28 Result(s)
-
Chapter
Cardiac Masses
1. To confirm or refute the presence of a mass identified on CXR or Echo 2. To establish the tumor location, size and relationship to surrounding cardiac structures 3. To assist with tissue characterization 4....
-
Chapter
Protons and Spins: The Origin of the MRI Signal
The primary origin of the MR signal is from water and fat within the patient’s tissue; specifically, it is from the hydrogen nuclei (consisting of a single proton) contained within free water and lipid molecules ...
-
Chapter
Relaxation Times, Gradient Echoes, and Spin Echoes
Immediately after the rf pulse, the spin system starts to return back to its original state, that is, equilibrium. This process is known as relaxation. In fact, there are two distinct relaxation processes that re...
-
Chapter
Pulmonary Vein Assessment
1. Anatomy module (Section 19.3.1) 2. LV function module (Section 19.4) 3. Breath-hold non-gated contrast-enhanced MRA performed in the coronal projection encompassing the pulmonary veins and left atrium (Sect...
-
Chapter
Image Space and k-Space
The way that the MR signals are generated and encoded by the use of magnetic field gradients gives rise to a particular relationship between the data points in the signal and those in the image. A single data ...
-
Chapter
Improving SNR with Surface Coils and Array Coils
Perhaps the most important aspect of MR in optimizing SNR is the choice of receiver coil. The integral body coil has a large field of view (Fig. 9.1a), but for imaging a smaller region of interest, it is much mor...
-
Chapter
Pulse Sequences and Image Contrast
The MR signal intensity at a particular location is represented by the image pixel intensity. In Chaps. 8 and 9 it was shown that the strength of the MR signal relative to the background noise (SNR) depends on a ...
-
Chapter
Black Blood Versus Bright Blood Imaging
The spin echo pulse sequence generates images that have intrinsic black blood contrast. This is because it uses two pulses, the 90° and 180° pulses, to produce the spin echo signal (Fig. 12.1). Both of these p...
-
Chapter
Dealing with Respiratory Motion
Respiratory Compensation methods (Respiratory Gating)
-
Chapter
The Basics of a CMR Study
A good referral is a key prerequisite for a clinically useful CMR study, providing relevant clinical background information, placing the scan in the appropriate context, and allowing the CMR department to opti...
-
Chapter
Diseases of the aorta
To establish the location, size and patency of the aorta and its major branches
-
Chapter
Pericardial Disease
Anatomy module including T1 and T2 weighting (page X)
-
Chapter
The MRI Environment
The examination room contains the magnet assembly and patient table (Fig. 2.1). To prevent environmental electrical noise from interfering with the MRI signal, this room is enclosed within a rf shield (or Faraday...
-
Chapter
Valvular Heart Disease
Echocardiography still plays a pivotal role in the evaluation of valvular heart disease. CMR can be useful in case of inadequate echocardiographic examination, in particular for the assessment of valvular regu...
-
Chapter
Interventional Cardiovascular Magnetic Resonance Imaging
Rapid advances in the field of CMR have developed this modality to the extent that it can now be used to guide interventions. CMR provides exceptional 2D and 3D structural delineation for visualization and mea...
-
Chapter
Generating a Signal: RF Pulses and Echoes
In order to generate a signal from the net magnetization that is detectable, the radiofrequency (rf) magnetic field described in Chap.1 is generated by the rf transmitter coil (the integral body coil) and used...
-
Chapter
Basic Adult Congenital Heart Disease (ACHD)
1. Anatomy module (Section 19.3.1) 2. LV function module (Section 19.4) 3. Axial stack of SSFP cines from the diaphragm to the top of the aortic arch (equivalent to RV function module (Section 19.4)) 4. MR ang...
-
Chapter
Making an Image: Locating and Encoding Signals in Space
Single MR echoes produced by rf pulses alone cannot be used to produce an image as they do not contain any information about position. This information is introduced by using the gradient coils described in to...
-
Chapter
Imaging Parameters and Image Attributes
The acquired matrix size, together with the field of view in each direction determines the pixel dimension in each direction and therefore the nominal spatial resolution of the image. These parameters, together w...
-
Chapter
Gradient Echo Versus Spin Echo
Spin Echo pulse sequences follow similar contrast behavior to that described in the previous section; however, there are some key differences between Gradient Echo and Spin Echo pulse sequences (Fig. 11.1). In...
