EVALUATING ADJUVANT HORMONAL THERAPY IN EARLY-STAGE BREAST CANCER: A COMPARISION OF PREDICTIVE MODELS

1
Aortic Flow Rates and Intra-Arterial Septum
Mobility in Type B Aortic Dissections Quantified
with Phase Contrast Magnetic Resonance Imaging C
Karmonik1,2 J Bismuth1, DJ Shah1, JE Anaya-Ayala,
MG Davies 1,AB Lumsden 1 1The Methodist DeBakey
Heart Vascular Center 2The Methodist Hospital
Neurological Institute Houston, TX 77030
2. Volumetric Flow Waveforms of True and False
Lumen
2. 2D pcMRI Flow Analysis
Introduction
Analogous to true lumen segmentation for IS
boundary movement quantification, false lumen
boundaries were determined in the transverse
magnitude images and volumetric flow was
calculated as the product between average
velocity and false lumen area for each time
point. Average Flow was calculated as average
over all time points.
Post-treatment prognosis of type Stanford B
aortic dissections (TB-AD) remains unclear with a
mortality rate of about 20 in 3 years after
hospital discharge 1. A better understanding of
this disease is necessary for improved management
and therapy to increase survival rates.
Recently, hemodynamic factors including
intra-arterial pressure differences have been
suggested as indicative of disease progression
1. To further characterize the hemodynamic
state in TB-AD , we quantified flow rates in true
and false lumen of 11 TB-ADs and compared with
intra-arterial septum (IS) mobility.

Methods
3. False Lumen and True Lumen Flow Correlation
1. Intra-Arterial Septum Motion Transverse
2D phase contrast magnetic resonance images (2D
pcMRI) were acquired in 11 patients immediately
distalto the aortic arch resulting in
cross-sectional images of the true (TL) and false
(FL) lumen. TL boundary was segmented
semi-automatically 2 and the movement of the
intra-arterial septum (IS) was characterized by
the maximum extension and maximum contraction.
Results

• Average Maximum Extension and Contraction and
  Flow Rates

Table 1 IS Movement and Average Flow Table 1 IS Movement and Average Flow Table 1 IS Movement and Average Flow Table 1 IS Movement and Average Flow Table 1 IS Movement and Average Flow
IS Maximum Distension mm IS Maximum Contraction mm Average Flow ml/sec Average Flow ml/sec
Case Septum Septum True Lumen False Lumen
1 2.4 -0.6 35.4 28.4
2 1.2 -1.6 36.7 -2
3 3.7 -2.0 20.6 4.5
4 2.0 -4.2 120 -18.9
5 2.0 -1.1 7.3 17.8
6 12.8 -7.8 34.1 13.3
7 0.3 -3.9 98.7 7.5
8 3.8 -0.9 120 2.3
9 13.5 -3 64.9 2.8
10 8.7 -1.8 41.3 26.3
11 3.0 -0.7 18.7 22.32
Discussion and Conclusion
IS distension ranged from 13.5 - 0.3 mm (mean 4.8
4.4mm), IS contraction from 7.8 to 0.6 mm (2.4
2.1 mm). In two cases, mean flow in the FL
was negative (retrograde flow). Mean TL and FL
flow rates were inversely correlated (r-0.63,
p0.04). No correlation was found between IS
mobility and flow rates (or their ratios). 2D
phase contrast MRI can quantify intra-septum
mobility and volumetric blood flow rates in true
and false lumen of type B aortic dissections.
Large variations in IS maximum distension and
contraction were found not correlating with
measured flow rates. Mean flow rates in true and
false lumen showed statistically significant
correlation.
phase difference Image
magnitude Image

case 8
IS motion
color-code true lumen flow
References
Average flow values represent averages for
cardiac cycle, in two cases (2 and 4) average
flow in the false lumen was negative.
1 Tsai TT, Schlicht MS, Khanafer K, et al.
Tear size and location impacts false lumen
pressure in an ex vivo model of chronic type B
aortic dissection. J Vasc Surg. Apr
200847(4)844-851. 2 Karmonik C, Bismuth JX,
Davies MG, K.Y. H, Lumsden AB. An Image
Processing Algorithm for the In-vivo
Quantification and Visualization of Septum Motion
in Type III B - Aortic Dissections with Cine
Magnetic Resonance Imaging. Paper presented at
EMBC 2009, 2009 Minneapolis.
maximum extension
maximum contraction