Imaging of calcific tendinopathy around the shoulder: usual and unusual presentations and common pitfalls

Abstract

Rotator cuff calcific tendinopathy (RCCT) is a very common condition, characterized by calcium deposition over fibrocartilaginous metaplasia of tenocytes, mainly occurring in the supraspinatus tendon. RCCT has a typical imaging presentation: in most cases, calcific deposits appear as a dense opacity around the humeral head on conventional radiography, as hyperechoic foci with or without acoustic shadow at ultrasound and as a signal void at magnetic resonance imaging. However, radiologists have to keep in mind the possible unusual presentations of RCCT and the key imaging features to correctly differentiate RCCT from other RC conditions, such as calcific enthesopathy or RC tears. Other presentations of RCCT to be considered are intrabursal, intraosseous, and intramuscular migration of calcific deposits that may mimic infectious processes or malignancies. While intrabursal and intraosseous migration are quite common, intramuscular migration is an unusual evolution of RCCT. It is important also to know atypical regions affected by calcific tendinopathy as biceps brachii, pectoralis major, and deltoid tendons. Unusual presentations of RCCT may lead to diagnostic challenge and mistakes. The aim of this review is to illustrate the usual and unusual imaging findings of RCCT that radiologists should know to reach the correct diagnosis and to exclude other entities with the purpose of preventing further unnecessary imaging examinations or interventional procedures.

Keywords: Calcific tendinopathy; Conventional radiography; Magnetic resonance; Pitfall; Rotator cuff; Ultrasound.

Fig. 1

Right shoulder antero-posterior plain radiography of a 35-year-old female patient with painful RCCT showing an opacity without trabeculation over the humeral head (arrows)

Fig. 2

Shoulder US of three different patients with painful RCCT. (A) A hard calcification, with hyperechoic rim and strong posterior acoustic shadow (arrows). (B) A soft calcification, appearing as homogeneously hyperechoic without posterior acoustic shadow (headarrows). (C) A fluid calcification, presenting a thin peripheral hyperechoic rim and an anechoic core (asterisk)

Fig. 3

Shoulder US of a 52-year-old male patient with recent onset of acute pain that was unresponsive to analgesics. The US (A, B) shows a large calcification in the resorptive phase presenting irregular profiles and focal breaks (arrows) with iso-hypoechoic fluid content (asterisks)

Fig. 4

Left shoulder MR of a 47-year-old female patient with painful RCCT. Coronal T1-weighted (A) and fat-suppressed proton-density weighted (B) images show a calcification appearing as focal area of low signal on all sequences (arrows) within the supraspinatus tendon

Fig. 5

Two cases of bursal migration of RCCT. Coronal fat-suppressed proton-density weighted (A), axial gradient-echo (B), and sagittal T2-weighted (C) MR images of a 26-year-old female patient with atraumatic shoulder pain shows intrabursal migration of a calcification (arrows) with acute bursitis characterized by effusion and synovial hypertrophy within the subacromial–subdeltoid bursa (asterisks). Right shoulder US of a 32-year-old female patient with atraumatic pain (D) showing the subacromial–subdeltoid filled with hyperechoic fluid containing calcium and debris (headarrows) over an intact supraspinatus tendon

Fig. 6

Intraosseous migration of RCCT. Axial shoulder-computed tomography image (A) of the left shoulder of a 45-year-old male patient with a large calcification of the subscapularis tendon, which has penetrated the cortical bone of the lesser humeral tuberosity (arrow). Antero-posterior shoulder CR (B) of a 54-year-old female patient with intraosseous migration of a large calcification of the supraspinatus tendon (arrow)

Fig. 7

Right shoulder US of a 62-year-old male patient with calcific enthesopathy. US image (A) shows a small lamellar hyperechoic area at the insertion of the supraspinatus tendon (arrows)

Fig. 8

A 47-year-old female patient with intense left shoulder pain resistant to oral anti-inflammatory drugs and no history of trauma. Oblique coronal fat saturated proton density-weighted MR image (A) performed 1 week after pain onset shows a focal area of hyperintensity within the supraspinatus tendon without fiber retraction, that was described as partial thickness bursal side tear (arrows). Anteroposterior CR of the left shoulder (B) performed 3 days later reveals a large calcification over the humeral head (arrows). The patient underwent shoulder US (C) three weeks later, with long-axis US image of supraspinatus tendon showing fragmented hyperechoic calcification with faint acoustic backs shadow (arrows). Notably, US also showed no evidence of supraspinatus tear

Fig. 9

Intramuscular migration of RCCT in a 51-year-old female patient. Long-axis US images of the infraspinatus tendon (A, B) and short-axis US images of the infraspinatus fossa (C, D) show the intramuscular migration of calcific deposits with ill-defined margins (arrows) at the myotendineous junction of the infraspinatus tendon (asterisk). H = Humeral head; G = Glenoid; TM = Teres Minor muscle belly

Fig. 10

Calcific tendinopathy of the long head of the biceps brachii in a 54-year-old male patient. Coronal fat-suppressed proton-density weighted (A) and coronal T1-weighted (B) MR images show a hypointense calcification ovoid in shape (arrows) close to extra-articular portion of the long head of the biceps brachii (headarrows). Short-axis US images (C–E) demonstrate a soft calcification (arrows) within the sheath of the tendon (headarrows). Short-axis US image during the US-PICT (D) shows the needle (void arrows) inside the calcification, which presents anechoic content and a thin calcific wall at the end of the procedure (E)

Fig. 11

A 54-year-old female patient with left shoulder pain. Antero-posterior shoulder CR (A) displays a large calcification (arrow) close to the humeral shaft. Coronal T1-weighted (B), coronal fat-suppressed proton-density weighted (C), sagittal T2-weighted (D), and axial gradient-echo (E) MR images confirm the presence of a large calcification (arrows) at the insertion of pectoralis major tendon (arrowheads)

Fig. 12

A 58-year-old female patient with intense left shoulder pain due to RCCT. Coronal proton-density weighted (A), sagittal proton-density weighted (B), axial gradient-echo (C, D, E) MR images show multiple calcifications located simultaneously in the deltoid (A, B, C, arrows), infraspinatus (A, B, D, curved arrows), and subscapularis (E) tendons. This rare picture was confirmed by US images showing hard calcifications in the deltoid (F, arrows), infraspinatus (G, curved arrows), and subscapularis (H, headarrows) tendons