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MRI of Pneumorachis in a Newborn Infant With Open Myelomeningocele
Case Reports
MRI of Pneumorachis in a Newborn Infant With Open Myelomeningocele Petra B. de Roos, MD*, Erik J. van Lindert, MD, PhD†, Ton A. van der Vliet, MD‡, and Lilian T. L. Sie, MD, PhD§ Pneumorachis, or air within the spinal canal, is a very rare radiographic finding, frequently of traumatic origin. A newborn infant with an open lumbosacral myelomeningocele presented with severe paraparesis and an unexpected dysfunction of the brainstem with somnolence, irregular respiration, and motor deficits of the upper extremities. Magnetic resonance imaging revealed hypoplasia of the brainstem and cerebellum and low-signal lesions on T2-weighted images at the cervicocranial junction, in the lateral ventricles, and in the spinal canal. Computed tomography confirmed the presence of intracranial and intraspinal air. The air disappeared 2 weeks later according to magnetic resonance imaging, but no clinical improvement occurred, even after 6 months. Pneumorachis and pneumocephalus can occur in newborn infants as an unexpected complication of an open myelomenigocele, with or without signs. The radiographic appearance of intraspinal air on magnetic resonance imaging was not described previously. Ó 2009 by Elsevier Inc. All rights reserved. de Roos PB, van Lindert EJ, van der Vliet TA, Sie LTL. MRI of pneumorachis in a newborn infant with open myelomeningocele. Pediatr Neurol 2009;40:377-379.
From the *Department of Neurology, †Department of Neurosurgery, ‡ Department of Radiology, and §Department of Pediatric Neurology, Radboud University Medical Center Nijmegen, Nijmegen, The Netherlands.
Ó 2009 by Elsevier Inc. All rights reserved. doi:10.1016/j.pediatrneurol.2008.11.019 0887-8994/09/$—see front matter
Introduction Pneumorachis, or intraspinal air, is an extremely rare radiographic finding, especially in the pediatric population. Etiologies include trauma (e.g., skull fractures or paranasal sinus and subarachnoid fistula after thoracic or spinal injury), iatrogenic lesions (e.g., after lumbar puncture, thoracotomy, and proctocolectomy), and malignancy with associated therapy [1-8]. Nontraumatic pneumorachis (e.g., spontaneous, infection-related, or tumor-related) is even more exceptional [1,4]. Pediatric nontraumatic pneumocephalus, as detected by ultrasound, x-rays of the skull, or cranial computed tomography, has been described mostly as a complication of mechanical ventilation and tension pneumothorax, and very rarely as a complication of a congenital defect of the dura, i.e., open myelomeningocele in newborn infants [9-12]. Intracranial air is thought to be the result of air entering the (enlarged) central canal through an open myelomeningocele, and ascending into the ventricular system. Air penetration into the spinal canal through a neural tube defect was reported and radiographically confirmed by fluoroscopy and postmortem myelography in only one case report, which concluded that the hydromyelia was probably the major factor permitting the ascent of air [9]. This case report describes a newborn infant with an open myelomeningocele presenting with unexpected somnolence, irregular respiration, and extensive motor deficits. Magnetic resonance imaging revealed a pneumorachis and pneumocephalus, as well as the cerebral malformations associated with myelomeningocele. The radiographic presentation of intraspinal air on magnetic resonance imaging as a complication of an open myelomeningocele was not described previously. Case Report A boy, born during week 37 of an uncomplicated pregnancy with maternal use of folic acid, presented at our hospital. No prenatal ultrasound had been performed. An emergency cesarean section was performed because of fetal distress during attempts to rotate the child out of his breech position. The APGAR score was 8 and 10, respectively, after 1 and 5 minutes. Upon physical examination, his birth weight was 2335 g, and an unexpected open lumbosacral myelomeningocele was evident, with leakage of cerebrospinal fluid. He was microcephalic with decreased vigilance, but without major clinical signs of increased intracranial pressure. There was generalized hypotonia and diminished movements of the arms, with almost complete
Communications should be addressed to: Dr. de Roos; Department of Neurology; Radboud University Medical Center Nijmegen; PO Box 9101; 6500 HB Nijmegen, The Netherlands. E-mail: [email protected] Received July 22, 2008; accepted November 25, 2008.
de Roos et al: Magnetic Resonance Imaging of Pneumorachis
377
Figure 1. Sagittal T1-weighted magnetic resonance image (TR/TE = 450/8 ms) of the brain and cervicocranial junction (at age 4 days). (A) Air in region of pineal gland (AIR), descent of cerebellum (DC), and flattened brainstem (BS). (B) Air entrapment in posterior fossa (AIR) and lateral ventricular system (AIR).
absence of movements of the legs, and clubfeet. Reflexes were absent. There was no reaction on pinprick from the L3 segment downward. The postnatal period was complicated by an irregular respiration pattern. Respiration was periodically very superficial, with apneas and desaturations up to 90%. At day 2 of age, an apneic attack occurred during breastfeeding, and ended in a resuscitation setting. He was referred to the
neonatal intensive care unit, and continuous positive airway pressure was started temporarily. Diagnostic and therapeutic intervention was postponed because of the patient’s unstable clinical condition. Laboratory investigations excluded infection and metabolic or hormonal dysfunction. Caffeine and constantly low-flow nasal oxygen therapy afforded little improvement of the recurrent (self-limiting) episodes of apnea. Transfontanellar sonography indicated slightly enlarged occipital horns, a corpus callosum hypoplasia, and remarkably hypodense cyst-like lesions in the lateral ventricles and infratentorial region. At day 4 of age, he was clinically stable enough to undergo magnetic resonance imaging of the neuroaxis. Magnetic resonance imaging revealed a lumbosacral myelomeningocele, slight ventriculomegaly, hypoplasia of the brainstem and cerebellum with remnants of cerebellar tissue within the posterior fossa and upper cervical spinal canal (Chiari II malformation), and an occipital encephalocele (Fig 1). In addition, there were low-signal lesions on T1-weighted and T2-weighted magnetic resonance imaging in the thoracic and lumbar spinal canal (T6 L2; Fig 2), at the cervicocranial junction (Fig 1), and in both lateral ventricles (Fig 1). A computed tomography scan of the brain was performed, and confirmed the presence of intracranial air. At 7 days of age, a neurosurgical closure of the open myelomeningocele was performed. Magnetic resonance imaging was repeated 2 weeks later, and demonstrated that the pneumorachis and pneumocephalus had disappeared, but without clinical improvement. Within 6 months, the patient’s vigilance gradually increased, and his respiration was less irregular, with only sporadic desaturations that spontaneously recovered. Therefore, Chiari decompression was not considered. The persisting paraplegia did not recover, and neither did the function of the upper extremities. At age 12 months, the patient was able to fixate visually for a short time at a close distance. He still exhibited problems swallowing fluids, without the need of drip feeding. He could grasp for objects and turn over from his side to his back. He could not sit without support. There were movements of the upper extremities against gravity, without any motor performance of the legs. The patient did not develop hydrocephalus. At age 28 months, the child was found in bed, not breathing, and with a weak heartbeat. In the preceding days, he had manifested an upper-airway infection without respiratory problems. Resuscitation was initiated, but was unsuccessful.
Discussion Figure 2. Sagittal T2-weighted magnetic resonance image (TR/TE = 4240/112 ms) of spinal canal (at age 4 days). Air entrapment in spinal canal (T6 T9) (AIR), with myelomeningocele (MMC).
378 PEDIATRIC NEUROLOGY Vol. 40 No. 5
We describe a newborn infant with an open lumbosacral myelomeningocele with severe paraparesis and unexpected
dysfunction of the brainstem with somnolence, irregular respiration, dysphagia, and motor deficits of the upper extremities. Magnetic resonance imaging revealed the expected spinal and cerebral malformations, in addition to unexpected pneumorachis and pneumocephalus. We will discuss the clinical signs and underlying pathophysiologic mechanisms. The brainstem dysfunction was caused by an intrinsic hypoplasia of the brainstem itself and by compression of the brainstem because of the occipital encephalocele and Chiari II malformation. Respiratory problems associated with the Chiari malformation are caused by depression of the respiratory center, dysfunction of the ascending reticular system activation, and vocal-cord paralysis [10]. When intracranial pressure is elevated by hydrocephalus or intracranial air, further compression of these structures may occur, leading to an exacerbation of signs [10]. In this patient, there were no clinical signs of an associated hydrocephalus. Pneumorachis, as described in adult case reports, can be asymptomatic and clinically unspecific. Occasionally it can present with signs of (multiple) radiculopathy and myelopathy attributable to compression of the nerve roots or the spinal cord [1]. Pneumocephalus, as previously described in a few case reports of newborn infants with a myelomeningocele, can increase intracranial pressure, with signs of respiratory distress and generalized muscle hypotonia [9,10]. It is unclear whether the pneumocephalus or pneumorachis played any compressive role in contributing to the clinical signs. This is less likely, considering that the air disappeared completely within 2 weeks, and only minor improvement of the clinical signs appeared during the first 6 months. There are two possible pathophysiologic mechanisms for air to enter the ventricular system [9]. In addition to a ballvalve mechanism, by which air is thought to be forced into the cranial cavity by coughing, sneezing, or straining, the most plausible mechanism of air entering the spinal canal and ascending to the cranial cavity is the so-called ‘‘inversed bottle effect’’ [1,9,10]. When a bottle is inverted and the liquid is evacuated, air enters to fill the dead space or compensate for negative pressure [9]. When a sufficient amount of cerebrospinal fluid has escaped and is not compensated by a corresponding increase in brain volume, the result is negative intracranial pressure, and air will enter via the same channel. The leakage of cerebrospinal fluid
through an open myelomeningocele creates negative pressure, allowing air to penetrate the subarachnoid space [9]. This mechanism, as demonstrated by fluoroscopy, was described by Trawo¨ger et al. in a case report of a newborn with myelomeningocele [9]. Suprisingly, this phenomenon is not observed more often. In conclusion, we present a case of a newborn with pneumorachis and pneumocephalus as a complication of an open myelomeningocele. It remains unclear whether these collections of air played any role in the presenting signs. Clinical signs and potentially irreversible damage because of pneumorachis and pneumocephalus are occasionally described in the literature. For this reason, early detection by magnetic resonance imaging or computed tomography is essential, but almost importantly, early operative closure of the neural-tube defect can prevent the movement of penetrating air into the intraspinal and intracranial cavities. References [1] Oertel MF, Korinth MC, Reinges MHT, Krings T, Terbeck S, Gilsbach JM. Pathogenesis and management of pneumorachis. Eur Spine J 2006;15:636-43. [2] Chibbaro S, Selem M, Tacconi L. Cervicothoracolumbar pneumorachis. Case report and review of the literature. Surg Neurol 2005;64:80-2. [3] Sinha PA, Mantle M. Cervical pneumorachis. Clin Radiol 2000; 55:569-78. [4] Oertel MF, Korinth MC, Reinges MHT, Gilsbach JM. Pneumorachis of the entire spinal canal. J Neurol Neurosurg Psychiatry 2005;76: 1036. [5] Lin MBK, Cheah FK, Ng SES, Yeo TT. Tension pneumocephalus and pneumorachis secondary to subarachnoid pleural fistula. Br J Radiol 2000;73:325-7. [6] Lin LC, Liao YM, Yang RC. Pneumorachis following lumbar puncture: A case report. Kaohsiumg J Med Sci 2006;22:39-43. [7] Holten LH, Migaly J, Rolandelli RH. Pneumorachis, subcutaneous emphysema, pneumomediastinum, pneumopericardium, and pneumoretroperitoneum after protocolectomy for ulcerative colitis: Report of a case. Dis Colon Rectum 2002;45:567-70. [8] Ristagno RL, Hiratzka LF, Rost RC Jr. An unusual case of pneumorachis following resection of lung carcinoma. Chest 2002;121:1712-4. [9] Trawo¨ger R, Strasser K, Ellemunter H, Gassner I. Spontaneous pneumocephalus in a newborn infant with myelomenigocele and hydromyelia. Dev Med Child Neurol 1994;36:924-7. [10] Erol FS, Kaplan M. Spontaneous pneumocephalus presenting with apnea attacks in a newborn with open myelomeningocele. Pediatr Neurosurg 2004;40:312-3. [11] Odemis E, Aslan Y. Spontaneous pneumocephalus associated with open myelomeningocele. Indian Pediatr 2004;41:289-90. [12] Kao SCS, Brown BP, Goedken J. Sonography of intracranial air in a newborn with meningomyelocele. Pediatr Radiol 1991;21:375-6.
de Roos et al: Magnetic Resonance Imaging of Pneumorachis
379
MRI of Pneumorachis in a Newborn Infant With Open Myelomeningocele Petra B. de Roos, MD*, Erik J. van Lindert, MD, PhD†, Ton A. van der Vliet, MD‡, and Lilian T. L. Sie, MD, PhD§ Pneumorachis, or air within the spinal canal, is a very rare radiographic finding, frequently of traumatic origin. A newborn infant with an open lumbosacral myelomeningocele presented with severe paraparesis and an unexpected dysfunction of the brainstem with somnolence, irregular respiration, and motor deficits of the upper extremities. Magnetic resonance imaging revealed hypoplasia of the brainstem and cerebellum and low-signal lesions on T2-weighted images at the cervicocranial junction, in the lateral ventricles, and in the spinal canal. Computed tomography confirmed the presence of intracranial and intraspinal air. The air disappeared 2 weeks later according to magnetic resonance imaging, but no clinical improvement occurred, even after 6 months. Pneumorachis and pneumocephalus can occur in newborn infants as an unexpected complication of an open myelomenigocele, with or without signs. The radiographic appearance of intraspinal air on magnetic resonance imaging was not described previously. Ó 2009 by Elsevier Inc. All rights reserved. de Roos PB, van Lindert EJ, van der Vliet TA, Sie LTL. MRI of pneumorachis in a newborn infant with open myelomeningocele. Pediatr Neurol 2009;40:377-379.
From the *Department of Neurology, †Department of Neurosurgery, ‡ Department of Radiology, and §Department of Pediatric Neurology, Radboud University Medical Center Nijmegen, Nijmegen, The Netherlands.
Ó 2009 by Elsevier Inc. All rights reserved. doi:10.1016/j.pediatrneurol.2008.11.019 0887-8994/09/$—see front matter
Introduction Pneumorachis, or intraspinal air, is an extremely rare radiographic finding, especially in the pediatric population. Etiologies include trauma (e.g., skull fractures or paranasal sinus and subarachnoid fistula after thoracic or spinal injury), iatrogenic lesions (e.g., after lumbar puncture, thoracotomy, and proctocolectomy), and malignancy with associated therapy [1-8]. Nontraumatic pneumorachis (e.g., spontaneous, infection-related, or tumor-related) is even more exceptional [1,4]. Pediatric nontraumatic pneumocephalus, as detected by ultrasound, x-rays of the skull, or cranial computed tomography, has been described mostly as a complication of mechanical ventilation and tension pneumothorax, and very rarely as a complication of a congenital defect of the dura, i.e., open myelomeningocele in newborn infants [9-12]. Intracranial air is thought to be the result of air entering the (enlarged) central canal through an open myelomeningocele, and ascending into the ventricular system. Air penetration into the spinal canal through a neural tube defect was reported and radiographically confirmed by fluoroscopy and postmortem myelography in only one case report, which concluded that the hydromyelia was probably the major factor permitting the ascent of air [9]. This case report describes a newborn infant with an open myelomeningocele presenting with unexpected somnolence, irregular respiration, and extensive motor deficits. Magnetic resonance imaging revealed a pneumorachis and pneumocephalus, as well as the cerebral malformations associated with myelomeningocele. The radiographic presentation of intraspinal air on magnetic resonance imaging as a complication of an open myelomeningocele was not described previously. Case Report A boy, born during week 37 of an uncomplicated pregnancy with maternal use of folic acid, presented at our hospital. No prenatal ultrasound had been performed. An emergency cesarean section was performed because of fetal distress during attempts to rotate the child out of his breech position. The APGAR score was 8 and 10, respectively, after 1 and 5 minutes. Upon physical examination, his birth weight was 2335 g, and an unexpected open lumbosacral myelomeningocele was evident, with leakage of cerebrospinal fluid. He was microcephalic with decreased vigilance, but without major clinical signs of increased intracranial pressure. There was generalized hypotonia and diminished movements of the arms, with almost complete
Communications should be addressed to: Dr. de Roos; Department of Neurology; Radboud University Medical Center Nijmegen; PO Box 9101; 6500 HB Nijmegen, The Netherlands. E-mail: [email protected] Received July 22, 2008; accepted November 25, 2008.
de Roos et al: Magnetic Resonance Imaging of Pneumorachis
377
Figure 1. Sagittal T1-weighted magnetic resonance image (TR/TE = 450/8 ms) of the brain and cervicocranial junction (at age 4 days). (A) Air in region of pineal gland (AIR), descent of cerebellum (DC), and flattened brainstem (BS). (B) Air entrapment in posterior fossa (AIR) and lateral ventricular system (AIR).
absence of movements of the legs, and clubfeet. Reflexes were absent. There was no reaction on pinprick from the L3 segment downward. The postnatal period was complicated by an irregular respiration pattern. Respiration was periodically very superficial, with apneas and desaturations up to 90%. At day 2 of age, an apneic attack occurred during breastfeeding, and ended in a resuscitation setting. He was referred to the
neonatal intensive care unit, and continuous positive airway pressure was started temporarily. Diagnostic and therapeutic intervention was postponed because of the patient’s unstable clinical condition. Laboratory investigations excluded infection and metabolic or hormonal dysfunction. Caffeine and constantly low-flow nasal oxygen therapy afforded little improvement of the recurrent (self-limiting) episodes of apnea. Transfontanellar sonography indicated slightly enlarged occipital horns, a corpus callosum hypoplasia, and remarkably hypodense cyst-like lesions in the lateral ventricles and infratentorial region. At day 4 of age, he was clinically stable enough to undergo magnetic resonance imaging of the neuroaxis. Magnetic resonance imaging revealed a lumbosacral myelomeningocele, slight ventriculomegaly, hypoplasia of the brainstem and cerebellum with remnants of cerebellar tissue within the posterior fossa and upper cervical spinal canal (Chiari II malformation), and an occipital encephalocele (Fig 1). In addition, there were low-signal lesions on T1-weighted and T2-weighted magnetic resonance imaging in the thoracic and lumbar spinal canal (T6 L2; Fig 2), at the cervicocranial junction (Fig 1), and in both lateral ventricles (Fig 1). A computed tomography scan of the brain was performed, and confirmed the presence of intracranial air. At 7 days of age, a neurosurgical closure of the open myelomeningocele was performed. Magnetic resonance imaging was repeated 2 weeks later, and demonstrated that the pneumorachis and pneumocephalus had disappeared, but without clinical improvement. Within 6 months, the patient’s vigilance gradually increased, and his respiration was less irregular, with only sporadic desaturations that spontaneously recovered. Therefore, Chiari decompression was not considered. The persisting paraplegia did not recover, and neither did the function of the upper extremities. At age 12 months, the patient was able to fixate visually for a short time at a close distance. He still exhibited problems swallowing fluids, without the need of drip feeding. He could grasp for objects and turn over from his side to his back. He could not sit without support. There were movements of the upper extremities against gravity, without any motor performance of the legs. The patient did not develop hydrocephalus. At age 28 months, the child was found in bed, not breathing, and with a weak heartbeat. In the preceding days, he had manifested an upper-airway infection without respiratory problems. Resuscitation was initiated, but was unsuccessful.
Discussion Figure 2. Sagittal T2-weighted magnetic resonance image (TR/TE = 4240/112 ms) of spinal canal (at age 4 days). Air entrapment in spinal canal (T6 T9) (AIR), with myelomeningocele (MMC).
378 PEDIATRIC NEUROLOGY Vol. 40 No. 5
We describe a newborn infant with an open lumbosacral myelomeningocele with severe paraparesis and unexpected
dysfunction of the brainstem with somnolence, irregular respiration, dysphagia, and motor deficits of the upper extremities. Magnetic resonance imaging revealed the expected spinal and cerebral malformations, in addition to unexpected pneumorachis and pneumocephalus. We will discuss the clinical signs and underlying pathophysiologic mechanisms. The brainstem dysfunction was caused by an intrinsic hypoplasia of the brainstem itself and by compression of the brainstem because of the occipital encephalocele and Chiari II malformation. Respiratory problems associated with the Chiari malformation are caused by depression of the respiratory center, dysfunction of the ascending reticular system activation, and vocal-cord paralysis [10]. When intracranial pressure is elevated by hydrocephalus or intracranial air, further compression of these structures may occur, leading to an exacerbation of signs [10]. In this patient, there were no clinical signs of an associated hydrocephalus. Pneumorachis, as described in adult case reports, can be asymptomatic and clinically unspecific. Occasionally it can present with signs of (multiple) radiculopathy and myelopathy attributable to compression of the nerve roots or the spinal cord [1]. Pneumocephalus, as previously described in a few case reports of newborn infants with a myelomeningocele, can increase intracranial pressure, with signs of respiratory distress and generalized muscle hypotonia [9,10]. It is unclear whether the pneumocephalus or pneumorachis played any compressive role in contributing to the clinical signs. This is less likely, considering that the air disappeared completely within 2 weeks, and only minor improvement of the clinical signs appeared during the first 6 months. There are two possible pathophysiologic mechanisms for air to enter the ventricular system [9]. In addition to a ballvalve mechanism, by which air is thought to be forced into the cranial cavity by coughing, sneezing, or straining, the most plausible mechanism of air entering the spinal canal and ascending to the cranial cavity is the so-called ‘‘inversed bottle effect’’ [1,9,10]. When a bottle is inverted and the liquid is evacuated, air enters to fill the dead space or compensate for negative pressure [9]. When a sufficient amount of cerebrospinal fluid has escaped and is not compensated by a corresponding increase in brain volume, the result is negative intracranial pressure, and air will enter via the same channel. The leakage of cerebrospinal fluid
through an open myelomeningocele creates negative pressure, allowing air to penetrate the subarachnoid space [9]. This mechanism, as demonstrated by fluoroscopy, was described by Trawo¨ger et al. in a case report of a newborn with myelomeningocele [9]. Suprisingly, this phenomenon is not observed more often. In conclusion, we present a case of a newborn with pneumorachis and pneumocephalus as a complication of an open myelomeningocele. It remains unclear whether these collections of air played any role in the presenting signs. Clinical signs and potentially irreversible damage because of pneumorachis and pneumocephalus are occasionally described in the literature. For this reason, early detection by magnetic resonance imaging or computed tomography is essential, but almost importantly, early operative closure of the neural-tube defect can prevent the movement of penetrating air into the intraspinal and intracranial cavities. References [1] Oertel MF, Korinth MC, Reinges MHT, Krings T, Terbeck S, Gilsbach JM. Pathogenesis and management of pneumorachis. Eur Spine J 2006;15:636-43. [2] Chibbaro S, Selem M, Tacconi L. Cervicothoracolumbar pneumorachis. Case report and review of the literature. Surg Neurol 2005;64:80-2. [3] Sinha PA, Mantle M. Cervical pneumorachis. Clin Radiol 2000; 55:569-78. [4] Oertel MF, Korinth MC, Reinges MHT, Gilsbach JM. Pneumorachis of the entire spinal canal. J Neurol Neurosurg Psychiatry 2005;76: 1036. [5] Lin MBK, Cheah FK, Ng SES, Yeo TT. Tension pneumocephalus and pneumorachis secondary to subarachnoid pleural fistula. Br J Radiol 2000;73:325-7. [6] Lin LC, Liao YM, Yang RC. Pneumorachis following lumbar puncture: A case report. Kaohsiumg J Med Sci 2006;22:39-43. [7] Holten LH, Migaly J, Rolandelli RH. Pneumorachis, subcutaneous emphysema, pneumomediastinum, pneumopericardium, and pneumoretroperitoneum after protocolectomy for ulcerative colitis: Report of a case. Dis Colon Rectum 2002;45:567-70. [8] Ristagno RL, Hiratzka LF, Rost RC Jr. An unusual case of pneumorachis following resection of lung carcinoma. Chest 2002;121:1712-4. [9] Trawo¨ger R, Strasser K, Ellemunter H, Gassner I. Spontaneous pneumocephalus in a newborn infant with myelomenigocele and hydromyelia. Dev Med Child Neurol 1994;36:924-7. [10] Erol FS, Kaplan M. Spontaneous pneumocephalus presenting with apnea attacks in a newborn with open myelomeningocele. Pediatr Neurosurg 2004;40:312-3. [11] Odemis E, Aslan Y. Spontaneous pneumocephalus associated with open myelomeningocele. Indian Pediatr 2004;41:289-90. [12] Kao SCS, Brown BP, Goedken J. Sonography of intracranial air in a newborn with meningomyelocele. Pediatr Radiol 1991;21:375-6.
de Roos et al: Magnetic Resonance Imaging of Pneumorachis
379