Nonmyelomatous monoclonal gammopathy: correlation of bone marrow MR images with laboratory findings and spontaneous clinical outcome.

PURPOSE: To determine the frequency of abnormal bone marrow magnetic resonance (MR) images in patients with nonmyelomatous monoclonal gammopathy and to compare the outcomes in patients with normal and in those with abnormal MR studies. MATERIALS AND METHODS: In 37 patients with monoclonal gammopathy of undetermined or borderline significance (19 men, 18 women; aged 28-85 years), MR imaging findings of the vertebral, pelvic, and femoral bone marrow were analyzed and correlated with initial laboratory findings and outcome after a follow-up of 15-60 months (median, 31 months) with no treatment. RESULTS: Thirty patients had normal MR studies; none required specific therapy after a median follow-up of 30 months. Seven had either diffuse (n = 4) or focal (n = 3) bone marrow abnormalities. Four required treatment after 15, 20, 50, or 58 months; three did not require treatment after 18, 26, or 40 months. Treatment-free survival curves in patients with normal and in those with abnormal MR studies were statistically significantly different (P = .005). CONCLUSION: Bone marrow abnormalities were detected with MR imaging in seven patients (19%) with monoclonal gammopathy of undetermined or borderline significance. All patients with a normal MR investigation still had not required treatment after a median follow-up of 30 months.

Stage I multiple myeloma: value of MR imaging of the bone marrow in the determination of prognosis.

PURPOSE: To determine the prognostic value of bone marrow findings at magnetic resonance (MR) imaging in patients with stage I multiple myeloma. MATERIALS AND METHODS: In 24 patients with stage I multiple myeloma, findings from MR imaging of the vertebral, pelvic, and femoral bone marrow were analyzed and correlated to spontaneous outcome. Progressive multiple myeloma was observed in 12 patients and stable stage I multiple myeloma was observed in 12 after a follow-up period of 4-67 months (median, 27 months). RESULTS: In 17 patients, MR imaging findings were normal, and in seven patients, bone marrow abnormalities were depicted on MR images. Of the 12 patients with progressive multiple myeloma, six had bone marrow abnormalities that were depicted at MR imaging. In the group of patients with progressive multiple myeloma, the six patients with abnormal MR imaging findings showed earlier disease progression (median, 10 months) than the six patients in whom MR imaging findings were normal (median, 32 months) (P < .0001). Multivariate analysis of clinical and MR imaging findings showed that MR imaging (P = .006) were two independent factors in the prediction of disease progression. CONCLUSION: MR imaging of the bone marrow in patients with stage I multiple myeloma is an independent factor in the prediction of disease progression.

Apparent focal bone marrow ischemia in patients with marrow disorders: MR studies.

OBJECTIVE: We sought to assess with MR the focal bone marrow abnormalities in patients with chronic marrow disorders and acute limb pain. MATERIALS AND METHODS: We investigated and followed with MRI four patients with proliferative or dysplastic marrow disorders presenting with acute but spontaneously resolving hip or thigh pain. RESULTS: Ten focal marrow lesions were demonstrated on T2-weighted images as high signal intensity (SI) areas. They remained undetected on T1-weighted images as they showed a low SI similar to the disease-related low SI of the entire marrow. Postcontrast images demonstrated lack of enhancement in the lesions. Follow-up enhanced MR images showed intense enhancement within the lesions, while unenhanced MR images remained unchanged. Later on, these focal marrow abnormalities completely resolved. These lesions most likely represent bone marrow ischemia, although histological proof is lacking. CONCLUSION: Acute bone pain in patients with bone marrow disorders may be related to focal marrow lesions suggestive of bone marrow ischemia.

MR imaging of avascular necrosis and transient marrow edema of the femoral head.

The value of high spatial resolution and contrast material-enhanced magnetic resonance (MR) imaging was assessed in 69 patients with either femoral head avascular necrosis (AVN) or transient bone marrow edema lesions. An AVN lesion was typically a well-demarcated epiphyseal area of variable signal intensity. A transient bone marrow edema lesion appeared as an ill-delimited low-signal-intensity epiphyseal area on T1-weighted images that converted to a high-signal-intensity area on T2-weighted images. T1- and T2-weighted spin-echo images helped distinguish from AVN lesions some transient lesions apt to simulate the segmental pattern of AVN lesions. T2-weighted images also helped detect necrotic tissue in some unusual AVN lesions that mostly showed ill-delimited edemalike marrow changes. In some cases, contrast-enhanced MR images may increase diagnostic confidence by showing homogeneous hypervascularization in bone marrow edema lesions and by depicting hypovascular marrow areas in AVN lesions. The authors believe sequential MR imaging is valuable in the assessment of equivocal femoral head lesions.

Intravertebral vacuum cleft: changes in content after supine positioning.

Sequential radiographic and magnetic resonance (MR) imaging examinations were performed in nine patients with an intravertebral vacuum cleft indicative of avascular necrosis. Progressive changes in the content of the cleft occurred within an hour after the patients were placed in a supine position. Initially, the cleft showed a gaslike pattern during extension of the spine, with a radiolucent band on radiographs and a signal void on MR images. Later, the vacuum phenomenon disappeared on radiographs, and a fluidlike high-signal-intensity pattern appeared on T2- or T2*-weighted MR images, suggestive of a slow fluid inflow within the intravertebral cleft. Because the recognition of a vacuum cleft in a collapsed vertebral body helps avoid confusion with malignancy or infection, it is important to search for this in examinations performed immediately after supine positioning.

Avascular necrosis of the hip: comparison of contrast-enhanced and nonenhanced MR imaging with histologic correlation. Work in progress.

In 15 hips with typical signs of avascular necrosis of the femoral head on plain radiographs and magnetic resonance (MR) images, gadolinium-enhanced spin-echo and fat-suppressed MR images were obtained and compared with nonenhanced T1- and T2-weighted images. Both enhanced and nonenhanced areas were consistently detected in the abnormal femoral heads. Enhanced areas showed a low signal intensity (SI) on T1-weighted MR images obtained before contrast material was administered and an intermediate to high SI on T2-weighted images. Nonenhanced areas showed an SI either identical (pattern 1) or hypointense (pattern 2) to that of fat on both sequences. Histologic correlation (six resected femoral heads) helped confirm that enhanced and nonenhanced areas corresponded respectively to viable and necrotic tissue. In most cases, SI analysis of nonenhanced T1- and T2-weighted images allows the differentiation of hypervascularized viable tissue from hypovascularized necrotic tissue of the sequestrum.