Apparatus and method for use in medical imaging

• US 5,349,956 A
• Filed: 12/04/1991
• Issued: 09/27/1994
• Est. Priority Date: 12/04/1991
• Status: Expired due to Term

• Current Assignee: Bonutti Skeletal Innovations LLC (Acacia Research Corporation)
• Original Assignee: Apogee Medical Products, Inc.
• Inventors: Bonutti, Peter M.
• Primary Examiner(s): Smith, Ruth S.
• Application Number:
  US07/802,358
• Time in Patent Office: 1,028 Days
• Field of Search: 128/653.1, 128/653.2, 128/653.5, 128/882, 5/601, 5/621-624, 378/208
• US Class Current: 600/425
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 6/0421 with immobilising means
• CPC Class Codes: A61B 6/0485 Inflatable rests for lifting of patients
• CPC Class Codes: A61G 13/12 Rests specially adapted therefor; Arrangements of patient-supporting surfaces rests for the surgeon A61B90/60; restraining devices A61F5/37
• CPC Class Codes: A61G 13/121 Head or neck
• CPC Class Codes: A61G 13/1225 Back
• CPC Class Codes: A61G 13/1235 Arms
• CPC Class Codes: A61G 13/124 Hands or wrists
• CPC Class Codes: A61G 13/1245 Knees, upper or lower legs
• CPC Class Codes: A61G 13/125 Ankles or feet
• CPC Class Codes: A61G 13/1255 Shoulders
• CPC Class Codes: A61G 2200/54 Shoulder

Abstract

An apparatus and method for use in medical imaging simulate within an imaging coil normal movements of body parts such as joints, and improve imaging of soft tissue and bony parts as compared to a static system in which images are taken of a joint in only one position. A joint or body parts is moved into various positions in multiple planes within its range of motion while a series of images are taken of the joint in the different positions. The images are collated into a cine format to effectively show the joint in motion. A surface or volume coil may be coupled for movement with the joint or body part and maintained in the proper spatial relationship with the primary coil'"'"'s electromagnetic field. The systems may be provided as mechanisms usable with existing imaging tables to reduce cost, or may be built into a new imaging table. It is possible to use a larger primary coil, allowing increased range of movement. Traction may be applied to a joint being imaged, in order to load the joint.

Claims

1. An apparatus for imaging a joint of a patient, said apparatus comprising an imaging unit, cuff means for holding a portion of the patient'"'"'s body adjacent to the joint, a rotatable support member at least partially disposed in said imaging unit, connector means for connecting said cuff means with said support member, said cuff means being movable along an arcuate path in said imaging unit upon rotation of said support member, and means for applying force to said cuff means to distract the joint while the joint is in the imaging unit.

2. An apparatus as set forth in claim 1 wherein said connector means includes means for rotating said support member under the influence of force transmitted through said connector means to said support member from the portion of the patient'"'"'s body held by said cuff means.

3. An apparatus as set forth in claim 2 further including means for retaining said support member against movement in a direction transverse to the axis about which said support member is rotatable to maintain the axis about which said support member is rotatable in the same orientation relative to the imaging unit during rotation of said support member.

4. An apparatus as set forth in claim 1 wherein said means for applying force to said cuff means to distract the joint includes said support member.

5. An apparatus imaging a shoulder joint of a patient, said apparatus comprising:

a magnetic resonance imaging unit having a primary coil;

a table slidable into and out of the primary coil, said table having a head end portion which is adjacent to the patient'"'"'s head when the patient is on the table and a foot end portion which is adjacent to the patient'"'"'s foot when the patient is on the table;

an index mechanism having an index member lockable in any selected one of a plurality of sequential index locations;

table attachment means connected with said index mechanism for attaching said index mechanism to the foot end portion of said table at a location adjacent the patient'"'"'s foot when the patient is on the table;

a cuff support member connected with said index member for movement with said index member; and

a cuff supported on said cuff support member for movement with said cuff support member and for clamping onto the patient'"'"'s arm at a location between the foot end portion and head end portion of the table and remote from said index member;

said index member being movable between successive index locations in response to movement of the patient'"'"'s arm, said cuff support member transmitting the force of movement of the patient'"'"'s arm from said cuff to said index member to move said index member between index locations;

said cuff support member being an elongate member extending between said index member at the foot end portion of the table and said cuff clamped to the patient'"'"'s arm at a location between the foot end portion and head end portion of the table.

6. Apparatus for controlling movement of a joint of patient at a plurality of imaging positions during imaging of the joint at successive imaging positions, said apparatus comprising a magnetic resonance imaging unit, a cuff adapted to clamp onto an extremity of the patient'"'"'s body which is adjacent the joint being imaged in the magnetic resonance imaging unit, and indexer means for moving said cuff between a series of discrete repeatable index locations, corresponding to the imaging positions, said indexer includes (1) means for supporting said cuff for movement between the plurality of imaging positions in response to forces applied to said cuff by the patient being imaged and (2) means for limiting movement of said cuff and thereby of the joint to rotational movement in only one degree of freedom during movement of the joint between the plurality of imaging positions.

7. An apparatus as set forth in claim 6 further including strap means for clamping said cuff to the extremity of the patient'"'"'s body which is adjacent the joint being imaged.

8. Apparatus for controlling movement of a joint of a patient during imaging of the joint, said apparatus comprising:

an imaging unit having a primary coil;

cuff means positioned within the primary coil for connection with an extremity portion of the patient'"'"'s body which is adjacent the joint being imaged; and

indexer means, connected with said cull means and having a plurality of discrete repeatable index locations and responsive to forces applied to said cuff means by the patient being imaged, for supporting said cuff means and thereby the joint for movement in only one degree of freedom during movement of the joint between successive index locations under the influence of said forces applied by the patient.

9. Apparatus as set forth in claim 8 wherein said indexer means includes:

a base fixable in position relative to the primary coil; and

means connected with said base and with said cuff means for supporting said cuff means for movement relative to said base in only one degree of freedom between a plurality of discrete repeatable index locations and in response to forces applied to said cuff means by the patient being imaged.

10. Apparatus as set forth in claim 9 wherein said cuff means includes surfaces for receiving forces from the portion of the patient'"'"'s body which is adjacent the joint being imaged;

and wherein said means for supporting said cuff means for movement relative to said base in only one degree of freedom includes an index block supported for rotation relative to said base about a single axis and constrained for movement in one plane only, and means connected intermediate said index block and said cuff means and fixing said index block for rotation with said cuff means for transmitting forces received by said cuff means from the portion of the patient'"'"'s body to said index block to rotate said index block about the single axis and in the one plane only.

11. Apparatus as set forth in claim 10 wherein said cuff means includes surfaces for receiving forces generated during normal bodily movement of the joint being imaged;

and wherein said means for transmitting forces includes means for transmitting forces generated during normal bodily movement of the joint being imaged and received by said cuff means to said index block to rotate said index block with said cuff means and thereby with the portion of the patient'"'"'s body.

12. Apparatus as set forth in claim 11 comprising index locking means movable between a first condition blocking rotational movement of said index block relative to said base at the plurality of index locations and a second condition enabling rotational movement of said index block relative to said base.

13. Apparatus for controlling movement of a joint of a patient during imaging of the joint, said apparatus comprising:

an imaging unit;

a support block fixed in position relative to the imaging unit;

an index block supported for rotation about an axis in a single plane relative to and parallel to said support block;

rotation control means connected in force-transmitting relationship between said support block and said index block for contacting a portion of said index block spaced radially outward of said axis to block rotation of said index block in the plane parallel to said support block at any selected one of a plurality of discrete repeatable index locations;

a cuff for connection with an extremity portion of the patient'"'"'s body which is adjacent the joint being imaged; and

a rigid cuff support interconnecting said index block and said cuff and fixing said cuff for rotation with said index block between the plurality of index locations.

14. Apparatus as set forth in claim 13 wherein said rotation control means is movable between a first condition blocking rotational movement of said index block out of the selected index locations and a second position allowing rotational movement of said index block relative to said support block.

15. Apparatus as set forth in claim 14 further including handle connected in force-transmitting relationship with said index block, said handle being manually engageable and movable by an operator other than the patient being imaged to effect rotation of said index block between successive positions of rotation and of said cuff between successive index locations.

16. Apparatus as set forth in claim 14 further including surfaces defining a plurality of index openings disposed in a circular pattern on said support block and a locator member movable toward and away from said support block openings.

17. An apparatus for imaging a shoulder joint of a patient, said apparatus comprising:

a magnetic resonance imaging unit having a primary imaging coil;

an imaging table having a foot end and a head end and being slidable into and out of the primary imaging coil of said magnetic resonance imaging unit;

an indexer base for attachment to the foot end of the table;

an indexer body supported on said indexer base;

an index block rotatable on said indexer body about an axis extending generally parallel to the length of the imaging table;

an elongate cuff support member extending from said indexer block in a direction axially along the table from the foot end for a substantial distance toward the head end of the table through an opening in said indexer body;

a cuff for clamping onto the patient'"'"'s arm when the patient is lying on the table with the patient'"'"'s feet at the foot end of the table and the patient'"'"'s head at the head end of the table, said cuff being supported on said cuff support member at an end of said cuff support member remote from said index block for rotational movement with said support member and with said index block about said axis; and

index locking means extensible between said indexer base and said index block and movable between a first condition blocking rotation of said index block relative to said indexer base and a second condition enabling rotation of said index block relative to said indexer base.

18. An imaging apparatus comprising:

a magnetic resonance imaging unit having a primary coil for taking a series of magnetic resonance images of a joint of a patient which joint can assume a series of successive imaging positions within its range of motion within said primary coil; and

an indexer positioned within said primary coil of said magnetic resonance imaging unit for controlling movement of the joint during imaging of the joint at successive imaging positions within said primary coil of said magnetic resonance imaging unit, said indexer including;

cuff means for connection within said primary coil with a portion of the patient'"'"'s body which is adjacent the joint being imaged; and

means responsive to forces applied to said cuff means by the patient being imaged for supporting said cuff means and thereby the joint for movement between successive imaging positions within said primary coil in only one degree of freedom during movement of the joint between successive imaging positions;

wherein said means responsive includes (1) a base fixable in position relative to the primary coil, (2) means connected with said base and with said cuff means for supporting said cuff means for movement relative to said base in only one degree of freedom in response to forces applied to said cuff means by the patient being imaged, and (3) surfaces on said cuff means for receiving forces from the portion of the patient'"'"'s body which is adjacent the joint being imaged; and

wherein said means for supporting said cuff means for movement relative to said base in only one degree of freedom includes a block supported for rotation relative to said base about a single axis and constrained for movement in one plane only, and a member connected intermediate said block and said cuff means and fixing said block for rotation with said cuff means, said member transmitting forces received by said cuff means from the portion of the patient'"'"'s body to said block to rotate said block about the single axis and in the one plane only.

19. Apparatus as set forth in claim 18 wherein said means responsive includes surfaces on said cuff means for receiving forces generated during normal bodily movement of the joint being imaged;

and wherein said member includes means for transmitting forces generated during normal bodily movement of the joint being imaged and received by said cuff means to said block to rotate said block with said cuff means and thereby with the portion of the patient'"'"'s body.

20. Apparatus as set forth in claim 19 comprising index means movable between a first condition blocking rotational movement of said block relative to said base at a plurality of repeatable incremental rotational positions of said block and said base and a second condition enabling rotational movement of said block relative to said base, and actuator means connected with said index means and manually operable to place said index means in the second condition to enable rotational movement of said block relative to said base and thereby enable movement of said cuff means relative to the primary coil.

21. An imaging apparatus comprising an imaging unit, cuff means for holding a portion of a patient'"'"'s body adjacent to a joint with both said cuff means and the joint in the imaging unit, and support means for supporting said cuff means with both said cuff means and the joint in the imaging unit, said support means including a rotatable member which is rotatable about an axis extending through said rotatable member, connector means for connecting said cuff means with said rotatable member and for rotating said rotatable member under the influence of force transmitted from said cuff means through said connector means to said rotatable member from the portion of the patient'"'"'s body held by said cuff means in the imaging unit, and means for retaining said rotatable member against movement in a direction transverse to the axis about which said rotatable member is rotated to maintain the axis about which said rotatable member is rotated in the same orientation relative to the imaging unit during rotation of said rotatable member with said cuff means in the imaging unit.

22. An apparatus as set forth in claim 21 wherein said cuff means includes surface means for engaging a portion of a patient'"'"'s arm adjacent to a shoulder joint with said cuff means and the shoulder joint in the imaging unit.

23. An apparatus as set forth in claim 21 wherein said cuff means includes surface means for engaging a patient'"'"'s hand adjacent to a wrist joint with said cuff means and the wrist joint in the imaging unit, said apparatus further including second cuff means for engaging an arm of the patient adjacent to the wrist joint with an axis about which said rotatable member is rotatable extending through the wrist joint.

24. An apparatus as set forth in claim 21 wherein said cuff means includes surface means for engaging a patient'"'"'s head with said cuff means and a neck portion of the patient in the imaging unit.

25. An apparatus as set forth in claim 21 wherein about which said rotatable member is rotatable about an axis which extends through the joint.

26. An apparatus as set forth in claim 21 further including index means for retaining said rotatable member against rotation to retain said cuff means and the joint in the imaging unit against movement relative to the imaging unit.

27. An apparatus as set forth in claim 21 further including means for applying force to said cuff means to distract the joint while the joint is in the imaging unit.

28. An apparatus as set forth in claim 21 further including index means for defining a plurality of positions of said rotatable member about its axis of rotation, and retainer means for releasably retaining said rotatable member in any one of the plurality of positions, said retainer means being releasable under the influence of force transmitted from said cuff means through said connector means to said rotatable member from the portion of the patient'"'"'s body held by said cuff means.

29. An apparatus as set forth in claim 28 wherein said means for defining a plurality of positions of said rotatable member includes means for defining an arcuate array of recesses, said retainer means including a spring loaded retainer element which is urged into engagement with anyone of said recesses, said spring loaded retainer element being disengagable from an engaged one of said recesses under the influence of force transmitted from said cuff means through said connector means to said rotatable member from the portion of the patient'"'"'s body held by said cuff means.

30. An apparatus for imaging a joint of a patient, said apparatus comprising an imaging unit, a base at least partially disposed in said imaging unit, a support rotatable relative to said base, first cuff means connected with said support for gripping a first portion of the patient adjacent to the joint, second cuff means connected with the base for gripping a second portion of the patient adjacent to the joint with the joint disposed between said first and second cuff means, said support being rotatable about an axis extending through space disposed between said first and second cuff means to move said first cuff means along an arcuate path with the joint disposed in the imaging unit, and means interconnecting said support and said base for retaining said first cuff means against movement from the arcuate path.

31. An apparatus as set forth in claim 30 further including a first imaging coil disposed adjacent to said first cuff means and a second imaging coil disposed adjacent to said second cuff means, said support being rotatable about an axis which extends through space between said first and second imaging coils.

32. An apparatus as set forth in claim 30 wherein said first cuff means is connected with said support by connector means for transmitting force applied to said first cuff means by the first portion of the patient'"'"'s body to said support, said support being rotatable about the axis extending through the space between said first and second cuff means under the influence of force transmitted from said first cuff means to said support by said connector means.

33. An apparatus as set forth in claim 32 wherein said connector means retains said first cuff means against movement relative to said support during rotation of said support about the axis extending through the space between said first and second cuff means.

34. Apparatus for magnetic resonance imaging a joint of a patient, comprising:

a magnetic resonance imaging unit having a primary coil for taking magnetic resonance images of the patient'"'"'s joint when the joint is disposed within said primary coil of said magnetic resonance imaging unit;

means connected with said magnetic resonance imaging unit for positioning the joint of the patient to be imaged within said magnetic resonance imaging unit;

means positioned within said primary coil for moving the joint of the patient between a series of successive imaging positions inside said primary coil within the range of motion of the joint under the influence of forces applied to the joint by the patient being imaged;

said magnetic resonance imaging unit having means for taking a series of magnetic resonance images one at each successive imaging position of the patient'"'"'s joint within said primary coil; and

said means for moving including means for limiting movement of the joint during imaging to movement in a single selected degree of freedom.

35. Apparatus as set forth in claim 34 wherein said means for moving the joint of the patient includes means for moving the joint of the patient under the influence of forces applied through normal bodily movement of the joint by the patient.

36. Apparatus as set forth in claim 35 wherein said means for limiting movement of the joint during imaging to movement in a single selected degree of freedom includes:

a device having a first part and having a second part which is movable relative to said first part in only one degree of freedom, said device being positioned adjacent to or within said magnetic resonance imaging unit;

means for blocking movement of said first device part relative to said magnetic resonance imaging unit primary coil;

means for connecting said second device part for movement with a portion of the patient'"'"'s body which is adjacent the joint being imaged; and

means for moving said second device part relative to said first device part in its one degree of freedom under the influence of forces applied to said second device part through the portion of the patient'"'"'s body with which said second device part is connected.

37. Apparatus as set forth in claim 36 wherein

said device includes a block supported for rotation on said first device part and a cuff member fixed for rotation with said block;

said means for connecting said second device part for movement with a portion of the patient'"'"'s body includes means for clamping said cuff member to the portion of the patient'"'"'s body for movement with the portion of the patient'"'"'s body;

said means for moving said second device part relative to said first device part includes

means for rotating said cuff member by applying forces to said cuff member through the portion of the patient'"'"'s body with which said second device part is connected by normal bodily movement of the joint being imaged, and

means for transmitting force from said rotating cuff member to said block to rotate said block relative to said first device part; and

said means for limiting movement of the joint during imaging to movement in a single selected degree of freedom includes means for limiting movement of said block to rotation in a single plane relative to said first device part.

38. Apparatus as set forth in claim 37 wherein said means for moving the joint of the patient and for taking a series of magnetic resonance images include:

means for moving the joint into a first repeatable incremental imaging position,

means for blocking movement of the joint out of the first repeatable incremental imaging position by blocking movement of said second device part relative to said first device part,

means for taking a first image while said joint is blocked from movement out of the first repeatable incremental imaging position,

means for releasing said second device part for movement relative to said first device part,

means for moving the joint out of the first repeatable incremental imaging position into a second repeatable incremental imaging position by normal bodily movement of the joint by the patient,

means for blocking movement of the joint out of the second repeatable incremental imaging position by blocking movement of said second device part relative to said first device part, and

means for taking a second image while the joint is blocked from movement out of the second repeatable incremental imaging position.

39. Apparatus as set forth in claim 36 wherein said first and second device parts are selectively movable and positionable in a vertical direction transverse to the longitudinal extent of the primary coil and relative to the primary coil, said first device part being movable vertically along rods fixed relative to the primary coil.

40. Apparatus as set forth in claim 36 wherein said first and second device parts are selectively movable and positionable in a horizontal direction transverse to the longitudinal extent of the primary coil and relative to the primary coil, said first device part having a guide member engaging in a slot.

41. Apparatus as set forth in claim 36 comprising traction applying means for applying traction to the joint being imaged, said traction applying means comprising a rod movable longitudinally between a first position applying a first amount of traction to the joint being imaged and a second position applying a second amount of traction to the joint being imaged.

42. An imaging apparatus comprising:

a magnetic resonance imaging unit having a primary coil for taking a series of magnetic resonance images of a joint of a patient; and

an indexer positioned within said primary coil of said magnetic resonance imaging unit for controlling movement of a joint of a patient during imaging of the joint at successive imaging positions within said primary coil of said magnetic resonance imaging unit;

said indexer including cuff for connection with a portion of the patient'"'"'s body which is adjacent the joint being imaged;

said indexer being movable within said primary coil between a first condition in which the joint is in a first repeatable incremental imaging position relative to and within said primary coil and a second condition in which the joint is in a second repeatable incremental imaging position relative to and within said primary coil and different from said first imaging position;

said indexer and said cuff being made of non-ferromagnetic material to prevent interference with the magnetic resonance imaging.

43. Apparatus as set forth in claim 42 wherein said indexer includes:

means for supporting said cuff for movement between successive repeatable incremental imaging positions in response to forces applied to said cuff by the patient being imaged, and

means for limiting movement of said cuff and thereby of the joint to movement in only one degree of freedom during movement of the joint between successive repeatable incremental imaging positions.

44. An apparatus as set forth in claim 43 wherein said cuff is form fitting to a patient'"'"'s lower arm.

45. An apparatus as set forth in claim 44 further including strap means for clamping said cuff to the patient'"'"'s lower arm.

46. An apparatus as set forth in claim 45 wherein said indexer fits entirely within said primary coil of said magnetic resonance imaging unit when the patient is being imaged with said magnetic resonance imaging unit.

47. A method of imaging a joint of a patient with an imaging unit, said method comprising the steps of gripping a portion of a patient'"'"'s body adjacent to the joint with a cuff, positioning the joint and the cuff in the imaging unit, rotating the cuff and a support connected with the cuff about an axis extending through the support while the cuff and the joint are in the imaging unit and while performing said step of gripping a portion of the patient'"'"'s body adjacent to the joint with the cuff, said step of rotating the cuff and the support about an axis extending through the support includes moving the cuff along an arcuate path in the imaging unit under the influence of force applied against the cuff by the portion of the patient'"'"'s body gripped by the cuff, transmitting force applied against the cuff by the gripped portion of patient'"'"'s body to the support to rotate the support about the axis extending through the support, and simultaneously therewith utilizing the support to retain the cuff against movement away from the arcuate path, and imaging the joint when the cuff is at each of a plurality of positions in turn along the arcuate path.

48. A method as set forth in claim 47 further including the steps of interrupting movement of the cuff at each of a plurality of predetermined positions along the arcuate path and maintaining the cuff stationary at each of the plurality of positions in turn, said step of imaging the joint being performed while the cuff is stationary at the predetermined positions along the arcuate path.

49. A method as set forth in claim 47 further including the step of applying traction to the joint during performance of said step of imaging the joint.

50. A method as set forth in claim 47 further including the step of distracting the joint during performance of said step of imaging the joint.

51. A method as set forth in claim 47 wherein said step of gripping a portion of the patient'"'"'s body adjacent to the joint with a cuff includes gripping a portion of a patient'"'"'s arm adjacent to a shoulder joint of the patient, said step of imaging the joint includes imaging the shoulder joint.

52. A method as set forth in claim 47 wherein said step of gripping a portion of the patient'"'"'s body adjacent to the joint with a cuff includes gripping a portion of the patient'"'"'s leg with the cuff.

53. A method as set forth in claim 52 wherein said step of imaging the joint includes imaging a hip joint of the patient.

54. A method as set forth in claim 47 wherein said step of gripping a portion of the patient'"'"'s body with a cuff includes gripping a portion of a hand of the patient'"'"'s adjacent to a wrist joint of the patient, said step of imaging the joint includes imaging the wrist joint, said method further including gripping a portion of the arm of the patient with a second cuff.

55. A method as set forth in claim 47 wherein said step of gripping a portion of a patient'"'"'s body adjacent to the joint with a cuff includes gripping a patient'"'"'s head with the cuff, said step of imaging the joint includes imaging a neck portion of the patient.

56. A method as set forth in claim 47 further including the steps of gripping a second portion of the patient'"'"'s body adjacent to the joint with a second cuff and holding the second cuff against movement while rotating the support about an axis extending through the support.

57. A method of imaging a joint of a patient with an imaging unit, said method comprising the steps of gripping a first portion of a patient'"'"'s body adjacent to the joint with a first cuff, gripping a second portion of a patient'"'"'s body adjacent to the joint with a second cuff and with the joint located between the first and second cuffs, rotating the first cuff relative to the second cuff about an axis located between the first and second cuffs with the joint in the imaging unit and while performing said steps of gripping a first portion of the patient'"'"'s body with the first cuff and gripping a second portion of the patient'"'"'s body with the second cuff, said step of rotating the first cuff relative to the second cuff including moving the first cuff along an arcuate path having a predetermined orientation relative to the imaging unit, and retaining the first cuff against movement away from the arcuate path under the influence of force applied against the first cuff by the first portion of the patient'"'"'s body during movement of the first cuff along the arcuate path, and imaging the joint when the first cuff is at each of a plurality of positions in turn along the arcuate path.

58. A method as set forth in claim 57 wherein said step of rotating the first cuff relative to the second cuff includes moving the first cuff along the arcuate path under the influence of force applied against the first cuff by the first portion of the patient'"'"'s body.

59. A method as set forth in claim 57 further including the step of maintaining the second cuff stationary while moving the first cuff along the arcuate path.

60. A method as set forth in claim 57 wherein said step of gripping a first portion of a patient'"'"'s body with a first cuff and gripping a second portion of a patient'"'"'s body with a second cuff are at least partially performed with the axis about which the first cuff is rotated extending through the joint.

61. A method as set forth in claim 57 further including the step of interrupting movement of the first cuff along the arcuate path at each of a plurality of predetermined positions along the arcuate path and maintaining the first cuff stationary at each of the plurality of predetermined positions in turn, said step of imaging the joint being performed while the first cuff is stationary at the predetermined positions along the arcuate path.

62. A method as set forth in claim 57 wherein said step of gripping a first portion of a patient'"'"'s body adjacent to the joint with a first cuff includes gripping a hand of the patient with a first cuff, said step of gripping a second portion of a patient'"'"'s body adjacent to the joint with a second cuff includes gripping an arm of the patient with the second cuff.

63. A method as set forth in claim 57 wherein said step of moving the first cuff along an arcuate path includes moving the first cuff to each of a plurality of predetermined positions along the arcuate path, said method further including operating a detent to an engaged condition maintain the first cuff in each of the predetermined positions in turn, and operating the detent to a released condition under the influence of force applied to the first cuff by the first portion of the patient'"'"'s body to release the first cuff for movement along the arcuate path from one predetermined position to a next succeeding predetermined position, said step of imaging the joint including imaging the joint while the first cuff is in the one predetermined position and the detent is in the engaged condition.