Distribution and deposition of tritiated cortisol using phonophoresis.

Tritiated cortisol cream was coupled with light-microscopic autoradiography to histologically trace the distribution and deposition of a topical application of cortisol driven in by a therapeutic dose of ultrasound. Fifteen dogs were divided into four distinct groups: Group 1 consisted of two control dogs; Group 2, four dogs that received 10% radioactive cortisol and no ultrasound; Group 3, four dogs that received 5% radioactive cortisol plus ultrasound; and Group 4, five dogs that received 10% radioactive cortisol plus ultrasound. Although the cortisol applied to all dogs was limited to the epidermis, penetration occurred beyond the stratum corneum. The combination of 10% cortisol and ultrasound showed more penetration than 10% cortisol alone (p = .018), suggesting that ultrasound may be useful in the transdermal delivery of cortisol cream. The difference between the penetration of 5% and 10% cortisol when treated with ultrasound was only marginally significant (p = .062).

MR imaging of the normal shoulder: variants and pitfalls.

In 30 volunteers with normal shoulders, the following conclusions were made with regard to normal anatomic features at magnetic resonance (MR) imaging: (a) The supraspinatus tendon has low signal intensity, except for a 1-cm area with intermediate signal intensity in the region of the "critical zone." (b) The deltoid tendon attachment on the inferior surface of the acromion may simulate a subacromial spur if not imaged in continuity. (c) Fluid in the long head of the biceps tendon sheath is normal if not completely surrounding the tendon. (d) The anterolateral branch of the anterior humeral circumflex vessels in the proximal bicipital groove adjacent to the biceps tendon mimics fluid in the tendon sheath. (e) Continuity or obliteration of the subacromial-subdeltoid bursal fat plane is an unreliable diagnostic sign since the fat plane is often focally absent. (f) Fluid is not detected in subacromial-subdeltoid bursae. (g) Undercutting of the anterior glenoid labrum by hyaline cartilage or a closely apposed middle glenohumeral ligament may simulate an anterior labral tear.