Medical Devices for Magnetic Resonance Imaging and Related Methods

Abstract

Medical devices useful in interventional procedures performed under magnetic resonance imaging (MRI) are described herein. A medical device comprises a body member and a marker formed of work-hardened stainless steel attached to the body member. The stainless steel of the marker has an ultimate tensile strength of between about 100 KSI and about 225 KSI. The marker can be attached to the body member in a manner that contributes work to the stainless steel or in a manner that does not contribute work to the stainless steel. Methods of making medical devices, medical imaging methods, and methods of performing interventional medical treatment are also described herein.

What is claimed is: 
     
         1 . A medical device useful in interventional procedures performed under magnetic resonance imaging, said medical device comprising:
 a body member; and   a marker attached to the body member, the marker comprising work-hardened stainless steel having an ultimate tensile strength of between about 100 KSI and about 225 KSI.   
     
     
         2 . The medical device of  claim 1 , wherein the marker comprises a tubular member having an outer surface and defining a marker lumen. 
     
     
         3 . The medical device of  claim 2 , wherein the marker lumen defines a substantially circular cross-sectional shape. 
     
     
         4 . The medical device of  claim 2 , wherein the marker is crimped on the body member. 
     
     
         5 . The medical device of  claim 2 , wherein the marker is swaged on the body member. 
     
     
         6 . The medical device of  claim 2 , wherein the ultimate tensile strength is between about 150 KSI and about 200 KSI. 
     
     
         7 . The medical device of  claim 2 , wherein the ultimate tensile strength is between about 170 KSI and about 200 KSI. 
     
     
         8 . The medical device of  claim 2 , wherein the ultimate tensile strength is between about 172 KSI and about 197 KSI. 
     
     
         9 . The medical device of  claim 2 , wherein the ultimate tensile strength is between about 187 KSI and about 191 KSI. 
     
     
         10 . The medical device of  claim 2 , wherein the ultimate tensile strength is about 189 KSI. 
     
     
         11 . The medical device of  claim 2 , wherein the marker has a mass of between about 0.05 mg and about 2.74 mg. 
     
     
         12 . The medical device of  claim 2 , wherein the marker has a mass of between about 0.1 mg and about 1.37 mg. 
     
     
         13 . The medical device of  claim 2 , wherein the ultimate tensile strength is between about 150 KSI and about 200 KSI; and
 wherein the marker has a mass of between about 0.1 mg and about 1.37 mg.   
     
     
         14 . The medical device of  claim 2 , wherein the ultimate tensile strength is between about 170 KSI and about 200 KSI; and
 wherein the marker has a mass of between about 0.1 mg and about 1.37 mg.   
     
     
         15 . The medical device of  claim 2 , wherein the ultimate tensile strength is between about 172 KSI and about 197 KSI; and
 wherein the marker has a mass of between about 0.1 mg and about 1.37 mg.   
     
     
         16 . The medical device of  claim 2 , wherein the ultimate tensile strength is between about 187 KSI and about 191 KSI; and
 wherein the marker has a mass of between about 0.1 mg and about 1.37 mg.   
     
     
         17 . The medical device of  claim 2 , wherein the ultimate tensile strength is about 189 KSI; and
 wherein the marker has a mass of between about 0.1 mg and about 1.37 mg.   
     
     
         18 . The medical device of  claim 1 , further comprising an elongate member;
 wherein the body member comprises an outer sheath member; and   wherein the elongate member is slidably disposed within the outer sheath member.   
     
     
         19 . A medical device useful in interventional procedures performed under magnetic resonance imaging, said medical device comprising:
 an outer sheath member;   an elongate member slidably disposed within the outer sheath member; and   a tubular marker attached to one of the outer sheath member and the elongate member, the marker having a mass of between about 0.1 mg and about 1.37 mg and comprising work-hardened stainless steel having an ultimate tensile strength of between about 100 KSI and about 225 KSI.   
     
     
         20 . A medical device useful in interventional procedures performed under magnetic resonance imaging, said medical device comprising:
 an outer sheath member;   an elongate member slidably disposed within the outer sheath member;   a first marker attached to the outer sheath member, the first marker comprising work-hardened stainless steel having an ultimate tensile strength of between about 100 KSI and about 225 KSI and defining a first marker lumen; and   a second marker attached to the elongate member, the second marker comprising work-hardened stainless steel having an ultimate tensile strength of between about 100 KSI and about 225 KSI.