Anne-Marie Koop

5 207 4.2. Anesthesia and fixation 4.2.1. Place the mouse in the induction chamber filled with a mixture of 5% isoflurane and 100% oxygen. Verify the effect of the anesthesia by giving a pain stimulus by a toe pinch. 4.2.2. Put eye ointment on the eyes of themouse to keep themmoist during scanning. 4.2.3. Place the mouse in the scanner’s animal bed with integrated air supply, a warmed (37 °C) mixture of 1.5%–2.5% isoflurane, 100% oxygen (0.15 L/min), and room air (0.3 L/min), and a pressure pad that enables observation of heart rate (aim for 400–500 bpm) and respiratory rate (aim for ~35 breaths per min) during scanning. Regulate the anesthesia based those two parameters. Make sure the bed is made of plastic, without any magnetic material. 4.2.4. Place the animal bed with the mouse into the scanner. 4.3. Performing cardiac magnetic resonance imaging 4.3.1. Make preacquisition adjustments by tuning the radiofrequency (RF) birdcage coil on 1 Hydrogen (1 H) resonance frequency. 4.3.2. Then set the magnetic field as homogeneous as possible using the automatic shimming procedure. NOTE: The computerized shimming is done by the so-called Tuning method, which uses the area under the 1 H FID as a quality parameter. In this Tuning procedure a user-defined group of shims (Z, Z2, X, Y, XZ, and YZ) is examined in an iterative cycle. Each shim in succession is adjusted individually to maximize the area under the FID. This is essentially a linear procedure that works well quickly. 4.3.3. Optimize the RF pulse by maximizing the one-dimensional image profile with adjustment of RF pulse power. 4.3.4. Assign the exact position of the heart in the scanner by making scout scans using a tripilot sequence. Use a fast gradient echo sequence to acquire the scout images through the thorax: a transversal, coronal, and sagittal slice. ( figure 1a,b,c ) 4.3.5. Adjust the axes to the actual axes of the axial, two-chamber, and four-chamber view ( figure 1d,e ). 4.3.6. Subsequently, position the cine slices perpendicular to an imaginary axis between the RV outflow tract and the utmost apical part of the RV. 4.3.7. Derive ten to eleven 1 mm-thick cine sliceswithout a slice gap to cover the entire top to base imaging of the RV ( figure 1f ) by means of the Self-gated IntraGate-fast