Assessment of aortic distensibility with ECG-gated 64-row multi-detector computed tomography in abdominal aortic aneurysms

Transcription

1 Assessment of aortic distensibility with ECG-gated 64-row multi-detector computed tomography in abdominal aortic aneurysms Poster No.: C-3106 Congress: ECR 2010 Type: Scientific Exhibit Topic: Vascular - CT Authors: H. Yokoyama, S. Sanada ; Sapporo/JP, Kanazawa/JP Keywords: Multi-detector CT, Imaging,three-Dimensional, Abdominal Aortic Aneurysm Rupture Keywords: Vascular, CT DOI: /ecr2010/C Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 25

2 Purpose Most abdominal aortic aneurysms (AAAs) are found accidentally, sometimes a calcified aneurysm can be recognized on plain abdominal x-rays. Surgery is indicated when the diameter of aneurysm exceeds 5.5cm,and AAAs are frequently fatal vascular condition. The aim of this study is that to detect the aortic distensibility can predict the rupture of AAAs using ECG-gated 64-row MDCT? Page 2 of 25

3 Methods and Materials Measurements of the aortic distensibility were performed in 80 (including 3 ruptured cases) patients with AAA, which all with thrombus. Equipment & Acquisition parameter Aquilion 64 SuperHeart MDCT(Toshiba medical Co.) Zio Station Workstation(ZIO Soft Co.) Dual shot GX Injector #Nemoto kyorindo Co.) Iomeron 350(Eisai pharmaceutical Co.) 100kV,350mA,0.35sec,1mm slice,fc 43,hp 5.6 Iomeprol 350mgI/ml 3.0ml/sec total 80ml +saline3.0m/se total40ml CTDIvol 47.0±2mGy DLP 1.99±0.8Gy.cm Radiation Dose First 32 cases were using 135 kilovoltage, rest 48 were using 100 kilovoltage. 135kV CTDIvol 129.6±3.3mGy DLP 5.37±0.1Gy.cm 100kV CTDIvol 47.0±2mGy DLP 1.99±0.8Gy.cm ECG-assisted MDCT is higher radiation dose than non ECG-assisted,but is acceptable since we only have vessel areas. Patients'clinical characteristics Subjects(n=80) Ø>5cm Ø<5cm Gender ratio male:female (52:28) 24:12 28:16 Mean age(years) 72±6 74±3 Systolic Blood Pressure(mmHg) 144±7 138±2 Diastolic Blood Pressure(mmHg) 79±6 74±3 Page 3 of 25

4 Mean of maximal aortic diameter (cm) 6.3± ±0.4 Aortic cross-sectional area of positions(fig.1) Above the renal artery Normal vessel size of artery Maximal diameter (aneurysm) Below the aneurysm Methods ( analysis of data aquisition fig.2-fig.4) 1.Reconstructed at 0%,10%,~90% of the RR interval 2.Calculated the vessel area using workstation 3.area-versus-time curve Elasticity quantification d = dsys # ddia d: dilation(mm) D = #A / Ao##p D:distensibility(Pa-1) #A:difference between maximum and minimum area Ao:minimum vessel area #p:change in blood pressure Page 4 of 25

5 Images for this section: Fig. 0 Page 5 of 25

6 Fig. 0 Page 6 of 25

7 Fig. 0 Page 7 of 25

8 Fig. 0 Page 8 of 25

9 Results Resulting area-versus-time curves were shown that the inner wall areas were larger than the outer wall areas, which mean the outer wall were stiffer. Distensibility of aneurysms exceed 5cm (36/80) were 0.2±0.5(10-4Pa-1), under 5cm (44/80) were 1.3±0.2 (10-4Pa-1).All in normal size were 3.2± 0.4 (10-4Pa-1). Three aneurysms of impending rupture indicated 0.19±0.1 (10-4Pa-1). The cine images also were seen the difference of movement clearly. (fig.1-fig.2) Changes of dilation d(mm) d(mm) Ø>5cm Ø<5cm Normal vessel size p. 2.1± ±1 Above the renal artery 1.8±1 1.7±0.9 At aneurysm 1.3± ±1 Below the aneurysm 1.4± ±0.8 Changes of cross-sectional areas sys/dia sys/dia Ø>5cm Ø<5cm Normal vessel size p 1.14± ±0.5 Above the renal artery 1.08± ±0.8 At aneurysm 1.07± ±0.5 Below the aneurysm 1.14± ±0.5 Distensibility D D[10-4 Pa-1] D[10-4 Pa-1] Ø>5cm Ø<5cm Normal vessel size p 3.2± ±0.6 Above the renal artery 4.1± ±0.5 At aneurysm 0.2± ±0.2 Below the aneurysm 2.1± ±0.6 Page 9 of 25

10 1mmHg=1.33Pa p<0.05 Case Report (fig.3) Clinical Summary: A 73-year-old man was referred to the Cardio-Vascular Center Hokkaido Ohno Hospital with abdominal pain.on the patient's admission,ct examination was performed.ct images revealed a 78.7x 64.8mm abdominal aneurysm in diameter. Patient condition was stable, therefore operation was scheduled electively. Two days after admission,patient complaint of backpain,then underwent CT immediately. Rupture of aneurysm was suspected and then emergent operation was carried out. Labo Data on admission onset(ruptured) 3 WBC(10 /µl) # 4 RBC(10 /µl) # Hb (g/dl) # Ht (%) # MCV (fl) MCH (pg) PLT (10 /µl) # Blood pressure 151/80 mmhg 163/88 mmhg Risk factor Hypertension Operative Impression: Impending rupture (Defect of Intima) (fig.4) Page 10 of 25

11 Discussion (fig.5-fig.6) We had experienced three cases which all with rupture of aneurysms, after underwent MDCT examinations. #1 case; time from routine study to onset 2days #2 case; time from routine study to onset 7days #3 case; time from routine study to onset 31days Distensibility D of ruptured cases were significantly lower in the aneurysms Distensibility #D) (10-4Pa-1) two days before onset (rupture) Normal vessel size p Above the renal artery At aneurysm Below the aneurysm Region of rupture 0.19 Factors influencing the rupture of AAAs Size of Aneurysm #5#5.5cm Aneurysm Formation saccular # fusiform Epidemic Factors gender,age,hypertention, smoking,copd Page 11 of 25

12 Images for this section: Fig. 0: VR(Volume Rendering Image) of AAA(abdominal aortic aneurysm Page 12 of 25

13 Fig. 4: 4D Image of AAA(abdominal aortic aneurysm). Page 13 of 25

14 Fig. 0: 4D images are seen the difference of movement clearly. Page 14 of 25

15 Fig. 2: 4D(Cine Mode) #1 Page 15 of 25

16 Fig. 3: 4D(Cine Mode)#2 Page 16 of 25

17 Fig. 1: 4D(Cine Mode) #3 Page 17 of 25

18 Fig. 0: Aneurysm VR(Volume Rendering image),two days after rupture was occured Page 18 of 25

19 Fig. 0 Page 19 of 25

20 Fig. 0 Brewster DC,et al:guidelines for the treatment of AAA J Vasc Surg,37; ,2003 Page 20 of 25

21 Fig. 0 Vardulaki KA,et al:growth rates and risk of rupture of AAABr J Surg,85; ,1998 Page 21 of 25

22 Conclusion The resulting area-versus-time curves were shown that the inner wall areas larger than the outer wall areas.the 4-D images were seen the difference of movement clearly. To detect distensibility changes that might predict an increased risk of rupture,regardless of AAA diameter. The authors acknowledge to all the scholars who are interested in Distensibility of the aorta,particularly to Dr.Ganten and her research papers. Page 22 of 25

23 Images for this section: Fig. 0: Wired frame method was useful to evaluate the aortic distensibility Page 23 of 25

24 References Ganten M-K.et al.motion characterization of aortic wall and intimal flap by ECG-gated CT in patients with chronic B-dissection.Eur J Radiol(2008) Ganten M-K,Krautter U,von Tengg-Koligk H,et al.quantification of aortic distensibility in abdominal aortic aneurysm using ECG-gated multi-detector computed tomography.eur Radiol 2008(Jan 12,Epub ahead of print) Ganten M,Boese JM,Leitermann D,et al.quantification aortic elasticity: development and experimental validation of a method using computed tomography.eur Radiol 2005;15(12) Ekaterinaris JA,Ioannou CV,Katsamouris AN.Flow dynamics in expantions characterizing abdominal aorta aneurysms.ann Vasc Surg2006;20(3):351-9 Page 24 of 25

25 Personal Information Hiroichi Yokoyama RT,MSc.,1) Shigeru Sanada ##.# 2) Dept.Diagnostic Imagings, Cardio-Vascular Center Hokkaido Ohno Hospital1) Kanazawa University Graduate School of Medical Science2) Nishino Nishiku Sapporo, Japan mail Page 25 of 25