Osseous metaplasia associated with amyloid-producing plasmacytoma of bone: a report of two cases

 Amyloid-producing plasmacytoma of bone is a rare myeloma variant. We describe two patients with plasmacytomas of bone with extensive amyloid deposition and metaplastic bone formation which can be confused on imaging with osteosarcoma. Histologic confirmation was obtained in both cases. Metaplastic new bone formation was identified within these lesions and appears to be responsible for the radiographic appearances.     

Extensively calcified synovial sarcoma

 Synovial sarcoma is an uncommon fibroblastic soft tissue neoplasm, commonly arising near, but not necessarily from, the synovium of joint capsules, bursae or tendon sheaths. The radiological diagnosis is difficult. We present a case of synovial sarcoma studied with plain film radiography, CT, and pathology that had an unusual extensive calcification, which complicated its radiological diagnosis.     

Extraosseous manifestation of Gaucher's disease type I: MR and histological appearance

Gaucher's disease type I is the most prevalent lysosomal storage disorder caused by an autosomal-recessive inherited deficiency of glucocerebrosidase activity with secondary accumulation of glucocerebrosides within the lysosomes of macrophages. The storage disorder produces a multisystem disease characterized by progressive visceral enlargement and gradual replacement of bone marrow with lipid-laden macrophages. Skeletal disease is a major source of disability in Gaucher's disease. Extraosseous extension of Gaucher cells is an extremely rare manifestation of skeletal Gaucher's disease. This is a report on the MRI and histopathological findings of an extraosseous Gaucher-cell extension into the midface in a patient with Gaucher's disease. Received: 27 January 2000; Revised: 15 March 2000; Accepted: 16 March 2000     

Syphilitic aneurysm of descending thoracic aorta causing vertebral body erosion and spastic paraparesis

Bone erosion from a syphilitic aortic aneurysm is uncommon, having been reported in only a few cases. Vertebral body erosion by a syphilitic aortic aneurysm is rarely associated with neurological deficits. We report a case of a syphilitic aneurysm of the descending thoracic aorta with associated vertebral body erosion and spinal cord compression causing spastic paraparesis.     

Gynecological disease causing acute abdominal pain in childhood

Summary In cases of acute abdominal pain in girls a gynecological cause must always be considered. Neoplasms and cystic adnexal lesions complicated by hemorrhage, torsion, and infarction can be diagnosed in childhood. Ovarian tumors without endocrine activity are frequently very large at the time of discovery. Intravaginal foreign bodies, inflammation, and congenital obstructive malformations are seldom found in patients with acute abdominal pain. Ultrasound has become the diagnostic method of choice. When used by an experienced examiner, its results are nearly as good as MRI. In evaluation with clinical data and serological results, an exact diagnosis can be made by ultrasound, even if the sonomorphological pattern seems confusing. Solid adnexal mass and complex malformations require MRI as a complementary diagnostic step. X-ray studies and computed tomography are less important diagnostic tools in girls with acute abdominal pain caused by gynecological disease. Eingegangen am 20. Dezember 1996 Angenommen am 5. Januar 1997     

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.     

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.     

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     

MR arthrography of the shoulder and hip after fluoroscopic landmarking

Purpose. To describe a technique for intra-articular injection in the MR suite after conventional fluoroscopic landmarking in order to streamline MR arthrography. Design and patients. This technique was performed on 33 consecutive patients referred for MR arthrography of the shoulder to evaluate the glenoid labrum and on 15 consecutive patients referred for MR arthrography of the hip to evaluate the acetabular labrum. The patients were landmarked in the fluoroscopy suite, followed by a conventional MR examination. The intra-articular injection was then performed on the MR table and the MR arthrographic sequences obtained. Results. One of the 48 injections was extra-articular, requiring a second injection. The other injections were performed without incident, and the average total procedure time for all injections was 10 min. Conclusions. This technique is a reliable method of streamlining intra-articular injections when performing conventional MR imaging prior to the MR arthrographic portion of the examination. It shortens the total MR examination time by eliminating a visit to the fluoroscopy suite in the middle of the MR study, and its use of a straight anterior approach for both the shoulder and hip joints should be familiar to most people who perform conventional arthrography. Received: 27 August 1999 Accepted: 26 October 1999     

Magnetic resonance imaging in coccidioidal arthritis

 Objective. The authors assessed the MRI findings of appendicular coccidioidal arthritis. Design. T1- and T2-weighted MR images of affected joints, both with and without intravenous gadopentetate dimeglumine, were performed in nine adult patients (ten studies) and evaluated by three masted readers, using a four-point certainty scale for: synovial abnormality, articular cartilage loss, subarticular bone loss, abnormal marrow signal, enhancement of osseous and articular structures, and assessment of disease activity. Findings were correlated with biopsy results or clinical course. Results. Eight patients had active and one had inactive arthritis, involving the knee (five patients), ankle (two patients), and elbow (one patient). Synovial complex was the most common finding in active arthritis (P<0.025). Cartilage and subarticular bone loss were seen 56% and 89% of patients with active disease, respectively. Abnormal marrow signal was uncommon (two patients). All cases showed synovial and/or osseus enhancement. Conclusions. MRI findings in coccidiodal arthritis are described. Enhancement of thickened synovium and erosions was seen after intravenous gadopentetate.     

Chondromalacia patellae: an in vitro study

 Objective. To develop MR criteria for grades of chondromalacia patellae and to assess the accuracy of these grades. Design. Fat-suppressed T2-weighted double-echo, fat-suppressed T2-weighted fast spin echo, fat-suppressed T1-weighted, and gradient echo sequences were performed at 1.5 T for the evaluation of chondromalacia. A total of 1000 MR, 200 histologic, and 200 surface locations were graded for chondromalacia and statistically compared. Results. Compared with gross inspection as well as with histology the most accurate sequences were fat-suppressed T2-weighted conventional spin echo and fat suppressed T2-weighted fast spin echo, although the T1-weighted and proton density images also correlated well. The most accurate MR criteria applied to the severe grades of chondromalacia, with less accurate results for lesser grades. Conclusions. This study demonstrates that fat-suppressed routine T2-weighted and fast spin echo T2-weighted sequences seem to be more accurate than proton density, T1-weighted, and gradient echo sequences in grading chondromalacia. Good histologic and macroscopic correlation was seen in more severe grades of chondromalacia, but problems remain for the early grades in all sequences studied.     

MR imaging of the knee in marathon runners before and after competition

Objective. To evaluate the findings in MRI-studies of the knee in recreational long-distance runners after competition and to assess the reversibility of the findings. Design and patients. Eight recreational long-distance runners underwent MRI studies of the knee before, immediately after and 6–8 weeks after taking part in the Vienna City Marathon. The studies were evaluated regarding alterations of pre-existing lesions and new pathological findings. Results. In six runners without major pre-existing alterations no negative effects were experienced. In one runner with pre-existing grade III alterations of the menisci, signs of progressive osteoarthritis were experienced 2 months after the competition. In all other cases increased meniscal signal alterations and minor signal changes in the bone marrow after the race were transitory. Conclusion. In healthy individuals no negative long-term-effects were experienced. Pre-existing high-grade lesions of the menisci might be a predisposing risk for osteoarthritis, triggered by the stress of long-distance running. Received: 17 February 2000 Revision requested: 13 June 2000 Revision received: 21 August 2000 Accepted: 9 September 2000     

MRI appearance of clear cell hidradenoma

We present the first reported MR imaging findings of a histologically proven clear cell hidradenoma. A fluid level was noted on all pulse sequences in this lesion, which demonstrated a prominent hemorrhagic component on sectioning. The presence of an enhancing nodule was also noted, differentiating this lesion from a post-traumatic hematoma. Fluid levels in a well-defined subcutaneous soft tissue mass should suggest the possibility of a hidradenoma. Received: 19 June 1998; Revision requested: 29 July 1998; Revision received: 28 October 1998; Accepted: 29 October 1998     

Sinus histiocytosis with massive lymphadenopathy: MRI findings of osseous lesions

 The case of a 20-year-old female with SHML and osseous involvement is presented. We describe three different patterns of involvement in the diametaphyseal portions of the long bones with similar MRI signal characteristics.     

Shoulder MRI after impingement test injection

Objective. To determine how long injected fluid from an impingement test remains in the bursa or adjacent soft tissues after an injection. Design and patients. Six patients prospectively underwent MRI of the shoulder immediately before and after an impingement test injection, and at 3 days, 2 weeks and 4 weeks later. MR images were evaluated and graded for fluid distribution within the bursa and adjacent soft tissues. The rotator cuff was evaluated for signal abnormalities related to the injection. Results and conclusion. Three days after the injection, the soft tissue fluid had returned to pre-injection levels or less in five of the six patients. No patients showed rotator cuff signal abnormalities related to the impingement test injection. We recommend a delay of 3 days before a shoulder MR examination after an injection has been performed, to avoid misinterpretations.     

A comparison of bone scintigraphy and MRI in the early diagnosis of the occult scaphoid waist fracture

Objective. To determine the accuracy of MRI in the assessment of the radiographically occult scaphoid fracture. Design. This prospective study compared the sensitivity and specificity of MRI for detection of radiographically occult scaphoid fractures with bone scintigraphy (BS), the currently accepted imaging modality of choice. Consecutive patients with clinical signs of a scaphoid injury but no evidence of fracture on plain radiographs at presentation and after 7–10 days were evaluated by MRI and BS. All images were reported in masked fashion and the sensitivities and specificities of the imaging modalities determined. All patients with a scaphoid fracture demonstrated by MRI or BS were followed for at least a year after injury. Patients. Forty-three subjects (aged 12–74 years) had both MRI and BS carried out on average 19 days from the injury date. Results and conclusions. Six patients (14%) had scaphoid waist fractures. There were other bony injuries in a further six. In 40 patients there was agreement between the BS and MRI findings. In three cases there was discrepancy between the imaging modalities; in all three MRI was found to be the more sensitive and specific. MRI could become the investigation of choice for this injury.     

Indirect wrist MR arthrography: the effects of passive motion versus active exercise

Purpose.In the wrist, to determine whether passive motion or active exercise yields a better indirect MR arthrographic effect following intravenous gadolinium administration. Design and patients. Twenty-six consecutive patients were studied by indirect wrist MR arthrography. In half active exercise and in half passive motion was performed. Four regions of interest were studied including the distal radioulnar joint, the radiocarpal joint, the midcarpal joint, and the triangular fibrocartilage. Ranges and means of signal intensity were calculated. Surgical follow-up was performed in 22 patients. Results. The joint fluid intensity was greatest in the distal radioulnar joint. Fluid signal intensity was greater and more consistent in the passive motion group although the results did not achieve statistical significance. Imaging accuracy appeared similar in the two groups and was excellent for the triangular fibrocartilage (100%) and scapholunate ligaments (96%). Conclusion. Active exercise and passive motion yield similar degrees of wrist arthrographic effect, but the effect of passive motion is somewhat more consistent. Preliminary data show good accuracy for internal derangements. Received: 4 June 1999 Revision requested: 6 August 1999 Revision received: 14 September 1999 Accepted: 20 September 1999     

Muscle impingement: MR imaging of a painful complication of osteochondromas

 The purpose of this study was to describe the magnetic resonance (MR) appearance of a newly recognized complication of osteochondromas. Two patients presented with pain and swelling over known osteochondromas. Plain radiographic studies were unrevealing. MR examinations were obtained to characterize the exostoses further and evaluate areas of palpable fullness. Increased signal was present in the muscles on T2-weighted images, which correlated with physical findings and was believed to represent muscle injury due to the osteochondroma. Pain and fullness may result from a number of osteochondroma-related complications, the most worrisome of which is malignant degeneration. Muscular impingement and injury should be considered in the differential diagnosis of pain and swelling in the region of an exostosis. MR imaging allows distinction of this entity, which may be radiographically occult and confused clinically with fracture, bursitis, or malignant degeneration.