Hemorrhagic prepatellar bursitis

 Simple prepatellar bursitis is easily diagnosed both clinically and by MRI. MRI shows the typical T1 and T2 lengthening of fluid within the bursa. However, because of complex MRI appearance of hemorrhage, chronic hemorrhagic bursitis and the size of the prepatellar mass the clinical and MRI appearance can be very different.     

Rice body formation in bicipito-radial bursitis: ultrasound, CT, and MRI findings

 The bicipito-radial bursa, which lies at the biceps tendon insertion on the radial tuberosity, is a rare site of chronic bursitis. We describe the clinical, radiological, and pathological findings in a case complicated by multiple rice body formation. In so doing, we describe MR appearances that allow discrimination of this entity from both synovial chondromatosis and pigmented villonodular synovitis.     

Imaging features of iliopsoas bursitis

The aim of this study was firstly to describe the spectrum of imaging findings seen in iliopsoas bursitis, and secondly to compare cross-sectional imaging techniques in the demonstration of the extent, size and appearance of the iliopsoas bursitis as referenced by surgery. Imaging studies of 18 patients (13 women, 5 men; mean age 53 years) with surgically proven iliopsoas bursitis were reviewed. All patients received conventional radiographs of the pelvis and hip, US and MR imaging of the hip. The CT was performed in 5 of the 18 patients. Ultrasound, CT and MR all demonstrated enlarged iliopsoas bursae. The bursal wall was thin and well defined in 83% and thickened in 17% of all cases. The two cases with septations on US were not seen by CT and MRI. A communication between the bursa and the hip joint was seen, and surgically verified, in all 18 patients by MR imaging, whereas US and CT failed to demonstrate it in 44 and 40% of the cases, respectively. Hip joint effusion was seen and verified by surgery in 16 patients by MRI, whereas CT (4 of 5) and US ( n=12) underestimated the number. The overall size of the bursa corresponded best between MRI and surgery, whereas CT and US tended to underestimate the size. Contrast enhancement of the bursal wall was seen in all cases. The imaging characteristics of iliopsoas bursitis are a well-defined, thin-walled cystic mass with a communication to the hip joint and peripheral contrast enhancement. The most accurate way to assess iliopsoas bursitis is with MR imaging; thus, it should be used for accurate therapy planning and follow-up studies. In order to initially prove an iliopsoas bursitis, US is the most cost-effective, easy-to-perform and fast alternative.     

The US,CT and MR findings of cubital bursitis: a report of five cases

 Objective. The purpose of the study was to evaluate the appearance of ”cubital bursitis” on ultrasonography and CT and MR imaging. ”Cubital bursitis” is a rare pathological condition involving a large swelling of the bicipito-radial or interosseous bursae located at the insertion of the distal biceps tendon on the radial tuberosity. Design and patients. We report on five patients with ”cubital bursitis” resulting from their work or sporting activities. All patients underwent an ultrasound and MR examination. CT scans were performed on two patients before and after contrast enhancement. Results. Ultrasound studies showed a fusiform anechoic or hypoechoic lesion. CT images showed the lesions but there were some difficulties in determining the exact extent of the bursae. MR imaging showed the enlarged bursae and their fluid content. Four patients each underwent a surgical procedure. Conclusion. Ultrasound and CT were effective in the evaluation of ”cubital bursitis”, but with some diagnostic difficulties. MR imaging is probably the method of choice for determining both the development of the bursae and their fluid content.     

Subacromial-subdeltoid lipoma arborescens associated with a rotator cuff tear

A 44-year-old man presented with lipoma arborescens of the right shoulder, associated with a rotator cuff tear. MRI revealed villous proliferations with signal intensity of fat on all pulse sequences. At surgery, this bursa was found to contain moderately yellow cloudy fluid without fat globules. Histological examination of the lesion showed subsynovial accumulation of mature fat cells. Received: 13 October 1998 Revision requested: 10 November 1998 Revision received: 22 January 1999 Accepted: 31 January 1999     

MRI abnormalities of foot and ankle in asymptomatic, physically active individuals

Objective. To assess MRI changes in the ankle and foot after physical exercise. Design and patients. Nineteen non-professional marathon runners and 19 age- and sex-matched controls volunteered for the study. All had ankle and foot MR images (1.5 T) taken in three perpendicular planes (STIR, T2F and T1FS sequences) within 3 h of running a full-length marathon (42.125 km). Three radiologists independently analysed the groups on a masked basis using a predefined form. Results. Severe bone marrow oedema was seen in one and slight bone marrow oedema in three marathon runners. Slight bone marrow oedema was found in three control subjects. Signal alteration within the soleus muscle, consistent with a grade 1 strain, was found in one marathon runner. Small punctate hyperintensities within the Achilles tendon were seen in 26% of the marathon runners and in 63% of controls (P=0.016). An increased amount of fluid in the retrocalcaneal bursa was found in one control and in none of the marathon runners. Small amounts of fluid in the retrocalcaneal bursa were seen in 68% of marathon runners and in 53% of controls. Grade 1 or 2 peritendinous joint fluid was found around 22% of tendons, among both marathon runners and controls, most often involving the tendon sheath of the flexor hallucis longus muscle. An increased amount of joint fluid was noted in 34% of the joints of the marathon runners, and in 18% of the controls. Conclusion. MRI shows several abnormalities in the ankle and foot both after marathon races and in asymptomatic physically active individuals without any preceding extraordinary strain. Recreational sports may lead to a number of positive MRI findings without correlation with clinical findings. Received: 3 May 2000 Revision requested: 11 July 2000 Revision received: 6 October 2000 Accepted: 13 November 2000     

Nontuberculous mycobacterial bursitis and arthritis of the shoulder

 A 56-year-old woman with systemic lupus erythematosus developed septic arthritis and bursitis of the left shoulder due to an atypical mycobacterium, M. xenopi. Plain radiography, ultrasound (US), and MRI were performed. Articular disease by tuberculous and nontuberculous mycobacteria have similar presentations, clinically as well as radiologically, and have to be differentiated from other chronic bacterial or fungal infections, pigmented villonodular synovitis, rheumatoid arthritis, gout, hemophilia, and synovial chondromatosis. Although atypical mycobacterial involvement of the skeleton and soft tissues is relatively uncommon, its incidence is increasing, as is the incidence of extrapulmonary tuberculosis in western countries. The triad of Phemister is reemphasized, and the US and MRI findings are demonstrated. The definitive diagnosis has to be made by culturing biopsied synovium or synovial fluid.     

Ischiogluteal bursitis: an uncommon type of bursitis

Ischiogluteal bursitis is a rare, infrequently recognized soft tissue mass of the buttock region. Of importance is the radiological differential diagnosis with other benign and malignant soft-tissue tumors. We describe the imaging findings of bursitis.     

Fracture of the lateral process of the talus: appearance at MR imaging and clinical significance

The case of a 59-year-old man with chronic lateral ankle pain following an inversion injury is presented. MR imaging performed to evaluate for soft tissue injury revealed an unsuspected fracture of the lateral process of the talus. The patient underwent surgical exploration of the fracture with debridement of adjacent loose bodies and is currently undergoing aggressive physical rehabilitation. Received: 23 November 1998 Revision requested: 18 December 1998 Revision received: 4 January 1999 Accepted: 4 January 1999     

Dedicated extremity MR imaging of the foot and ankle

The purpose of this review is to provide illustrative examples of diseases of the foot and ankle when imaged with a low-field MR imaging system. A retrospective review of 268 foot and ankle examinations, performed in our institution within the past 3 years with a 0.2-T (Artoscan Esaote, Genoa, Italy) dedicated extremity MR system was done. Additionally, illustrative comparison with conventional radiography and high-field MR imaging is presented in patients in whom these examinations were also performed. Although motion artifact limited the value of a few studies, in the majority of examinations low-field MR imaging provided diagnostic image quality for the full spectrum of disorders affecting the foot and ankle and seemed to be a feasible alternative to high-field MR imaging in establishing an accurate diagnosis. Received: 23 November 1998; Revision received: 8 February 1999; Accepted: 4 June 1999     

Magnetic resonance imaging findings in anterolateral impingement of the ankle

Objective. To demonstrate the MR imaging findings of anterolateral impingement (ALI) of the ankle. Design and patients. Nine patients with a history of ankle inversion injury and chronic lateral ankle pain were imaged with MR imaging, and the findings correlated with the results of arthroscopy. Three additional patients with clinically suspected ALI of the ankle were also included. Ankle MR imaging studies from 20 control patients in whom ALI was not suspected clinically were examined for similar findings to the patient group. Results. MR imaging findings in the patients with ALI included a soft tissue signal mass in the anterolateral gutter of the ankle in 12 of 12 (100%) cases, corresponding to the synovial hypertrophy and soft tissue mass found at arthroscopy in the nine patients who underwent arthroscopy. Disruption, attenuation, or marked thickening of the anterior talofibular ligament was seen in all cases. Additional findings included signs of synovial hypertrophy elsewhere in the tibiotalar joint in seven of 12 patients (58%) and bony and cartilaginous injuries to the tibiotalar joint in five of 12 (42%). None of the control patients demonstrated MR imaging evidence of a soft tissue mass in the anterolateral gutter. Conclusions. ALI of the ankle is a common cause for chronic lateral ankle pain. It has been well described in the orthopedic literature but its imaging findings have not been clearly elucidated. The MR imaging findings, along with the appropriate clinical history, can be used to direct arthroscopic examination and subsequent debridement. Received: 22 July 1999 Revision requested: 20 September 1999 Revision received: 7 October 1999 Accepted: 8 October 1999     

Magnetic resonance imaging of injuries to the ankle joint: can it predict clinical outcome?

 Objective. To predict clinical outcome after ankle sprains on the basis of magnetic resonance (MR) findings. Design and patients. Twenty-nine consecutive patients (mean age 32.9 years, range 13–60 years) were examined clinically and with MR imaging both after trauma and following standardized conservative therapy. Various MR abnormalities were related to a clinical outcome score. Results. There was a tendency for a better clinical outcome in partial, rather than complete, tears of the anterior talofibular ligament and when there was no fluid within the peroneal tendon sheath at the initial MR examination (P=0.092 for either abnormality). A number of other MR features did not significantly influence clinical outcome, including the presence of a calcaneofibular ligament lesion and a bone bruise of the talar dome. Conclusion. Clinical outcome after ankle sprain cannot consistently be predicted by MR imaging, although MR imaging may be more accurate when the anterior talofibular ligament is only partially torn and there are no signs of injury to the peroneal tendon sheath.     

Os sustentaculi: depiction on MR images

 We describe a 14-year old patient with pain in the medial ankle. The MR study depicted a rare accessory ossicle called the os sustentaculi. This accessory bone should not be confused with a fracture of the sustentaculum tali of the calcaneus.     

Calcific tenosynovitis associated with calcific myonecrosis of the leg: imaging features

 The findings with histologically proven calcific tenosynovitis of the tibialis anterior tendon associated with calcific myonecrosis are described. This case emphasizes the typical appearance of this unusual relationship such as peripheral plaque-like calcifications of the tendon sheath, fluid-calcium levels, presentation as painless mass, and calcification and liquefaction of muscle bundles.     

Sacral hydatidosis: value of MRI in the diagnosis

We present a case of primary hydatid disease of the sacrum. The diagnosis was made on MR imaging obtained to evaluate the spine for recurrent disc disease. The patient had previously undergone laminectomy elsewhere for L4–5 radiculopathy.Ultrasound-guided aspiration and visualisation of scolices confirmed the diagnosis. No other site of involvement was found.     

Fat-suppressed MRI of musculoskeletal infection: fast T2-weighted techniques versus gadolinium-enhanced T1-weighted images

 Purpose. To investigate gadolinium’s role in imaging musculoskeletal infection by comparing the conspicuity and extent of inflammatory changes demonstrated on gadolinium-enhanced fat-suppressed T1-weighted images versus fat-suppressed fast T2-weighted sequences. Design. Eighteen patients with infection were imaged in a 1.5-T unit, using frequency-selective and/or inversion recovery fat-suppressed fast T2-weighted images (T2WI) and gadolinium-enhanced frequency-selective fat-suppressed T1-weighted images (T1WI). Thirty-four imaging planes with both a fat-suppressed gadolinium-enhanced T1-weighted sequence and a fat-suppressed T2-weighted sequence were obtained. Comparison of the extent and conspicuity of signal intensity changes was made for both bone and soft tissue in each plane. Results. In bone, inflammatory change was equal in extent and conspicuity on fat-suppressed T2WI and fat-suppressed T1WI with gadolinium in 19 planes, more extensive or conspicuous on T2WI in three planes, and less so on T2WI in two planes. Marrow was normal on all three sequences in 10 cases. In soft tissue, inflammatory change was seen equally well in 20 instances, more extensively or conspicuously on the T2WI in 11 instances, and less so on T2WI in 2 instances. One case had no soft tissue involvement on any of the sequences. Five abscesses and three joint effusions were present, all more conspicuously delineated from surrounding inflammatory change on the fat-saturated T1WI with gadolinium. The average imaging time for the fat-saturated T1WI with gadolinium was 6.75 min, while that of the T2-weighted sequences was 5.75 min. Conclusion. Routine use of gadolinium is not warranted. Instead, gadolinium should be reserved for clinically suspected infection in or around a joint, and in cases refractory to medical or surgical treatment due to possible abscess formation.     

Assessment of instability of the long head of the biceps tendon by MRI

Objective. To determine whether MRI can identify instability of the long head of the biceps tendon (LBT) in the rotator interval. Design and patients . A retrospective review was carried out of 19 patients, all arthroscopically examined, nine of whom had surgically confirmed instability of the LBT. Results. A LBT perched on the lesser tuberosity correctly indicated all nine cases of instability with one false positive. In six of seven cases where the LBT was oval in shape, no instability of the biceps tendon existed, whereas LBT instability was present in eight of 12 patients with a flat long head of the biceps tendon. In seven of eight acutely angled intertubercular sulci there was no instability of the LBT while eight of 11 obtusely angled sulci were associated with LBT instability. By consensus impression, instability of the LBT could be determined with 67% sensitivity, 90% specificity, 86% positive predictive value, and 75% negative predictive value. Conclusions. A flat LBT perched on the lesser tuberosity with an obtusely angled intertubercular sulcus suggests the diagnosis of instability of the LBT in the correct clinical setting. Received for publication: 3 May 2000 Revision requested: 2 July 2000 Revision received: 27 September 2000 Accepted: 27 November 2000     

Association of posterior tibial tendon abnormalities with abnormal signal intensity in the sinus tarsi on MR imaging

Objective. To evaluate the association of abnormal signal intensity within the sinus tarsi with abnormalities of the posterior tibial tendon (PTT) on MR imaging. Design and patients. Sinus tarsi abnormalities were identified on 30 ankle MR examinations in 29 patients. The PTT and anterior talofibular ligament were retrospectively analyzed for abnormalities in these same patients. Results and conclusions. Tears of the anterior talofibular ligament were found in 13 of 30 (43%) ankles. PTT abnormalities (complete tear, partial tear or dislocation) were seen in 14 of 30 (47%) studies, and were distributed relatively equally between those patients with and without lateral ligament tears. Our results provide evidence of an association between abnormalities of the PTT and the sinus tarsi. The finding of abnormal signal intensity within the sinus tarsi on MR imaging should alert the radiologist to potential abnormalities of the PTT. Received: 17 March 2000 Accepted: 17 May 2000     

The MR imaging features of the posterior intermalleolar ligament in patients with posterior impingement syndrome of the ankle

Objective. To describe the MR imaging features of the posterior intermalleolar ligament (IML) in patients with posterior impingement syndrome (PIS) of the ankle. Design and patients. Three patients (one male and two females, 13–25 years of age) are presented. Each patient presented clinically with symptoms of PIS of the ankle. Plain film examination was negative for a structural cause of the PIS in all patients. MR images were obtained with a 1.5 T scanner using an extremity coil. Clinical data and, in one patient, findings at ankle arthroscopy, were correlated with the results of MR imaging. Results. Ankle MR images from the three patients with a clinical diagnosis of PIS are presented. Findings in all patients included: (1) absence of another structural cause of the PIS (i.e., an os trigonum, trigonal process, fracture, loose bodies, etc.), (2) identification of the IML as a structure discrete from the posterior talofibular and tibiofibular ligaments, and (3) prominence of the IML as indicated by (a) identification of the IML in three different imaging planes, and (b) a caliber of the IML comparable to that of the conventional posterior ankle ligaments visualized in the same imaging plane. Arthroscopic resection of a meniscoid IML resulted in resolution of the PIS in one of the patients presented. Conclusions. MR imaging is an effective means of investigating the IML as a potential cause of PIS. The identification of a prominent IML in the absence of another structural cause of PIS indicates that impingement of the IML is the most likely cause of PIS. Received: 11 March 1999 Revision requested: 5 May 1999 Revision received: 2 June 1999 Accepted: 4 June 1999