Prospective study of bone marrow infiltration in aggressive lymphoma by three independent methods: whole-body MRI, PET/CT and bone marrow biopsy

PURPOSE: Initial lymphoma staging requires bone marrow assessment in aggressive lymphomas. Bone marrow lymphoma infiltration is routinely assessed by bone marrow biopsy (BMB), considered as the "gold standard". The aim of this study was to compare the performance of BMB, whole-body MRI and PET/CT for evaluation of BM infiltration. METHODS: Patients with newly diagnosed aggressive lymphoma were evaluated by BMB, MRI and PET/CT. Two radiologists, two nuclear medicine physicians and one pathologist independently assessed the results of the three modalities. Bone was considered as involved if BM was positive or if PET/CT or MRI was positive and if there was a resolution of the abnormal image shown on PET/CT or MRI halfway or at the end of therapy. RESULTS: Both MRI and PET/CT detected bone marrow lesions in the 9/43 patients, but two patients with multiple lesions had more lesions detected by PET/CT compared to MRI. Among these nine patients, two with an iliac crest lesion detected by both MRI and PET/CT had bone marrow involvement with large-cell lymphoma on histological examination. The other seven patients had focal MRI and PET/CT lesions in areas other than the iliac crest, where the blind BMB was done. The other patients had bone marrow without large-cell lymphoma involvement. In all cases, after lymphoma therapy bone marrow involvement regressed on histological examination, PET and MRI. CONCLUSION: These preliminary results suggest that non-invasive morphological procedures could be superior to BMB for bone marrow assessment in aggressive lymphomas. Ongoing study is underway to validate these results.     

The importance of bone marrow examination for hemoblastoses]

Morphological bone marrow evaluation is an integral component in staging patients with hematological malignancies. In acute leukemias or myelodysplastic syndromes cytologic examination is crucial since it allows precise analysis on the individual cell level. Histological examination of an iliac crest trephine biopsy is mandatory in malignant lymphomas because of the frequent nodular involvement of bone marrow in these diseases. In recent years magnetic resonance tomography (MRT) has been shown to be a sensitive method for detecting marrow infiltration in a variety of marrow diseases. In malignancies with focal marrow involvement, such as malignant lymphoma, MRT is today a useful complement to morphological bone marrow evaluation.     

Response assessment in lymphoma

The lymphomas are a heterogeneous group of malignant diseases. They are divided into two broad groups: Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL). Patients suffering from HD and NHL can be cured by appropriate chemotherapy and/or radiotherapy. Accurate staging and response assessment is essential to guide management decisions. The International Workshop Group (IWG) criteria, published in 1999, have become the widely accepted standard for response assessment in NHL. Although the IWG criteria have proved extremely useful in the standardization of treatment response, they do have a number of limitations. As a consequence of this, together with advances in functional imaging, revised criteria have been published recently. The aim of this review is to describe the evidence supporting the available imaging techniques, the limitations of each technique, and how these should be applied in clinical practice. We briefly review the corresponding response criteria for central nervous system (CNS) lymphomas, and take a look at novel imaging techniques that may play a role in the future.     

The relation of bone marrow scintigraphy and unilateral bone marrow biopsy in malignant lymphoma

To assess the diagnostic role of bone marrow scintigraphy (BMS) for detecting bone marrow infiltration by malignant lymphomas, 47 patients, 14 with malignant Hodgkin's and 33 with non-Hodgkin's lymphoma underwent BMS with 99mTc-sulphur-colloid and also unilateral iliac crest bone marrow biopsy (BMB). BM involvement in BMB was observed in 11 of the 47 patients. Four of these patients also had BMS lesions. Eight patients had BMS lesions not detected by BMB. There was poor agreement between the two modalities (kappa=0.137). Considering BMB as the gold standard, sensitivity, specificity, positive predictive value, negative predictive value and accuracy of BMS were 36%, 77%, 33%, 80%, and 68% respectively. In conclusion, BMS has a high negative predictive value and may be used as a complementary screening test for lymphoma to assess the extent of BM involvement, especially if magnetic resonance imaging-guided biopsy or positron emission tomography studies are not available, as is the case in developing countries.     

Rektumkarzinom – Lokales Staging und Bildgebung unter neoadjuvanter Therapie

CLINICAL/METHODICAL ISSUE: Rectal cancer restaging after neoadjuvant therapy is based on two principles: an anatomic definition of the tumor allowing surgical planning and prognostic stage grouping. STANDARD RADIOLOGICAL METHODS: Emerging data suggest that reassessment using a combination of different imaging modalities may help to provide valuable prognostic information before definitive surgery. METHODICAL INNOVATIONS: Perfusion computed tomography (CT) may provide special information regarding tumor vascularity. PERFORMANCE: Evaluation of therapy response, especially of the circumferential resection margin (CRM) is necessary for surgical planning. ACHIEVEMENTS: For local staging high-resolution and diffusion-weighted magnetic resonance imaging has proven to be of high diagnostic accuracy. PRACTICAL RECOMMENDATIONS: The M status should be assessed using multidetector computed tomography (MDCT) according to response evaluation criteria in solid tumors (RECIST) while lymph node evaluation requires either magnetic resonance imaging or positron emission tomography/computed tomography scanning.     

Role of 99mTc-hexakis-2-methoxyisobutylisonitrile for detecting marrow metastases in childhood solid tumours

AIM: To evaluate the role of 99mTc-hexakis-2-methoxyisobutylisonitrile (99mTc-MIBI) for detecting bone marrow metastases in childhood solid tumours, including lymphomas. METHODS: Twenty-six children (18 males, eight females) were studied. They all had proven malignant solid tumours [Hodgkin's lymphoma (5), non-Hodgkin's lymphoma (3), neuroblastoma (9), Ewing's sarcoma (3), Langerhans cell histiocytosis (4), rhabdomyosarcoma (1) and germ cell tumour (1)] with suspected bone marrow metastases. All patients underwent computed tomography and/or magnetic resonance imaging, 99mTc-MIBI and Tc-methylene diphosphonate bone scans and bone marrow aspiration and/or biopsy. The scintigraphic evaluation of 99mTc-MIBI scans was performed according to the visual assessment of the extent and intensity of uptake. The scintigraphic score, which is the sum of the extent and intensity of uptake, was calculated for each patient. Scores of more than 2 were considered to be positive for bone marrow involvement. RESULTS: Twenty-seven 99mTc-MIBI scans were studied for 26 patients. Twenty-two 99mTc-MIBI scans were accepted as normal bone marrow. Bone scans were also normal in these patients. Five of the 27 99mTc-MIBI scans had scores of more than 2. Bone marrow cytology revealed bone marrow metastases in these patients. CONCLUSION: Abnormal 99mTc-MIBI uptake correlated extremely well with bone marrow aspiration/biopsy cytology results. Non-invasive 99mTc-MIBI imaging in children with malignant solid tumours appears to be promising for the evaluation of bone marrow metastases.     

Magnetic resonance imaging in the bone sites of malignant non-Hodgkin's lymphoma. Apropos of 16 cases]

The primordial role of MRI in the staging of primary or secondary bone tumors has been clearly established. The authors report a study of 16 patients with NHL with suspected bone involvement, investigated by conventional radiography, bone scan, CT, bone marrow biopsy and MRI. The authors believe that, in the future, MRI will have an important role in the staging and follow-up of treatment of bone lymphomas. Better than any other techniques, MRI provides a precise assessment of tumor extension. It also represents a valuable method for monitoring patients during treatment by visualising the course of the disease.     

Stellenwert der PET/CT in der Lymphomdiagnostik

CLINICAL/METHODICAL ISSUE: Staging or re-staging of lymphomas using conventional imaging modalities is based on morphological changes, usually on the diameter of lesions. However, vitality of tumors cannot be evaluated. STANDARD RADIOLOGICAL METHODS: In this context computed tomography (CT) has been used as a standard modality. METHODICAL INNOVATIONS: Since the introduction of positron emission tomography (PET), evaluation of tumor vitality has become possible. Moreover PET/CT hybrid scanners were brought onto the market one decade ago. PERFORMANCE: The fluorodeoxyglucose (FDG) PET/CT technique is now accepted as one of the most accurate modalities in the diagnosis of aggressive lymphomas due to a high FDG uptake (overall accuracy?>?90%, sensitivity >90%). However, indolent lymphomas suffer from lower FDG uptake due to a moderate metabolic activity. After the introduction of PET/CT hybrid imaging the specificity of this diagnostic technique increased significantly compared to PET alone (from?>?80% to?>?90%). With the utilization of PET approximately 20% more lesions are detected when comparing to CT alone and in up to 15% of the patients this also results in a change of the therapeutic regime. As post-chemotherapy scar tissue usually persists for months, evaluation of vitality within residual bulks using FDG-PET can predict therapy response much earlier than CT, enabling therapy stratification. Other PET tracers apart from FDG have low impact in imaging of lymphomas and only the thymidine analogue fluorothymidine (FLT) is used in some cases for non-invasive measurement of proliferation. ACHIEVEMENTS: Despite the capability of FDG-PET/CT there is no evidence that the improvement in diagnostics is translated into a better patient outcome and therefore warrants the high costs. False positive findings in PET can result in unnecessary treatment escalation with subsequent higher therapy-associated toxicity and costs. PRACTICAL RECOMMENDATIONS: Some pitfalls can be avoided by scheduling PET scans carefully. As treatment-induced inflammation early after therapy can be misinterpreted as vital tumor tissue, it is recommended to wait at least 3 weeks between the last treatment cycle and the subsequent FDG-PET follow-up. Until the results of the prospective multicenter trials "PETAL" and "HD-18" become available, in Germany FDG-PET is only recommended generally for restaging Hodgkin's disease with a known rest bulk of >?2.5?cm in justifiable individual cases or in clinical trials.     

Ossäre Manifestationen beim Non-Hodgkin-Lymphom im Kindes- und Jugendalter

PURPOSE: Skeletal manifestation of Non-Hodgkin's lymphoma is rare in pediatric patients. Objective of the study was to determine imaging features, before and after treatment, and to correlate these features with clinical outcome. METHODS: A retrospective analysis of 1246 patients from two therapy studies (NHL-BMF-90 and 95) was performed. Imaging studies of 63 patients with bone involvement of lymphoma were reevaluated. RESULTS: Incidence of initial bone involvement in Non-Hodgkin's lymphoma was 6.8%. Distribution was best assessed by bone scan, MRI revealed larger areas of marrow involvement and detected additional lesions. Sites of predilection were long bones of the lower extremities with epiphyseal involvement in 39%. Residual signal alterations in MRI after successful therapy remained in 71%. Osteonecrosis after therapy was a common finding. Clinical outcome war not correlated to the presence of bone involvement. CONCLUSIONS: Since clinical outcome is not effected by bone involvement in childhood NHL, value of screening may be limited. Knowledge of imaging characteristics is mandatory for initial evaluation of primary osseous lymphomas and symptomatic lesions as well as for therapy controls.     

Whole-body MRI for the detection of bone marrow involvement in lymphoma: prospective study in 116 patients and comparison with FDG-PET

Objective

To assess and compare the value of whole-body MRI with FDG-PET for detecting bone marrow involvement in lymphoma.

Methods

A total of 116 patients with newly diagnosed lymphoma prospectively underwent whole-body MRI and blind bone marrow biopsy (BMB) of the posterior iliac crest. Of 116 patients, 80 also underwent FDG-PET. Patient-based sensitivities of whole-body MRI for detecting bone marrow involvement were calculated using BMB as reference standard and compared with FDG-PET in aggressive and indolent lymphomas separately.

Results

Sensitivity of whole-body MRI in all lymphomas was 45.5 % [95 % confidence interval (CI): 29.8–62.0 %]. Sensitivity of whole-body MRI in aggressive lymphoma [88.9 % (95 % CI: 54.3–100 %)] was significantly higher (P?=?0.0029) than that in indolent lymphoma [23.5 % (95 % CI: 9.1–47.8 %)]. Sensitivity of FDG-PET in aggressive lymphoma [83.3 % (95 % CI: 41.8–98.9 %)] was also significantly higher (P?=?0.026) than that in indolent lymphoma [12.5 % (95 % CI: 0–49.2 %)]. There were no significant differences in sensitivity between whole-body MRI and FDG-PET (P?=?1.00)

Conclusion

Sensitivity of whole-body MRI for detecting lymphomatous bone marrow involvement is too low to (partially) replace BMB. Sensitivity of whole-body MRI is significantly higher in aggressive lymphoma than in indolent lymphoma and is equal to FDG-PET in both entities.

Key Points

? Bone marrow involvement in lymphoma has prognostic and therapeutic implications. ? Blind bone marrow biopsy (BMB) is standard for bone marrow assessment. ? Neither whole-body MRI nor FDG-PET can yet replace BMB. ? Both techniques have higher sensitivity in aggressive than in indolent lymphoma. ? Both imaging techniques are complementary to BMB.     

Can [18F]fluorodeoxyglucose positron emission tomography imaging complement biopsy results from the iliac crest for the detection of bone marrow involvement in patients with malignant lymphoma?

OBJECTIVES: To assess the usefulness of [18F]fluorodeoxyglucose positron emission tomography in the detection of bone marrow involvement in malignant lymphoma, and its impact in clinical management. METHODS: One hundred and six consecutive patients with a confirmed diagnosis of lymphoma, referred for staging or restaging of Hodgkin's lymphoma (n=18) or non-Hodgkin's lymphoma (n=88), were reviewed retrospectively. A positron emission tomography scan and bone marrow biopsy of the iliac crest were performed in all patients. The assessment of bone marrow involvement by lymphoma was confirmed by histology and/or progression of bone marrow lesions in clinical follow-up. RESULTS: In 28 of 106 patients, bone marrow involvement was found. Positron emission tomography was more sensitive (86%) than bone marrow biopsy (57%). Positron emission tomography and bone marrow biopsy were concordant by positive correlation in 12 of 28 cases (43%) and by negative correlation in 77 of 78 cases (99%). Ten cases of non-Hodgkin's lymphoma and two cases of Hodgkin's lymphoma with positive positron emission tomography results and an initial negative bone marrow biopsy showed clinical progression of the bone marrow lesions and/or subsequent positive histology. These were considered as false-negative results for bone marrow biopsy. In seven of the 12 positive cases with negative bone marrow biopsy, positron emission tomography uptake distant from the site of the biopsy was seen. In four cases of follicular lymphoma, the bone marrow biopsy was positive and the positron emission tomography scan was normal. CONCLUSIONS: Positron emission tomography and bone marrow biopsy are complementary in assessing the presence of bone marrow involvement in patients with malignant lymphoma. In our series, positron emission tomography was more sensitive than bone marrow biopsy in Hodgkin's and non-Hodgkin's lymphoma, except in follicular lymphoma.     

Malignant lymphoma: bone marrow imaging versus biopsy

In 107 patients with malignant Hodgkin and non-Hodgkin lymphoma, bone marrow was evaluated with scintigraphy, magnetic resonance (MR) imaging, and biopsy to detect bone marrow infiltration. Imaging and biopsy results were classified as normal (class 0), suggestive of reactive changes (class 1), or suspicious for infiltration (class 2). About one-half of biopsy and imaging results agreed completely. In patients with chronic lymphocytic leukemia, false-negative findings were frequent with both imaging techniques. Although a positive biopsy result is usually accepted as proof of bone marrow infiltration, results indicate that negative biopsy findings do not exclude tumor involvement. When suspected infiltration was found with MR imaging or scintigraphy but results were normal or suggestive of reactive changes in the first blind biopsy, repeat blind or guided biopsy helped confirm the imaging results. Autopsy findings in two patients completely confirmed previous results with MR imaging and scintigraphy, although findings at antemortem biopsy were different. Scintigraphy and MR imaging should be included routinely in the staging of malignant lymphoma as an adjunct to blind biopsy in the complete evaluation of bone marrow status.     

Erwartungen des Rheumatologen an die Bildgebung

CLINICAL/METHODICAL ISSUE: Clinical examination and laboratory results are often insufficient to support therapeutic decisions. STANDARD RADIOLOGICAL METHODS: Diagnosis and organ-related imaging may provide important additional information for initial diagnosis (differential diagnoses), follow-up and prognosis. Especially functional imaging techniques, such as ultrasound and magnetic resonance imaging are becoming more and more important for early diagnosis. METHODICAL INNOVATIONS: Imaging is already recognized in the classification criteria of several rheumatic diseases and new criteria for spondyloarthritis and polymyalgia rheumatica aim more and more at early diagnosis using functional imaging techniques, such as ultrasound and magnetic resonance imaging. PERFORMANCE: Specific imaging findings are helpful for eliminating differential diagnoses. During follow-up disease control the status as well as progression of structural damage can be documented. In selected diseases imaging allows prognostic statements on both disease progression and therapeutic response to specific medication. ACHIEVEMENTS: The evidential value of imaging results varies with the rheumatological expectations. PRACTICAL RECOMMENDATIONS: Overall rheumatological expectations on imaging differ widely and therefore support a differentiated use of imaging techniques.     

Multiples Myelom: Aktuelle Empfehlungen für die Bildgebung

CLINICAL/METHODICAL ISSUE: Imaging in monoclonal plasma cell disease serves to detect end organ damage, i.e., osteoporosis or bone destruction. Diffuse or circumscribed bone marrow infiltration without damage to mineralized bone is so far not regarded as end organ damage. STANDARD RADIOLOGICAL METHODS: Skeletal plain x-ray film survey to detect bone destruction, osteoporosis or fractures. METHODICAL INNOVATIONS: Whole body low-dose computed tomography (CT) and whole body magnetic resonance imaging (MRI) allow a more sensitive assessment of both mineralized bone and bone marrow, with greater patient comfort and in the case of MRI without ionizing radiation. PERFORMANCE: According to the literature, cross-sectional imaging is clearly superior to skeletal surveys and MRI is more sensitive than CT. Every locally destructive lesion will be detectable with MRI but for assessing the damage to mineralized bone CT is indispensible. The sensitivities of positron emission tomography (PET)/CT and MRI are comparable. ACHIEVEMENTS: If available whole body MRI and whole body low dose CT should replace conventional skeletal surveys. This has already been implemented in several centers in Germany. PRACTICAL RECOMMENDATIONS: For the initial diagnosis of monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma or symptomatic multiple myeloma, a whole-body MRI and a whole body low-dose CT should be performed. For MGUS and asymptomatic myeloma, whole body MRI only should be performed for follow-up until detection of first bone destruction. Patients with symptomatic multiple myeloma and known bone destruction will usually have whole body low-dose CT, supplemented by MRI studies where clinically required.     

Importance of SPECT/CT for knee and hip joint prostheses

CLINICAL/METHODICAL ISSUE: Complications, such as loosening or infections are common problems after hip or knee arthroplasty. STANDARD RADIOLOGICAL METHODS: If conventional X-rays are equivocal bone scintigraphy is the classical second-line imaging modality. METHODICAL INNOVATIONS: Single photon emission computed tomography/computed tomography (SPECT/CT) offers metabolic and morphologic information in one imaging step and is becoming increasingly more available in larger hospitals. PERFORMANCE: The SPECT/CT procedure is a promising method and is increasingly being used in daily routine to evaluate joint arthroplasty. The additional benefit compared with classical conventional bone scintigraphy has to be evaluated in further prospective studies. ACHIEVEMENTS: In our hospital SPECT/CT regularly gives important additional information regarding prosthetic joint complications. PRACTICAL RECOMMENDATIONS: SPECT/CT is increasingly being used as the second step imaging standard modality if conventional X-rays are equivocal.     

Evaluation of central nervous system involvement in nasal lymphomas

OBJECTIVES: To clarify the usefulness of evaluating central nervous system (CNS) involvement in patients with nasal lymphomas at the initial staging procedure, and of CNS prophylaxis for patients with clinical stage I/II. PATIENTS AND METHODS: We retrospectively reviewed 43 patients with nasal lymphomas who had been treated from 1973 through 1999. The staging procedure included mainly computed tomography (CT), ultrasonography, gallium scintigraphy, upper gastrointestinal study, magnetic resonance (MR) imaging, and bone marrow biopsy. Forty-two patients received radiotherapy, and 25 patients received chemotherapy. All 38 patients with stage I/II were not subjected to CNS prophylaxis. RESULTS: Four patients demonstrated CNS involvement at the staging procedure. MR imaging demonstrated the tumor had directly infiltrated the skull base in 3 patients, but CT demonstrated CNS infiltration in only one patient. In another patient, cerebrospinal fluid (CSF) cytologic analyses demonstrated CNS involvement, but MR imaging and CT did not. These 4 patients complained of frontonasal pain and/or cerebral nerve dysfunction. No patient with stage I/II developed CNS relapse. CONCLUSIONS: MR imaging and CSF cytologic analyses should be performed at the initial staging of nasal lymphomas, especially in patients with frontonasal pain and/or cerebral nerve dysfunction. Patients with stage I/II might not need CNS prophylaxis.     

Bone marrow investigation with technetium-99m microcolloid and magnetic resonance imaging in patients with malignant myelolympho-proliferative diseases

In 63 patients with primary extramedullary malignant lymphoma or plasmacytoma, a study was performed in order to evaluate bone marrow involvement. All patients underwent a 99mTc microcolloid bone marrow whole body imaging (scintigraphy), using a gamma camera interfaced with a computer, followed by nuclear magnetic resonance bone marrow imaging (MRI), (1.5 Tesla). MR images were made of the lumbosacral region, the pelvic region, both femoral and other parts of the skeleton, according to focal lesions in the scintigraphy. A posterior iliac crest bone marrow biopsy was used as a standard reference. In the present study, both scintigraphy and MRI showed a dissiminated or focal involvement or a combination of both. In 53 of the 63 patients (84%) the results were in accordance. Pathological MR signals or pathological findings in scintigraphy did not always correspond to tumorous bone marrow involvement, and were shown to reflect reactive changes in the central part of the skeleton in combination with a periphery radionuclide extention interpreted as a periphery compensatory hematopoietic proliferation. The negative predictive value of scintigraphy and MRI was 92% and 100%, respectively. When combining the results of both examinations, the positive predictive value increased from 49% to 58%, if the bone marrow biopsy is accepted as gold standard. The results indicate that bone marrow investigation performed simultaneously using scintigraphy and MRI is superior both to the use of either of the methods alone and to the traditional iliac crest bone marrow biopsy.     

Imaging of bone tumors for the musculoskeletal oncologic surgeon

The appropriate diagnosis and treatment of bone tumors requires close collaboration between different medical specialists. Imaging plays a key role throughout the process. Radiographic detection of a bone tumor is usually not challenging. Accurate diagnosis is often possible from physical examination, history, and standard radiographs. The location of the lesion in the bone and the skeleton, its size and margins, the presence and type of periosteal reaction, and any mineralization all help determine diagnosis. Other imaging modalities contribute to the formation of a diagnosis but are more critical for staging, evaluation of response to treatment, surgical planning, and follow-up.When necessary, biopsy is often radioguided, and should be performed in consultation with the surgeon performing the definitive operative procedure. CT is optimal for characterization of the bone involvement and for evaluation of pulmonary metastases. MRI is highly accurate in determining the intraosseous extent of tumor and for assessing soft tissue, joint, and vascular involvement. FDG-PET imaging is becoming increasingly useful for the staging of tumors, assessing response to neoadjuvant treatment, and detecting relapses.Refinement of these and other imaging modalities and the development of new technologies such as image fusion for computer-navigated bone tumor surgery will help surgeons produce a detailed and reliable preoperative plan, especially in challenging sites such as the pelvis and spine.     

Systemic mastocytosis: MRI of bone marrow involvement

Systemic mastocytosis (SM) is an abnormal proliferation of mast cells, located in different structures: skin, bone marrow, spleen, liver and lymph nodes. Magnetic resonance imaging was prospectively performed in ten patients diagnosed by bone marrow biopsy in order to describe the different patterns of bone marrow involvement. Coronal T1-weighted spin-echo images were obtained in vertebral, pelvic, humeral and femoral bones. Depending on the extension of the cell infiltration, three patterns of bone marrow involvement were used: normal/no involvement (N), non-homogeneous (NH) and homogeneous (H). All ten patients presented bone infiltration. The patterns observed were: spine (50 % NH, 50 % H), pelvis (70 % NH), humerus 100(NH) and femur 40 % (NH). T1-weighted MR imaging is a sensitive technique for detecting marrow abnormalities in patients with systemic mastocytosis. There is no correlation between percentage of mast cells in bone marrow biopsy and extent or pattern of bone marrow involvement. Received: 5 June 1998; Revision received: 23 November 1998; Accepted: 15 January 1999     

Magnetic resonance imaging of the bone marrow in hematological malignancies

Despite its lack of specificity, magnetic resonance imaging (MRI) of the bone marrow has the potential to play a role in the management of patients with primary neoplastic disorders of the hematopoietic system, including lymphomas, leukemias and multiple myeloma. In addition to its use in the assessment of suspected spinal cord compression, bone marrow MRI could be used as a prognostic method or as a technique to assess the response to treatment. The current review addresses the common patterns of bone marrow involvement observed in primary neoplasms of the bone marrow, basic technical principles of bone marrow MRI, and several applications of MRI in selected clinical situations. Received 22 May 1997; Revision received 27 January 1998; Accepted 29 January 1998