Martti Kormano

University of Turku, Turku, Western Finland, Finland

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Publications (93)251.78 Total impact

  • Academic Radiology 06/2002; 9 Suppl 1:S266-9. · 1.75 Impact Factor
  • Academic Radiology 05/2002; 9(1). DOI:10.1016/S1076-6332(03)80453-1 · 1.75 Impact Factor
  • Marianne Maass · Marjatta Kosonen · Martti Kormano
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    ABSTRACT: Introduction of a picture archiving and communication system (PACS) into an old hospital poses several problems since the system cannot be implemented instantaneously. We analysed the costs of a halfway implemented PACS in Turku University Central Hospital (TUCH) during 1998. Manual and digital archiving in 1998 continued parallel so that only 10% reduction of film usage was achieved. A 21% increase in image manipulation and storage expenses occurred. A calculation based on potential 90% reduction of film usage and changes in the amount of personnel suggest some direct savings. Also, indirect savings due to more efficient patient treatment and the reduction of time spent in the hospital, and overhead costs of information handling are expected to lead to savings. However, these savings were not included in our calculations. When full-scale PACS is installed, equipment investments, network and digital ware maintenance costs will drop from 121 to 116% compared with traditional film archiving activity costs.
    Computer Methods and Programs in Biomedicine 08/2001; 66(1):41-5. DOI:10.1016/S0169-2607(01)00133-X · 1.90 Impact Factor
  • Marianne Maass · Aaro Kiuru · Martti Kormano
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    ABSTRACT: This study was designed to evaluate effectiveness of radiological image data compression in terms of image quality and archiving material costs using DLT tapes, and to assess the relationship between loss of quality and cost savings. Six radiologists used Subjective Fidelity Criteria (SFC) in random fashion to evaluate the quality of 105 digitally acquired radiological images. In addition, 5 radiologists and 2 nonradiologists evaluated at random three phantom images exposed in conditions mimicking chest, bone, and colon examinations, displayed in five modes (a total of 15 images). Both patient images and phantom images were submitted to 3:1 (Ziv-Lempel method) and 10:1 compression (wavelet-based compression method). Cost information on material cost savings and the effect of compression on tape space requirements were compared. The results indicate that image quality was not degraded using either of the compression ratios. The interobserver proportion of agreement exceeded overwhelmingly the limit of a good proportion of agreement regarding each compression ratio and each image type. The divergence in the rest of the assessments was not consistent. The adoption of 10:1 compression would not bring a substantial decrease of archiving costs as compared to the total yearly operating costs, and especially as considering the consequences of possible image quality deterioration.
    Telemedicine and e-Health 02/2001; 7(3):267-71. DOI:10.1089/153056201316970975 · 1.67 Impact Factor
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    ABSTRACT: The development of a novel positioning device for magnetic resonance imaging of the upper cervical spine and an evaluation of motion patterns of the craniovertebral junction in asymptomatic volunteers as a part of the whole cervical spine motion. To design and construct a positioning device that enables magnetic resonance imaging of the cervical spine in rotation, lateral bending, flexion, and extension in a horizontally open magnetic resonance scanner, and to define reference values for movements of the occiput (C0), the atlas (C1), and the axis (C2) in asymptomatic volunteers. In previously used devices, the direction of motion is limited usually to flexion-extension, or the position of the head and neck are adjusted without a positioning device using semihard wedges or pillows. Magnetic resonance imaging of the upper cervical spine in 20 asymptomatic individuals (10 men and 10 women) was performed in a horizontally open 0.23-T magnetic resonance imager in progressive steps during rotation, lateral bending, and flexion-extension using axial, coronal, and sagittal imaging planes, respectively. The positions of C0, C1, and C2 were measured, and pattern of motions between segments analyzed. Lateral displacement of the atlas during lateral bending and cranial migration distance during flexion-extension were assessed. The nonferromagnetic positioning device was designed and constructed. The motion patterns of the craniovertebral junction during rotation did not differ between the men and women, but in lateral bending there was a small difference between genders at C1-C2. In men, the position of C1 during flexion-extension was consistently more extended in relation to C0 and C2 than in women. The new positioning device allows magnetic resonance imaging of the upper cervical spine during flexion, extension, rotation, and lateral bending. To assess the relationship between C0-C1 and C1-C2 in flexion and extension, separate reference values for men and women are recommended.
    Spine 11/1999; 24(19):2046-56. DOI:10.1097/00007632-199910010-00015 · 2.30 Impact Factor
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    ABSTRACT: A prospective 9-year follow-up study involving randomized matched subgroups of 15-year-old schoolchildren with or without low back pain at baseline. To evaluate the long-term persistence of initially reported recurrent low back pain, and to examine the significance of abnormalities found in magnetic resonance imaging of lumbar discs in individuals 15 and 18 years of age as possible contributors to persistently recurrent low back pain. In surveys among children and teenagers during the past few years, as many as half of all children in a community report a history of low back pain. The current results, in accordance with previous findings, indicate that there is a subgroup of adolescents with more chronic symptoms which, in the authors' opinion, deserves more attention. Disc disease accompanying low back pain is a key issue both in research and clinical practice. The significance of early degenerative findings in the lumbar discs is not known. In the survey of 14-year-olds (n = 1503), a subgroup (7.8%) with recurrent low back pain was found. A random sample of individuals with recurrent low back pain (n = 40) and an equal number of completely asymptomatic control subjects were selected for a comparative study. The selected groups were examined by magnetic resonance imaging at 15 and 18 years of age. The participation rate of youth at 14, 18, and 23 years of age for all three questionnaires was 82% (29 boys and 33 girls). Imaging data were interpreted by two blinded radiologists experienced in low-field-strength magnetic resonance imaging. In calculations of relative risks, the participants reporting recurrent low back pain in all phases of the study were compared with participants who had no persistently recurrent pain. Eleven participants (35%) in the original group with low back pain persistently reported recurrent pain. In 15-year-old participants with disc degeneration, the relative risk of reporting recurrent low back pain up to the age of 23 years was 16 (95% confidence interval 2.2-118) compared with those having no disc degeneration. In addition, disc protrusion and Scheuermann-type changes at 15 years contributed to the risk of persistently recurrent low back pain. The authors' earlier findings already favored the hypothesis of a causal relation between the early evolution of a degenerative process of lower lumbar discs and recurrent low back pain in the near future. The current results further strengthen this hypothesis, indicating that individuals with disc degeneration soon after the phase of rapid physical growth not only have an increased risk of recurrent low back pain at this age, but also a long-term risk of recurrent pain up to early adulthood.
    Spine 08/1999; 24(13):1316-21. DOI:10.1097/00007632-199907010-00008 · 2.30 Impact Factor
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    ABSTRACT: The aim of the study 'Dynamic Chest Image Analysis' is to develop computer analysis and visualization methods for showing focal and general abnormalities of lung ventilation and perfusion based on a sequence of digital chest fluoroscopy frames collected at different phases of the respiratory/cardiac cycles in a short period of time. We have proposed a framework for ventilation study with an explicit ventilation model based on pyramid images. In this paper, we extend the framework to pulmonary perfusion study. A perfusion model and the truncated pyramid are introduced. The perfusion model aims at extracting accurate, geographic perfusion parameters, and the truncated pyramid helps in understanding perfusion at multiple resolutions and speeding up the convergence process in optimization. Three cases are included to illustrate the experimental results.
    Proceedings of SPIE - The International Society for Optical Engineering 07/1998; DOI:10.1117/12.312589 · 0.20 Impact Factor
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    ABSTRACT: The purpose of this study was to evaluate 1/T1ρ in relation to 1/T1 and 1/T2 in characterizing normal and diseased muscle. We measured the muscle relaxation rates 1/T1 and 1/T2 at 0.1 T and 1/T1ρ at on-resonance locking fields B1 between 10 and 160 μT in myositis patients and normal volunteers. 1/T2 and 1/T1ρ of muscle were lower in the patients than in the volunteers, whereas there was no difference in the 1/T1 values. The lower relaxation rates 1/T2 and 1/T1ρ in the diseased muscle may be due to fat and connective tissue infiltrations and edema. 1/T1ρ contrast between muscle and subcutaneous fat was higher than 1/T2 and 1/T1 contrast. This may be explained by the different B1 dispersion behavior of these two tissue types. 1/T1ρ of fat is B1 field independent, whereas 1/T1ρ of muscle decreases clearly with increasing B1 field. In conclusion, 1/T1ρ provides a useful tool in manipulating contrast in magnetic resonance imaging of diseased muscle.
    Magnetic Resonance Imaging 05/1998; 16(4):385-391. DOI:10.1016/S0730-725X(98)00004-6 · 2.09 Impact Factor
  • Anette Virta · Markku Komu · Nina Lundbom · Martti Kormano
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    ABSTRACT: The authors evaluated the value of T1 rho in relation to T1 and T2 in the characterization of human muscles. The authors studied the effect of muscle type (anterior tibial [AT] and gastrocnemius [GC]), sex, and age on 1/T1 and 1/T2 at 0.1 T and on 1/ T1 rho at locking-field B1s (spin-locking radio-frequency magnetic induction field) of 10-160 microT in 38 healthy volunteers. The contrast-to-noise ratio (CNR) between muscle and fat was evaluated with different T1-, T2-, and T1 rho-weighted magnetic resonance (MR) sequences. The 1/T1, 1/T2, and 1/T1 rho were slightly higher in AT than in GC muscles. The 1/T2 and 1/T1 rho of AT muscles showed a sex dependence, whereas no correlation with age was found. The CNR of the T1 rho-weighted images did not markedly differ from that of the T1- and T2-weighted images. T1 rho is as sensitive as T2 to the composition of muscle, whereas T1 is less sensitive. In MR imaging of normal muscle, T1 rho and T2 provide a relatively similar tissue contrast.
    Academic Radiology 03/1998; 5(2):104-10. DOI:10.1016/S1076-6332(98)80130-X · 1.75 Impact Factor
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    ABSTRACT: The recently introduced horizontally open configuration imagers allow imaging of knee, hip or shoulder during whole range of motion, which is not possible in conventional MR imagers. Special joint motion devices can be used to provide accurate and reproducible studies. In cervical spine, functional MR imaging may be useful in evaluating alarligament stability in patients with late sequelae of a whiplash injury, and in patients with rheumatoid arthritis who are clinically suspected of having a cervical myelopathy or superior migration of the odontoid process. In shoulder, full range of motion abduction study may be helpful in assessing the supraspinatus tendon impingement. To evaluate patellofemoral malalignment, quadriceps loading is recommended since associated contracting muscles and related soft tissue structures can be evaluated. The position of the femoral head relative to the acetabulum during different positions can be assessed. Open-configuration scanners provide an access to patients during scanning procedure, and therefore permit interventional procedures to be monitored with MRI. Such interventions include aspiration cytology/biopsy and different drainage procedures.
    Der Radiologe 11/1997; 37(10):819-24. DOI:10.1007/s001170050288 · 0.43 Impact Factor
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    ABSTRACT: The aim of the study 'dynamic chest image analysis' is to develop computing analysis and visualization methods for showing focal and general abnormalities of lung ventilation and perfusion based on a sequence of digital chest fluoroscopy frames collected at different phases of the respiratory/cardiac cycles. A multiresolutional method for ventilation study with an explicit ventilation model based on pyramid images is proposed in this paper. The ventilation model is sophisticated enough in coverage of both inhalation and exhalation phases, but also remains simple enough in model realization. This model plays a critical role in extracting accurate, geographic ventilation parameters; while the pyramid helps in understanding ventilation at multiple resolutions and speeding up the convergence process in optimization. A number of patients have been studied with a research prototype produced in MATLAB. The prototype has proven to be useful aid in dynamic pulmonary ventilation study. However, for clinical use, further work must be done in the future.
    Proceedings of SPIE - The International Society for Optical Engineering 05/1997; DOI:10.1117/12.274032 · 0.20 Impact Factor
  • Anette Virta · Markku Komu · Martti Kormano
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    ABSTRACT: The effect of molecular weight, concentration, and structure on 1/T1rho, the rotating frame relaxation rate, was investigated for several proteins using the on-resonance spin-lock technique, for locking fields B1 < 200 microT. The measured values of 1/T1rho were fitted to a simple theoretical model to obtain the dispersion curves 1/T1rho(omega1) and the relaxation rate at zero B1 field, 1/T1rho(0). 1/T1rho was highly sensitive to the molecular weight, concentration, and structure of the protein. The amount of intra- and intermolecular hydrogen and disulfide bonds especially contributed to 1/T1rho. In all samples, 1/T1rho(0) was equal to 1/T2 measured at the main magnetic field Bo = 0.1 T, but at higher locking fields the dispersion curves monotonically decreased. The results of this work indicate that a model considering the effective correlation time of molecular motions as the main determinant for T1rho relaxation in protein solutions is not valid at very low B1 fields. The underlying mechanism for the relaxation rate 1/T1rho at B1 fields below 200 microT is discussed.
    Magnetic Resonance in Medicine 01/1997; 37(1):53-7. DOI:10.1002/mrm.1910370109 · 3.57 Impact Factor
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    ABSTRACT: To study splenic perfusion with use of computed tomography (CT). Twenty-six control patients without splenoportal disease, six with cirrhosis, and seven with other splenic disease were examined with electron-beam CT. Twenty-five milliliters of iohexol (300 mg of iodine per milliliter) was given intravenously at 10 mL/sec followed by a saline bolus. Multiple single-level axial sections were acquired 8-90 seconds after injection. Perfusion was calculated by dividing maximal splenic enhancement by the area under the circulation-corrected aortic time-enhancement curve. Subjective assessments of enhancement heterogeneity were made, and regional perfusion was calculated in 10 patients with heterogeneous enhancement. Total splenic volume and blood flow were computed in 21 patients. Mean perfusion (controls: 1.29 mL/min/mL, miscellaneous group: 1.07 mL/min/mL) was close to predictions. There was a trend toward lower perfusion in cirrhotic patients (0.87 mL/min/mL), but the difference was not statistically significant. Total splenic blood was increased in patients with cirrhosis (P < .01). Marked perfusion heterogeneity was observed in 41% of spleens, but by 2 minutes splenic enhancement was uniform. CT shows promise in the study of splenic blood flow.
    Academic Radiology 01/1997; 4(1):13-20. DOI:10.1016/S1076-6332(97)80155-9 · 1.75 Impact Factor
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    ABSTRACT: Objective: To determine whether T1- or T2*-weighted sequences are more informative and practical in dynamic Gd-DTPA-enhanced MR imaging for the evaluation of renal blood flow and function. Materials and Methods: Dynamic Gd-DTPA-enhanced MR imaging of the kidney was performed in 7 patients by either Tl-weighted TurboFLASH (TR/TE/TI/FA = 9/4/27/8) or T2*-weighted FLASH (TR/TE/FA = 32/22/10) sequences for comparison of the enhancement pattern. None of the subjects had a suspicion of renal dysfunction from laboratory data, and the absence of renal artery stenosis was confirmed by conventional angiography. Results: During the early phase, the marked signal increase in T1-weighted imaging in the renal cortex corresponded to a similar marked decrease in signal intensity in T2*-weighted imaging. During the middle and late phases, the medulla was dramatically decreased in intensity on the T2*-weighted imaging resulting in a good contrast between the cortex and medulla. Conclusion: Both sequences may provide almost similar information about the renal cortical blood flow. However, T2*-weighted dynamic MR imaging may be more informative than T1-weighted dynamic MR imaging about the concentrating ability in the renal medulla. A high concentration of Gd-DTPA in the tubular structure was suspected to cause a dramatic decrease in intensity in the medulla in T2*-weighted imaging.Copyright © 1996 S. Karger AG, Basel
    American Journal of Nephrology 11/1996; 16(6):506-512. DOI:10.1159/000169051 · 2.67 Impact Factor
  • Academic Radiology 09/1996; 3 Suppl 2:S176-8. DOI:10.1016/S1076-6332(96)80526-5 · 1.75 Impact Factor
  • Timo Kurki · Nina Lundbom · Markku Komu · Martti Kormano
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    ABSTRACT: T1s and magnetization transfer (MT) parameters of 36 intracranial tumors were determined in vivo at 0.1 T to assess their use in tissue characterization. The mobile water relaxation times (T1w) did not differ between tumor groups, whereas the T1s, the apparent MT relaxation times (T1a), and the parameters MT contrast (MTC) differed significantly between several tumor types. The MT rates (Rwm) demonstrated the most significant differences; Rwm values could reliably separate high grade and low grade gliomas. T1ws of the tumors were commonly in the same range as that of normal gray matter, whereas other parameters differed from those of normal brain. The results indicate that MT rates are superior to other parameters in the characterization of intracranial tumors and may be also useful clinically in the grading of gliomas.
    Journal of Magnetic Resonance Imaging 07/1996; 6(4):573-9. DOI:10.1002/jmri.1880060403 · 3.21 Impact Factor
  • Anette Virta · Martti Kormano · Jorma Paranko
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    ABSTRACT: Magnetization transfer (MT) imaging provides a novel opportunity to characterize interactions between tissue water and macromolecules. Although several in vitro investigations have shown that proteins and lipids are important determinants of MT, the contribution of DNA is still unknown. This study was designed to determine whether DNA and cell nuclear material exhibit MT. We measured the magnetization transfer effect of pure DNA strands and purified bovine sperm head nuclei. Although no transfer of magnetization could be detected in samples of pure DNA strands, the sperm head nuclei exhibited a strong MT effect that increased with increasing solid content of the samples. Since the purified bovine sperm head samples consist of large nuclei with only minor traces of perinuclear matrix, the measured MT effect arises from the chromatin of the nuclei. The DNA fills 90% of the nuclear volume and it is extremely tightly packed as chromatin fibers by nucleoproteins. We hypothesize that the numerous intra- and intermolecular disulfide bonds that stabilize the chromatin fibers restrict the movement of the surface water binding sites of both DNA and protamines and thus facilitate the transfer of magnetization. Therefore, the results indicate that the amount of nuclear material may positively contribute to MT in tissues.
    MAGMA Magnetic Resonance Materials in Physics Biology and Medicine 07/1996; 4(2):135-8. DOI:10.1007/BF01772520 · 2.87 Impact Factor
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    ABSTRACT: In the present study we introduce a new device for exercise magnetic resonance spectroscopy (MRS). It operates in a standard whole-body scanner. Mechanical exertion unit allows maximal 10 to 15 short-arc knee extensions. The device operates hydraulically and is based on isokinetic movement. The force and work conducted are automatically controlled by the electronic control and computer unit. A small surface coil placed on the vastus medialis muscle allows the collection of spectra without interfering spectra from nearby resting muscles. The force used for the extensions can be followed simultaneously as a curve on the screen in the operator's room and the data is transferred to a personal computer for later analysis. Total work and fatigue percentage are also calculated by the device. It also allows the use of different isokinetic exercise protocols. The measurements of force proved reliable in repeat measurements using an isokinetic test device as a control.This device has been used clinically for over a year, is easy to operate, and offers reliable measurements. It is well suited to trials where muscle energy states versus time are followed since it allows noninvasive simultaneous quantification of muscle performance and collecting MRS spectra at rest, during exercise, and in the recovery phase.
    MAGMA Magnetic Resonance Materials in Physics Biology and Medicine 05/1996; 4(2):115-122. DOI:10.1007/BF01772518 · 2.87 Impact Factor
  • Sami Kajander · Markku Komu · Pekka Niemi · Martti Kormano
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    ABSTRACT: In order to study the applicability of magnetization transfer contrast (MTC) to tissue differentiation, the determination of the magnetization transfer (MT) parameters of normal tissues is necessary for the evaluation of pathological conditions. The time-dependent saturation transfer technique was used to investigate the observed magnetization transfer parameters in several human tissues in vivo at 0.1 T. The length of the off-resonance saturation pulse varied from 0 to 750 ms. The magnetization transfer contrast (MTC) was 0.71 in striated muscle, 0.49 in liver, 0.49 in renal cortex, and 0.50 in spleen. The observed magnetization transfer rates (Rwm) were 5.5 s-1 for muscle, 3.1 s-1 for liver, and 1.5 s-1 for both renal cortex and spleen. Our results indicate that measuring Rwm and possibly other relaxation parameters could be useful in tissue differentiation.
    Magnetic Resonance Imaging 02/1996; 14(4):413-7. DOI:10.1016/0730-725X(96)00029-X · 2.09 Impact Factor
  • Anette Virta · Markku Komu · Martti Kormano · Nina Lundbom
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    ABSTRACT: We observed the magnetization transfer rates in a variety of protein solutions at 0.1-T magnetic field and compared our results with previous investigations at high magnetic fields (> 0.5 T). The effects of protein concentration, size, pH, denaturation, cross linking, and fiber formation were investigated. We used the saturation transfer technique to determine the transfer of magnetization in gamma globulin, fibronectin, collagen, fibrinogen, and albumin solutions. The observed transfer rate increased with increasing concentration and size of the protein. Protein degradation decreased the transfer rate. Cross linking and fiber formation each increased the transfer rate, whereas buffer pH had no effect. Protein denaturation, aggregation, and fiber formation are important determinants of magnetization transfer in vitro. The size, concentration, and cross linking of the proteins contribute strongly to the transfer of magnetization at low fields, and the effect seems to be at least as important as at the higher fields.
    Academic Radiology 09/1995; 2(9):792-8. DOI:10.1016/S1076-6332(05)80488-X · 1.75 Impact Factor

Publication Stats

1k Citations
251.78 Total Impact Points


  • 1983–2002
    • University of Turku
      • Department of Diagnostic Radiology
      Turku, Western Finland, Finland
  • 1989–2001
    • Turku University Hospital
      • • Department of Radiology
      • • Department of Pediatrics
      Turku, Varsinais-Suomi, Finland
    • Central Hospital Central Finland
      Jyväskylä, Province of Western Finland, Finland
  • 1994
    • University of Helsinki
      Helsinki, Uusimaa, Finland
  • 1993
    • University of Chicago
      • Department of Radiology
      Chicago, Illinois, United States
  • 1980
    • University of Rochester
      Rochester, New York, United States