DBP3:Utah:Reg Motiv - Revision history

Ggardner at 04:41, 9 January 2012

2012-01-09T04:41:11Z

Ggardner at 04:37, 9 January 2012

2012-01-09T04:37:03Z

Ggardner at 04:22, 9 January 2012

2012-01-09T04:22:16Z

Ggardner at 01:03, 9 January 2012

2012-01-09T01:03:45Z

Ggardner at 00:36, 9 January 2012

2012-01-09T00:36:25Z

Ggardner at 23:25, 8 January 2012

2012-01-08T23:25:36Z

Ggardner at 00:10, 7 January 2012

2012-01-07T00:10:52Z

Ggardner at 23:51, 6 January 2012

2012-01-06T23:51:42Z

Ggardner at 23:34, 6 January 2012

2012-01-06T23:34:36Z

Ggardner at 22:53, 6 January 2012

2012-01-06T22:53:37Z

@@ Line 33: / Line 33: @@
 This image shows the registration of a pair of pre- and post-ablation MRI scans from the same patient.  There is a clear misregistration of the LA walls.  We are working to obtain better registration of both the LA wall and the pulmonary veins.
-= LA Wall Abnormalities =
+= Variable Anatomical Landmarks=
 * In addition to smaller, more common variations in LA shape, size, and wall thickness, there are some common disease states and procedurally-induced changes that affect registration of the LA.  For example, some patients may have an abnormally large LA.  Edema and non-enhanced regions in the LGE-MRI scans have also been observed that in some patients immediately after ablation therapy.
@@ Line 49: / Line 51: @@
 |}
-= Pulmonary Vein Anatomy =
+== Pulmonary Vein Anatomy ==
 * The pulmonary veins (PVs) are important in the initiation and sustainment of AF, often harboring the electrical triggers responsible for AF.  In an effort to remove or isolate these extraneous electrical signals, the PVs are often the target of ablation procedures; this often induces changes in the gross-anatomical structure of the PVs.  The changes in PVs shape and structure caused by ablation make registration of the PVs non-trivial.
@@ Line 87: / Line 89: @@
 |}
-= LA Appendage Variability =
+== LA Appendage Variability ==
 * The LA appendage is a muscular pouch connected to the upper, left portion of the LA.  While the appendage doesn't aid in contraction, it is a common site for blood clot formation.  The size, shape, and point of attachment of this region is also quite variable; this makes finding consistent registration landmarks in this region of the LA difficult.

@@ Line 26: / Line 26: @@
 * The hallmark of atrial fibrillation is structural remodeling of the LA tissues.  Changes to the LA myocardium are manifest as changes in the shape, composition, and thickness of the LA wall.  Such changes can affect the accuracy of registration landmarks.  In more extreme cases, the underlying anatomy can differ between patients, or even time points for the same patient, such that registration landmarks may appear or disappear from one case to the next.
 *Common landmarks for image registration of the LA are the LA wall itself, the pulmonary veins, and the LA appendage.
 = LA Wall Abnormalities =

@@ Line 23: / Line 23: @@
 |-
 |}
 = LA Wall Abnormalities =
+* In addition to smaller, more common variations in LA shape, size, and wall thickness, there are some common disease states and procedurally-induced changes that affect registration of the LA.  For example, some patients may have an abnormally large LA.  Edema and non-enhanced regions in the LGE-MRI scans have also been observed that in some patients immediately after ablation therapy.
 {| class="wikitable"
@@ Line 79: / Line 82: @@
 = LA Appendage Variability =
+* The LA appendage is a muscular pouch connected to the upper, left portion of the LA.  While the appendage doesn't aid in contraction, it is a common site for blood clot formation.  The size, shape, and point of attachment of this region is also quite variable; this makes finding consistent registration landmarks in this region of the LA difficult.
 {| class="wikitable"

@@ Line 35: / Line 35: @@
 | [[File:carma_no_reflow.png|thumb|center]]
 |-
-| M
+| Here the LA (blood pool delineated by the orange label mask) is quite a bit larger than normal; the left side (right side of the image) appears very dilated.
-| M
+| In this image the LA wall (region surrounding the blood pool -- orange label mask) has dark regions of non-enhancement.  Large bright regions surround the LA wall tissue (possibly edema from the ablation procedure).
 |-
 |}
@@ Line 83: / Line 83: @@
 {| class="wikitable"
 |-
-! Pre-ablation LGE-MRI Image
+! Typical LA Appendage
-! Post-ablation LGE-MRI Image
+! Small, Vertical LA Appendage
 |-
-| [[File:carma_ex_pre.png|thumb|center]]
+| [[File:carma_norm_LAA.png|thumb|center]]
-| [[File:carma_ex_post.png|thumb|center]]
+| [[File:carma_vert_LAA.png|thumb|center]]
 |-
-| M
+| A "typical" LA appendage that extends out and then wraps back on the body of the LA.  The appendage is denoted with "LAA".
-| M
+| A smaller and more vertical LA appendage than is typical.
 |-
 |}

@@ Line 21: / Line 21: @@
 | The MRA is acquired after contrast injection and before the LGE-MRI images above.  This image type highlights the blood pool of the LA and some surrounding structures.
 | Manual segmentation of the LA is performed on pre- and post-ablation LGE-MRI images by the CARMA team.  Here the blue mask denotes the LA wall and the orange the blood pool.
 |-
 |}
@@ Line 39: / Line 55: @@
 | [[File:carma_Norm_RPVs.png|thumb|center]]
 |-
-| Normally, there are 2 distinct LPVs: one inferior and one superior.  The superior vein tends to be larger than the inferior.
+| Normally, there are 2 distinct LPVs: one inferior and one superior.  The superior vein tends to be larger than the inferior. (The blue volume represents the LA wall; the orange, the blood pool.)
 | Normally, there are 2 distinct RPVs: one inferior and one superior.  These veins tend to be roughly the same size.
 |-
@@ Line 59: / Line 75: @@
 | This LA has 4 RPVs; the "middle" 2 RPVs are smaller than the other 2.  There are 2 normal LPVs.
 | Here, the number and placement of the veins is typical.  However, the size of the 2 RPVs is atypical: one is larger and the other smaller than normal.
 |-
 |}

@@ Line 1: / Line 1: @@
-= Left Atrial Registration =
+= Left Atrial Registration Image Types =
 * The CARMA Center uses contrast-enhanced MRI images to evaluate new patients, predict procedural success, and evaluate therapeutic outcomes.  The MRI images for each patient are further accompanied by MR angiographic images (MRA) and manual segmentations of relevant structures.  These images are acquired longitudinally over the course of a patient's evaluation, treatment, and follow-up (i.e. months or years).  Registration is often necessary to compare images from different time points in a patient's treatment, or even across patient cohorts at the same stage of disease progression or treatment.
@@ Line 46: / Line 46: @@
 |-
 | [[File:carma_Com_LPV.png|thumb|center]]
-| [[File:carma_3RPVs.png|thumb|center]]
+| [[File:carma_3RPV.png|thumb|center]]
 |-
 | This LA has 2 LPVs; however, they share a common, larger-than-normal trunk.  There are 2 normal RPVs.
@@ Line 54: / Line 54: @@
 ! Small and Large RPV
 |-
-| [[File:carma_4rpvs.png|thumb|center]]
+| [[File:carma_4RPV.png|thumb|center]]
 | [[File:carma_RPVs_small.png|thumb|center]]
 |-

← Older revision		Revision as of 22:53, 6 January 2012
Line 1:		Line 1:
	= Left Atrial Registration =		= Left Atrial Registration =
	* Targeting the LA wall and pulmonary veins		* Targeting the LA wall and pulmonary veins
		+
		+	{\| class="wikitable"
		+	\|-
		+	! Pre-ablation LGE-MRI Image
		+	! Post-ablation LGE-MRI Image
		+	\|-
		+	\| [[File:carma_ex_pre.png\|thumb\|center]]
		+	\| [[File:carma_ex_post.png\|thumb\|center]]
		+	\|-
		+	\| MRI image acquired approx. 15 minutes after contrast injection and prior to ablation. (The LA is the gray, horizontally oriented structure above the spine in the center of the image)
		+	\| MRI image acquired approx. 15 minutes after contrast injection and after the ablation was performed. Sections of the LA wall which were ablated appear as hyper-enhanced pixels in the LA wall.
		+	\|-
		+	! MRA Image
		+	! Segmentation of LGE-MRI Image
		+	\|-
		+	\| [[File:carma_ex_mra.png\|thumb\|center]]
		+	\| [[File:carma_ex_pre_seg.png\|thumb\|center]]
		+	\|-
		+	\| The MRA is acquired after contrast injection and before the LGE-MRI images above. This image type highlights the blood pool of the LA and some surrounding structures.
		+	\| manual segmentation of the LA is performed on pre- and post-ablation LGE-MRI images by the CARMA team. Here the blue mask denotes the LA wall and the orange the blood pool.
		+	\|-
		+	\|}