part 2 radionuclide venography

J SRIPRAPAPORNPart 2: RNV

Siriraj Hospital

Mahidol University, Thailand


VENOUS SYSTEMVENOUS SYSTEM


Deep Vein ThrombosisDeep Vein Thrombosis

Incidence: 2.5 million in USIncidence: 2.5 million in USComplication: most important Complication: most important = = pulmonary embolismpulmonary embolismDxDx of DVTof DVT

Clinical Clinical DxDx is unreliableis unreliableNoninvasive testsNoninvasive testsInvasive testsInvasive tests


DiagnosisDiagnosis oof Df DVTVT

ClinicalsClinicals :: UnreliableUnreliableLab tests Lab tests :: DD--DimerDimerCompression Compression ultrasonographyultrasonography ******RadionuclideRadionuclide VenographyVenographyInIn--111111 labeled plateletlabeled plateletInIn--111111 labeled labeled antifibrinantifibrin AbAbTcTc--9999m labeled peptides m labeled peptides ((AcutectAcutect))Contrast Contrast VenographyVenography ****** [[Gold Gold standardstandard]]CTVCTVMRVMRV


U/S & U/S & DD--dimerdimer

Normal compression Normal compression ultrasonographicultrasonographic test test and and SimpliREDSimpliRED rapid wholerapid whole--blood bedside Dblood bedside D--dimerdimer assay are sufficient to Rassay are sufficient to R//O DVT with O DVT with cumulative incidence of VTE complications of cumulative incidence of VTE complications of 1.3%1.3% during the following during the following 33 monthsmonths..[[KraaijenhagenKraaijenhagen et alet al.. Arch Intern Arch Intern MedMed 2002]2002]

Normal DNormal D--dimerdimer concentration and a nonconcentration and a non--high high pretest clinical probability score is a safe pretest clinical probability score is a safe strategy to exclude DVT strategy to exclude DVT [[SchutgensSchutgens et al et al Circulation 2003Circulation 2003]]


RadionuclideRadionuclide VenographyVenography

Ascending Ascending RadionuclideRadionuclide VenographyVenography((RNVRNV))

TcTc--9999m m phytatephytate// SCSCTcTc--9999m MAAm MAA** (+(+Q Q scanscan))

TcTc--9999m labeled RBC m labeled RBC RadionuclideRadionuclideVenographyVenography

TcTc--99m 99m labelledlabelled peptide peptide venographyvenography


Indications for RNVIndications for RNVTo evaluate Pts To evaluate Pts

with clinically with clinically suspected DVTsuspected DVT

To evaluate highTo evaluate high--risk Pts risk Pts for developing DVTfor developing DVTTo detect source & extent of DVT in Pts To detect source & extent of DVT in Pts with documented DVTwith documented DVTTo F/U the efficacy of treatment in Pts To F/U the efficacy of treatment in Pts with documented DVTwith documented DVT


AscendingAscending RNVRNV

PrinciplePrinciple:: Direct injection of the Direct injection of the radiotracerradiotracer in to foot veinsin to foot veinsMechanismMechanism:: To evaluate venous flowTo evaluate venous flow;;venous occlusion or evidence of venous occlusion or evidence of collateral circulationcollateral circulationAnatomyAnatomy:: calf veinscalf veins*,*, poplitealpopliteal veinvein,,femoralfemoral,, extext iliac iliac && common iliaccommon iliac,, IVCIVC


AscendingAscending RNVRNV:: TechniquesTechniques

RadiopharmRadiopharm:: TcTc--9999m m phytatephytate// sulfur colloidsulfur colloid,, TcTc--9999m m MAAMAA** (+(+ Q lung scanQ lung scan))Inject a tracer via Inject a tracer via ((bilateralbilateral)) foot veinsfoot veinsOn tourniquets above ankles to visualize deep On tourniquets above ankles to visualize deep veins and off tourniquets for superficial veinsveins and off tourniquets for superficial veins


AscendingAscending RNVRNV:: InterpretationInterpretation

Bilateral comparisonBilateral comparison,, on on && off off TQTQ

Normal: Normal: GoodGood flow without signs of flow without signs of venous venous occlusionocclusion

Abnormal: Abnormal: ObliterationObliteration of flowof flow,, filling filling defectdefect,, asymmetric flow asymmetric flow +/+/--collateralscollaterals


PositivePositive CriteriaCriteria

Abrupt termination of the flowAbrupt termination of the flowPresence of filling defectPresence of filling defectIrregular or asymmetric flowIrregular or asymmetric flowAbnormal Abnormal collateralscollateralsNonfillingNonfilling of the deep veinsof the deep veins,, with with ++ve ve other signsother signs


NormalNormal AscAsc RNVRNV

Whole-body Images

phytate

Multiple Static Images


NormalNormal vvs s AbnormalAbnormal RNVRNV


DVT WITH PEDVT WITH PE


AccuracyAccuracy oof f AscAsc RRNVNV

Authors Year No. (studies)

Sen (%)

Spec (%)

Corr (%)

Site of DVT

Webber (12) 1974 30 65 92 77 Overall Henkin (13) 1974 25 100 86 96 Proximal Van Kirk (14) 1976 19 100 95 95 Overall Vlahos (15) 1976 52 100 100 100 Pelvis 98 89 100 97 Thigh 98 92 97 95 Calf Ennis (16) 1977 154 90 89 95 Overall Cordoba (17) 1977 44 100 80 94 Overall Ryo (18) 1977 47 89 66 89 Overall Gomes (19) 1982 51 88 65 67 Overall Mohamadiyeh(20) 1993 32 90 73 89 Proximal Mangkharak 1998 72 88 96 90 Overall 55 95 97 96 Pelvic 72 95 100 90 Thigh 72 77 96 83 Calf Mangkharak J, et al. J Med Assoc Thai 1998;81:432-441


RRNVNV--UUpperpper ExtremitiesExtremities

Normal

Abnormal


Advantages & DisadvantagesAdvantages & Disadvantages

Most reliable for Most reliable for DxDx (gold (gold std.)std.)Need skilled teamNeed skilled teamGood anatomic visualization Good anatomic visualization (calf (calf iliac veins & IVC)iliac veins & IVC)More InvasiveMore InvasivePotential risksPotential risksNot suitable for frequent Not suitable for frequent F/UF/UNot provide information Not provide information about associated PEabout associated PE

Reliable results esp. Reliable results esp. proximal v proximal v SimplerSimplerPoorer anatomic details Poorer anatomic details (Good for proximal v.)(Good for proximal v.)Less invasiveLess invasiveSafe Safe More suitable for frequent More suitable for frequent F/UF/UProvide information about Provide information about associated PE (Tcassociated PE (Tc--99m 99m MAA)MAA)

Contrast Venography Radionuclide Venography


TcTc--9999m labeled RBC m labeled RBC RadionuclideRadionuclide VenographyVenography

Or Or bloodblood--pool pool radionuclideradionuclide venographyvenographyequilibriumequilibrium stagestage

Inject the Inject the radiotracerradiotracer via any veinvia any veinNeed highNeed high--resolution collimatorresolution collimatorImage quality depends on labeling Image quality depends on labeling efficiencyefficiency


TcTc--9999m RBC RNVm RBC RNV

Whole-body vs

multiple overlapping static images


TcTc--9999m RBC RNVm RBC RNV


TcTc--9999m m LLabeledabeled RBC RBC vsvs Ascending RNVAscending RNV

ADVANTAGESADVANTAGESDo not need foot Do not need foot vein accessvein access,,easiereasierPossible less Possible less painfulpainful

DISADVANTAGESDISADVANTAGESImage quality depends on Image quality depends on labeling efficiencylabeling efficiencyNot direct evaluation of venous Not direct evaluation of venous flowflowLess anatomical detailsLess anatomical detailsConcomitant Q lung scan is Concomitant Q lung scan is impossibleimpossible..

Both cannot DDx acute vs chronic DVT !


TcTc--9999m m ApcitideApcitide ScintigraphyScintigraphy

FDA approved in Sept 1998Tc-99m apcitide is a radiolabeled peptide that binds with high affinity and specificity to theglycoprotein IIb/IIIa receptors expressed on activated platelets being involved in acute thrombosis.Therefore, 99mTc-apcitide scintigraphy should be negative with residual abnormalities caused by old, inactive thrombi and positive with new, active thrombi.



TcTc--9999m m apcitideapcitide is a is a radiolabeledradiolabeled peptide that peptide that binds with binds with high affinity and specificity to the high affinity and specificity to the glycoproteinglycoprotein IIbIIb//IIIaIIIareceptors expressed on activated plateletsreceptors expressed on activated platelets being being involved in acute thrombosisinvolved in acute thrombosis.. [[FDA approved in Sept FDA approved in Sept 1998]1998]

ThereforeTherefore,, 9999mmTcTc--apcitideapcitide scintigraphyscintigraphy should be should be negative with residualnegative with residual abnormalities caused by oldabnormalities caused by old,,inactive thrombi and positive withinactive thrombi and positive with newnew,, active thrombiactive thrombi..

If If 20%20% prevalence of DVTprevalence of DVT,, sensen ofof 9999mmTcTc--apcitideapcitidescintigraphyscintigraphy is about is about 90%90% and specand spec of of 85%85%--90%90% ---->> a a scan with normal results would have a NPV of about scan with normal results would have a NPV of about 98%.(98%.(similar to that of ascending similar to that of ascending venographyvenography && serialserialcompression UScompression US))



Method: Method: PlanarPlanarscintigraphicscintigraphic images at images at 10, 60,12010, 60,120--180180 min pimin pi..

ResultsResults::

New onset New onset DVT DVT << 33DD:: sesen 90.6%n 90.6%, , specspec83.9%83.9%,, agreemenagreement t 87.3 %87.3 % [[TailleferTaillefer RR JNM JNM 0000]]

WWithith && wowo previous previous VTEVTE:: sensen 92%92% spec spec 90%90% [[Bates et alBates et al..Arch Intern Arch Intern MedMed..2003;163:4522003;163:452--456]456]

Conclusion:The combination of at least two sets ofimages provided the highest accuracy indetecting ADVT.TailleferTaillefer R R etet alal.. J J NuclNucl MedMed2000;41(72000;41(7):1214):1214--12231223


SummarySummary

Diagnosis of DVT needs clinical and diagnostic tests eg. venous US, radionuclide venography, etc.Nuclear Medicine has an important role in evaluation of patients with suspected PE &/or DVT as a single test.V/Q lung scan is helpful in an appropriate setting eg. normal CXR, reproductive women, pregnant women, C/I for CTAIt can be used not only for diagnosis but also for follow-up after treatment.

part 2 radionuclide venography

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