Magnetic resonance and computed tomography imaging in multiple myeloma.

This article reviews current knowledge on the various lesion patterns that can be observed at magnetic resonance (MR) imaging and on computed tomography images in patients with plasma cell neoplasms. It reviews limitations in specificity of imaging features and emphasizes difficulties in the recognition of the benign or malignant origin of vertebral fractures in these patients. The prognostic significance of MR imaging findings with respect to the natural history of the disease or to survival after treatment is discussed.

Idiopathic bone marrow edema lesions of the femoral head: predictive value of MR imaging findings.

PURPOSE: To determine the frequency of several subchondral magnetic resonance (MR) imaging features observed in bone marrow edema lesions of the femoral head and to determine their value for differentiation of irreversible from transient lesions. MATERIALS AND METHODS: The authors reviewed MR images of 72 femoral head lesions in 42 men and 25 women (median age, 48 years) with equivocal radiographic findings and bone marrow edema seen at MR imaging (T1- and T2-weighted images in all patients and contrast material-enhanced T1-weighted images in 39 patients). Follow-up MR images showed 57 lesions to be transient and 15 to be irreversible. The presence and size of subtle subchondral features observed on initial MR images were compared for both types of lesion. RESULTS: Lack of any additional subchondral change on T2-weighted or contrast-enhanced T1-weighted images had 100% positive predictive value for transient lesions. For irreversible lesions, presence of a subchondral area of low signal intensity at least 4 mm thick or 12.5 mm long had positive predictive values of 85% and 73%, respectively, on T2-weighted images and 87% and 86%, respectively, on contrast-enhanced T1-weighted images. CONCLUSION: Careful assessment of subchondral changes enables confident differentiation between early irreversible lesions and transient bone marrow edema lesions.

Stage III multiple myeloma: clinical and prognostic value of spinal bone marrow MR imaging.

PURPOSE: To determine the clinical and prognostic value of spinal bone marrow magnetic resonance (MR) imaging in stage III multiple myeloma. MATERIALS AND METHODS: In 80 patients with untreated, newly diagnosed stage III multiple myeloma, initial MR imaging patterns of spinal bone marrow involvement were correlated with hematologic parameters and response to induction chemotherapy. The influence of these patterns on survival was studied in 57 patients who did not undergo cytotoxic therapy with stem cell transplantation. RESULTS: MR imaging patterns of marrow involvement were normal in 19 (24%) patients, focal in 35 (44%), and diffuse in 26 (32%). Patients with the diffuse pattern had higher marrow plasmacytosis (P < or = .003) and cellularity (P < or = .001), higher serum calcium (P < or = .005) and beta 2-microglobulin (P < or = .008) levels, and lower hemoglobin values (P < or = .001) than did those with the normal or focal patterns. Patients with the normal pattern responded better to therapy (P = .007) and survived longer than patients with an abnormal pattern (P = .026). MR imaging findings and C-reactive protein level were the best independent prognostic indicators of survival. CONCLUSION: MR imaging patterns of spinal bone marrow involvement are correlated with several clinical parameters of disease severity and have prognostic value in stage III multiple myeloma.

Development of vertebral fractures in patients with multiple myeloma: does MRI enable recognition of vertebrae that will collapse?

PURPOSE: We assessed the relationship between the presence and size of focal marrow abnormalities detected with MRI in vertebral bodies and the subsequent occurrence of vertebral fractures at follow-up in patients with multiple myeloma (MM). METHOD: We reviewed 179 follow-up MR examinations of the thoracic and lumbar spine prospectively obtained in 37 patients with Stage 3 MM. For each of 131 vertebral bodies that fractured during follow-up, the status of the vertebral bone marrow was assessed on the last MR study obtained at a mean time interval of 4 months prior to fracture occurrence. When focal lesions were observed before fracture in vertebral bodies that later collapsed, their size was compared with that of the contemporary lesions observed in vertebrae that did not collapse. RESULTS: Of 131 fractures, 82 (63%) appeared in vertebrae previously free of focal bone marrow abnormality at MRI and 49 (37%) appeared in vertebrae in which focal lesions were present on the previous MR study. The size of the lesions that preceded fractures (median 15 mm; range 6-50 mm) was not statistically different from the size of the contemporary lesions (median 15 mm; range 5-60 mm) that did not lead to fracture (p > 0.30). CONCLUSION: This study in patients with MM suggests a lack of correlation between the preexistence of focal vertebral marrow lesions detected with MRI and the subsequent development of vertebral fractures.

Ganglion cysts of the knee: articular communication revealed by delayed radiography and CT after arthrography.

OBJECTIVE: The diagnosis of ganglion cysts of articular origin may sometimes be uncertain when communication with the joint is not evident. Because we have observed that opacification of ganglion cysts revealed by arthrography can be significantly delayed, the purpose of this study was to determine retrospectively in 20 cases the time delay needed to show with arthrography a communication between the articular cavity and ganglion cysts of the knee. CONCLUSION: Arthrographic evidence of a communication between the articular cavity of the knee and communicating ganglion cysts requires delayed radiography performed at least 1 hr after intraarticular injection of contrast material. The best results are obtained with additional CT performed 1-2 hr after injection.

Chronic lymphocytic leukemia: changes in bone marrow composition and distribution assessed with quantitative MRI.

The purposes of this study were (a) to determine the prevalence of bone marrow abnormalities in patients with chronic lymphocytic leukemia (CLL) using quantitative MR assessment of axial marrow composition and peripheral marrow distribution; (b) to assess the agreement between both quantitative MR methods and compare their sensitivities to detect marrow alterations; and (c) to correlate MR findings with clinical and laboratory parameters. Twenty-nine consecutive patients with biopsy-proven CLL were investigated on a .5-T MR imager to determine bulk T1 relaxation times of the vertebral bone marrow and proportion of proximal femur surface area occupied by nonfatty marrow on coronal T1-weighted MR images of one hip. Of the 29 patients, 12 (41%) had abnormal increase in lumbar marrow T1 values (>600 msec) and 16 (55%) had increased proportion of surface area occupied by nonfatty marrow in the proximal femur (>+1 SD compared to normal values determined in sex- and age-matched healthy subjects). The results of both quantitative MR methods were normal in 12 patients and abnormal in 11 patients (agreement, 79%). Patients with alterations in peripheral marrow distribution had significantly higher T1 relaxation times (P = .001) than those with normal peripheral marrow. Patients with abnormal marrow composition or distribution at MRI had significantly higher blood and marrow lymphocytosis than patients without these features. In conclusion, the agreement between both quantitative MR methods suggests a parallelism between changes in axial marrow composition and in peripheral marrow distribution in patients with CLL. The limits of quantitative MRI in CLL must be kept in mind, because quantitative MR methods failed to detect leukemic marrow infiltration in 41% of patients.

Magnetic resonance imaging-detected avascular osteonecrosis in systemic lupus erythematosus: lack of correlation with antiphospholipid antibodies.

We determined prospectively the prevalence of avascular osteonecrosis (AON) by magnetic resonance imaging (MRI) of both lower limbs in a group of 40 systemic lupus erythematosus (SLE) patients, and correlated the results with their serum antiphospholipid antibody (APL Ab) status and their glucocorticoid (GC) intake. APL Ab were detected by anticardiolipin ELISA and by lupus anticoagulant assays. Cumulated prednisolone doses were computed by chart review. The prevalence of AON was 37.5%, with most patients being asymptomatic despite involvement of multiple sites. The number of epiphyseal, metaphyseal and diaphyseal AON sites per patient did not differ between APL Ab-positive and APL Ab-negative patients nor between patients with high and low APL Ab titres. By contrast, a striking correlation was found between the prevalence and severity of AON and GC therapy. In conclusion, this prospective MRI study indicates that the prevalence of AON in SLE patients correlates strongly with GC therapy, but not with APL Ab status.

Early irreversible osteonecrosis versus transient lesions of the femoral condyles: prognostic value of subchondral bone and marrow changes on MR imaging.

OBJECTIVE: The purpose of this study was to determine the MR imaging features that enable differentiation between early irreversible osteonecrosis and transient lesions in nontraumatic lesions of the femoral condyle having the "bone marrow edema" pattern on MR imaging. MATERIALS AND METHODS: We reviewed 23 nontraumatic painful lesions of the femoral condyle in 23 patients (12 men and 11 women; mean age, 62 years). All patients had undergone radiography of the knee with findings that were normal or inconclusive. Also, all patients underwent MR imaging that revealed the bone marrow edema pattern in a condyle. Lesions observed after trauma, surgery, or glucocorticoid medication, or with epiphyseal collapse or degenerative joint disease on initial plain radiographs, were excluded from this study. Of the 23 lesions, 14 showed complete resolution (and were designated as transient epiphyseal lesions). The remaining nine lesions were irreversible and, on follow-up radiographic and MR imaging studies, evolved to collapsed osteonecrosis (and were designated as early osteonecrosis). The presence and size of the subchondral features observed by two radiologists on initial MR studies were compared for both irreversible and transient epiphyseal lesions. RESULTS: Initial MR imaging characteristics indicative of an early irreversible osteonecrosis included a subchondral area of low signal intensity on T2-weighted images with a thickness of more than 4 mm (sensitivity, 100% and 100%; specificity, 82% and 74% for the two observers) or a length of more than 14 mm (sensitivity, 89% and 88%; specificity, 93% and 87% for the two observers), focal epiphyseal contour depressions, and lines of low signal intensity located deep in the affected condyle. The extent of edema was similar for both transient epiphyseal lesions and early osteonecrosis. CONCLUSION: Careful assessment of MR imaging changes occurring in the subchondral area can enable confident differentiation between transient epiphyseal lesions and early irreversible osteonecrosis of the femoral condyle.

Treated plasma cell lesions of bone with MRI signs of response to treatment: unexpected pathological findings.

Two cases of treated plasma cell lesions of bone are reported for which contrast-enhanced MRI had suggested necrosis, based on lack of enhancement after gadolinium injection, and in which pathologic examinations revealed the presence of extensive viable neoplastic tissue. These cases highlight the need for cautious interpretation of contrast-enhanced MRI signs of response to treatment and inactivity of lesions in the setting of plasma cell neoplasms.

Early chronic lymphocytic leukemia: prognostic value of quantitative bone marrow MR imaging findings and correlation with hematologic variables.

PURPOSE: To determine the frequency of abnormal findings from quantitative bone marrow magnetic resonance (MR) imaging in patients with early-stage chronic lymphocytic leukemia, to correlate these findings with clinical parameters, and to compare spontaneous outcome in patients with normal or abnormal MR imaging findings. MATERIALS AND METHODS: In 21 patients with Binet stage A (Rai stage 0-I) disease, bulk T1 values of the vertebral bone marrow were determined and correlated with initial clinical, laboratory, histopathologic, and cytogenetic findings and with treatment-free survival. RESULTS: Bulk T1 values were normal (< 600 msec) in 14 patients and prolonged in seven. Patients with increased T1 had significantly higher blood (P = .017) and bone marrow (P = .015) lymphocytosis. None of the 14 patients with normal T1 values required specific therapy after a median follow-up of 13 months. Of the seven patients with abnormal T1 values, five required treatment after progression to Binet stage B or C disease at a median of 10 months. CONCLUSION: In patients with abnormal quantitative MR imaging findings, treatment-free survival appears to be significantly shorter (P < .001) than in patients with normal MR imaging findings.

Vertebral compression fractures in multiple myeloma. Part II. Assessment of fracture risk with MR imaging of spinal bone marrow.

PURPOSE: To determine the utility of bone marrow magnetic resonance (MR) imaging in the assessment of risk of vertebral compression fractures in patients with multiple myeloma. MATERIALS AND METHODS: In 50 patients with stage III multiple myeloma, 280 MR examinations of the thoracolumbar spine obtained at diagnosis and during treatment (mean follow-up, 28 months) were analyzed to determine MR patterns of bone marrow involvement before treatment and the occurrence of vertebral compression fracture at follow-up. Four MR patterns of marrow involvement were determined: A, normal marrow appearance; B, fewer than 10 focal lesions; C, more than 10 focal lesions; and D, diffuse infiltration. Fracture-free survival was compared according to these patterns. RESULTS: During follow-up, 131 vertebral compression fractures appeared in 37 patients. Patients with pattern A (n = 10) or B (n = 16) had significantly longer fracture-free survival before occurrence of the first, second, and third fractures than those with pattern C or D (P < 10(-5)). Relative risks of first, second, and third fracture occurrence for patients with pattern C or D compared with those with pattern A or B were 6.2, 9.1, and 11.0, respectively. CONCLUSION: Determination of MR patterns of spinal bone marrow involvement is a potential relevant factor to predict the risk of vertebral fractures in patients with stage III multiple myeloma.

Vertebral compression fractures in multiple myeloma. Part I. Distribution and appearance at MR imaging.

PURPOSE: To study the appearance and distribution of vertebral compression fractures on magnetic resonance (MR) images in patients with multiple myeloma. MATERIALS AND METHODS: Two hundred twenty-four vertebral compression fractures were studied on 216 sagittal T1-weighted spin-echo and T2*-weighted gradient-echo MR images of the thoracolumbar spine obtained before and during treatment in 37 patients with multiple myeloma. Vertebral compression fractures observed at diagnosis and during follow-up were determined as being benign- or malignant-appearing at MR imaging according to literature criteria, and their distribution along the spine was recorded. RESULTS: One hundred forty-nine (67%) of the 224 vertebral compression fractures appeared benign; 75 (33%) appeared malignant. Of the 37 patients, 14 (38%) had only benign-appearing vertebral compression fractures at diagnosis. One hundred five fractures (87%) were observed between T-6 and L-4, and 112 (50%) occurred between T-11 and L-3. Eight (4%) vertebral compression fractures involved the upper three thoracic vertebrae. CONCLUSION: Most vertebral compression fractures in patients with multiple myeloma appear benign at MR imaging, and their distribution is similar to that observed in osteoporotic fractures. The possibility of multiple myeloma should not be excluded in patients with benign-appearing vertebral compression fractures at MR imaging.

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.

Sequential quantitative MR analysis of bone marrow: differences during treatment of lymphoid versus myeloid leukemia.

PURPOSE: To assess the use of bulk T1 measurements with magnetic resonance (MR) imaging for monitoring treatment response in leukemic patients, with separate analysis of patients with acute lymphoid (ALL) and those with acute myeloid leukemia (AML). MATERIALS AND METHODS: Bulk T1 values were determined repeatedly during the first 4 weeks of treatment in 16 patients with ALL (age range, 16-72 years) and the first 6 weeks of treatment in 51 patients with AML (age range, 17-75 years). Bulk T1 values were compared in all patients with AML or ALL and in those who did or did not respond to treatment. RESULTS: MR imaging of lumbar bone marrow demonstrated statistically significant differences in initial bulk T1 values and in changes in bulk T1 values during treatment between patients with ALL and those with AML. Changes in bulk T1 after the 2nd week of treatment were statistically significantly different between patients with and those without a response who had ALL but not in those with AML. CONCLUSION: Sequential quantitative MR imaging during treatment appears valuable for prediction of response in patients with ALL but not in those with AML. Further investigations are needed to determine what influence MR imaging can have on patient care, but patients with ALL should be analyzed separately from those with AML.

MR imaging of the acetabular labrum: variations in 200 asymptomatic hips.

OBJECTIVE: The purpose of this study was to describe the MR appearance of the acetabular labrum in asymptomatic subjects and correlate the MR appearance with age and sex. MATERIALS AND METHODS: We evaluated high-resolution T1-weighted spin-echo coronal MR images of one hip in each of 200 asymptomatic individuals (84 men, 116 women; mean age, 44 years old; range, 15-82 years old). The labral shapes (triangular, round, flat, or absent), the intralabral signal intensity changes, and the possible extension of the intralabral signal intensity changes to the labral surface were assessed on two sections for each subject and correlated with age and sex. RESULTS: Triangle was the dominant shape seen on MR imaging (66%). However, its frequency decreased significantly with age. Absence of labrum was the second most frequent pattern (14%) and increased significantly with age. Round and flat labra were found in 11% and 9% of subjects, respectively, with no significant age correlation. The frequency of homogeneous labra with low signal intensity decreased with age. Intralabral areas of high signal intensity communicating with the free surface increased with age. CONCLUSION: The large variability of the MR appearance of the labrum in asymptomatic hips must be considered when interpreting MR examinations of patients in whom labral lesions are suspected.

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.

MRI of the spine in cobalamin deficiency: the value of examining both spinal cord and bone marrow.

We observed a case of pernicious anaemia in which MRI of the spine demonstrated both intrinsic lesions of the spinal cord and abnormal signal in the bone marrow. The latter resolved with replacement therapy. Only partial recovery of the cord lesions was observed.

Distribution of serouslike bone marrow changes in the lower limbs of patients with anorexia nervosa: predominant involvement of the distal extremities.

OBJECTIVE: To assess the distribution of marrow changes in the bones of the lower limbs of patients with anorexia nervosa (AN) and to correlate the importance of the extent of marrow changes with clinical and hematologic data. MATERIALS AND METHODS: The frequency of serouslike marrow (low signal intensity on T1-weighted images and very high signal intensity on T2-weighted images) was determined with MR imaging in the bones of the feet, distal tibias, and proximal femurs in 19 patients with AN. RESULTS: Serouslike marrow was found with an increasing frequency from proximal to distal in the lower-limb bones (femur, 31%; distal phalanx of the first toe, 79%). The patients with abnormal femoral marrow (n = 6) were more severely emaciated and had lower leukocyte and neutrophil counts than the patients with normal femoral marrow (n = 13). Among these patients, the six patients with at least two involved bones in the feet had lower blood cell counts than the seven patients with fewer than two involved bones. CONCLUSION: In the lower limbs of patients with AN, marrow changes predominate in the distal aspects. This distribution pattern is the reverse of that seen in most bone marrow disorders but is similar to the normal conversion of hematopoietic to fatty marrow. The importance of the blood cell count changes is correlated with the extent of marrow changes in the limbs.