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Prolonged bone marrow T1-relaxation in patients with polycythemia vera
Magnelrc Resonance Imaging, Vol. 6, pp. 291.292, Printed m the USA. All rights reserved.
1988
0730-725X/88 $3.00 + .Ofl Copyright Cl 1988 Pergamon Pre\5 plc
l Original Contribution
PROLONGED
BONE MARROW Tl-RELAXATION WITH POLYCYTHEMIA VERA
IN PATIENTS
KARL ERIK JENSEN, * TORBEN GRUBE,~‘ CARSTEN THOMSEN, * PETER GRUNDTVIG S@RENSEN,~ PER CHRISTOFFERSEN,$ HANS KARLE,~’ AND OLE HENRIKSEN* Departmentsof Magnetic Resonance,* Haematology,l_and Pathology,$ Hvidovre Hospital, University of Copenhagen, Denmark In vitro as well as in vivo studies have shown prolonged T, relaxation times in patients with acute leukemia. The mechanism behind this finding is not known. In order to evaluate if this was specific for leukemia we examined eight patients with polycythemia Vera, representing a condition with a rather benign bone marrow neoplasia. In this group of patients we found prolonged T, relaxation times but normal T2 relaxation times. This may indicate that the prolonged T, relaxation time seen in leukemic bone marrow is not due to the malignant cell per se.
Keywords: Polycythemia acterization
Vera; Magnetic resonance imaging; T, and Tz relaxation processes; In vivo tissue charof bone marrow.
INTRODUCTION
None of the patients had received chemotherapy or radiation therapy. Bone marrow biopsy and aspiration were obtained from the posterior-superior iliac spine within three days in relation to the MRI investigation. The bone marrow was evaluated for total cellularity and differential count, myelofibrosis, fat content and iron content.
Magnetic resonance imaging (MRI) offers a unique possibility to study the bone marrow, as the mineral osseous tissue does not contribute to the signal. In a previous study5 we found a two to three time increase in T, relaxation times of the bone marrow in patients with acute leukemia at the time of diagnosis, whereas the values were in the normal range during remission. In these patients the T2 relaxation times fell within the normal range. Polycythemia vera in the chronic erythaemic phase, is a relatively benign proliferative disorder of the haematopoetic tissue characterized by hyperplasia of all myeloid cell lines and a rapid cell turnover. In order to evaluate if prolonged T, relaxation time is specific for the leukemic bone marrow, we examined eight patients with polycythemia Vera. PATIENTS
MRI Investigation
The study was carried out on a Siemens Magnetom 1.5 Tesla wholebody scanner (Siemens AG, Erlangen, West Germany). The measurements were obtained in the bone marrow thoracic spine Th 6 to 8 using the body coil. T, and T2 relaxation processes were measured as previously described.’ Statistics
Mann-Whitney rank sum test for unpaired samples was used for comparison between groups.
AND METHODS
Eight patients, age 52-75 years, with histopathological confirmed polycythemia vera were included. All patients were regularly treated with phlebotomy in order to maintain a haematocrit value below 0.48. RECEIVED 10/6/87;
RESULTS
In all eight patients the bone marrow showed uniform changes with hyperplasia of erythropoietic, mypartment of Magnetic Resonance, Hvidovre Hospital, DK2650 Copenhagen.
ACCEPTED 1 l/5/87.
Address correspondence to Karl Erik Jensen, MD, De291
292
Magnetic
Resonance
Imaging
elopoietic and megacaryopoetic ceil lines. No reticular tissue was detected and the marrow was iron depleted. Figure 1 shows the initial slope of the longitudinal relaxation process T, and the T2 relaxation time compared to the normal range. In all patients T, relaxation times were prolonged with a median of 971 ms (range 690-1390 ms) compared to the normal range 380-600 ms, (p < 0.001). Regarding the transversal relaxation process no changes were found in the Tz relaxation times, median 85 ms (range 70-l 10 ms). In all patients we found a biexponential longitudinal relaxation process, but were not able to resolve the two components.
l Volume 6, Number
3, 1988
T, relaxation msec.
time
T2 relaxation msec
1500
time
1000
DISCUSSION Both in vitro4 and in vivo’,2*‘,’ studies of the bone marrow in patients with acute leukemia in relapse have shown prolonged T, relaxation time, while no significant change was seen in the Tz relaxation time compared to normal individuals. In a previous study’ we found a 2-3-fold increase in the T, relaxation time. During chemotherapy the T, relaxation time decreased toward the normal range concomitant with remission induction. There was no correlation between the T, and the cellularity, number of blast cells, or the fat content of the bone marrow. In the present study of patients with polycythemia vera we found an increase of similar magnitude in the T, relaxation time as seen in the patients with acute leukemia. Both conditions are characterized by increased cellularity and increased cell turnover and the identical pattern might indicate that the T, relaxation time is better correlated to the number of cells in active cycle and cell turnover than to malignancy per se. The failure to resolve the two components in the longitudinal relaxation process is due to the limited sensitivity, when imaging techniques are used. The use of volume selective spectroscopy with individual relaxation time measurements of the water and fat content in the bone marrow may solve this problem and give further useful information. REFERENCES 1. Cohen, M.D.; Klatte, E.C.; Baehner, R.; Smith, J.A.; Martin-Simmerman, P.; Carr, B.E.; Provisor, A.J.;
500
I Fig. I. Initial slope of the longitudinal relaxation curve T, and the T, relaxation time for the eight patients with polycythemia Vera. The normal range is given as hatched areas.
Weetman, R.M.; Coates, T.; Siddiqui, A.R.; Weisman, S.J.; Berkow, R.; McKenna, S.; McQuire, W.A. Magnetic resonance imaging of bone marrow disease in children. Radiology 151:715-718; 1984. Moore, G.S.; Gooding, C.A.; Brasch, R.C. Bone marrow in children with acute lymphocytic leukemia: MRrelaxation times. Radiology 160:237-240; 1986. Nyman, R.; Rehn, S.; Ericsson, A.; Glimelius, B.; Hagberg, H.; Hemmingsson, A.; Jung, B.; Simonsson, B.; Sundstrom, C. Tissue characterization with magnetic resonance imaging in malignant lymphoma. Book of Abstracts, European Workshop on Magnetic Resonance in Medicine, London, 1987; 56-57. Renade, S.S.; Smita, S.; Advani, S.H.; Kasturi, S.R. Pulsed nuclear magnetic resonance studies of human bone marrow. Physiol. Chem. Phys. 9:297-299; 1977. Thomsen, C.; Sorensen, P.G.; Karle, H.; Christoffersen, P.; Henriksen, 0. Prolonged bone marrow T,-relaxation in acute leukaemia. Magn. Reson. Imaging 5:251257; 1987.
1988
0730-725X/88 $3.00 + .Ofl Copyright Cl 1988 Pergamon Pre\5 plc
l Original Contribution
PROLONGED
BONE MARROW Tl-RELAXATION WITH POLYCYTHEMIA VERA
IN PATIENTS
KARL ERIK JENSEN, * TORBEN GRUBE,~‘ CARSTEN THOMSEN, * PETER GRUNDTVIG S@RENSEN,~ PER CHRISTOFFERSEN,$ HANS KARLE,~’ AND OLE HENRIKSEN* Departmentsof Magnetic Resonance,* Haematology,l_and Pathology,$ Hvidovre Hospital, University of Copenhagen, Denmark In vitro as well as in vivo studies have shown prolonged T, relaxation times in patients with acute leukemia. The mechanism behind this finding is not known. In order to evaluate if this was specific for leukemia we examined eight patients with polycythemia Vera, representing a condition with a rather benign bone marrow neoplasia. In this group of patients we found prolonged T, relaxation times but normal T2 relaxation times. This may indicate that the prolonged T, relaxation time seen in leukemic bone marrow is not due to the malignant cell per se.
Keywords: Polycythemia acterization
Vera; Magnetic resonance imaging; T, and Tz relaxation processes; In vivo tissue charof bone marrow.
INTRODUCTION
None of the patients had received chemotherapy or radiation therapy. Bone marrow biopsy and aspiration were obtained from the posterior-superior iliac spine within three days in relation to the MRI investigation. The bone marrow was evaluated for total cellularity and differential count, myelofibrosis, fat content and iron content.
Magnetic resonance imaging (MRI) offers a unique possibility to study the bone marrow, as the mineral osseous tissue does not contribute to the signal. In a previous study5 we found a two to three time increase in T, relaxation times of the bone marrow in patients with acute leukemia at the time of diagnosis, whereas the values were in the normal range during remission. In these patients the T2 relaxation times fell within the normal range. Polycythemia vera in the chronic erythaemic phase, is a relatively benign proliferative disorder of the haematopoetic tissue characterized by hyperplasia of all myeloid cell lines and a rapid cell turnover. In order to evaluate if prolonged T, relaxation time is specific for the leukemic bone marrow, we examined eight patients with polycythemia Vera. PATIENTS
MRI Investigation
The study was carried out on a Siemens Magnetom 1.5 Tesla wholebody scanner (Siemens AG, Erlangen, West Germany). The measurements were obtained in the bone marrow thoracic spine Th 6 to 8 using the body coil. T, and T2 relaxation processes were measured as previously described.’ Statistics
Mann-Whitney rank sum test for unpaired samples was used for comparison between groups.
AND METHODS
Eight patients, age 52-75 years, with histopathological confirmed polycythemia vera were included. All patients were regularly treated with phlebotomy in order to maintain a haematocrit value below 0.48. RECEIVED 10/6/87;
RESULTS
In all eight patients the bone marrow showed uniform changes with hyperplasia of erythropoietic, mypartment of Magnetic Resonance, Hvidovre Hospital, DK2650 Copenhagen.
ACCEPTED 1 l/5/87.
Address correspondence to Karl Erik Jensen, MD, De291
292
Magnetic
Resonance
Imaging
elopoietic and megacaryopoetic ceil lines. No reticular tissue was detected and the marrow was iron depleted. Figure 1 shows the initial slope of the longitudinal relaxation process T, and the T2 relaxation time compared to the normal range. In all patients T, relaxation times were prolonged with a median of 971 ms (range 690-1390 ms) compared to the normal range 380-600 ms, (p < 0.001). Regarding the transversal relaxation process no changes were found in the Tz relaxation times, median 85 ms (range 70-l 10 ms). In all patients we found a biexponential longitudinal relaxation process, but were not able to resolve the two components.
l Volume 6, Number
3, 1988
T, relaxation msec.
time
T2 relaxation msec
1500
time
1000
DISCUSSION Both in vitro4 and in vivo’,2*‘,’ studies of the bone marrow in patients with acute leukemia in relapse have shown prolonged T, relaxation time, while no significant change was seen in the Tz relaxation time compared to normal individuals. In a previous study’ we found a 2-3-fold increase in the T, relaxation time. During chemotherapy the T, relaxation time decreased toward the normal range concomitant with remission induction. There was no correlation between the T, and the cellularity, number of blast cells, or the fat content of the bone marrow. In the present study of patients with polycythemia vera we found an increase of similar magnitude in the T, relaxation time as seen in the patients with acute leukemia. Both conditions are characterized by increased cellularity and increased cell turnover and the identical pattern might indicate that the T, relaxation time is better correlated to the number of cells in active cycle and cell turnover than to malignancy per se. The failure to resolve the two components in the longitudinal relaxation process is due to the limited sensitivity, when imaging techniques are used. The use of volume selective spectroscopy with individual relaxation time measurements of the water and fat content in the bone marrow may solve this problem and give further useful information. REFERENCES 1. Cohen, M.D.; Klatte, E.C.; Baehner, R.; Smith, J.A.; Martin-Simmerman, P.; Carr, B.E.; Provisor, A.J.;
500
I Fig. I. Initial slope of the longitudinal relaxation curve T, and the T, relaxation time for the eight patients with polycythemia Vera. The normal range is given as hatched areas.
Weetman, R.M.; Coates, T.; Siddiqui, A.R.; Weisman, S.J.; Berkow, R.; McKenna, S.; McQuire, W.A. Magnetic resonance imaging of bone marrow disease in children. Radiology 151:715-718; 1984. Moore, G.S.; Gooding, C.A.; Brasch, R.C. Bone marrow in children with acute lymphocytic leukemia: MRrelaxation times. Radiology 160:237-240; 1986. Nyman, R.; Rehn, S.; Ericsson, A.; Glimelius, B.; Hagberg, H.; Hemmingsson, A.; Jung, B.; Simonsson, B.; Sundstrom, C. Tissue characterization with magnetic resonance imaging in malignant lymphoma. Book of Abstracts, European Workshop on Magnetic Resonance in Medicine, London, 1987; 56-57. Renade, S.S.; Smita, S.; Advani, S.H.; Kasturi, S.R. Pulsed nuclear magnetic resonance studies of human bone marrow. Physiol. Chem. Phys. 9:297-299; 1977. Thomsen, C.; Sorensen, P.G.; Karle, H.; Christoffersen, P.; Henriksen, 0. Prolonged bone marrow T,-relaxation in acute leukaemia. Magn. Reson. Imaging 5:251257; 1987.