• 1.

    Meij BP, Voorhout G & Van den Ingh TSGAM, et al. Transsphenoidal hypophysectomy in beagle dogs: evaluation of a microsurgical technique. Vet Surg 1997;26:295309.

    • Search Google Scholar
    • Export Citation
  • 2.

    Meij BP, Voorhout G & Van den Ingh TSGAM, et al. Results of transsphenoidal hypophysectomy in 52 dogs with pituitary-dependent hyperadrenocorticism. Vet Surg 1998;27:246261.

    • Search Google Scholar
    • Export Citation
  • 3.

    Rijnberk A. Clinical endocrinology of dogs and cats. Dordrecht, The Netherlands: Kluwer Academic Publishers, 1996;1134.

  • 4.

    Van der Vlugt-Meijer RH, Voorhout G, Meij BP. Imaging of the pituitary gland in dogs with pituitary-dependent hyperadrenocorticism. Mol Cell Endocrinol 2002;197:8187.

    • Search Google Scholar
    • Export Citation
  • 5.

    Van der Vlugt-Meijer RH, Meij BP & Van den Ingh TSGAM, et al. Dynamic computed tomography of the pituitary gland in dogs with pituitary-dependent hyperadrenocorticism. J Vet Intern Med 2003;17:773780.

    • Search Google Scholar
    • Export Citation
  • 6.

    Van der Vlugt-Meijer RH, Meij BP, Voorhout G. Dynamic computed tomographic evaluation of the pituitary gland in healthy dogs. Am J Vet Res 2004;65:15181524.

    • Search Google Scholar
    • Export Citation
  • 7.

    Kooistra HS, Voorhout G & Mol JA, et al. Correlation between impairment of glucocorticoid feedback and the size of the pituitary gland in dogs with pituitary-dependent hyperadrenocorticism. J Endocrinol 1997;152:387394.

    • Search Google Scholar
    • Export Citation
  • 8.

    Love NE, Fisher P, Hudson L. The computed tomographic enhancement pattern of the normal canine pituitary gland. Vet Radiol Ultrasound 2000;41:507510.

    • Search Google Scholar
    • Export Citation
  • 9.

    Chong BW, Newton TH. Hypothalamic and pituitary pathology. Radiol Clin North Am 1993;31:11471183.

  • 10.

    Elster AD. Modern imaging of the pituitary. Radiology 1993;187:114.

  • 11.

    Escourelle H, Abecassis JP & Betagna X, et al. Comparison of computerized tomography and magnetic resonance imaging for the examination of the pituitary gland in patients with Cushing's disease. Clin Endocrinol (Oxf) 1993;39:307313.

    • Search Google Scholar
    • Export Citation
  • 12.

    Fitzpatrick M, Tartaglino LM & Hollander MD, et al. Imaging of sellar and parasellar pathology. Radiol Clin North Am 1999;37:101121.

  • 13.

    Lee BCP, Deck MDF. Sellar and juxtasellar lesion detection with MR. Radiology 1985;157:143147.

  • 14.

    Colombo N, Berry I & Kucharczyk J, et al. Posterior pituitary gland: appearance on MR images in normal and pathological states. Radiology 1987;165:481485.

    • Search Google Scholar
    • Export Citation
  • 15.

    Fujisawa I, Asato R & Nishimura K, et al. Anterior and posterior lobes of the pituitary gland: assessment by 1.5T MR imaging. J Comput Assist Tomogr 1987;11:214220.

    • Search Google Scholar
    • Export Citation
  • 16.

    Fujisawa I, Nishimura K & Asato R, et al. Posterior lobe of the pituitary in diabetes insipidus: MR findings. J Comput Assist Tomogr 1987;11:221225.

    • Search Google Scholar
    • Export Citation
  • 17.

    Kurakowa H, Fujisawa I & Nkano Y, et al. Posterior lobe of the pituitary gland: correlation between signal intensity on T1-weighted MR images and vasopressin concentration. Radiology 1998;207:7983.

    • Search Google Scholar
    • Export Citation
  • 18.

    Duesberg CA, Feldman EC & Nelson RW, et al. Magnetic resonance imaging for diagnosis of pituitary macrotumors in dogs. JAm Vet Med Assoc 1995;206:657662.

    • Search Google Scholar
    • Export Citation
  • 19.

    Bertoy EH, Feldman EC & Nelson RW, et al. Magnetic resonance imaging of the brain in dogs with recently diagnosed but untreated pituitary-dependent hyperadrenocorticism. J Am Vet Med Assoc 1995;206:651656.

    • Search Google Scholar
    • Export Citation
  • 20.

    Bertoy EH, Feldman EC & Nelson RW, et al. One-year follow-up evaluation of magnetic resonance imaging of the brain in dogs with pituitary-dependent hyperadrenocorticism. J Am Vet Med Assoc 1996;208:12681273.

    • Search Google Scholar
    • Export Citation
  • 21.

    Graham JP, Roberts GD, Newell SM. Dynamic magnetic resonance imaging of the normal canine pituitary gland. Vet Radiol Ultrasound 2000;41:3540.

    • Search Google Scholar
    • Export Citation
  • 22.

    Kippenes H, Gavin PR & Kraft SL, et al. Mensuration of the normal pituitary gland from magnetic resonance images in 96 dogs. Vet Radiol Ultrasound 2001;42:130133.

    • Search Google Scholar
    • Export Citation
  • 23.

    Meij BP, Mol JA & Hazewinkel HAW, et al. Assessment of a combined anterior pituitary function test in beagle dogs: rapid sequential intravenous administration of four hypothalamic releasing hormones. Domest Anim Endocrinol 1996;13:161170.

    • Search Google Scholar
    • Export Citation
  • 24.

    Katz DA, Marks MP & Napel SA, et al. Circle of Willis: evaluation with spiral CT angiography, MR angiography, and conventional angiography. Radiology 1995;195:445449.

    • Search Google Scholar
    • Export Citation
  • 25.

    Daniel PM, Pritchard MML. Studies of the hypothalamus and the pituitary gland. Acta Endocrinol Suppl (Copenh) 1975;80:S27S63.

  • 26.

    Hullinger RL. The endocrine system. In: Evans HE, ed. Miller's anatomy of the dog. 3rd ed. Philadelphia: WB Saunders Co, 1993;559585.

    • Search Google Scholar
    • Export Citation
  • 27.

    Hamon-Kerautret M, Leclerc X & Dewilly D, et al. Pituitary microadenomas: experience with Gd-DOTA-enhanced MR imaging at 0.5 Tesla. Eur J Radiol 1994;18:185190.

    • Search Google Scholar
    • Export Citation
  • 28.

    Stadnik T, Stevenaert A & Beckers A, et al. Pituitary microadenomas: diagnosis with two- and three-dimensional MR imaging at 1.5 T before and after injection of gadolinium. Radiology 1990;176:419428.

    • Search Google Scholar
    • Export Citation
  • 29.

    Elster AD. Sellar susceptibility artifacts: theory and implications. AJNR Am J Neuroradiol 1993;14:129136.

  • 30.

    Dyce KM, Sack WO, Wensing CJG. The head and ventral neck of the carnivores. In: Textbook of veterinary anatomy. Philadelphia: WB Saunders Co, 2002;367392.

    • Search Google Scholar
    • Export Citation
  • 31.

    Elster AD. Gradient-echo MR imaging: techniques and acronyms. Radiology 1993;186:18.

  • 32.

    Brown MA, Semelka RC. MR imaging abbreviations, definitions and descriptions: a review. Radiology 1999;213:647662.

  • 33.

    Hesselink JR, Martin JF, Edelman RR. Fast imaging. Neuroradiology 1990;32:348355.

  • 34.

    Kalender WA. Thin section three-dimensional spiral CT: is isotropic imaging possible? Radiology 1995;197:578580.

  • 35.

    Mark L, Peck P & Daniels D, et al. The pituitary fossa: a correlative anatomic and MR study. Radiology 1984;153:453457.

  • 36.

    Terano T, Seya A & Tamura Y, et al. Characteristics of the pituitary gland in elderly subjects from magnetic resonance images: relationship to pituitary hormone secretion. Clin Endocrinol (Oxf) 1996;45:273279.

    • Search Google Scholar
    • Export Citation
  • 37.

    Brooks BS, Gammal TE & Allison JD, et al. Frequency and variation of the posterior bright signal. AJNR Am J Neuroradiol 1989;10:943948.

  • 38.

    Sato N, Ishizaka H & Matsumoto M, et al. MR detectability of posterior pituitary high signal and direction of frequency encoding gradient. J Comput Assist Tomogr 1991;15:355358.

    • Search Google Scholar
    • Export Citation
  • 39.

    Miki Y, Asato R & Okumura R, et al. Contrast enhanced area of posterior pituitary gland in early dynamic MRI exceeds hyperintense area on T1-weighted images. J Comput Assist Tomogr 1992;16:845848.

    • Search Google Scholar
    • Export Citation
  • 40.

    Voorhout G. Cisternography combined with linear tomography for the visualization of the pituitary gland in healthy dogs: a comparison with computed tomography. Vet Radiol Ultrasound 1990;31:6873.

    • Search Google Scholar
    • Export Citation
  • 41.

    Niebauer GW. Hypophysectomy. In: Slatter D, ed. Textbook of small animal surgery. 2nd ed. Philadelphia: WB Saunders Co, 1993;14961510.

    • Search Google Scholar
    • Export Citation

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Thin-slice three-dimensional gradient-echo magnetic resonance imaging of the pituitary gland in healthy dogs

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  • 1 Division of Diagnostic Imaging, Faculty of Veterinary Medicine, Utrecht University, 3508 TD Utrecht, The Netherlands.
  • | 2 Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, 3508 TD Utrecht, The Netherlands.
  • | 3 Division of Diagnostic Imaging, Faculty of Veterinary Medicine, Utrecht University, 3508 TD Utrecht, The Netherlands.

Abstract

Objective—To evaluate thin-slice 3-dimensional gradient-echo (GE) magnetic resonance imaging (MRI) of the pituitary gland in healthy dogs.

Animals—11 healthy dogs.

Procedures—By use of a 0.2-Tesla open magnet, MRI of the skull was performed with T1-weighted GE sequences and various protocols with variations in imaging plane, slice thickness, and flip angle before and after administration of contrast medium; multiplanar reconstructions were made. The pituitary region was subjectively assessed, and its dimensions were measured. Image quality was determined by calculation of contrast-to-noise and signal-to-noise ratios.

Results—Best-detailed images were obtained with a T1-weighted GE sequence with 1-mm slice thickness and 30° flip angle before and after administration of contrast medium. Images with flip angles > 50° were of poor quality. Quality of multiplanar reconstruction images with 1-mm slices was better than with 2-mm slices. The bright signal was best seen without contrast medium. With contrast medium, the dorsal border of the pituitary gland was clearly delineated, but lateral borders were more difficult to discern.

Conclusions and Clinical Relevance—MRI of the canine pituitary gland with a 0.2-Tesla open magnet should include a T1-weighted GE sequence with 1-mm slice thickness and flip angle of 30° before and after administration of contrast medium. The neurohypophysis was best visualized without contrast medium. The MRI examination permitted differentiation between the pituitary gland and surrounding structures.

Contributor Notes

Dr. van der Vlugt-Meijer's present address is ACE Pharmaceuticals BV, PO Box 1262, 3890 BB Zeewolde, The Netherlands.

Address correspondence to Dr. van der Vlugt-Meijer.