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Case report: Post-traumatic thoracolumbar pseudomeningocoele — An unusual cause of upper lumbar pain
Clinical Radiology(1997) 52, 715-717
Case Report: Post-traumatic Thoracolumbar Pseudomeningocoele An Unusual Cause of Upper Lumbar Pain D. B. S T A F F O R D J O H N S O N a n d F. P. M C G R A T H
Department of Radiology, Beaumont Hospital, Dublin, Ireland S p i n a l p s e u d o m e n i n g o c o e l e is a rare e n t i t y t h a t m a y c o m p l i c a t e m a j o r trauma. W e r e p o r t t h e c a s e o f a f e m a l e p a t i e n t w h o p r e s e n t e d w i t h a 1-year h i s t o r y o f b a c k p a i n that o c c u r r e d after a fall. M a g n e t i c r e s o n a n c e ( M R ) e x a m i n a t i o n showed a pseudomeningocoele in the thoraco-lumbar r e g i o n . W e d e s c r i b e the i m a g i n g f i n d i n g s a n d r e v i e w the literature o f this r a r e c o n d i t i o n .
s u b a r a c h n o i d space; it is t h e r e f o r e e x p r e s s e d as i n c r e a s e d s i g n a l i n t e n s i t y p a r t i c u l a r l y o n l o n g T R s e q u e n c e s w h e r e the intrinsic signal o f C S F is h i g h [3]. N o difference was detected in the s i g n a l f r o m the C S F c o n t a i n e d w i t h i n the p s e u d o m e n i n g o c o e l e o n s h o r t T R s e q u e n c e s as in t h e s e s e q u e n c e s the C S F s i g n a l is c h a r a c t e r i s t i c a l l y o f l o w intensity. B e f o r e t h e a d v e n t o f M R I , m y e l o g r a p h y or c o m p u t e d
CASE REPORT A 57-year-old woman presented to the orthopaedic department with a 1-year history of upper lumbar back pain that had begun following a fall. Clinical examination revealed normal lumbar spine movements with weakness (power grade 4/5) of both legs and absent ankle jerks. The general examination was otherwise uuremarkable. Plain films of the lumbosacral spine revealed an old compression fracture through the body of L1. Due to the neurological deficit, the patient underwent MRI (1.5 T) of the thoraco-himbar spine. Sagittal T1- and T2-weighted sequences revealed marked anterior wedging of the body of LI. In addition, a 5 x 3 cm extradural cystic mass was seen which extended from the level of T12 to the upper body of L2. The mass was within the spinal canal and caused compression of the conus and proximal cauda equina; dorsal tethering of the cord was also noted (Figs 1-4). On T2-weighted sequences, the mass exhibited higher signal characteristics than that associated with cerebrospinal fluid (CSF). A small disc herniation was noted at L5/S1 but there was no associated root compression. CT myelogram using Iohexol demonstrated contrast medium within the cyst which confirmed communication between it and the subarachnoid space (Fig. 5). The patient had a T12/L1 laminectomy during which a posteriorly located thin-walled cyst was found. This was causing significant compression and tethering of the thecal sac. At the level ofT12, a small dural defect was identified; no nerve-root avulsion was evident. The cyst lining was completely removed and the dural defect repaired. Histological analysis of the well of the pseudomeningocoele revealed it to be composed entirely of connective tissue; there was also evidence of haemosiderin deposition. No meningeal elements were identified in the wall of the cyst. Following surgery, the patient made an uneventful recovery with resolution of back pain and improvement in her neurological signs.
DISCUSSION P s e u d o m e n i n g o c o e l e s are C S F - f i l l e d p o u c h e s t h a t arise f o l l o w i n g a t e a r in the d u r a t h a t a l l o w s a c c u m u l a t i o n o f C S F into the p a r a s p i n a l tissues. T h e y p r i m a r i l y o c c u r i n the c e r v i c a l r e g i o n a n d are u s u a l l y d u e to o b s t e t r i c or b l u n t t r a u m a w h i c h c a u s e a v u l s i o n o f the c e r v i c a l n e r v e r o o t s o f the b r a c h i a l p l e x u s [1]. I n c o m p a r i s o n , l u m b a r n e r v e root injuries are less c o m m o n d u e to t h e p r o t e c t i o n a g a i n s t m a j o r t r a u m a t h a t is offered b y the b o n y p e l v i s [2]. T y p i c a l l y in cases o f l u m b a r n e r v e r o o t a v u l s i o n , m u l t i p l e i p s i l a t e r a l n e r v e r o o t s are i n v o l v e d [2]. I n this case, M R i m a g e s s h o w e d t h e p s e u d o m e n i n g o c o e l e as a n e x t r a d u r a l cystic c o l l e c t i o n e x t e n d i n g f r o m T 1 2 to L2. C S F w i t h i n a p s e u d o m e n i n g o c o e l e is c o n f i n e d a n d does not p u l s a t e to t h e s a m e d e g r e e as t h a t w h i c h is i n the Correspondence to Dr D.B. Stafford Johnson, Department of Radiology, University of Michigan Medical Center, 1500 East Medical Drive, Ann Arbor, MI 48109=0030, USA. © 1997 The Royal College of Radiologists.
Fig. 1 - Sagittal T2-weighted MRI sequence (TR = 4000msec, TE = 80 msec) of the thoracolumbar spine demonstrating a pseudomemingocoele (arrow) with significant compression of the thecal sac which is displaced anteriorly. A compression fracture of the vertebral body of L1 and a disc prolapse at L5/S 1 level are also noted.
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CLINICALRADIOLOGY
Fig. 2 - Axial T2-weighted MRI (TR = 4000msec, TE = 80msec) sequence at the level of L1 demonstrating a large extradural mass which is compressing the thecal sac.
Fig. 4 - Axial T2-weighted sequence (TR = 4000 msec, TE = 80 msec) demonstrating a large extra-dural mass which has a loculated appearance.
tomographic (CT) myelography were the imaging techniques of choice in the evaluation of pseudomeningocoeles [4,5]. tn the presence of a pseudomeningocoele, CT myelography~ typically demonstrates either delayed filling of the pseudomeningocoele or a hypodense mass if filling fails to occur. In this case, CT myelography clearly demonstrated communication between the cyst and the subarachnoid space which was not evident on MR. CT myelography also showed compression of the thecal sac at L1 which was previously noted on MR. No nerve-root avulsion was identified either by CT myelography or MR examination. There are several unusual features about this case. The pseudomeningocoele occurred following relatively minor
spinal injury as evidenced by vertebral collapse of L1 as the only bony abnormality. In previously reported cases, most have been associated with major spinal and pelvic trauma. The pseudomeningocoele was noted at T12/L1, an unusual site for post-traumatic pseudomeningocoele as these more commonly occur in the cervical region [6]. It is also significant that no definite nerve root avulsion was identified either on MR, CT myelography or at surgery. The aetiology of the pseudomeningocoele reported here is unclear as there were no radiological or operative features consistent with nerve root avulsion or haematoma. However nerve-root avulsion, requires considerably more severe traction than that necessary for a dural tear. It is probable that the pathophysiology of the pseudomeningocoele in this
Fig. 3 - Axial T2-weighted sequence (TR = 4000 msec, TE = 80 msec) demonstrating a large extra-dural mass of high signal intensity,
Fig. 5 - CT myelogram (1 h following intra-thecal injection of contrast medium) demonstrating leakage of contrast medium from the subarachnoid space into the pseudomeningocoele (arrow); flattening and anterior displacement of the thecal sac is also noted. © 1997 The Royal College of Radiologists, Clinical Radiology, 52, 715-724.
CASE REPORTS case was a dural tear from an injury severe enough to cause a dural rent but insufficient to result in frank nerve root avulsion. We assume that this is a traumatic pseudomeningocoele based on its close anatomic relationship to a crush fracture of a vertebral body, the timing of onset of symptoms and the finding of haemosiderin deposition within the wall of the cyst. Although there was evidence of previous haemorrhage from the histological examination of the cyst, this was not detected on MR as a signal void. It is possible that a gradient-echo sequence might have demonstrated this abnormality although in this case it was not performed. The major differential diagnosis of these radiological findings is an extradural arachnoid cyst. Arachnoid cysts are rare expanding lesions that occur within the intraspinal canal. They are thought to be congenital and develop as a result of herniation of the arachnoid through a dural defect which results in the formation of a thin-walled cyst that contains CSF. Arachnoid cysts usually occur in the midthoracic spine and are usually an incidental finding as patients are often asymptomatic; their association with trauma is unknown. In patients with an arachnoid cyst, plain radiography may reveal widening of the interpedicular distance, pedicular erosion and enlargement of the spinal canal [7]. Pathological examination of the wall of an arachnoid cyst suggests that it is formed by splitting of the arachnoid which is then reinforced by a thick layer of collagen; the cyst wall is totally independent of the inner layer of dura mater [8]. The treatment of pseudomeningocoeles depends on the severity of symptoms and the size of the mass. Most authors advocate conservative management initially with the head-down or flat bedrest positions in such patients [9]. Failure of resolution of symptoms, persistent neurological deficits or the presence of a large mass are indications for surgery [10]. Surgery usually involves direct repair of the
717
dural defect although one patient has been reported who was treated with a lumboperitoneal shunt with good therapeutic results [10]. This is an unusual case of a thoracolumbar pseudomeningocoele that occurred after relatively minor trauma. We recommend that MR should be undertaken in all patients who present with delayed focal post-traumatic back pain, even in the absence of neurological signs or symptoms.
Acknowledgements. The help of Mr Eljamel, Senior Registrar in Neurosurgery and Dr Michael Farrell, Consultant Neuropathologist, in the preparation of this manuscriptis gratefullyacknowledged. REFERENCES 1 Taylor PE. Traumatic intradural avulsion of the nerve roots of the brachial plexus. Brain 1962;85:579-602. 2 Verstraete KL, Martens F, Smets Pet aL Traumaticlumbosacralnerve root rrieningocoeles.Neuroradiology 1989;31:425-429. 3 EnzmannD, Rubin J, De LaPaz R et al. Cerebrospinalfluidpulsations: benefits and pitfalls in MR imaging.Radiology 1986;161:773-778. 4 Sutton D, de Silva RDD. Water soluble contrast medium in the localisation of cord and dural stab wounds. Clinical Radiology 1984;34:483-484. 5 Primeau M, Carrier L, Milette PC et aL Cerebrospinal fluid leak demonstrated by radioisotope cisternography. Clinical Nuclear Medicine 1988;13:701-703. 6 Patronas NJ, Jafafr J, Brown F. Pseudomeningocoelesdiagnosed by metrizamide myelography and computerized tomography. Surgical Neurology 1981;16:188-191. 7 Congia S, Coraddu M, Tronci Set al. Myelogn'aphicand MRI appearances of a thoracic spinal extradural arachnoid cyst of the spin with extra- and intraspinalextension.Neuroradiology 1992;34:444-446. 8 SchachenmayerW, FriedeLR. Fine structureof arachnoidcyst. Journal of Neuropathology and Experimental Neurology 1979;38:434-446. 9 Barbera J, Broseta J, Arguelles F et al. Traumatic lumbrosacral meningocoele.Journal of Neurosurgery 1977;46:536-541. 10 Kitchen N, Bradford R, Platts A. Occult spinal pseudomeningocoele following a trivial injury successfullytreated with a lumboperitoneal shunt. Surgical Neurology 1992;38:46-49.
Clinical Radiology (1997) 52, 717-719
Case Report: MR Angiography of Cervical Aortic Arch S. KUMAR, R. BAJAJ* and R. GUJRAL Departments o f Radiology and *Cardiology, Sanj a y Gandhi Post Graduate Institute o f Medical Sciences, Lucknow, India Cervical aortic arch, a rare congenital anomaly, is usually asymptomatic. Its recognition by a non-invasive modality is desirable. In this case report, the diagnosis of a right cervical aortic arch in a 19-year-old man is made by magnetic resonance angiography. Cervical aortic arch is a rare congenital anomaly with only 50 cases reported by 1989 [1]. Though it may be associated with cardiac or aortic anomalies, this condition commonly occurs as an isolated anomaly and is usually silent. Presenting features vary from a pulsatile mass in the supraclavicular fossa to symptoms simulating a respiratory tract infection. Hence its diagnosis by non-invasive means is desirable. Reports o f cervical aortic arch diagnosed by computed tomography and magnetic resonance imaging (MRI) have appeared in the recent literature [2-4]. Correspondenceto: Dr S. Kumar,Departmentof Radiology, SGPGIMS, Rae Bareli Road, Lucknow-226014, India. © 1997The RoyalCollegeof Radiologists,ClinicalRadiology,52, 715-724.
We report a case of cervical aortic arch diagnosed by magnetic resonance angiography (MRA).
CASE REPORT A 19-year-oldman presented with an asymptomaticpulsating lump on the right side of the lower neck for 2 years. On physical examinationthere was a 8-cmdiameterpulsatilemass in the right supraclavicularfossa. There was a palpable thrill over the mass and a grade 2/6 bruit on auscultation. The patient also had a loud pansystolicmurmurof a smallventricularseptal defect. Chest radiographrevealeda smoothright-sidedsuperiormediastinal mass with mild tracheal shift (Fig. 1). The descendingaortic shadow was seen in the usual location with a suggestion of the aortic knuckle in its usual position on the left side. Echocardiography demonstrated a small perimembranousventricularseptal defect. In view of minimal symptoms, conventionalangiographywas deferred and the patientwas referred for MR study for evaluationof the vascularanatomyof the superior mediastinum. MRA was performed on a 1.5 T MR scanner(MagnetomSP, SiemensAG, Germany)usinga circularlypolarizedbody coil. A three dimensional(3-D)
Case Report: Post-traumatic Thoracolumbar Pseudomeningocoele An Unusual Cause of Upper Lumbar Pain D. B. S T A F F O R D J O H N S O N a n d F. P. M C G R A T H
Department of Radiology, Beaumont Hospital, Dublin, Ireland S p i n a l p s e u d o m e n i n g o c o e l e is a rare e n t i t y t h a t m a y c o m p l i c a t e m a j o r trauma. W e r e p o r t t h e c a s e o f a f e m a l e p a t i e n t w h o p r e s e n t e d w i t h a 1-year h i s t o r y o f b a c k p a i n that o c c u r r e d after a fall. M a g n e t i c r e s o n a n c e ( M R ) e x a m i n a t i o n showed a pseudomeningocoele in the thoraco-lumbar r e g i o n . W e d e s c r i b e the i m a g i n g f i n d i n g s a n d r e v i e w the literature o f this r a r e c o n d i t i o n .
s u b a r a c h n o i d space; it is t h e r e f o r e e x p r e s s e d as i n c r e a s e d s i g n a l i n t e n s i t y p a r t i c u l a r l y o n l o n g T R s e q u e n c e s w h e r e the intrinsic signal o f C S F is h i g h [3]. N o difference was detected in the s i g n a l f r o m the C S F c o n t a i n e d w i t h i n the p s e u d o m e n i n g o c o e l e o n s h o r t T R s e q u e n c e s as in t h e s e s e q u e n c e s the C S F s i g n a l is c h a r a c t e r i s t i c a l l y o f l o w intensity. B e f o r e t h e a d v e n t o f M R I , m y e l o g r a p h y or c o m p u t e d
CASE REPORT A 57-year-old woman presented to the orthopaedic department with a 1-year history of upper lumbar back pain that had begun following a fall. Clinical examination revealed normal lumbar spine movements with weakness (power grade 4/5) of both legs and absent ankle jerks. The general examination was otherwise uuremarkable. Plain films of the lumbosacral spine revealed an old compression fracture through the body of L1. Due to the neurological deficit, the patient underwent MRI (1.5 T) of the thoraco-himbar spine. Sagittal T1- and T2-weighted sequences revealed marked anterior wedging of the body of LI. In addition, a 5 x 3 cm extradural cystic mass was seen which extended from the level of T12 to the upper body of L2. The mass was within the spinal canal and caused compression of the conus and proximal cauda equina; dorsal tethering of the cord was also noted (Figs 1-4). On T2-weighted sequences, the mass exhibited higher signal characteristics than that associated with cerebrospinal fluid (CSF). A small disc herniation was noted at L5/S1 but there was no associated root compression. CT myelogram using Iohexol demonstrated contrast medium within the cyst which confirmed communication between it and the subarachnoid space (Fig. 5). The patient had a T12/L1 laminectomy during which a posteriorly located thin-walled cyst was found. This was causing significant compression and tethering of the thecal sac. At the level ofT12, a small dural defect was identified; no nerve-root avulsion was evident. The cyst lining was completely removed and the dural defect repaired. Histological analysis of the well of the pseudomeningocoele revealed it to be composed entirely of connective tissue; there was also evidence of haemosiderin deposition. No meningeal elements were identified in the wall of the cyst. Following surgery, the patient made an uneventful recovery with resolution of back pain and improvement in her neurological signs.
DISCUSSION P s e u d o m e n i n g o c o e l e s are C S F - f i l l e d p o u c h e s t h a t arise f o l l o w i n g a t e a r in the d u r a t h a t a l l o w s a c c u m u l a t i o n o f C S F into the p a r a s p i n a l tissues. T h e y p r i m a r i l y o c c u r i n the c e r v i c a l r e g i o n a n d are u s u a l l y d u e to o b s t e t r i c or b l u n t t r a u m a w h i c h c a u s e a v u l s i o n o f the c e r v i c a l n e r v e r o o t s o f the b r a c h i a l p l e x u s [1]. I n c o m p a r i s o n , l u m b a r n e r v e root injuries are less c o m m o n d u e to t h e p r o t e c t i o n a g a i n s t m a j o r t r a u m a t h a t is offered b y the b o n y p e l v i s [2]. T y p i c a l l y in cases o f l u m b a r n e r v e r o o t a v u l s i o n , m u l t i p l e i p s i l a t e r a l n e r v e r o o t s are i n v o l v e d [2]. I n this case, M R i m a g e s s h o w e d t h e p s e u d o m e n i n g o c o e l e as a n e x t r a d u r a l cystic c o l l e c t i o n e x t e n d i n g f r o m T 1 2 to L2. C S F w i t h i n a p s e u d o m e n i n g o c o e l e is c o n f i n e d a n d does not p u l s a t e to t h e s a m e d e g r e e as t h a t w h i c h is i n the Correspondence to Dr D.B. Stafford Johnson, Department of Radiology, University of Michigan Medical Center, 1500 East Medical Drive, Ann Arbor, MI 48109=0030, USA. © 1997 The Royal College of Radiologists.
Fig. 1 - Sagittal T2-weighted MRI sequence (TR = 4000msec, TE = 80 msec) of the thoracolumbar spine demonstrating a pseudomemingocoele (arrow) with significant compression of the thecal sac which is displaced anteriorly. A compression fracture of the vertebral body of L1 and a disc prolapse at L5/S 1 level are also noted.
716
CLINICALRADIOLOGY
Fig. 2 - Axial T2-weighted MRI (TR = 4000msec, TE = 80msec) sequence at the level of L1 demonstrating a large extradural mass which is compressing the thecal sac.
Fig. 4 - Axial T2-weighted sequence (TR = 4000 msec, TE = 80 msec) demonstrating a large extra-dural mass which has a loculated appearance.
tomographic (CT) myelography were the imaging techniques of choice in the evaluation of pseudomeningocoeles [4,5]. tn the presence of a pseudomeningocoele, CT myelography~ typically demonstrates either delayed filling of the pseudomeningocoele or a hypodense mass if filling fails to occur. In this case, CT myelography clearly demonstrated communication between the cyst and the subarachnoid space which was not evident on MR. CT myelography also showed compression of the thecal sac at L1 which was previously noted on MR. No nerve-root avulsion was identified either by CT myelography or MR examination. There are several unusual features about this case. The pseudomeningocoele occurred following relatively minor
spinal injury as evidenced by vertebral collapse of L1 as the only bony abnormality. In previously reported cases, most have been associated with major spinal and pelvic trauma. The pseudomeningocoele was noted at T12/L1, an unusual site for post-traumatic pseudomeningocoele as these more commonly occur in the cervical region [6]. It is also significant that no definite nerve root avulsion was identified either on MR, CT myelography or at surgery. The aetiology of the pseudomeningocoele reported here is unclear as there were no radiological or operative features consistent with nerve root avulsion or haematoma. However nerve-root avulsion, requires considerably more severe traction than that necessary for a dural tear. It is probable that the pathophysiology of the pseudomeningocoele in this
Fig. 3 - Axial T2-weighted sequence (TR = 4000 msec, TE = 80 msec) demonstrating a large extra-dural mass of high signal intensity,
Fig. 5 - CT myelogram (1 h following intra-thecal injection of contrast medium) demonstrating leakage of contrast medium from the subarachnoid space into the pseudomeningocoele (arrow); flattening and anterior displacement of the thecal sac is also noted. © 1997 The Royal College of Radiologists, Clinical Radiology, 52, 715-724.
CASE REPORTS case was a dural tear from an injury severe enough to cause a dural rent but insufficient to result in frank nerve root avulsion. We assume that this is a traumatic pseudomeningocoele based on its close anatomic relationship to a crush fracture of a vertebral body, the timing of onset of symptoms and the finding of haemosiderin deposition within the wall of the cyst. Although there was evidence of previous haemorrhage from the histological examination of the cyst, this was not detected on MR as a signal void. It is possible that a gradient-echo sequence might have demonstrated this abnormality although in this case it was not performed. The major differential diagnosis of these radiological findings is an extradural arachnoid cyst. Arachnoid cysts are rare expanding lesions that occur within the intraspinal canal. They are thought to be congenital and develop as a result of herniation of the arachnoid through a dural defect which results in the formation of a thin-walled cyst that contains CSF. Arachnoid cysts usually occur in the midthoracic spine and are usually an incidental finding as patients are often asymptomatic; their association with trauma is unknown. In patients with an arachnoid cyst, plain radiography may reveal widening of the interpedicular distance, pedicular erosion and enlargement of the spinal canal [7]. Pathological examination of the wall of an arachnoid cyst suggests that it is formed by splitting of the arachnoid which is then reinforced by a thick layer of collagen; the cyst wall is totally independent of the inner layer of dura mater [8]. The treatment of pseudomeningocoeles depends on the severity of symptoms and the size of the mass. Most authors advocate conservative management initially with the head-down or flat bedrest positions in such patients [9]. Failure of resolution of symptoms, persistent neurological deficits or the presence of a large mass are indications for surgery [10]. Surgery usually involves direct repair of the
717
dural defect although one patient has been reported who was treated with a lumboperitoneal shunt with good therapeutic results [10]. This is an unusual case of a thoracolumbar pseudomeningocoele that occurred after relatively minor trauma. We recommend that MR should be undertaken in all patients who present with delayed focal post-traumatic back pain, even in the absence of neurological signs or symptoms.
Acknowledgements. The help of Mr Eljamel, Senior Registrar in Neurosurgery and Dr Michael Farrell, Consultant Neuropathologist, in the preparation of this manuscriptis gratefullyacknowledged. REFERENCES 1 Taylor PE. Traumatic intradural avulsion of the nerve roots of the brachial plexus. Brain 1962;85:579-602. 2 Verstraete KL, Martens F, Smets Pet aL Traumaticlumbosacralnerve root rrieningocoeles.Neuroradiology 1989;31:425-429. 3 EnzmannD, Rubin J, De LaPaz R et al. Cerebrospinalfluidpulsations: benefits and pitfalls in MR imaging.Radiology 1986;161:773-778. 4 Sutton D, de Silva RDD. Water soluble contrast medium in the localisation of cord and dural stab wounds. Clinical Radiology 1984;34:483-484. 5 Primeau M, Carrier L, Milette PC et aL Cerebrospinal fluid leak demonstrated by radioisotope cisternography. Clinical Nuclear Medicine 1988;13:701-703. 6 Patronas NJ, Jafafr J, Brown F. Pseudomeningocoelesdiagnosed by metrizamide myelography and computerized tomography. Surgical Neurology 1981;16:188-191. 7 Congia S, Coraddu M, Tronci Set al. Myelogn'aphicand MRI appearances of a thoracic spinal extradural arachnoid cyst of the spin with extra- and intraspinalextension.Neuroradiology 1992;34:444-446. 8 SchachenmayerW, FriedeLR. Fine structureof arachnoidcyst. Journal of Neuropathology and Experimental Neurology 1979;38:434-446. 9 Barbera J, Broseta J, Arguelles F et al. Traumatic lumbrosacral meningocoele.Journal of Neurosurgery 1977;46:536-541. 10 Kitchen N, Bradford R, Platts A. Occult spinal pseudomeningocoele following a trivial injury successfullytreated with a lumboperitoneal shunt. Surgical Neurology 1992;38:46-49.
Clinical Radiology (1997) 52, 717-719
Case Report: MR Angiography of Cervical Aortic Arch S. KUMAR, R. BAJAJ* and R. GUJRAL Departments o f Radiology and *Cardiology, Sanj a y Gandhi Post Graduate Institute o f Medical Sciences, Lucknow, India Cervical aortic arch, a rare congenital anomaly, is usually asymptomatic. Its recognition by a non-invasive modality is desirable. In this case report, the diagnosis of a right cervical aortic arch in a 19-year-old man is made by magnetic resonance angiography. Cervical aortic arch is a rare congenital anomaly with only 50 cases reported by 1989 [1]. Though it may be associated with cardiac or aortic anomalies, this condition commonly occurs as an isolated anomaly and is usually silent. Presenting features vary from a pulsatile mass in the supraclavicular fossa to symptoms simulating a respiratory tract infection. Hence its diagnosis by non-invasive means is desirable. Reports o f cervical aortic arch diagnosed by computed tomography and magnetic resonance imaging (MRI) have appeared in the recent literature [2-4]. Correspondenceto: Dr S. Kumar,Departmentof Radiology, SGPGIMS, Rae Bareli Road, Lucknow-226014, India. © 1997The RoyalCollegeof Radiologists,ClinicalRadiology,52, 715-724.
We report a case of cervical aortic arch diagnosed by magnetic resonance angiography (MRA).
CASE REPORT A 19-year-oldman presented with an asymptomaticpulsating lump on the right side of the lower neck for 2 years. On physical examinationthere was a 8-cmdiameterpulsatilemass in the right supraclavicularfossa. There was a palpable thrill over the mass and a grade 2/6 bruit on auscultation. The patient also had a loud pansystolicmurmurof a smallventricularseptal defect. Chest radiographrevealeda smoothright-sidedsuperiormediastinal mass with mild tracheal shift (Fig. 1). The descendingaortic shadow was seen in the usual location with a suggestion of the aortic knuckle in its usual position on the left side. Echocardiography demonstrated a small perimembranousventricularseptal defect. In view of minimal symptoms, conventionalangiographywas deferred and the patientwas referred for MR study for evaluationof the vascularanatomyof the superior mediastinum. MRA was performed on a 1.5 T MR scanner(MagnetomSP, SiemensAG, Germany)usinga circularlypolarizedbody coil. A three dimensional(3-D)