perichondrium. More cephalad, a
subperiosteal collection is seen to
contain high signal intensity (fat)
globule

24. Osteomyelitis of the distal tibial metaphysis in 7-year-old boy. (a) Coronal
T1-weighted MR image shows diffuse irregularity of the bone marrow in the
distal metaphysis and a low signal intensity subperiosteal collection with
high signal intensity fat globules within the collection (arrows). (b) Sagittal
gadolinium-enhanced fat-suppressed T1-weighted image shows areas of
decrease enhancement in the bone marrow (arrows) related to the infectious
process.

25. Ultra sound
to depict extra osseous findings such
as
• sub periosteal abscess
•soft-tissue abscess, joint effusion,
•deep venous thombosis
•Abscess sinus tract
•Joint aspiration

26. Ultra sound
Periosteal elvation: hyperechoic line
With anechoic subperisteal fluid collection
Sonogram demonstrates the elevated
echogenic periosteum (black arrow)
and the sonolucent subperiosteal
collection between the periosteum and
the cortex (white arrow