Methods of cardiothoracic imaging - (MET-30)
Methods for imaging stationary targets, including thrombi, are disclosed. The methods allow the imaging of stationary targets in areas of the body subject to physiologic motion.
1 . A method for determining the presence or absence of a stationary target in a bodily location of an animal, said bodily location subject to physiologic motion, said method comprising:
a) administering a MRI contrast agent to said animal, said MRI contrast agent capable of binding to said stationary target;
b) allowing said MRI contrast agent to bind to said stationary target; and
c) acquiring one or more MR images of said bodily location, wherein said acquisition of said one or more MR images is capable of reducing motion artifacts in said one or more MR images.
2 . The method of claim 1 , wherein said physiologic motion is periodic motion.
3 . The method of claim 2 , wherein said periodic motion is due to respiratory motion or cardiac motion of said animal.
4 . The method of claim 1 , wherein said physiologic motion is due to musculoskeletal motion of said animal.
5 . The method of claim 3 , wherein said physiologic motion is due to both respiratory and cardiac motion of said animal.
6 . The method of claim 1 , wherein said reduction of motion artifacts is achieved by acquiring MR data at a predetermined time during said animal's cardiac cycle.
7 . The method of claim 1 , wherein said reduction of motion artifacts is achieved by acquiring MR data during a predetermined period of said animal's respiratory cycle.
8 . The method of claim 6 , wherein said MR data acquisition at a predetermined time during said animal's cardiac cycle occurs by coordinating said MR data acquisition with a physiologic electrical or pressure signal of said animal.
9 . The method of claim 8 , wherein said physiologic electrical or pressure signal is selected from the group consisting of an ECG signal, a heartbeat, and a pulse of said animal.
10 . The method of claim 8 , wherein said pressure signal of said animal is detected using an acoustic technique, an ultrasound technique, or a transducer.
11 . The method of claim 9 , wherein said physiologic signal is an ECG signal, and wherein said MR data acquisition occurs during mid- or late-diastole of said ECG signal.
12 . The method of claim 7 , wherein said acquisition of MR data during a predetermined period of said animal's respiratory cycle occurs by coordinating said MR data acquisition with a location of said animal's diaphragm, liver, or lung.
13 . The method of claim 12 , wherein said location of said diaphragm, liver, or lung is determined using a MR navigator, a tracking MR navigator, high speed MR projection images, or full MR images.
14 . The method of claim 7 , wherein said predetermined period of said respiratory cycle is determined by using a respiratory bellows.
15 . The method of claim 7 , wherein said predetermined period of said animal's respiratory cycle is the end of expiration.
16 . The method of claim 7 , wherein said predetermined period of said animal's respiratory cycle is a breath-hold of said animal.
17 . The method of claim 1 , wherein said one or more MR images are acquired using a contrast-enhancing imaging pulse sequence.
18 . The method of claim 17 , wherein said contrast-enhancing imaging pulse sequence is capable of suppressing the MR signal of in-flowing blood and is further capable of enhancing the MR signal of said stationary target.
19 . The method of claim 17 , wherein said contrast-enhancing imaging pulse sequence comprises a turbo field echo sequence, a spoiled gradient echo sequence, or a high speed 3D acquisition sequence.
20 . The method of claim 17 , wherein said contrast-enhancing imaging pulse sequence comprises a black blood MR angiography sequence.
21 . The method according to claim 20 , wherein said black blood MR angiography sequence comprises a fast spin echo sequence, a flow-spoiled gradient echo sequence, an inversion recovery sequence, a double inversion recovery sequence, a fast gradient echo sequence, or an out-of-volume in-flow suppression sequence.
22 . The method of claim 1 , wherein said stationary target comprises a protein.
23 . The method of claim 22 , wherein said protein is selected from the group consisting of fibrin, collagen, elastin, decorin, and a Toll-like receptor.
24 . The method of claim 1 , wherein said stationary target is selected from the group consisting of oxidized LDL, matrix metalloproteinases, LTB4, and hyaluronan.
25 . The method according to claim 1 , wherein said stationary target is selected from the group consisting of a thromboembolism, an aneurism, an embolism, a thrombus, a tumor, a region of fibrosis, a region of infarcted tissue, a region of ischemic tissue, an atherosclerotic plaque, and a vulnerable plaque.
26 . The method of claim 1 , wherein said stationary target is a region of heart, liver, kidney, or lung tissue.
27 . The method of claim 26 , wherein said heart, liver, kidney, or lung tissue is ischemic or infarcted.
28 . The method of claim 17 , wherein said contrast-enhancing imaging pulse sequence comprises an in-flow-independent technique, said in-flow-independent technique capable of enhancing the contrast ratio of a magnetic resonance signal of said stationary target having said MRI contrast agent bound thereto relative to a magnetic resonance signal of background blood or tissue.
29 . The method of claim 28 , wherein said background blood is in-flowing blood.
30 . The method of claim 28 , wherein said background tissue is fat, muscle, or tissue.
31 . The method of claim 28 , wherein said in-flow-independent technique comprises an inversion-recovery prepared sequence, a saturation-recovery prepared sequence, a T 2 preparation sequence, or a magnetization transfer preparation sequence.
32 . The method of claim 1 , wherein said bodily location is the heart, lung, kidneys, great blood vessels, or the liver of said animal.
33 . The method of claim 32 , wherein said bodily location is the myocardium, an atrium, a ventricle, a coronary artery, or a valve of the heart.
34 . The method of claim 1 , wherein said bodily location is a skeletal joint.
35 . The method of claim 1 , wherein said contrast agent is selected from the group consisting of:
36 . The method of claim 1 , wherein said animal is a human.
37 . A method for determining the presence or absence of a stationary target in a bodily location of an animal, said bodily location subject to physiologic motion, said method comprising:
a) administering a MRI contrast agent to said animal, said MRI contrast agent capable of binding to said stationary target;
b) allowing said MRI contrast agent to bind to said stationary target;
c) acquiring one or more MR images of said bodily location, said acquisition of said one or more MR images capable of reducing motion artifacts in said one or more MR images; and
d) examining said one or more MR images, wherein said stationary target is determined to be present when a contrast-enhanced region is observed.
38 . The method of claim 37 , wherein said presence of said stationary target is correlated with a pathology of said animal.
39 . The method of claim 38 , wherein said pathology is selected from the group consisting of a coronary syndrome, a coronary stent thrombosis, fibrosis of the lung, ischemic myocardial tissue, infarcted myocardial tissue, a pulmonary embolism, and a deep venous thrombosis.