Cardiac Clinical Protocols

Basic Sequences

Black Blood Imaging
Bright Blood Imaging
Velocity-Encoded Cine (phase contrast)
Gd-Enhanced MR Angiography

Cardiac Imaging (Download)

Cardiac Mass
Arrhythmogenic Right Ventricular Dysplasia
Left Atrium/Pulmonary Vein Protocol
Cardiac Viability
General Congenital Cardiac Anomaly
Aortic Coarctation
Tetralogy of Fallot

Black Blood Imaging [Top]

• ECG-gated SE or FSE (TSE)
• ECG-gated db-HASTE (double IR-half-Fourier single-shot turbo spin echo)

  Uses: Anatomy, to identify extraluminal aortic pathology, intramural hematoma or dissection.
  
  Cardiac gating: TR = R-R interval for SE or FSE.
  
  Gating not absolutely needed for HASTE.
  Can be performed breath hold (fast imaging) or multiple averages non breath hold.
  To get more slices, may need to concatenate slices.
  HASTE can be used in arrhythmias.

Bright Blood Imaging [Top]

• cine GRE
• FASTCARD
• true FISP

  Uses: Flow, motion, aortic valvular disease.
  
  Cardiac gating: Choose temporal resolution based on TR and R-R interval.
       # temporal phases 0.85 x (R-R/TR).
  
  Can be performed breath hold (segmented k-space) or 3 - 4 averages NBH. Real-time true FISP can be used in arrhythmias.
  Retrospectively gated sequences can be used with peripheral pulse gating if necessary.

Velocity-Encoded Cine (phase contrast) [Top]

• Fastcard PC

  Uses: Quantify flow at stenoses to estimate pressure gradient or collateral blood flow.
  
  Encoding velocity (venc) = 250 - 500 cm/sec for through plane velocity.
  Cardiac gating: Choose temporal resolution based on TR and R-R interval.
       # temporal phases 0.85 x (R-R/TR).
  
  Can be performed breath hold (segmented k-space, view-sharing) or multiple averages NBH.

Modified Bernouilli's equation: P (mm Hg) = 4vmax^2      P = pressure gradient across stenosis      vmax = peak velocity at or just distal to stenosis

Regurgitant fraction =      reverse flow during diastole / total forward flow Total blood flow (e.g. cardiac output = total flow at ascending aorta) =      Area under flow-time curve

Gd-Enhanced MR Angiography [Top]

• 3D spoiled GRE (with interpolation)

  Uses: Aortography or pulmonary angiography.
  
  Preferably breath hold (ungated).
  Single or double dose (0.1 - 0.2 mmol/kg) Gd-contrast.
  Timing based on test dose or fluroscopic triggering (Care bolus, Smart prep, etc).