Venous thromboembolic diseases
Clinical evidence tables
E.6 PE diagnosis (V/Q scan)
In people with suspected PE, what it is the effectiveness of ventilation perfusion scans in detecting PE?
Study Patients Diagnostic tools Measure of Disorders Results Comments
details
Gutte 2010a178 Patient group: Assessment tool under V/Q SPECT Funding: Patients were eligible investigation: three dimensional if there was a V/Q SPECT. The pulmonary SPECT None suspicion of included a perfusion SPECT study Study design: Comp Comp Total pulmonary embolism and a ventilation SPECT study osite + osite- Diagnostic (PE) , defined as an obtained simultaneously within 13 Limitations: No acute onset of new or minutes and performed VQ 10 3 13 information reported Prospective worsening shortness immediately after the MDCT SPECT regarding severity of PE. study of breath or chest pain acquisition with the patient still in + without any obvious the supine position. V/Q SPECT The V/Q SPECT has 3 cause and with a was read blinded to clinical history patients missing from VQ 0 20 20 positive D-dimer test of the patients, and the reviewers the analysis. Duration of SPECT (>0.5 mg/l) or a Wells did not have access to the follow-up: at - score of more than 2. contemporaraneous chest least 6 months radiograph. Total 10 23 33 Additional
Planar V/Q scintigraphy was tests: blood pressure Exclusion criteria: viewed by reviewers blinded to the measurement, blood Allergy to iodine clinical history of the patient. 1 100% contrast agents, sample impaired renal Sensitivity 87%
function (P- The CT protocol consisted of two Specificity 77% creatinine>0.120 Notes: mmol/l/l), not willing successive acquisitions with the PPV 100% 234 Venous thromboembolic diseases
Clinical evidence tables
Study Patients Diagnostic tools Measure of Disorders Results Comments
details to participate, lack of patients scanned in the supine Aim of study was to look cooperation, absence position. The first acquisition NPV 11/36 (31%) head to head V/Q SPECT of peripheral venous consisted of a low-dose CT scan and Planar VQ Prevalence 7.7 access, or technical and the second MDCT acquisition scintigraphy issues consisted of a pulmonary MDCT Positive LR 0 angiography in suspended, deep inspiration. Negative LR 5/41
Indeterminable (no reference All patients available, due to suboptimal N: 41 The pulmonary MDCT angiography technical quality of the 72 met inclusion and V/Q SPECT were all performed datasets) criteria, 31 were using an integrated two headed y- excluded due to: camera and an MDCT (16 slice) Non diagnostic rate 8 (2-22) allergy to iodine manner. contrast agents (n=1), impaired renal function (n=21), Reference standard: Composite of Planar VQ scintigraphy decision not to MDCT, VQ spect and CT, clinical participate in the history, follow-up data, D-dimer, study (n=4), lack of ECG, Ultrasound and Echocardia cooperation (, absence MDCT MDCT Total A + A- of peripheral venous access or technical Planar 7 7 14 issues (n=1). One was VQ+ ineligible because of low clinical suspicion Planar 4 18 22 caused by Wells score VQ - less than 2 and negative D-dimer. Total 11 25 36 Mean age (range): (mean (sd); 74 (15) among those with PE, 235 Venous thromboembolic diseases
Clinical evidence tables
Study Patients Diagnostic tools Measure of Disorders Results Comments
details 71 (13) among those without PE Drop outs: 5/41 Sensitivity 64% patients were excluded as final Specificity 72% diagnosis was indeterminable due to PPV 50% suboptimal technical quality of the datasets. NPV 82% Prevalence 11/36 (31%)
Positive LR 2.28
Negative LR 0.5
Indeterminable(no reference 5/41 available, due to suboptimal technical quality of the datasets)
Non diagnostic rate 0 (0-7)
236 Venous thromboembolic diseases
Clinical evidence tables
Study Patients Diagnostic tools Measure of Disorders Results Comments
details
Wang 2009455 Patient group: Assessment tool under CTPA Funding: patients in whom PE investigation: lung perfusion was suspected and scans combined with ventilation No reported gave informed (V/Q) scans and/or chest Study design: VQ scans (n=28) CTPA+ CTPA- Total Limitations: pulmonary consent, who had a radiography (CR). Lung perfusion angiography was not normal creatinine level scan was performed using a single Diagnostic VQ+ 11 1 12 performed in all and were willing to head gamma camera equipped patients. V/Q scan (or Prospective undergo V/Q scan (or with low energy, his resolution, VQ - 1 13 14 perfusion scan combined study perfusion scan parallel-hole collimators. All with CR) was included as combined with CR) patients remained in supine Total 12 14 26 a component of the and CTPA were position throughout the composite reference for included in the study. examination. Duration of determing Sensitivity follow-up: not 11/12 (91.7%) absence/presence of PE, reported thus may introducing Specificity Exclusion criteria: Reference standard: contrast 13/14 (92.9%) bias. V/Q scans were
pregnant women, enhanced multislice spiral CT PPV 91.67% unavailable for the patients who were pulmonary angiography (CTPA). majority of patients to currently experiencing CTPA studies were performed NPV 92.86% compare with CTPA. circulatory shock or using a standard protocol. had hypotension or Positive LR 13.14 renal failure, were Negative LR 0.07 Additional hemodynamically
unstable, were on Non diagnostic results 2/28 (7.1%) VQ; 0/28 CTPA tests:
237 Venous thromboembolic diseases
Clinical evidence tables
Study Patients Diagnostic tools Measure of Disorders Results Comments
details ventilatory support, had chronic pulmonary All patients underwent CTPA, lung CTPA (overall results) hypertension, received perfusion scan and CR. 28 patients Notes: anticoagulation, or also underwent a V/Q scan. The Also results were had a history of allergy perfusion scan combined with CR Sensitivity 36/37 (97.3%) presented from a to contrast media. was used for the diagnosis of PE, segment based analysis thus, V/Q scan was not performed. Specificity 37/38 (97.4%) of PE on Perfusion scan Prevalence 42/82 (51.2%) and CTPA.
All patients Positive LR 32.33 N: 82 but only 28 were given V/Q scan Negative LR 10.03
Mean age (range): 51 years (14-81) CTPA (n=28) Drop outs: 2 were
nondiagnostic. Sensitivity 11/12 (91.7%)
Specificity 14/14(100%)
Positive LR -
Negative LR 0
Non diagnostic result 0/28 (0%)
238 Venous thromboembolic diseases
Clinical evidence tables
Study Patients Diagnostic tools Measure of Disorders Results Comments
details
Perfusion scan combined with CR (N=54)
Sensitivity 22/25(88%)
Specificity 22/24 (91.7%)
Positive LR 11
Negative LR 0.13
Non diagnostic result 3/54 (5.6%)
CTPA (N=54)
Sensitivity 25/25 (100%)
Specificity 23/24 (95.8%)
Positive LR 25
Negative LR 0
Non diagnostic result 2/54 (3.7%)
Non diagnostic result Overall results
V/Q scan or perfusion scan combined with CR; 5/82 (6.1%)
CTPA; 2/82 (2.4%)
239 Venous thromboembolic diseases
Clinical evidence tables
Study Patients Diagnostic tools Measure of Results Comments Disorders details
Ohno 2004299 Patient group: Assessment tool under PA Funding: investigation: Patients believed to Daiichi Pharmaceutical have a pulmonary 1) Time resolved contrast Company Study design: embolism. enhanced MR angiography alone Ventilation PA + PA- Total perfusion Diagnostic 2) Contrast enhanced MDCT alone scintigraphy alone VQ + 8 8 16 Limitations: 1) the Prospective Exclusion criteria: 3) contrast enhanced MDCT with VQ - 4 28 32 overall prevalence of study patients younger than time resolved contrast enhanced pulmonary emoblism 18 years, pregnant, MR angiography (combined with Sensitivity Total 12 36 48 was 25%, lower than
patients with renal SENSE) that of the PIOPED Specificity Duration of failure were excluded. STUDY. 2) They 4) ventilation perfusion follow-up: 1 PPV 8/12 (67%) interpreted contrast scintigraphy alone; was performed year enhanced 4-MDCT according to the procedures NPV 28/36 (78%) system for every
described in the PIOPED and the 1.25mm section All patients Advances in New Technologies Positive LR 8/16(50%) thickness, however if a N: 48 Evaluating the Localization of thinner detector and Mean age (range): 55 Negative LR 28/32 (88%) Pulmonary Embolism studies. reconstruction years (27-73) collimations was used, Drop outs: none 5) contrast enhanced MDCT with 3.05 the diagnostic capability reported. ventilation perfusion scintigraphy 0.42
240 Venous thromboembolic diseases
Clinical evidence tables
Study Patients Diagnostic tools Measure of Results Comments Disorders details of contrast enhanced Time resolved contrast enhanced MR MDCT in the peripheral angiography alone vascular zone may be Reference standard: pulmonary improved. 3) the sample angiography size was small. Aim of 11/12 (92%) study was to see if time- Sensitivity resolved MR 34/36 (94%) angiography with SENSE Specificity was effective in 11/13 (85%) diagnosing PE so not PPV much data given for 34/35 (97%) NPV VQ.Indeterminate 15.3 results not reported. Positive LR 0.08 Negative LR Additional Contrast enhanced MDCT alone tests: none
Sensitivity 10/12 (83%) Notes: Specificity 34/36 (94%)
PPV 10/12 (83%)
NPV 34/36 (94%)
Positive LR 13.83
Negative LR 0.18
241 Venous thromboembolic diseases
Clinical evidence tables
Study Patients Diagnostic tools Measure of Results Comments Disorders details
Contrast enhanced MDCT with time resolved contrast enhanced MR angiography
11/12 (92%) Sensitivity 34/36 (94%) Specificity 11/13 (85%) PPV 34/35 (97%) NPV 15.3 Positive LR 0.08 Negative LR
Contrast enhanced MDCT with ventilation perfusion scintigraphy
11/12 (92%) Sensitivity 34/36 (94%) Specificity 11/13 (85%) PPV 34/35 (97%) NPV 15.3 Positive LR 0.08 Negative LR
242 Venous thromboembolic diseases
Clinical evidence tables
Study Patients Diagnostic tools Measure of Results Comments Disorders details
Prevalence 12/48 (25%)
Severity of PE 12/48 patients were diagnosed as having PE with a total of 35 central vascular zone and 41 peripheral vascular zone pulmonary embolisms.
Study Patients Diagnostic tools Measure of Disorders Results Comments
details
Gray 1990177 Patient group: Assessment tool under PA Funding: patients who had just investigation: ventilation undergone or who perfusion scanning; images were were to undergo obtained in the posterior Study design: PA + PA- Total Limitations: pulmonary projection using an IGE Diagnostic angiography. Maxicamera II with a standard low VQ VQ+ 15 1 15 It is unclear from the energy parallel collimator, with 3 study design whether it
Study (not clear min wash in and 3 min washout VQ - 0 32 33 was a prospective study whether phases. An oblique ventilation with consecutive Exclusion criteria: Total (high and sign prospective or study was performed 24 h later in Total 16 32 48 patients; 40% of patients probability together) retrospective or Not reported. some patients, as dictated by the had lung scanning mixed. The perfusion scan finding. All patients Sensitivity before angiography, 20% authors N: 78 (30 patients on the same day and 100% mentioned that (38%) were non Specificity 40% had angiography they were diagnostic and 48 Reference standard: 97% before scanning. careful to (62%) had a diagnostic PPV eliminate the finding). Pulmonary angiography; 93.75% NPV
243 Venous thromboembolic diseases
Clinical evidence tables
Study Patients Diagnostic tools Measure of Disorders Results Comments
details error prevalent Mean age (range): 56 intraluminal filling defects or in retrospective years (20-80) multiple cut-off vessels were Positive LR 100% Additional studies, where Drop outs: 30 were reported as “pulmonary Negative LR 33 tests: information angiography non-diagnostic. embolism”, normal angiography or collected on symptoms series are biased minor perfusion abnormalities Non diagnostic results 0 and signs (sudden by excess Total patients at start were reported as “no pulmonary dyspnoe, haemoptysis, patients with was 101, but fourteen embolism”. 30/78 V/Q; 9/78 PA. pleuritic pain, history of indeterminate were eliminated from PE/DVT, surgery/bed lung scans) the study because the PA rest, radiograph, ECG lung scan or the chest change) radiograph was unavailable. Eight Duration of VQ PA + PA- Total were excluded follow-up: not because angiogram Notes: clear VQ + 11 0 11 was non-diagnostic (although table says 9 VQ - 0 32 32 patients had an indeterminate Total 11 32 43 pulmonary
angiogram). Sensitivity (high probability) 100%
Specificity (high probability) 100%
PPV 100%
NPV 100%
Positive LR Cannot calculated
Negative LR 0
244 Venous thromboembolic diseases
Clinical evidence tables
Study Patients Diagnostic tools Measure of Disorders Results Comments
details
PA
VQ PA + PA- Total
VQ+ 4 1 5
VQ - 0 32 32
Total 4 33 37
Sensitivity (sign. probability) 100%
Specificity (sign. probability) 96.9%
PPV 80%
NPV 100%
Positive LR 33
Negative LR 0
3 month VTE rate Not reported.
Non diagnostic rate 30/78 (12/30 had PE in the pulmonary angiography and 19/30 did not have PE).
245 Venous thromboembolic diseases
Clinical evidence tables
Study Patients Diagnostic tools Measure of Disorders Results Comments
details
Severity of PE 11/48 had PE present with a high probability, 4/48 had PE present with a significant probability, 32/48 had PE absent.
Mortality 1/13 in the scan positive patients who died had embolism; 2/24 in the indeterminate probability group died without autopsy; 1/28 in the scan negative group who died did not have embolism in the autopsy.
Study Patients Diagnostic tools Measure of Disorders Results Comments
details
Vreim 1990452 Patient group: Assessment tool under PA Funding: contracts NO1- investigation: HR-34007, NO1-HR- Patients 18 years or ventilation/perfusion scan; PA+ PA- Total 34008, -34009, -34010, - older, inpatients and perfusion scans were satisfactory 34011, -34012, -34013 Study design: High probability VQ + 102 14 116 outpatients, in whom or better in 96% of cases, from the National Heart, ventilation/perfusion
246 Venous thromboembolic diseases
Clinical evidence tables
Study Patients Diagnostic tools Measure of Disorders Results Comments
details symptoms that ventilation scans adequate or scan Lung, and Blood Diagnostic suggested pulmonary better in 95%. VQ - 149 466 615 Institute, Bethesda, Md. embolism were Prospective Total 251 480 731 present within 24 study Sensitivity hours of study entry Reference standard: Limitations: Clinical and contraindications Specificity investigators made to angiography such as Angiography; the femoral-vein 41% diagnosis of pulmonary Duration of pregnancy, serum Prevalence Seldinger technique with a embolism based on an follow-up: 1 creatinine level 97% multiple side-holed, 6 F to 8F agreed set of Year greater than Positive LR pigtail catheter was used. 102/124 information but without 260µmol/L or Pulmonary angiograms were Negative LR standardized diagnostic hypersensitivity to adequate or better in 95% of 13.66 algorithms. Random contrast material. cases. Non-diagnostic results sample taken and no 0.61 Exclusion criteria: details of randomisation. VQ: 105 with PE present on PA; 217 with
Patients with PE absent on PA; PA: 24 uncertain. No recurernces were not angiogram in 175 patients. Additional approached for recruitment a second PA tests: time. High or intermediate PA+ PA- Total probability All patients ventilation/perfusion VQ + 207 231 438 Notes: The authors N: 931 scan suggested in the Mean age (range): VQ - 44 249 293 discussion that attention 56.1 years should be paid to the Drop outs: 23/931 Total 251 480 731 angiographic criteria’s (2.5%) had incomplete Sensitivity design for acute
(16/931) or no (7/931) pulmonary embolism, Specificity follow-up. 82% the variable time Prevalence between angiographic 52% 247 Venous thromboembolic diseases
Clinical evidence tables
Study Patients Diagnostic tools Measure of Disorders Results Comments
details 1493 patients gave evaluation and the consent and a random Positive LR 207/488 patients’ deaths, and the sample was taking of variability in Negative LR 1.7 933 and 560 were not pathophysiology and selected for sensitivity 0.35 pathological and specificity interpretation of analyses. thromboemboli in 2 scans were not evolution. completed n=931 and angiogram not PA completed for 176 patients, therefore High, intermediate or PA + PA- Total n=755. low probability PE was uncertain in ventilation/perfusion VQ + 246 430 676 24/755. N=731 scan VQ - 5 50 55
Total 251 480 731
Sensitivity
Specificity 98% Prevalence 10% Positive LR 246/800 Negative LR 1.08
0.2
Non diagnostic rate 24/755 (3%) of patients who completed angiography had angiograms in which the presence of thromboemboli was uncertain.
248 Venous thromboembolic diseases
Clinical evidence tables
Study Patients Diagnostic tools Measure of Disorders Results Comments
details
Severity of PE Not reported
Mortality 1 patient died before the V/Q scan (unknown aetiology)/
hospital mortality: 9/931
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