Three-dimensional Doppler images show angiogenesis in RA synovium

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Rheumawire

June 3, 2004

Three-dimensional Doppler images show angiogenesis in RA synovium, offer

way to monitor treatment response

Bad Nauheim, Germany - The tumorlike proliferation of synovial tissue

that leads to joint destruction in rheumatoid arthritis (RA) is

accompanied by tumorlike angiogenesis. Dr Johannes Strunk (University of

Giessen, Bad Nauheim, Germany) reports in the May 2004 issue of the

Journal of Rheumatology that 3-dimensional (3D) Doppler ultrasonography

can be used to visualize this joint neovascularization in painful and

swollen joints of RA patients and to detect its reversal following

disease-modifying treatment [1].

" Probably visualization of synovial microvascular blood flow as sign of

inflammation in RA will become one of the most important tools to

monitor disease activity in RA patients. Since ultrasound is broadly

available, easy to handle, and inexpensive (in comparison with magnetic

resonance imaging [MRI]), it will play a major role in the future, "

Strunk tells rheumawire.

Strunk used ultrasound to investigate inflamed wrist, knee,

metocarpophalangeal (MCP), or proximal interphalangeal (PIP) joints in

21 patients with active RA. " Since 3D-power Doppler sonography plays an

important role in obstetrics and oncology for assessing the vascular

system, we use it to visualize intra-articular synovial new blood-vessel

formation in painful and swollen joints of patients with RA, " he said.

An online 3D-power Doppler function provided by the scanner software was

used to generate 3-dimensional images of the peri- and intra-articular

blood vessels. " The acquired data were digitally stored on hard disk as

a cine loop in which the 3D blood-vessel tree could be viewed as it

rotates, which enhances depth perception and gives a true 3D

perspective, " Strunk writes.

The 3D imaging showed very striking blood-vessel tree branching from

periarticular small blood vessels into the joint capsule in wrists (15

patients), knees (3 patients), and finger joints (3 patients).

Strunk reports finding clinical evidence of arthritis in all of the

examined joints, which was confirmed by elevated C-reactive protein or

increased erythrocyte sedimentation rate in 20 of 21 patients.

" In comparison with 2D-power Doppler, 3D mode reveals more, very small

blood vessels in connection with the whole blood-vessel tree, " Strunk

reports.

As with any new approach, the question arises of how to validate 3D

imaging of neovascularization in RA. Strunk says, " Currently we are

comparing 3D sonography with contrast-enhanced MRI. In healthy controls

it has not been possible to obtain 3D images of synovial vasculature,

because we could not find strong enough microvascular Doppler flow. We

are also comparing RA patients with single cases of other rheumatic

diseases such as gout, psoriatic arthritis, ankylosing spondylitis, and

osteoarthritis. "

Strunk tells rheumawire that he found " drastic changes of synovial

circulation by means of 3D imaging during treatment with systemic and

local glucocorticoids " and plans further studies during treatment with

infliximab.

" We investigated changes of the new blood vessels after intra-articular

administration of steroids. The preliminary result is a dramatic

decrease of synovial blood flow and of the blood-vessel tree after 1

week, " Strunk says. " We also observed a single RA patient with systemic

steroid therapy and infliximab therapy who also showed rapid and drastic

reduction of synovial blood flow. We plan a controlled study to

investigate and compare these therapies and to correlate 3D imaging with

biomarkers of angiogenesis and endothelial activation such as vascular

endothelial growth factor. "

Strunk expects 3D imaging to be useful in clinical trials of new RA

therapies for assessing therapeutic response, monitoring disease

activity, and obtaining information about the reaction of the synovial

vasculature to different therapeutic agents.

To establish 3D imaging as a useful monitoring tool in the ordinary

treatment of RA patients, Strunk says, " First we need more studies to

validate conventional Doppler sonography and power Doppler to monitor

arthritic activity in RA. Currently we propose to use 3D imaging as an

in vivo model to study synovial vascular alterations, including

angiogenesis in RA. "

Equipment availability is also an issue. " We use the ATL/Philips HDI

5000, a high-end ultrasound machine, which is widely available. In

Germany you find high-end ultrasound equipment in rheumatologic clinics

and centers. The typical rheumatologist does not use it because it is

too expensive, but I think in near future this situation will change

because of rapid and dramatic technological development, " Strunk says.

Janis

Source

1. Strunk J, Lange U. Three-dimensional power Doppler sonographic

visualization of synovial angiogenesis in rheumatoid arthritis. J

Rheumatol 2004 May; 31(5):1004-6.

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