CT Chapter 10 - Valves

Question 1

What is the incidence of aortic valve calcification on chest CT scans?

Answer 1

6-18%

Question 2

Describe the findings and diagnosis:

• bAVR 2 years prior for severe AS
• two months of fatigue and chest pain

Answer 2

Perivalvular abscess

• significant proliferation of surrounding soft tissue with an outpouching hear the septal leaflet of the tricuspid valve (white arrow) that represents peri-valvular abscess
• Black arrow - well defined border between contrasted LA and RA

Question 3

What is the principle purpose of cardiac CT pre pulmonary vein isolation?

Answer 3

• identify anomalous pulmonary venous anatomy
• exclude LAA thrombus

Question 4

What are the indications for cardiac CTA in infective endocarditis?

Answer 4

• Perivalvular complications suspected
• Helpful imaging modality in setting of prosthetic valves (both ACC/AHA)

Question 5

What are specific findings on Cardiac CT in setting of IE?

Answer 5

• Detection of:
  
  • perivavlvular abscess
  • peri-aortic abscess
  • extent of involvement
  • presence of pseudoaneurysms/fistulae
  • extra-cardiac complications (pulmonary)
• Other cardiac structures:
  
  • coronary arteries
  • aorta

Question 6

Describe the findings:

Answer 6

Filling defect in the LAA

• acquired immediately after contrast injection is not uncommon, particularly in A-fib patients
• DDx:
  
  • slow LAA emptying velocities (spontaneous echocontrast on TEE)
  • thrombus

Question 7

What is the next step in diagnosis?

Answer 7

Immediately repeat cardiac CT acquisition without additional contrast bolus

• non-contrast cardiac CT acquisition performed 30 seconds after the initial acquisition
  
  • slow emptying velocities → contrast opacification of the LAA
  • LAA thrombus → persistent filling defect

Question 8

What LAA / Ascending aorta HU attenuation would be most consistent with LAA thrombus as the cause of a filling defect on cardiac CT?

Answer 8

0.18 on delayed phase imaging

Question 9

Describe the relationship with LAA morphology / CVA risk / A-fib ablation

Answer 9

No LAA morphology is associated with an increased risk for thromboembolism following A-fib ablation

Question 10

Describe the findings:

Answer 10

aortic valve endocarditis

Question 11

When compared to TEE, what is the most significant weakness of cardiac CT in evaluation of endocarditis?

Answer 11

Leaflet perforation

• Very close correlation with TEE:
  
  • vegetation size
  • vegetation mobility
  • perivalvular abscess formation

Question 12

Describe the findings:

Answer 12

Soft tissue density on ventricular surface of mechanical valve - thrombus

• HU < 90 → thrombus / good response to thrombolytic therapy (100%)
• HU > 145 → pannus

Question 13

What findings on the coronal reformatted image is associated with an increased risk fo annular root injury during TAVR?

Answer 13

LVOT calcification within 2 mm of the aortic valve annulus

• median calcium volume within the LVOT → increased aortic injury

Question 14

What are risk factors for increased aortic root injury during TAVR implantation?

Answer 14

• TAVR oversizing ≥ 20%
• LVOT calcification
• Need to post-dilate the TAVR valve following initial deployment

Question 15

Describe the differences in sizing of TAVR valves:

• TEE
• MDCT

Answer 15

• CT
  
  • more TAVR oversizing (14% vs. 9%)
• TEE
  
  • ⅓ of patients would have been recommended larger TAVR valve
  • 25% will have > mild PAR

Question 16

What Cardiac CTA protocol is most appropriate for:

• aortic annular sizing
• assessment of LV function
• evaluation of lower extremity vascular access sites

Answer 16

Retrospective, ECG-gated helical acquisiiton

from the carinal bifurcation through the diaphragm

+

Followed by a non-gated, helical acquisition from the aortic arch through the lesser trochanter of the femurs

Question 17

Describe the use of MDCT prior to TAVR to assess for CAD

Answer 17

• PPV
  
  • coronary arteries → 50-70%
  • bypass grafts → > 90%
• Factors contributing to difference in PPV:
  
  • vessel size
  • low calcium burden
  • minimal graft motion

Question 18

What is the risk of increased aortic calcium volumes?

What level carries this risk?

Answer 18

• increased risk of Paravalvular Regurgitation (PAR)
• mean volume 1216 mm3

Question 19

Describe the findings:

Answer 19

Measured basal annular ring-LM distance 9.8 mm portends an increased risk for coronary occlusion following TAVR

• basal annular ring-LM distance 10-14 mm is recommended for balloon-expandable valve systems.
• normal average distance from basal annular ring to ostium:
  
  • LM → 15.5 +/- 2.9 mm
  • RCA → 17.3 +/- 3.6 mm