J. Malghem

Magnetic resonance imaging of normal bone marrow.

Abstract. The appearance in magnetic resonance imaging (MRI) of the bones depends, to a large extent, on the unmineralized content of the bone cavities. Because yellow marrow contains a large number of fat protons and red marrow a significant number of water protons, MRI offers the opportunity to map the distribution of red and yellow marrow. In addition, red marrow MR appearance varies according to the relative proportion of fat and nonfat cells. Variations in the composition of red marrow and its distribution among normal subjects, mainly in relation to age and sex, contribute to creating a wide spectrum in bone MR appearance, which must be known in order to avoid confusion with bone marrow abnormalities.

Magnetic resonance imaging of the bone marrow in hematological malignancies

Abstract. 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.

Long-term effects of localized spinal radiation therapy on vertebral fractures and focal lesions appearance in patients with multiple myeloma.

The occurrence of new vertebral fractures and focal marrow lesions was determined and compared in irradiated and nonirradiated vertebrae of 12 patients with multiple myeloma (MM), prospectively followed using magnetic resonance imaging (MRI) of the thoraco‐lumbar spine after localized spinal radiation therapy. During follow‐up (mean 35 months), fractures appeared in 5% of irradiated vertebrae and in 20% of nonirradiated vertebrae; new focal lesions appeared in 4% of irradiated vertebrae and in 27% of nonirradiated vertebrae. This study demonstrates a beneficial long‐term effect of localized radiation therapy, consisting of a reduced incidence of vertebral fractures and focal marrow lesions in irradiated vertebrae.

Radiographic skeletal survey and radionuclide bone scan in Langerhans cell histiocytosis of bone

Background. The lack of a consensus in the literature on the imaging strategy in Langerhans cell histiocytosis (LCH) bone lesions in childhood.Objective. To evaluate the relative value of radionuclide bone scan (RBS) and radiographic skeletal survey (RSS) in the detection of LCH bone lesions, both in the initial work-up of the disease and during the follow-up period.Materials and methods. Ten children with bone lesions evaluated by means of RSS and RBS in a retrospective study (1984–1993).Results. Fifty radiologically and/or scintigraphically abnormal foci were detected: 27 anomalies in the initial work-up (12 by both RSS and RBS, 8 by RSS only and 7 by RBS only) and 23 additional anomalies during follow-up (10 by both RSS and RBS, 10 by RSS only and 3 by RBS only). RSS+/RBS- lesions (n =18) are more frequently encountered in the skull (P = 0.038), and more frequently lack radiologic signs of osteoblastic activity (P = 0.020), than RSS+/RBS+ lesions (n = 22). RSS-/RBS+ abnormalities (n = 10) were most frequently insignificant.Conclusion. In the initial work-up both RSS and RBS should be carried out, while in the follow-up only RSS should be performed.

Ferumoxides-enhanced quantitative magnetic resonance imaging of the normal and abnormal bone marrow: preliminary assessment.

The purpose of our study was to assess the effects of intravenous administration of ferumoxides on normal and abnormal vertebral bone marrow T1 and T2 relaxation times. Changes in bulk T1 and T2 relaxation times induced by intravenous administration of ferumoxides were determined in the normal vertebral marrow of two healthy subjects and four patients. In the four patients, changes in bulk T1 and T2 values induced by furomoxides injection were also determined in 12 vertebral metastases. Relative to precontrast relaxation time values, bulk T1 and T2 values of normal bone marrow had declined by a mean of 24% and 19%, respectively, in the two subjects and the four patients 45 minutes after ferumoxides administration. Relative to precontrast values, bulk T1 and T2 values of abnormal bone marrow had decreased by a mean of 16% and 2%, respectively. Decreases in bulk T1 and T2 values in normal bone marrow and in bulk T1 values in metastases were statistically significant (P < 0.001). Changes in bulk T2 values observed in metastases were not statistically significant. Quantitative MRI demonstrates that ferumoxides infusion induces a decrease in bulk T1 and T2 relaxation times of normal bone marrow. It also suggests a lack of T2 shortening in bone metastases.J. Magn. Reson. Imaging 1999;9:322–328.

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.

Diffusion-weighted MR imaging in musculoskeletal diseases: current concepts

MR imaging is currently regarded as a pivotal technique for the assessment of a variety of musculoskeletal conditions. Diffusion-weighted MR imaging (DWI) is a relatively recent sequence that provides information on the degree of cellularity of lesions. Apparent diffusion coefficient (ADC) value provides information on the movement of water molecules outside the cells. The literature contains many studies that have evaluated the role of DWI in musculoskeletal diseases. However, to date they yielded conflicting results on the use and the diagnostic capabilities of DWI in the area of musculoskeletal diseases. However, many of them have showed that DWI is a useful technique for the evaluation of the extent of the disease in a subset of musculoskeletal cancers. In terms of tissue characterization, DWI may be an adjunct to the more conventional MR imaging techniques but should be interpreted along with the signal of the lesion as observed on conventional sequences, especially in musculoskeletal cancers. Regarding the monitoring of response to therapy in cancer or inflammatory disease, the use of ADC value may represent a more reliable additional tool but must be compared to the initial ADC value of the lesions along with the knowledge of the actual therapy.

Case report : elastofibroma dorsi : a pseudomalignant lesion

Elastofibroma dorsi is an uncommon soft tissue lesion that appears in elderly individuals as a mass in the chest soft tissues, just anterior to the tip of the scapula [1-3]. Recent reports have shown MR and CT features such as ill-defined margins and heterogeneous signal or density which may suggest an aggressive lesion [4-7]. This case report presents the morphologic and signal characteristics of elastofibroma dorsi on MR that allow a prospective diagnosis to be made.

Histological beta-2-microglobulin amyloidosis 10 years after a successful renal transplantation

In a patient successfully transplanted 10 years earlier, we confirm that wrist and shoulder bone cysts, present at the time of transplantation, remain unchanged in size and number and demonstrate, for the first time, that they still contain beta-2-microglobulin (beta2m) amyloid. Regression of beta2m amyloid deposits in bone cysts disappears, if at all, very slowly.

Paget9s disease of bone.

were corrected in three days by intravenous perfusions of saline solutions, without nasal oxygen therapy or artificial ventilation. The treatment of metabolic alkalosis is based on the correction of hypovolaemia by perfusions of chloride-containing solutions, since hypochloraemia maintains metabolic alkalosis. The spontaneous ventilatory compensation of metabolic alkalosis in these patients suggests that the respiratory centre depression produced in severe alkalosis predominates over the stimulatory effects of hypercapnia and hypoxia. By recognition of such hypercapnia as a life-saving response unjustified artificial ventilation may be avoided. T CONSTANS J L GUILMOT Clinique Medicale A P CHEVALLIER D PERROTIN