Prospective evaluation of bone marrow signal changes on magnetic resonance tomography during high-dose chemotherapy and peripheral blood stem cell transplantation in patients with breast cancer

Indolent enhancing spinal lesions mimicking spinal metastasis in pediatric patients with malignant primary brain tumors

Spinal metastasis from malignant primary brain tumors (MPBTs) in pediatric patients is rare and often appears as enhancing lesions on MRI. However, some indolent enhancing spinal lesions (IESLs) resulting from previous treatment mimic metastasis on MRI, leading to unnecessary investigation and treatment. In 2005–2020, we retrospectively enrolled 12 pediatric/young patients with clinical impression of spinal metastasis and pathological diagnosis of their spinal lesions. Three patients had MPBT with IESL, and 9 patients had malignant tumors with metastases. The histopathologic diagnosis of IESL was unremarkable marrow change. We evaluated their MRI, CT, and bone scan findings. The following imaging findings of IESL vs. spinal metastasis were noted: (1) IESLs appeared round/ovoid (3/3, 100%), whereas spinal metastasis appeared irregular (9/9, 100%) (P = 0.005); (2) target-shaped enhancement was noted in (3/3, 100%) vs. (0/9, 0%) of cases, respectively (P = 0.005); (3) pathologic fracture of the vertebral body was noted in (1/3, 33.3%) vs. (9/9, 100%) of cases, respectively (P = 0.045); (4) expansile vertebral shape was noted in (0/3, 0%) vs. (9/9, 100%) of cases, respectively (P = 0.005); (5) obliteration of the basivertebral vein was noted in (0/3, 0%) vs. (9/9, 100%) of cases, respectively (P = 0.005); and (6) osteoblastic change on CT was noted in (3/3, 100%) vs. (2/9, 22.2%) of cases, respectively (P = 0.034). IESL in pediatric patients with MPBT can be differentiated from metastasis based on their imaging characteristics. We suggest close follow-up rather than aggressive investigation and treatment for IESL.

Therapy-Related Imaging Findings in Patients with Sarcoma

Knowledge of imaging findings related to therapy administered to patients with sarcoma is pivotal in selecting appropriate care for these patients. Imaging studies are performed as surveillance in asymptomatic patients or because symptoms, including anxiety, develop. In addition to detection of recurrent disease and assessment of response to therapy, diagnosis of conditions related to therapy that may or may not need treatment has a marked positive impact on quality of life. The purpose of this review is to assist radiologists, nuclear physicians, and others clinicians involved in the diagnosis and treatment of these patients in recognizing imaging findings related to therapy and not to activity of the previously treated sarcoma. Imaging findings are time dependent and often specific in relation to therapy given.

Fat fraction estimation of morphologically normal lumbar vertebrae using the two-point mDixon turbo spin-echo MRI with flexible echo times and multipeak spectral model of fat: Comparison between cancer and non-cancer patients

PURPOSE

This study aims to compare fat fraction of lumbar vertebrae between cancer and non-cancer patients, using the two-point modified Dixon (mDixon) turbo spin-echo (TSE) MRI with flexible echo times and multipeak fat spectral model.

MATERIALS AND METHODS

Fat fraction was calculated from fat and water images reconstructed by the mDixon TSE technique. Fat fraction of fat-water phantoms measured with the mDixon TSE method was compared with actual fat percentages. Patients who had undergone mDixon spine MRI and dual-energy X-ray absorptiometry within one year and had no bone metastasis were divided into cancer (n=7) and non-cancer (n=23) groups. Fat fraction and bone mineral density (BMD) were compared between the two groups.

RESULTS

Fat fraction of phantoms measured with mDixon MRI was highly correlated with their actual fat percentages (P<0.01, R(2)=0.93). Fat fraction of lumbar vertebrae was significantly lower in cancer patients (58.27±3.16%) than in non-cancer patients (70.48±1.83%) (P<0.01). BMD was not different between cancer (0.912±0.057g/cm(2)) and non-cancer patients (0.876±0.032g/cm(2)) (P=0.58). Fat fraction and BMD showed no significant correlation (P=0.95, R=0.006).

CONCLUSIONS

A two-point mDixon TSE method for assessing fat fraction was reliable. Fat fraction of morphologically normal lumbar vertebrae was significantly lower in cancer patients compared to non-cancer patients, using the two-point mDixon TSE technique.

Imaging of lymphoma of the musculoskeletal system

Imaging plays a crucial role in staging and the assessment of treatment response in patients who have lymphoma of the musculoskeletal system. This article reviews imaging features of lymphoma of bone, muscles, cutaneous, and subcutaneous tissue. At radiography, lymphoma of the bone is most commonly lytic, but the affected bone also can appear deceivingly normal, even when a large tumor is present. At CT, lymphoma of muscle can be homogenous in attenuation, and it may not show contrast enhancement, making tumor detection more difficult. Post-treatment changes often are encountered at MR imaging and positron emission tomography, and when considered in light of the patient's therapy regimen (eg, radiation therapy and granulocyte-colony stimulating factor), they usually can be differentiated from tumor. Post-treatment changes include diffuse FDG uptake in marrow after chemotherapy, indicating rebound of normal marrow, and MR imaging signal abnormalities that may persist for anywhere from a few months to years after treatment.

Imaging of lymphoma of the musculoskeletal system

Imaging plays a crucial role in staging and the assessment of treatment response in patients who have lymphoma of the musculoskeletal system. This article reviews imaging features of lymphoma of bone, muscles, cutaneous, and subcutaneous tissue. At radiography, lymphoma of the bone is most commonly lytic, but the affected bone also can appear deceptively normal, even when a large tumor is present. At CT, lymphoma of muscle can be homogenous in attenuation, and it may not show contrast enhancement, making tumor detection more difficult. Post-treatment changes often are encountered at MR imaging and positron emission tomography, and when considered in light of the patient's therapy regimen (eg, radiation therapy and granulocyte-colony stimulating factor), they usually can be differentiated from tumor. Post-treatment changes include diffuse FDG uptake in marrow after chemotherapy, indicating rebound of normal marrow, and MR imaging signal abnormalities that may persist for anywhere from a few months to years after treatment.

(1)H MR spectroscopy of skeletal muscle, liver and bone marrow

Proton magnetic resonance spectroscopy ((1)H MRS) offers interesting metabolic information even from organs outside the brain. In the first part, applications in skeletal muscle for determination of intramyocellular lipids (IMCL), which are involved in the pathogenesis of insulin resistance, are described. Peculiarities of spectral pattern are discussed and studies for short-term regulation of IMCL, as dietary intervention, exercise and fasting are presented. The second part deals with quantification of small amounts of lipids in the liver (hepatic lipids, HL), which is also of increasing interest in the field of diabetes research. Recommendations for correct assessment of spectra in this "moving organ" are given and the importance of HL is described by examples of a cohort at increased risk for type 2 diabetes. Regulation of HL is described on the basis of a few studies. The third part concentrates on spectral characterization of bone marrow. Peripheral bone marrow of adults consists mainly of fat, while central marrow regions in the pelvis, spinal column and breast bone (and the peripheral bone marrow of children as well) contribute to blood formation and show a variable composition of adipocytes (fat cells), interstitial fluid and water containing precursor cells for erythrocytes, leucocytes and thrombocytes. Adapted (1)H spectroscopic techniques allow a semi-quantitative analysis of bone marrow composition.

Magnetic resonance imaging of bone marrow in oncology, Part 2

Magnetic resonance imaging plays an integral role in the detection and characterization of marrow lesions, planning for biopsy or surgery, and post-treatment follow-up. To evaluate findings in bone marrow on MR imaging, it is essential to understand the normal composition and distribution of bone marrow and the changes in marrow that occur with age, as well as the basis for the MR signals from marrow and the factors that affect those signals; these points have been reviewed and illustrated in part 1 of this two-part article. Part 2 will emphasize the practical application of MR imaging to facilitate differentiation of normal marrow, tumor, and treatment-related marrow changes in oncology patients, and will review complementary MR techniques under development.

Quantitative and semiquantitative evaluation of erythropoietin-induced bone marrow signal changes in lumbar spine MRI in patients with tumor anemia

BACKGROUND

The topic of this article is the quantitative and semiquantitative assessment of bone marrow signal alteration in magnetic resonance imaging (MRI) of the lumbar spine in patients with tumor anemia during therapy with epoietin beta or placebo.

PATIENTS AND METHODS

We examined 32 patients with head or neck cancer (16 epoietin beta, 16 placebo) during radiotherapy in a double-blind multicenter trial. During radiotherapy, the patients underwent epoietin beta therapy for 7-9 weeks. Lumbar spine measurements using T1-w SE, OPP and Turbo- STIR were taken prior to the first epoietin beta or placebo therapy, after the acquired hemoglobin level had been reached, and after the final radiotherapy. The semiquantitative assessment was made blinded by 2 independent radiologists.

RESULTS

We found significant differences between both groups. The first MRI showed normal marrow signals. The second MRI revealed a quantified decrease in bone marrow signal in T1-w SE (p < 0.018) and an increase in OPP (p < 0.01) and Turbo-TIR (p < 0.048) sequences. At the third MR imaging, quantified relative marrow signals returned to baseline level in all sequences. Semiquantitative assessment confirmed these results.

CONCLUSION

In both analyses, lumbar spine MRI demonstrates significant bone marrow changes in T1-w SE, OPP and Turbo-STIR sequences during epoietin beta therapy.

Effect of granulocyte colony-stimulating factor (G-CSF)-supported chemotherapy on MR imaging of normal red bone marrow in breast cancer patients with focal bone metastases

PURPOSE

To investigate the effect of granulocyte colony-stimulating factor (G-CSF)-supported chemotherapy on normal red bone marrow MR imaging in breast cancer patients with focal bone metastases.

MATERIAL AND METHODS

Fifteen breast cancer patients who were examined before and after chemotherapy with T1-weighted-SE and long echo-time inversion-recovery turbo-spin-echo (long TE IR-TSE) sequences in the thoracolumbar spine and pelvis were retrospectively studied. Nine of them received G-CSF therapy after the administration of each chemotherapy course. Of these 9 patients, the MR follow-ups were performed during G-CSF in 4 patients and after G-CSF therapy in 5 patients. Six patients did not receive G-CSF. Signal intensity (SI) changes in normal bone marrow were evaluated visually in all patients and quantitatively in 13 patients.

RESULTS

In all 4 patients investigated during G-CSF therapy a diffuse, homogeneous SI increase on long TE IR-TSE was observed visually and quantitatively in initially normal bone marrow. This change obscured some focal lesions in 2 patients. No such SI change was visible after G-CSF therapy (p = 0.008) or in patients not receiving G-CSF. On T1-weighted images an SI decrease was found both during and after G-CSF therapy, but an increase occurred in patients not receiving G-CSF.

CONCLUSION

G-CSF-supported chemotherapy can induce diffuse SI changes in normal red bone marrow on MR imaging. On long TE IR-TSE, the changes are visible during G-CSF treatment and can lead to misinterpretations in the response evaluation of bone metastases to therapy.

Extent and time course of morphological changes of bone marrow induced by granulocyte-colony stimulating factor as assessed by magnetic resonance imaging of healthy blood stem cell donors

The aim of this study was to assess the time course and extent of signal alterations of red bone marrow after short-term stimulation by recombinant human granulocyte-colony stimulating factor (rHuG-CSF) in healthy peripheral blood stem cell donors using magnetic resonance imaging (MRI) at low-field strength. Twelve healthy blood stem cell donors without evidence of bone marrow disorders were prospectively investigated and underwent four MRI studies of their lumbar spine. Sagittal T1- and T2-weighted spin-echo sequences and a gradient-echo (GE) sequence with an echo time for out-of-phase imaging were performed prior to rHuG-CSF application (baseline MRI), on the day of first stem cell harvest (after 70 microg/kg body weight rHuG-CSF, second MRI) followed by two studies 9-18 days (median 14.5 days, third MRI) and 26-48 days (median 39.5 days, fourth MRI) after discontinuation of rHuG-CSF application. Baseline MRI showed normal marrow signal in all patients. The second MRI revealed a decrease of quantified bone marrow signal relative to nucleus pulposus in T1- and T2-weighted images and an increase of relative signal in out-of-phase GE sequences. The greatest changes of relative marrow signal were observed at the third MRI. Compared to baseline MRI, relative marrow signal was diminished by 12% in T1-weighted images and increased by 59% in GE sequences, consistent with a rise in marrow cellularity simulating diffuse marrow disease. At the fourth MRI quantified relative marrow signal returned to baseline levels in all sequences. In healthy individuals rHuG-CSF application leads to significant signal changes of bone marrow in lumbar vertebra that are maximal about 2 weeks after discontinuation of rHuG-CSF application. In patients with underlying marrow disorders who receive hematopoietic growth factors during treatment, these changes should not be confused with disease progression.