Brought to you by
ECR 2013 / C-1840
CT angiography in patients with acute spontaneous intracranial hemorrhage:detection and characterisation of intracranial aneurysms: comparison of Volumen Rendering and Maximum Intensity Projection algorithms
Congress: ECR 2013
Poster No.: C-1840
Type: Scientific Exhibit
Keywords: Neuroradiology brain, Vascular, CT-Angiography, Catheter arteriography, Diagnostic procedure, Aneurysms, Haemorrhage
Authors: Z. Merhemic1, M. Niksic1, S. Milisic1, E. Burazerovic1, I. Omerhodzic1, E. Avdagic1, D. Bulja1, M. M. Thurnher2; 1Sarajevo/BA, 2Vienna/AT
DOI:10.1594/ecr2013/C-1840

Results

In 121 patients 150 aneurysms were detected.  In 101 patients was detected one aneurysm (83%), in 14 two aneurysms (12%), in 4 patients  three aneurysms (3%), in 1 patient four and in 1 five aneurysms (1%).

Most of aneurysms were diagnose on MCA (41%), and were medium size (60%) (Table 1.)

 

Table 1. Aneurysms diagnosed on surgery and DSA („gold standard“)

 

 

3mm

4-10mm

11-24mm

25mm

 

ACA

9

33

5

0

47             31%

MCA

12

36

13

1

62             41%

PCA

0

0

1

0

1                1%

ICA

5

15

11

2

33             22%

VBA

1

6

0

0

 7                  5%

 

27
18%

90
60%

30
20%

3
2%

150
                100%

 

 

On MIP CT angiography were diagnosed 7 fals negativ and 4 fals positive aneurysms and  sensitivity/ specificity/PPV/NPV/ accuracy  was 95.3/87.9/97.3/80.6/93.9%.

On VR CTangiography were diagnosed 3 fals negative and 3 fals positive aneurysms, and sensitivity/ specificity/PPV/NPV/ accuracy  was  98.0/90.9/98.0/90.9/96.7%.

For MIP+VR algorithm sensitivity/ specificity/PPV/NPV/ accuracy  was 98.0/84.8/96.7/90.3/95.6%, respectively. (Table 2)

 

 

Table 2.

 

MIP

VR

MIP + VR

 

Sensitivity (%)

 

 

95.3   (92 – 97 )

 

98   (95 – 99.3)

 

98  (95 – 99)

 

Specificity (%)

 

 

87.9    (74.6 – 95.5)

 

 

90.9    (79 – 96.7)

 

84.8    (72.5 – 91)

 

Pozitive predictive value PPV(%)

 

 

97.3 %  (94.4 – 99 %)

 

98 %   (95.4 – 99.3 %)

 

96.7 %  (94 – 98 %) 

Negative predictive value NPV(%)

 

 

80.6 % (68.4 – 87.6 %)

 

90.9 %  (79 – 96.7 %)

 

90.3 % (77 – 97 %)

 

Accuracy (%)

 

 

93.9

 

96.7

 

95.63

*Intervals with  95% confidence

 

 

 Area under Roc curve for  MIP algorithm is 0.916, for VR is 0.945  in relation to gold standard and show high accuracy for both tests (MIP and VR) , but there is no significant different between thise two methods and gold standard (OP, DSA)    p=0.18.

 

All aneurysms larger than 3mm were diagnosed on CT angiography on both MIP and VR reconstruction.

Using Wilcoxon Signed Rank Test, p=0.057,  there was  no significant different between VR vs. DSA finding in size of aneurysms,  but there was significant different between VR vs. surgical finding in size of aneurysms (p=0.005). On surgery, anurysms were found  significantly large then on VR CT angiography.

 

Disscusion    

 

Table 3. Localization of aneurysms                                  

 

 

    ACA (%)

  MCA (%)

  ICA (%)

 PCA (%)

 VBA (%)

Merhemic

     31

     41

   22

        1

        5

Osborn

   30-35

     20

  30-35

     

10

Numminen

      22

     39

    31

         3

        5

Zhang

      29

     16

    48

         1

        6

Hwang

      36.5

     28.5

    28

          0.5

        6.5

Donmez

      30

     32

    30

                           

8

Merhemic

      26.5

     34.5

    28

         3

         8

                 

 

In our study most aneurysms were found on MCA, like in Numminen et al. study.

There was significant different between VR vs. surgical finding in size of aneurysms (p=0.005). On surgery, anurysms were found  significantly large then on VR CT angiography. Despide the fact that surgical finding is gold standard, we can not rely on that when size of aneurysm is questioned. Surgent does not measure aneurysms with any instrument and their finding is approximative, rely on expirience.(Fig.1.)

All aneurysms larger than 3mm were diagnosed on CT angiography on both MIP and VR reconstruction. Three aneurysms smaller then 4mm (one on PICA, and two on ICA) were not diagnosed on VR algorithm CT angiography (Fig.2), and three aneurysms on MCA were fals positive diagnosed.

 

Table 4. Intracranial aneurysms: CTA findings in different studies

 

Sensitivity

Specificity

  PPV

 NPV

Accuracy

Merhemic MIP

  95.3

  87.9

  97.3

  80.6

 83.2

                     VR

  98.0

  90.92

  98.0

  90.9

 96.7

            MIP+VR

  98.0

  84.8

  96.7

  90.3

 95.63

McKinney

   97.4

  90.0

  97.4

  90.0

 95.63

Donmez

   95.1

  94.1

 

 

 95.0

Yoon

   92.5

  93.3

 

 

 92.6

Zhang

   91.5

  95.0

  97.7

  82.6

 92.5

 

   95.7

  95.0

  97.8

  90.5

 95.5

Ramasudara

   94.0

  80.0

  94.0

  80.0

 

Li

   98.1

  100

 100

  85.7

 

 

   99.0

  100

 100

  92.3

 

Hiratsuka

   87

    79.0

 

 

  85.0

 

 

Most of studies were  performed on 64-row spiral CT unit. In our study,  only 30 patient  underwent CTA on 64-row unit, and all others on 4-row CT unit.In our study  all patients were evaluated  by two  radiologist with more than 10 years of experience, and this is the reason that our results were very good.

In all studies only small aneurysms were not diagnosed on CTA,  like in our study. Volume rendering (VR) reconstruction has much higher sensitivity, specificity, PPV, NPV and accuracy than MIP. (Fig.3.)

                                    

POSTER ACTIONS Add bookmark Contact presenter Send to a friend Download pdf
SHARE THIS POSTER
2 clicks for more privacy: On the first click the button will be activated and you can then share the poster with a second click.

This website uses cookies. Learn more