A

ABLAVAR^®^1,2: The first and only blood pool contrast agent specifically designed and FDA-approved for contrast-enhanced magnetic resonance angiography. ABLAVAR^® is indicated for evaluation of aortoiliac occlusive disease in adults with known or suspected peripheral vascular disease.

Accuracy³: The extent to which a measurement is close to the true value.

B

Blood-pool agent⁴: A contrast agent characterized by prolonged vascular enhancement.

Blood-pool imaging: See steady-state imaging.

C

Chelate⁵: A compound having a ring structure that usually contains a metal ion held by coordinate bonds.

Contrast-enhanced magnetic resonance angiography (CE-MRA)⁶: CE-MRA is a form of magnetic resonance imaging (MRI) that uses magnetic field and pulse radio waves in combination with a gadolinium-based contrast agent to image vasculature. CE-MRA has several advantages over other forms of angiography. Unlike X-ray methods (conventional X-ray angiography or CT angiography), it involves no ionizing radiation. In addition, unlike conventional angiography, it does not involve insertion of a catheter.

D

Dynamic phase imaging¹: Imaging during the initial distribution of a blood-borne contrast agent. Dynamic phase imaging is also known as first-pass imaging

E

Equilibrium-phase imaging: See steady-state imaging.

F

First-pass imaging: See dynamic-phase imaging.

K

K-space⁷: An area in the array proccessor where data on spatial frequencies are stored.

M

Maximum intensity projection (MIP)⁸: MRA images can be processed by Maximum Intensity Projection to interactively create different projections. The MIP connects the high intensity dots of the blood vessels in three dimensions, providing an angiogram that can be viewed from any projection. Each point in the MIP represents the highest intensity experienced in that location on any partition within the imaging volume.

Multiplanar reconstruction or reformat (MPR)⁹: MPR is a post-processing data reformatting process which does not alter the MRA voxels in any way; instead it presents them in off-axis views and displays the images in a new orientation. On most systems MPR views of a 3D data set are primarily obtained in the standard orthogonal planes (i.e. axial, sagittal, and coronal views).

N

Nephrogenic systemic fibrosis (NSF); also nephrogenic fibrosing dermopathy^1,10: Nephrogenic systemic fibrosis (NSF) is a fibrosing disease, primarily identified in the skin and subcutaneous tissues but also known to involve other organs, such as the lungs, esophagus, heart, and skeletal muscles. Initial symptoms typically include skin thickening and/or pruritis. Symptoms and signs may develop and progress rapidly, with some affected patients developing contractures and joint immobility. Death may result in some patients, presumably as a result of visceral organ involvement. NSF may be related to the dose of gadolinium and the total cumulative dose of gadolinium, so the lowest possible dose of gadolinium should be used for MRA. NSF has not been reported in the over 90,000 patients studied with ABLAVAR^®¹¹

R

Relaxivity¹²:The ability of magnetic compounds to increase the relaxation rates of the surrounding water proton spins. Relaxivity improves the contrast of an image, and is used to study tissue-specific areas where the contrast agent better diffuses or to perform imaging. The relaxivity of MRI contrast agents depends on the molecular structure and kinetic of the complex.

Relaxation time¹³: After radio frequency (RF) excitation, the spins will tend to return to their equilibrium distribution in which there is no transverse magnetization and the longitudinal magnetization is at its maximum value and oriented in the direction of the static magnetic field. The transverse magnetization decays toward zero with a characteristic time constant T2, and the longitudinal magnetization returns toward equilibrium with a characteristic time constant T1.

S

Sensitivity¹⁴: Sensitivity of the test represents the proportion of truly diseased persons in a screened population who are identified by the test as having the disease. It is a measure of the probability of correctly diagnosing an abnormal condition.

Signal-to-noise ratio (SNR)¹⁵: Used in MRI to describe the relative contributions to a detected signal of the true signal and random superimposed signals (ie, background noise) - a criterion for image quality.

Spatial resolution¹⁶: The ability to distinguish 2 adjacent points of similar density as being separate.

Specificity¹⁷: Specificity of a test represents the proportion of truly nondiseased persons who are identified by the test as not having the disease. It is a measure of the probability of correctly diagnosing a normal condition.

Steady-state imaging¹⁸: Imaging data acquisition started after a contrast agent is evenly distributed in the arterial and venous vascular system. With an intravascular contrast agent such as ABLAVAR^®, which has an increased data acquisition window of up to 1 hour after administration, steady-state imaging can be used for acquisition of high-resolution MRA data sets, which allows for high spatial resolution, increased signal-to-noise ratios, and acquisition of isotropic voxels. Steady-state imaging provides enhanced flexibility in MRA data acquisition.

T

T1 relaxation time; spin lattice or longitudinal relaxation time¹⁹: T1 relaxation time is a biological parameter that is used in MRIs to distinguish between tissue types. This tissue-specific time constant for protons, is a measure of the time taken to realign with the external magnetic field. The T1 constant will indicate how quickly the spinning nuclei will emit their absorbed RF into the surrounding tissue.

Time of flight (TOF)Angiography²⁰: Time of flight angiography is an MRA technique used for imaging of vessels without contrast.

V

Voxel²¹: A three-dimensional pixel. A voxel represents a quantity of 3-D data just as a pixel represents a point or cluster of points in 2-D data. It is used in scientific and medical applications that process 3-D images.

References

1. ABLAVAR^® [package insert]. North Billerica, MA: Lantheus Medical Imaging, Inc.; 2011. 2. US Food and Drug Administration Web site. http://www.fda.gov/drugs. Accessed July 24, 2010. 3. Accuracy. The Free Dictionary Web site. http://medical-dictionary.thefreedictionary.com/accuracy. Accessed October 13, 2009. 4.Leiner T, Goyen M, Rohrer M, Schönberg S, eds. Clinical Blood Pool MR Imaging. Heidelberg, Germany: Springer Medizin Verlag; 2008. 5. Chelate. Medline Plus Medical Dictionary Web site. http://www.merriam-webster.com/medlineplus/chelate. Accessed October 13, 2010. 6. MR angiography (MRA). RadiologyInfo.org Web site. http://www.radiologyinfo.org/en/info.cfm?pg=angiomr. Accessed September 16, 2010. 7. Westbrook C, Roth CK, Talbot,MRI In Practice 3rd Ed. Blackwell Publishers; 1998:393-401.8. Magnetic Resonance – TIP Web site. www.mr-tip.com/serv1.php?type=db1&dbs=mip http://www.mr-tip.com/serv1.php?type=db1&dbs=mip. Accessed April 20, 2011. 9. Douek PC, Hernández-Hoyos M, Orkisz M. Image Processing in Contrast-Enhanced MR Angiography. In: Schneider G, Prince MR, Meaney JFM, Ho VB eds. Magnetic Resonance Angiography Techniques, Indications and Practical Applications. Milan: Springer: 2005.10. Manual on Contrast Media v7. American College of Radiology Web site. http://www.acr.org/secondarymainmenucategories/quality_safety/contrast_manual.aspx. Accessed July 29, 2010. 11. Data on file, Lantheus Medical Imaging, Inc.12. Magnetic Resonance – TIP Web site. www.mr-tip.com/serv1.php?type=db1&dbs=Relaxivity http://www.mr-tip.com/serv1.php?type=db1&dbs=Relaxivity . Accessed April 5, 2011 13. Magnetic Resonance – TIP Web site. www.mr-tip.com/serv1.php?type=db1&dbs=Relaxation%20Time http://www.mr-tip.com/serv1.php?type=db1&dbs=Relaxation%20Time . Accessed April 5, 2011. 14. Dorland's Illustrated Medical Dictionary. 30th ed. Philadelphia, PA: Elsevier; 2003. (p 1680). 15 Magnetic Resonance – TIP Web site. www.mr-tip.com/serv1.php?type=db1&dbs=Signal%20to%20Noise%20Ratio http://www.mr-tip.com/serv1.php?type=db1&dbs=Signal%20to%20Noise%20Ration .Accessed April 5, 2011. 16. Spatial resolution. The Free Dictionary Web site. http://medical-dictionary.thefreedictionary.com/spatial+resolution. Accessed October 28, 2010 17. Dorland's Illustrated Medical Dictionary. 30th ed. Philadelphia, PA: Elsevier; 2003. (p 1730). 18. Quick HH. Technical aspects of contrast enhanced MRA—first pass and steady state. In: Leiner T, Goyen M, Rohrer M, Schönberg S, eds. Clinical Blood Pool MR Imaging. Heidelberg, Germany: Springer Medizin Verlag; 2008:24. 19. Magnetic Resonance – TIP Web site. www.mr-tip.com/serv1.php?type=db1&dbs=T1%20Time http://www.mr-tip.com/serv1.php?type=db1&dbs=T1%20Time. Accessed April 20, 2011. 20. Magnetic Resonance – TIP Web site. www.mr-tip.com/serv1.php?type=db1&dbs=Time%20of%20Flight%20Angiography http://www.mr-tip.com/serv1.php?type=db1&dbs=Time%20of%20Flight%20Angiography. Accessed April 20, 2011. 21. Voxel. The Free Dictionary Web site. http://encyclopedia2.thefreedictionary.com/voxel. Accessed October 11, 2010.

INDICATIONS:

ABLAVAR^® is indicated for use as a contrast agent in magnetic resonance angiography (MRA) to evaluate aortoiliac occlusive disease (AIOD) in adults with known or suspected peripheral vascular disease.

CONTRAINDICATIONS:

History of a prior allergic reaction to a gadolinium-based contrast agent.

IMPORTANT SAFETY INFORMATION:

WARNING: NEPHROGENIC SYSTEMIC FIBROSIS (NSF)

Gadolinium-based contrast agents (GBCAs) increase the risk for NSF among patients with impaired elimination of the drugs. Avoid use of GBCAs in these patients unless the diagnostic information is essential and not available with non-contrasted MRI or other modalities. NSF may result in fatal or debilitating fibrosis affecting the skin, muscle and internal organs.

The risk for NSF appears highest among patients with:

chronic, severe kidney disease (GFR < 30 mL/min/1.73m²), or
acute kidney injury.

Screen patients for acute kidney injury and other conditions that may reduce renal function. For patients at risk for chronically reduced renal function (e.g. age > 60 years, hypertension or diabetes), estimate the glomerular filtration rate (GFR) through laboratory testing.
For patients at highest risk for NSF, do not exceed the recommended ABLAVAR dose and allow a sufficient period of time for elimination of the drug from the body prior to re-administration.

ABLAVAR^® Injection: As with other contrast media, the possibility of serious or life-threatening anaphylactic or anaphylactoid reactions, including cardiovascular, respiratory and/or cutaneous manifestations, should always be considered. As with other gadolinium based contrast agents, caution should be exercised in patients with renal insufficiency due to the possibility of further deterioration in renal function.

In clinical trials, a small increase (2.8 msec) in the average change from baseline in QTc was observed at 45 minutes following ABLAVAR^® administration. These QTc prolongations were not associated with arrhythmias or symptoms. Caution should be used in patients at high risk for arrhythmias due to baseline QTc prolongation.

Have emergency resuscitative equipment available prior to and during ABLAVAR^® administration.

Please see full Prescribing Information, including boxed WARNING regarding Nephrogenic Systemic Fibrosis (NSF).