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Radionuclide imaging in infection and inflammation. Inflammation. A basic way in which the body reacts to infection , irritation or other injury Inflammation is now recognized as a type of nonspecific immune response. Morfology of inflammation. Blood hyperperfussion
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Inflammation • A basic way in which the body reacts to infection, irritation or other injury • Inflammation is now recognized as a type of nonspecific immune response
Morfology of inflammation • Blood hyperperfussion • Increased cappilars permeability • Exudation • Swelling • Leukocytes migration • Dysfunction of organ or tissue
Diagnosis of inflammation • Physical examination • Laboratory tests • X-ray • Ultrasound • MRI
Symptoms • Dolor • Rubor • Tumor • Calor Hallmarks of inflammation were first described by Aulus (Aurelius) Cornelius Celsus, a Roman physician and medical writer, who lived from about 30 B.C. to 45 A.D.
X-ray and ultrasound • Do we really need other modalities? • What we see in X-ray or ultrasound? • Is X-ray or ultrasound specific technique for inflammatory process?
Diagnosis of inflammation • Physical examination • Laboratory tests • X-ray • Ultrasound • MRI Scintigraphy
Specific radionuclide techniques • In vitro labelled leukocytes • In vivo labelled leukocytes • Labelled poliklonal IgG • Labelled antibiotics • Gallium-67 scan
Non specific radiomuclide techniques • Bone scintigraphy • Renal static scintigraphy • Salivary gland scintigraphy • Brain perfussion scan
In vitro labelled leukocytes • Indium-111 oxin • Technetium-99m – HmPAO • Labelling process outside of body • Separation of leucocytes in centrifugal machine • Labelling by diffusion of radioactive complex into a cell
In vivo labelled leucocytes • Immunoscintigraphy • Monoclonal IgG antibody Fab’ fragment labeled with Technetium-99m • Injected targets NCA-90, found on the cell membrane of graunlocytes
Indications • Abscess in abdomen (appendicitis) • Fever of unknown origin • Artery graft infections • Infection ortopaedic prothesis • Bowel inflamatory disease
Appendicitis Atypical presentation of acute appendicitis in high-risk populations, such as children, make correct diagnosis difficult. Rate of complications, including death, is directly correlated with delay in diagnosis and surgery.
Appendicitis Tc99m-HmPAO labelled leukocytes scintigraphy is a rapid and very accurate method for detecting acute appendicitis in patients with acute lower abdominal pain and equivocal clinical findings.
Fever of Unknown Origin (FUO) • 30% of patiens with FUO have silent infection • After surgery 60% • Very often negative X-ray and US • Tc99m-HmPAO labelled scintygraphy is method of choice
Arterial graft infections • 2-6% of grafts • Mortality very high 25-75% • The highest sensitivity of Tc99m-HmPAO labelled leukocytes scintigraphy • 100% ! • Early diagnosis saves live
Bowel inflamatory diseases • Crohn disease • Colitis ulcerosa • Non specific bowel inflamation • The same efficacy that colonoscopy with mucosa biopsy • Control of treatement
Gallium-67 citrate • Labelling in vivo leucocytes • Binds to transport protein laktoferrin • Expensive • Less specific than labelled leucocytes • Also binds transferrine in tumours cells (lymphoma, HCC, leucemia)
Gallium-67 scan Spondyllitis VTh5
Policlonal human immunoglobins IgG labelled with Tc99m • Accumulation in focus of inflammation • Circulating IgG`s are premeabling to intercellular space • Easy to preparation and cost effective • No differentiation between inflamation and infection
Bone scintigraphy • Three-phase scintigraphy • Early phase: perfussion • Late phase: bone metabolism • Usefull in incection and inflammation • Non specific
99mTc-MDP Normal 99mTc-MDP RA Rheumatoid artritis
Entesopaties Achilles Tendinitis 99mTc-MDP
Pyelonephritis • High incidence in children • 1% leads to renal failure and transplantation • 10% asymptomatic • Renal scars
99m Tc - DMSA - DMSA-Tc99m scan