Transcript EVALUAREA TERMOGRAFICA A PICIORULUI DIABETIC

THE INFRARED IMAGING
OF THE DIABETIC FOOT
–
A LITTLE HISTORY
– Infrared Thermography in Diabetes Mellitus
– P.I.Branemark, S.E.Fagerberg, L.Langer and
Save –Soderbergh, Diabetologia 3, 1967
16 diabetics, 12 women and 4 man, mean age 28,
average disease length 13 years
• The emission over toes and metatarsophalangeal regions was distinctly decreased and
gave a sharp transverse boundary. Little or no
reduction of the emission was shown over the
dorsum of the foot and tibia. Asymmetric
patterns were recorded from the only diabetic
with local gangrene.
• Disturbances in the arterial circulation
• Detection of areas at high risk for ulceration or
re-ulceration
• Assessment of tissues viability, amputation level,
and the intra-operative skin flap viability
• Diagnosis of osteomyelitis
• Evaluation of the medical treatment
effectiveness
• Assessment of microangiopathy and others
vascular changes caused by the neuropathy
The examination of the diabetic foot
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Room temperature : 24 C
Acclimatization time: 20 minutes
Undressed legs
Position : Orthostatism or seated with the
lowers extremities hanging freely
• The images are taken at fixed camera/object
distances from the both legs in the anterior
view, the foot from a top view and the soles
• Hot spot is defined as an area at least 0,5 C
warmer than surroundings
• The thermal gradient represents the difference
between the skin temperature at the knee and at
the dorsum of the foot.
• Thermal imaging of skin changes on the feet of type II
diabetics – K.Ammer, P. Melnizky, O.Rathkolb, E.F. Ring2001 – 23rd Annual EMBS International Conference
Changes in the arterial circulation
• Eco-Doppler
• Angiography
• Thermography
• The “macro-circulation” pathology localizes
more often below the popliteal fossa, than at the
level of the aorta or iliac vessels
• The injuries respect the distal (pedal) arteries
• The changes are usually asymmetric, the tibial –
peroneal triangle being the most commonly
affected.
• Thermography is especially useful to
differentiate between “ischemic foot”(cold) and
the “neuropathic foot(warm).
• Detecting areas of critical ischemia
ARTERYOGRAPHY
• Severe atheromatosis affecting the entire
length of the tibial-peroneal trunk
ULCERATION
• Neuropathic ( 40%)
• Neuro-ischemic
• Ischemic ( 10%)
• It was suggested that examining thermographic
patterns, patients with diabetis could be
screened for risk of ulceration and that high
temperature were predictive of ulceration.
• In patients with diabetes peripheral
neuropathies, and no additional pathology, the
temperature of the right and the left lower
extremities were not different.
• Infrared dermal thermometry for the HighRisk diabetic foot
• D.Armstrong, L.Lavery, P.Liswood, W.Todd,
J.Tredweell-Physical Therapy, 77, 2, february
1997
• All patients who experienced ulceration or re • ulceration during the follow-up period showed
elevated skin temperature gradients.
• The patients can be monitored to prevent
ulcerations, higher temperatures having a
predictive role for ulceration or re-ulceration
(20- 58% of patients develop another ulcer
within one year)
• We have to keep in mind that the increased
temperature indicates there is a problem and
where it is, NOT WHAT IT IS !
• The temperature monitoring is also
recommended in patients with Charcot’s
fractures, in the post-acute phase, after the
inflammation had subsided.
• Thermography is also useful in detecting subtle
temperature changes that may persist in the post
acute phase; a premature reactivation indicating
reoccurrence.
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OSTEOMYELITIS
• Infrared imaging is a sensitive indicator of the
presence or absence of osteomyelitis complicating
the diabetic foot ulceration when compared with
other imaging modalities
• Imaging in diabetic foot ulceration: a blinded comparison
of infrared imaging with a plain film radiology, MRI,
clinical assessment, and haematological and biochemical
investigation- R.Harding, J.Jones, A. Griffiths, H. Morris –
Royal Gwent & ST Woolos Hospital, Newport, Gwent, UK
• The temperature on infrared imaging is
significantly increased not only around the ulcer
but also in the entire sole of the foot in patients
with radiologically confirmed osteomyelitis.
• Quantitative infrared imaging can point out the
osteomyelitis installation, reducing morbidity
and mortality by selecting those patients who
will benefit from appropriate aggressive
antibiotic therapy.
THERMOGRAPHY IN THE ASSESSMENT
OF THE AMPUTATION LEVEL
VIABILITY
• Diabetic foot amputation: the need for an objective
assessment tool (Wounds 15(7):241-245, 2003, Health
management publication)
• Thermography and later the clearance of the radioisotope
were successfully used to determine the viability of skin
flaps for below the knee amputation. The combination of
these techniques yielded a success rate of 93% for
transifibial amputation. ( Ninewells Hospital, Dundee,
Scotland)
• Amputation of the ischemic limb: selection of the
optimum site by thermography – V.A.Spence,
W.F.Walker, I.M.Troup – Vascular Laboratory,
Ninewelles Hospital and Medical School , Dundee
, Scotland
• Results from 104 patients demonstrate that the
thermographic method is a reliable indicator for
the level of a major limb amputation.
• IR lacks information about the local anatomy
and only indirectly estimate the changes in the
cutaneous microcirculatory blood supply.
• The obtained data by merging both imaging
techniques (IR&MRI) allows the determination
of the extent of anatomic and physiological
compromise, thus leading to a better and more
adequate surgical intervention
MICROANGIOPATHY AND
NEUROPATHY
• These two topics can be discussed together, since the
microangiopathy of the vasa nervorum contributes to the
neuropathy pathogenesis, which in turn induces changes in the
capillary circulation, thus partially compensating for the
reduction in flow caused by the microangiopathy.
• In the initial stages of neuropathy, when the microangiopathic
changes are dominant, there is a symmetric hypothermia in the
toes and the distal one third of the foot. Severe hypothermia may
appear as “thermic amputation” , generated by a combination of
obstructive microangiopathy and sympathetic hyperactivity
caused by partial nerve damage.
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MICROANGIOPATHY AND
NEUROPATHY
After the onset of the neuropathic process, the
skin temperature increases
The diabetic neuropathy affects the
microcirculation by increasing the blood flow
through arteriovenous shunts, which are
normally under the control of sympathetic
system.
• E.Boyko (Skin temperature in the neuropathic
diabetic foot -2001) quotes a study in which the
mean skin temperature on the plantar foot is
between 33,2 and 33,5C among diabetic subjects
with either painful or sensory neuropathy
compared to a mean of 27,8 in diabetic subject
without neuropathy.
• The dynamic measurements of the plantar mean
temperature can be useful in detecting the
perfusion anomalies due to neuropathy .
• The plantar temperature modifications are the
result of the circulatory insufficiency, neuropath
disorders, skeleton modifications, infections or
any combinations of these factors.