Lungemboli och CT. Var står r vi idag?

Transkript

1 Lungemboli och CT Var står r vi idag? Ulf Nyman, docent Institutionen för f translationell medicin Divisionen för f r medicinsk radiologi Skånes universitetssjukhus, Malmö

2 SBU-report 158/2002 Blodpropp förebyggande, diagnostik och behandling av venös tromboembolism Stefan Rosfors klinisk fysiolog, Södersjukhuset, S Stockholm Diagnostik Klas Måre Stefan Rosfors radiolog, Universitetssjukhuset, klinisk fysiolog, Södersjukhuset, Linköping Stockholm Klas Måre radiolog, Universitetssjukhuset, Linköping Ulf Nyman radiolog, Ulf Lasarettet Nyman i Trelleborg radiolog, Lasarettet Trelleborg Margareta Margareta Hellgren-Wångdahl ngdahl gynekolog, gynekolog, SU/Östra Sjukhuset, SU/Östra Sjukhuset, Göteborg. G Göteborg. SoS:s arbetsgrupp Vård av blodpropp David Bergqvist Mats Eliasson Bengt Eriksson Henry Eriksson kärlkirurgi internmedicin ortopedi internmedicin Margareta Hellgren-Wångdahl ngdahl gyn/obstetrik Karl-Gösta Ljungström Ulf Nyman Sam Schulman kirurgi radiologi hematologi

3 Googla Koagulationscentrum Region Skåne D-dimer Clinical probability CT = computed tomography Scintigraphy US = Ultrasonography

4 Klinisk osannolik PE & negativ D-dimer 3 månaders uppföljning för VTE Antal (metaanalys) PE frekvens 21% Klinisk osannolik & neg D-dimer 27% (22-34) Falskt negativa (95% KI) 0.4% ( ) 0.7) Lucassen Meta-analysis analysis Ann Intern Med 2011;155: Bayes theorem Thomas Bayes ( ) 1761) English clergyman/mathematician Fellow of Royal Society Essays towards solving a proba- bility in the doctrine of chances Found after his death and published 1763 Taube & Malmquist. Räkna med vad du tror. Bayes sats i diagnostiken. Läkartidningen 2001;98(24): Barnard Biometrika 1958;45(parts 3&4):

5 Bayes theorem PIOPED II (NEJM 2006;345: ) 27) Prospective multicenter investigation in USA

6 CT for acute pulmonary embolism Sens Spec PIOPED-II II 83% 96% 84% 4-row 4 detector 16% row detector Stein et al. New Eng J Med 2006;354; Negative computed tomography Low sensitivity Bilateral ultrasound on all negative CT (80%) Fedullo & Tapson NEJM 2003;349: Routine CT venography (100%) Cham et al. Radiology 2005;234:

7 Wells clinical criteria of DVT and PE VTE% 80 DVT (20%) LE (17%) 11 studies 4 studies n: 3034 n: DVT LE Låg Måttlig Hög Low Moderate High Percentage J Thromb Haemost 2003;1:1888 Bayes teorem Prevalens (%): Sjukdom Test Ja Nej Pos PPV (%) Neg NPV (%) Sens (%) Spec (%) 1000

8 Bayes teorem PIOPED II (NEJM 2006;345: ) 27) Clinicians (and radiologists) should probably think twice before accepting a PE diagnosis in a patient in whom the disease is thought to be clinically unlikely unless CTA is undisputedly positive Perrier & Bounameaux. Letter to the Editor JAMA 2006;345:2383-4

9 Bayes teorem Prevalens (%): Sjukdom Test Ja Nej Pos PPV (%) Neg NPV (%) Sens (%) Spec (%) Bayes teorem

10 Management study Patients w. negative CT are not anticoagulated apart from other indications than VTE Clinical follow-up for 3 months Objective testing in case of DVT/PE symptoms VTE 1.5% (upper 95% CI <3%) acceptable Negative CT - Outcome studies Pos D-dimerD or high clin prob/clin likely PE Author Year N VTE (3mo f/u) Frequency Upper 95% CI van Strijen % 1.6% Perrier % 2.8% Ghanima % 1.9% van Belle % 1.8% Andersen % 0.9% Righini % 1.7%

11 Konklusion CT missar små LE som inte tycks kräva behandling Ingen indikation för f r rutinmässig venundersökning vid negativ CT Huvudsakliga problemet med CT är överdiagnostik Isolated subsegmental (ISS) PE Multi-slice CT allows better visualization of subsegmental arteries, hence the rate of isolated subsegmental PE may increase It is unclear whether the risk-benefit ratio of anticoagulant therapy is favorable Carrier et al. J of Thrombosis & Haemostasis 2010;8:

12 Rate of isolated subsegm PE Systematic review & meta-analyses analyses Single-slice (n=15) Multi-slice (n=11) Carrier et al. J of Thrombosis & Haemostasis 2010;8: Rate of isolated subsegm PE Systematic review & meta-analyses analyses Single-slice (n=15) Multi-slice (n=11) 3-55 mm slices 1-22 mm slices 4.7% 9.4% Higher rate of VTE during f/u of neg CT due to FN diagnosis? 4-det: 7.1% 16-det: 6.9% 64 det: : 15% Carrier et al. J of Thrombosis & Haemostasis 2010;8:

13 Rate of isolated subsegm PE Systematic review & meta-analyses analyses Single-slice (n=15) Multi-slice (n=11) 3 months VTE risk after negative CT 0.9% 1.1% 4-det: 1.4% 16-det: 0.6% 64 det: 0.8% Carrier et al. J of Thrombosis & Haemostasis 2010;8: Rate of isolated subsegm PE Multi-slice CT increases the rate of subsegm PE w/o lowering the 3 mos risk of VTE of negative CT suggesting that they are not clinically relevant Carrier et al. J of Thrombosis & Haemostasis 2010;8:

14 Rate of subsegmental PE Subsegmental PE most prevalent in low- probability V/Q scan (PIOPED) Patients w. low/intermediate V/Q and negative serial proximal US can be safely left without anticoagulation Carrier et al. J of Thrombosis & Haemostasis 2010;8: Isolated subsegmental PE Reported isolated subsegmental PE should be reviewed by an experienced radiologist Poor interobserver agreement If isolated subsegmental,, consider serial proximal US, especially if at risk for AC Prospective management study underway No AC if normal bilateral serial proximal US France, Switzerland and Canada

15 V/Q mismatch Differentialdiagnoser SBU-rapport 158-II/2002 Kapitel 3.6 Skintigrafi, sid 130 Pulmonary embolism? Man, 44 years, arabic origin Hodgkin lymphoma High-quality CT May-Oct 2009 neg for PE 370 HU, no artefacts peripheral vessels well depicted

16 Planar V/Q Lungembolism? SPECT Ventilation Perfusion Extensive PE despite normal high quality CT:s????? Ventilation Perfusion Anterior Posterior

17 Anatomisk obstruktionsgrad 1. BNP (brain natriuretic peptide), computed tomography or echocardiography. 2. Cardiac troponin, T or I-positive a) In case of chock/hypotensionthere is no need to evaluate the right ventricle European Society of Radiology guidelines (

18 Risk stratification Anatomical obstruction score Right ventricular dysfunction dilatation RV ( load)( secondary to pulmonary resistance inflow to left heart,, reduced left ventricle coronary insufficiency, right ventricular failure initially increased pulmonary artery pressure now falls 65% obstruction index RV/LV ratio 2:1 <1 normal >1.5 warning! Septum

19 Renal impairment Doses decreases with increased detector rows Dose per kg body weight 120 kvp 80 kvp increased iodine attenuation*1.6 Decreased cardiac output high age + renal impairment cardiac disease Halved CM dose mg I/kg Increased tube loading (mas)*4 to keep image noise constant, radiation increased by 50% Acta Radiol 2009;50: Eur Radiol 2010;20:

20 16-channel MDCT for PE Bae et al. Radiology 2005;236: (120 ml 350 mg I/ml, 3-4 ml/s; sec) Holmquist Kristiansson 200 mg I/kg 150 mg I/kg 80 kvp 16-MDCT for PE 87 yrs, 43 kg, 156 cm 113 mol, egfr HU 150 mg I/kg, 12 sec inj time 394 HU 20 ml, 320 mg I/mL 6.4 gram-iodine 1.7 ml/s g-i/gfr ratio 6/21 = 0.3

21 Acta Radiol 2012;53: Effective doses in Chest CT Background radiation/yr - Sweden ~3 msv V/Q scintigraphy 2.4 msv statistics in Sweden 2005 CT pulmonary angiography msv Mettler et al. Radiology 2008;248: CT thorax Sweden msv SSI report 2008:02 Trelleborg 80 kvp/100 mas mas eff msv

22 Läkartidningen 2010;107(15); year old, pregnant 20th week Leung et al. Radiology 2012;262:

23 Cancer risk per Q-scintigraphy CT (half dose 50 MBq) (100 kvp/100 mas) Breast per mgy (30 yrs) (0.25 mgy) (7.5 mgy) Maternal lethal per msv (10-30yrs) (0.5 msv) (2.5 msv) Child lethal (<15 yrs) per mgy (<15 yrs) (0.37 mgy) (0.13 mgy) Diagnosing PE in pregnancy D-dimer not in routine Symptoms of DVT venous ultrasound CXR (strong recommendation of ATS/STR) Q-scint (half dose) if CXR is normal less radiation to the mother,, high rate of conclusive examinations, CT abnormal abnormal CXR,, V/Q unavailable or non-diagnostic optimize exposure and injection parameters! Inform mother - risk of any method for the baby and herself is far less than a misdiagnosis of PE

24 Sammanfattning Över- ej underdiagnostik största problemet Hö-kammarpåverkan kan identifieras Stråldoserna under kontroll Risk för kontrastnefropati minimalt problem Skint 1:a handsmetod för gravida, CT när skint kan vara inkonklusivt eller inte är tillgängligt