Rotational angiography for diagnosis and surgical planning in the … · General Electric Innova 3131 biplane fluoroscopy system (GE Healthcare). Patients received intravenous conscious

Neurosurg Focus / Volume 32 / May 2012

Neurosurg Focus 32 (5):E6, 2012

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Vascular lesions of the spine are rare and difficult to diagnose by means of noninvasive imaging modalities.2,6,7,26 Spinal dural arteriovenous fis-tulas are the most common type of SVM; patients with SDAVFs usually present with progressive myelopathy and weakness,21,25 and the lesions require prompt diag-nosis and treatment.3 Spinal AVMs are less common than SDAVF, and the classification of these lesions has been a

subject of considerable debate.17,29 Aneurysms also occur in the spinal arterial circulation and are commonly as-sociated with fistulas. Spinal aneurysm rupture may lead to acute neurological deficits. Over the last 2 decades, imaging techniques have evolved to better visualize these heterogeneous lesions that may occur in the spinal vas-culature.

Multiple case series8,23,28 and meta-analysis27 have underscored the utility and benefits of microsurgical treatment for spinal vascular lesions. Precise localiza-tion and detailed knowledge of the vascular architecture is essential for preoperative planning. Multiple imaging modalities have been used for the diagnosis of vascular malformation of the spine including CTA, MRI, and cath-eter-based DSA. Although traditional DSA is the most sensitive methodology for detecting SVMs, it is limited

Rotational angiography for diagnosis and surgical planning in the management of spinal vascular lesions

*AlexAnder e. ropper, M.d., ning lin, M.d., BrAdley A. gross, M.d., HekMAt k. ZArZour, M.d., rutH tHiex, M.d., pH.d., JoHn H. CHi, M.d., M.p.H., rose du, M.d., pH.d., And kAi u. FreriCHs, M.d.Department of Neurosurgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts

Object. The management of spinal vascular malformations has undergone significant evolution with the advent of advanced endovascular and angiographic technology. Three-dimensional rotational spinal angiography is an ad-vanced tool that allows the surgeon to gain a better appreciation of the anatomy of these spinal vascular lesions and their relation to surrounding structures. This article describes the use of rotational angiography and 3D reconstruc-tions in the diagnosis and management of spinal vascular malformations.

Methods. The authors present representative cases involving surgical treatment planning for spinal vascular mal-formations with focus on the utility and technique of rotational spinal angiography. They report the use of rotational spinal angiography for a heterogeneous collection of vascular pathological conditions.

Results. Eight patients underwent rotational spinal angiography in addition to digital subtraction angiography (DSA) for the diagnosis and characterization of various spinal vascular lesions. Postprocessed images were used to characterize the lesion in relation to surrounding bone and to enhance the surgeon’s ability to precisely localize and obliterate the abnormality. The reconstructions provided superior anatomical detail compared with traditional DSA. No associated complications from the rotational angiography were noted, and there was no statistically significant difference in the amount of radiation exposure to patients undergoing rotational angiography relative to traditional angiography.

Conclusions. The use of rotational spinal angiography provides a rapid and powerful diagnostic tool, superior to conventional DSA in the diagnosis and preoperative planning of a variety of spinal vascular pathology. A more detailed understanding of the anatomy of such lesions provided by this technique may improve the safety of the surgical approach.(http://thejns.org/doi/abs/10.3171/2012.1.FOCUS11254)

key Words • spinal angiography • spinal artery aneurysm • spinal dural arteriovenous fistula • 3D rotational angiography

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Abbreviations used in this paper: AP = anteroposterior; ASA = anterior spinal artery; AVM = arteriovenous malformation; CTA = CT angiography; DAP = dose-area product; DSA = digital subtrac-tion angiography; MIP = maximum intensity projection; PSA = posterior spinal artery; RA = rotational angiography; SAH = sub-arachnoid hemorrhage; SDAVF = spinal dural arteriovenous fistula; SVM = spinal vascular malformation.

* Drs. Ropper and Lin contributed equally to this work.

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A. E. Ropper et al.

2 Neurosurg Focus / Volume 32 / May 2012

by its planar nature, and anatomical correlation with the surrounding soft tissue and bony anatomy can be diffi-cult. The combination of high-resolution vascular images from selective transarterial DSA with the tomographic images of a cross-sectional modality such as CT or MRI provides greater anatomical detail for localization of vas-cular pathology and for preoperative planning of either endovascular or surgical treatments. The use of 3D RA has become routine in the management of intracranial aneurysms.10,11 The utility of this technique in the diagno-sis and treatment planning of SVMs is not nearly as well established.14,19,24

We report a heterogeneous collection of cases of SVMs involving patients who underwent 3D RA with de-tailed postprocessing of the rotational dataset, including standard and optimized tomographic maximum inten-sity projections (MIPs) and 3D volume rendering prior to operative obliteration or radiosurgery. Postprocessed images from the 3D RA provided superior diagnostic information compared with traditional DSA in operative planning for SVMs by precise localization of the lesion in relation to the surrounding bony anatomy and should be considered part of the standard angiographic work-up for these lesions.

MethodsThe study population consisted of all patients who

underwent diagnostic spinal angiography at the Brigham and Women’s Hospital between 2007 and 2010. Angio-grams performed for the purpose of targeted intervention (for example, preoperative tumor embolization) or post-operative evaluations were excluded from the study. All medical records were reviewed to extract demographic information, clinical symptoms, imaging findings, an-giography parameters, and information about hospital courses. The study was approved by the Brigham and Women’s Hospital and Partners Healthcare Institutional Review Board.

All angiographic procedures were performed on the General Electric Innova 3131 biplane fluoroscopy system (GE Healthcare). Patients received intravenous conscious sedation and local anesthesia prior to the procedure. All angiograms were performed via 5-Fr transfemoral sheath access. A 4-Fr Berenstein II catheter was used to access the internal iliac, vertebral, and carotid arteries as well as the thyro- and costocervical trunks, and a 5-Fr Mickelson catheter was used to access the thoracolumbar segmental and middle sacral arteries. The rotational angiogram was configured to carry out a 200° spin from the AP x-ray projector with one of 3 preset rotation speeds (40°/second, 20°/second, or 10°/second), depending on the amount of soft tissue and bony information desired for the recon-structed images. Contrast medium (Ultravist 240) was injected at a rate of 1–2 ml/second for a total of 10–20 ml during each rotational angiogram depending on the duration of the rotation. Postprocessing analyses were completed on an AW workstation (Innova 3D software, GE Healthcare) to reconstruct 3D vascular models and produce adjustable maximum intensity projection (MIP) images of various thicknesses. Images for postprocessing

were available in near real-time (with a delay of only 60–90 seconds) following acquisition, and postprocessing could therefore be carried out with the catheter remain-ing in the selected vessel to ensure that the quality of the acquired dataset was adequate or if further manipulation was required.

Radiation exposure was evaluated with cumula-tive air kerma (in Gy) and dose-area product (DAP, in Gy⋅cm2), both of which were obtained directly from the angiography station. The cumulative air kerma (or cumu-lative dose) was measured 15 cm below the isocenter of the fluoroscopy tubing, and the DAP was calculated as the integral of air kerma across the x-ray beam emission. These radiation exposure parameters were routinely re-corded for all neuroangiography procedures.

Differences in demographic and clinical character-istics for patients who received 3D RA and traditional spinal angiography were examined using chi-square and 2-tailed t-tests for categorical and continuous variables, respectively. Statistical significance was defined as a probability of Type I error less than 0.05. All statistical analyses were performed using SAS version 9.2 (SAS In-stitute, Inc.) and Excel 2007 (Microsoft Corporation).

ResultsBetween 2007 and 2010, 37 patients underwent diag-

nostic spinal angiography at the Brigham and Women’s Hospital; of these, 3D RA was performed in 8 patients. Demographic and clinical characteristics are summa-rized in Table 1. The average age of patients who under-went 3D RA was 46.5 years, and 5 of these 8 patients

TABLE 1: Demographic and clinical information for patients who underwent spinal angiography*

Variable2D DSA

(29 patients)3D RA

(8 patients) p Value

age at procedure (yrs) 0.63 mean 52.5 ± 15.6 46.5 ± 17.4 range 25–79 20–65sex 0.71 male 16 5 female 13 3diagnosis 0.001 negative for SVM 23 0 SDAVF 5 3 spinal AVM 1 3 aneurysm 0 2radiation dosage (Gy) 0.61 mean 2.96 ± 1.94 3.44 ± 2.45 range 0.72–6.43 0.55–6.75DAP (Gy⋅cm2) 0.66 mean 372.7 ± 267.8 409.5 ± 318.6 range 65.9–808.0 60.9–932.0

* Values represent numbers of patients unless otherwise indicated. Mean values are presented with SDs.



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were male. Although the mean cumulative dose and DAP were higher for patients who were examined with 3D RA than those examined with 2D traditional DSA, the differ-ence was not statistically significant (p = 0.61).

Table 2 summarizes the clinical and specific imaging findings in the 8 patients who underwent 3D RA. Cases 1 and 3, who had intradural aneurysms (one of which was associated with an SDAVF), and Case 8, who had a cer-vical intramedullary AVM, presented with spontaneous intradural hemorrhage and acute onset of neurological deficits, whereas the patients with Type I SDAVFs and a pial AVM presented with progressive neurological defi-cits. Case 6 presented with radiographic recanalization of an intramedullary AVM that was previously embolized. Initial MRI and/or CTA demonstrated stigmata of vascu-lar pathology, and all patients underwent spinal angiogra-phy prior to operative or radiosurgical management. No intra- or periprocedural complications were encountered in those undergoing 3D RA.

Illustrative CasesCase 1

This 52-year-old woman presented with sudden onset of severe headache, right-sided neck spasm, upper-extrem-ity paresthesias, and episodic vertigo after chiropractic manipulation of her neck. Physical examination revealed minimal left biceps weakness, and a noncontrast head CT scan demonstrated evidence of hydrocephalus with dilated temporal horns and SAH in the basal cisterns (Fig. 1A). Magnetic resonance imaging revealed SAH in the anterior cervical canal, extending down to the level of C-7 (Fig. 1B). Standard cerebral and cervical spinal angiograms demonstrated an arteriovenous fistula supplied by the ASA and musculoskeletal branches of the left vertebral artery, draining superiorly into the anterior median spinal vein

(Fig. 1C). The fistula was associated with a small aneu-rysm. Incidentally, the ASA had an aberrant supply from the costocervical trunk. Three-dimensional RA was per-formed from the right costocervical trunk, which showed the dural AVF to be located on the left anterior surface of the cervical spinal cord associated with a 3-mm ASA aneurysm located between the levels of C-4 and C-5 (Fig. 1D–F, rotational angiogram slow spin of 20°/second). The ability to freely tumble the 3D model allowed analysis of the anatomy in any projection (Fig. 1G, rotational angio-gram fast spin of 40°/second). The patient underwent C3–6 laminectomies for resection of the fistula and clipping of the aneurysm. The patient recovered well from surgery, and her initial mild proximal left upper extremity weak-ness had resolved at 6-month follow-up.

Case 2This 58-year-old man presented with progressively

worsening paresthesias and weakness in his legs over 6 weeks. He also reported occasional urinary retention and constipation. Neurological examination demonstrated bi-lateral ankle clonus but no strength or sensory deficits. An MRI study of the spine revealed T2 prolongation and gadolinium enhancement from T-9 to the conus medul-laris, consistent with chronic venous congestion, and mul-tiple flow voids in thoracic and lumbar spine (Fig. 2A and B). Spinal DSA demonstrated an SDAVF fed by the radic-ulomedullary branches of the left T-12, bilateral L-1, and left L-2 segmental arteries and draining superiorly into a perimedullary vein as well as a paraspinal vein (Fig. 2C and D). Three-dimensional RA was performed from the left L-1 and left T-12 segmental arteries and showed that the fistula was directly behind the L-1 vertebral body, anterior to the spinal cord, and just medial to the left L-1 pedicle (Fig. 2E–G, slow spin of 20°/second; Fig. 2H, fast spin of 40°/second). The arteriovenous transition could be

TABLE 2: Demographic and clinical summary for patients who underwent 3D rotational spinal angiography*

Case No.

Age (yrs), Sex Symptoms

Noninvasive Imaging Diagnosis (levels) Arterial Supply Management

FU (mos)

mRS at FU

1 52, F headache, neck pain, paresthesias, lt arm weakness

MRI, CTA SDAVF (C4–5), ASA aneurysm

ASA, lt VA 3D RA, surgical obliteration

15 1

2 58, M paresthesias MRI SDAVF (T12–L2) lt T-12, bilat L-1, & lt L-2 segmental artery

3D RA, surgical obliteration

2 0

3 42, M back pain, lt leg weakness & numbness

MRI PSA aneurysm (T-11)

lt L-1 segmental artery 3D RA, surgical obliteration

3 1

4 61, M urinary retention, myelopathy MRI pial AVM (T-6) rt T-6 segmental artery 3D RA, surgical obliteration

11 1

5 65, F myelopathy, urinary retention MRI SDAVF (T-10) rt T-10 segmental artery 3D RA, surgical obliteration

2 1

6 20, M paraplegia, radiographic residual spinal AVM after embolization

MRI residual intramedullary AVM (T-8)

lt T-9 segmental artery 3D RA, radiosurgery

6 5

7 53, F paresthesias MRI SDAVF (L-1) rt L-1 segmental artery 3D RA, surgical obliteration

1 0

8 21, M hemiplegia, paresthesias MRI intramedullary AVM (C2–3)

ASA 3D RA, radiosurgery

5 0

* FU = follow-up; mRS = modified Rankin Scale score; VA = vertebral artery.


A. E. Ropper et al.


traced through the thin-slice (2-mm) tomographic MIP images from coronal reconstructions of the 3D RA (Fig. 3A–H, slow spin of 20°/second). The reconstructed im-ages enhanced the view of the fistulous point in multiple projections. The patient underwent T12–L2 laminecto-mies and resection of the SDAVF with clipping of the feeding artery (Fig. 2I). He recovered well from the op-eration with no neurological deficits and resolution of the preoperative paresthesias.

Case 3This 42-year-old man developed acute onset of low

back pain and left leg numbness and weakness, which persisted for 1 day. His left leg weakness rapidly wors-ened and he was unable to ambulate. Physical examina-tion revealed a plegic left leg, distal right leg weakness, a left T-11 sensory level, and absent rectal tone. Magnetic resonance imaging showed an acute intradural hem-orrhage in the thoracic and lumbar spine without clear evidence of a vascular abnormality (Fig. 4A). Spinal an-giogram with 3D RA demonstrated a fusiform aneurysm of the left posterior spinal artery at level of T-11, fed by the left L-1 segmental artery (Fig. 4B). Tomographic MIP reconstructions from the 3D RA allowed tracing of the

feeding artery from the anterior canal to the posterior ca-nal, demonstrating that the aneurysm was fed by the pos-terior spinal artery (Fig. 4C–F, slow spin of 20°/second). He underwent urgent T10–L1 decompressive laminecto-mies and obliteration of the left posterior spinal artery aneurysm. The patient made a complete recovery after surgery, was able to ambulate without difficulty, and had normal bowel and bladder functions.

Case 4This 61-year-old man presented to another institution

with urinary retention and increased tone in both legs that limited his gait. He underwent L3–5 laminectomies for presumed lumbar stenosis, but his symptoms did not improve following surgery. At presentation to our institu-tion, 10 days after his laminectomies, he had preserved strength in his lower extremities but bilateral ankle clo-nus and increased tone in both legs (to a greater extent on the right). There was numbness over the dorsal and ventral aspects of both feet, but it was more pronounced on the right. An MRI study showed increased T2 signal in the lower thoracic cord suggestive of venous conges-tion, and a formal angiogram was performed. The right T-6 segmental artery injection demonstrated arteriove-

Fig. 1. Case 1. A 52-year-old woman with headache and neck pain. She had a C4–5 SDAVF and an ASA aneurysm at that lev-el, which was successfully treated with surgical clipping. A: Noncontrast head CT scan obtained at admission, demonstrating acute SAH in the basal cisterns and evidence of hydrocephalus with dilated temporal horns. Subarachnoid blood is also present in both sylvian fissures. B: Sagittal T1-weighted MR image demonstrating SAH in the anterior cervical canal (arrowhead). C: A DS angiogram, AP view, showing a fistula at C4–5 supplied by the ASA, which has an aberrant supply via the costocervical trunk. The arrowhead indicates the ASA; the single arrow, a median spinal vein; the double arrows, a lateral perimedullary vein; and the asterisk, the aneurysm. D–F: Tomographic MIP axial (D), coronal (E), and sagittal (F) reconstructions of a 3D rotational angiogram showing the presence of the SDAVF and ASA aneurysm in relation to the vertebral bodies and laminae. The location of the aneurysm in the anterior portion of the spinal canal is elucidated by the sagittal reconstruction. The arrowhead indicates the ASA; the single arrow, a median spinal vein; and the asterisk, the aneurysm. G: Magnified 3D reconstruction of the SDAVF and the ASA aneurysm. The asterisk indicates the aneurysm; the arrowhead, the ASA; the single arrow, a median spinal vein; the double arrows, a lateral perimedullary vein.




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nous shunting with early opacification of a large, caudally draining perimedullary vein (Fig. 5A). Analysis of the 3D RA suggested that this lesion represented an AVM with a plexiform nidus located on the right posterior surface of the spinal cord, displacing the cord anteriorly (Fig. 5B–E, fast spin of 40°/second). He underwent T5–6 laminecto-mies and ligation-resection of the AVM. Postoperatively, the patient’s sensory symptoms improved.

DiscussionSpinal vascular malformations are rare in the gen-

eral population, and the majority (60%–80%) are in the form of SDAVFs.13 They are usually supplied by dural branches of radicular arteries and drain into medullary veins at the dural sleeve of a nerve root and ultimately into the coronal venous plexus of the spinal cord.27 Symp-toms are thought to arise secondary to vascular steal or venous congestion and may include myelopathy, weak-ness, sensory disturbance, gait disturbance, and bowel or urinary problems. These lesions are classically difficult to diagnose and may be confused with radiculopathy from degenerative disc disease, neuromuscular disease, or de-myelinating neuropathy. The median time from onset of

Fig. 2. Case 2. A 58-year-old man with paresthesias secondary to a T12–L2 SDAVF. A and B: Sagittal (A) and axial (B) T2-weighted MR images of the thoracolumbar spine demonstrating increased T2 signal intensity within the parenchyma, cord expansion, and large flow voids, suggestive of an SDAVF. C and D: Oblique AP views of the DSA, obtained with selective left L-1 segmental artery injection (C) and left L-2 segmental artery injection (D) demonstrating an SDAVF. The asterisks indicate the fistula point; the arrowheads, an epidural venous pouch; the single arrows, a draining perimedullary vein; the double arrows, a draining paraspinal vein. E–G: Tomographic MIP axial (E), coronal (F), and sagittal (G) reconstructions of a 3D rotational angiogram showing the presence of the SDAVF. The fistula point is visible just medial to the left pedicle and is indicated by an asterisk in each image. The single arrows indicate a draining perimedullary vein; the double arrows, a draining paraspinal vein; the arrowheads, an epidural venous pouch. H: A 3D reconstruction based on the original angiogram demonstrating multiple feeding arteries supplying the SDAVF. The double arrowheads indicate the left L-1 segmental artery; the asterisk, the fistula point; the arrowhead, an epidural venous pouch; the single arrow, a draining perimedullary vein. I: Intraoperative photograph of the SDAVF, showing the clipping of a feeding artery in the predicted location of the fistulous point (to the left of center). Multiple dilated perimedullary veins are visible.


A. E. Ropper et al.


Fig. 3. Case 2. A–H: Sequential (anterior to posterior) thin-cut coronal reconstructions of the 3D angiogram (the asterisk in-dicates the fistula point). This technique allows for detailed anatomical views of the SDAVF in relation to the surrounding pedicles, laminae, and disc spaces, essential for preoperative planning.

Fig. 4. Case 3. A 42-year-old man with acute left leg numbness and weakness. Imaging demonstrated a PSA aneurysm that was subsequently clipped. A: Sagittal T2-weighted MR image showing evidence of subarachnoid blood (arrowheads) surrounding the thoracolumbar spinal cord. B: An AP-view DS angiogram obtained with selective left L-1 segmental artery injection demonstrating an aneurysm (asterisk) rostral to the injected level. C–E: Tomographic MIP axial (C), coronal (D), and sagittal (E) reconstructions of a 3D rotational angiogram showing the presence of a PSA aneurysm (asterisk) inferior to the left pedicle of T-11. These images helped to demonstrate that the aneurysm was in the posterior portion of the spinal canal and its precise level relative to the vertebrae. F: Magnified 3D reconstruction of the PSA aneurysm at the T-11 level, fed by the left L-1 segmental artery inferiorly.




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symptoms to diagnosis of an SDAVF is between 12 and 44 months.13 Spinal artery aneurysms are even less common than fistulas and may occur either in association with an SDAVF22 or in isolation. A recent review reported only 26 cases of ruptured isolated spinal artery aneurysms in the literature.15 Seven of those 26 aneurysms were located on the ASA, 5 on the artery of Adamkiewicz, 4 on the PSA, and the remaining aneurysms were fed by segmental or radiculomedullary branches.

Despite the improvements in technology discussed below, neither cross-sectional imaging modality—MRI or CT—currently approaches the necessary degree of sensitivity and spatial resolution of standard DSA to rule out spinal vascular lesions. Therefore, DSA remains the “gold standard” in the diagnosis of these often-elusive spinal vascular lesions. Magnetic resonance imaging has emerged as the standard initial diagnostic screening tool for the workup of SVMs. Characteristic MRI findings of SDAVF include centrally located T2 hyperintensity with peripheral sparing12 and tortuous “flow voids” on both T1- and T2-weighted images.7 Contrast enhanced MRA has been used to visualize SVMs in multiple studies with promising results. Binkert and colleagues4 reviewed MRA and DSA studies performed in 12 consecutive pa-tients with suspected SVMs and found that MRA correct-ly identified the categories of 9 vascular lesions (6 AVMs, 3 SDAVFs). Mull et al.20 studied how accurately MRA could localize SVMs compared with DSA and reported that MRA-derived spinal levels agreed with DSA in 14

of 19 SDAVF cases. Ali et al.1 used the newer technology of dynamic multiphase time-resolved MRA in 11 patients with suspected SVMs. The authors correctly diagnosed 6 vascular lesions and were able to localize within 1 verte-bral level in 5 of the 6 cases. In general, however, the im-aging quality of MR-based modalities is easily affected by motion degradation secondary to respirations, espe-cially in the thoracolumbar region, and the spatial resolu-tion does not yet approach the sensitivity or anatomical detail provided by standard DSA.19

Three-dimensional CTA has also been used to di-agnose spinal vascular lesions and has the advantage of excellent visualization of bony anatomy. Lai et al.18 evalu-ated 8 patients with suspected SDAVF via multidetector CTA and DSA and reported good correlation between the 2 modalities in all 8 cases. Differentiation of arterial from venous phases on “dynamic” multidetector CTA has proven to be quite challenging and tends to degrade imag-ing quality.19

The utility of 3D RA has been described before, spe-cifically by those evaluating its role in the endovascular treatment of spinal vascular lesions. Prestigiacomo et al.24 reviewed their experience with 17 3D spinal angiograms in 14 patients, who had undergone angiography for the diagnosis and treatment of a variety of SVMs. Surgical planning for hemangioblastoma resection after emboli-zation has also benefitted from the use of 3D rotational angiograms, as described by Kern et al.16 One signifi-cant technical difference in our approach is the ability

Fig. 5. Case 4. A 61-year-old man with a history of myelopathy and urinary retention. Previous lumbar decompression for radiographic stenosis did not relieve his symptoms. MR imaging of the spine was nondiagnostic, but an angiogram revealed a pial AVM. Surgery confirmed this diagnosis and he underwent thoracic laminectomies and surgical obliteration of the AVM. A: Pre-operative DS angiogram, AP view of the right T-6 segmental artery injection showing the malformation. B–D: Tomographic MIP axial (B), coronal (C), and sagittal (D) reconstructions of a 3D rotational angiogram demonstrating the nidus of the pial AVM and its relation to the vertebral canal. The asterisk indicates the plexiform nidus; the arrow, a perimedullary draining vein. E: A 3D reconstruction of the pial AVM (asterisk) with a T-6 segmental artery feeder (arrowhead) and draining perimedullary vein (arrow).


A. E. Ropper et al.


to choose varying rotational speeds depending on the amount of soft tissue and bony details desired from the angiogram. Fast spin (40°/second, used for all 3D render-ing models) allows crisp vascular imaging with relatively less soft tissue information. Slow spin (20°/second, used for Case 2 as described above) maximizes bony detail in addition to providing good delineation of angioarchitec-ture. The quality of rotational spinal angiography can be influenced by the stability of the catheter position and the degree of cooperation from the patient if he or she is not in a state of general anesthesia. High-flow AVMs may not allow a sufficient volume of contrast agent to be injected during the rotation flow.19 In addition, image quality can be limited due to respiratory artifacts.24 Rotational spinal angiography does require marginally more contrast me-dium (10–20 ml) than standard 2D DSA, but does not ex-pose the patient to significantly more radiation (Table 1). Radiation exposure in our series was comparable to that reported in the spinal angiography literature.9,24 Further-more, the mean dose area product (DAP) (409.5 Gy⋅cm2) delivered to patients receiving 3D RA was comparable to the mean DAP (413 Gy⋅cm2) delivered to patients during cranial aneurysm embolization procedures.5

The cases presented in this series demonstrate the specific benefits of 3D RA as an adjunct to traditional DSA—in particular the utility and superior anatomical detail provided by the adjustable tomographic MIP im-ages, as well as the volume-rendered 3D reconstructions. Rapid, near real-time postprocessing of the image dataset allowed us to create a 3D model of the lesion and tumble it in any desired projection. Features of the malformation can be easily correlated with bony and even soft tissue anatomy. The anatomical detail obtained from these re-constructions in conjunction with the standard DSA find-ings can be used to better differentiate an SDAVF from an AVM, as in Case 4 in the current report. Differentia-tion of an aneurysm associated with the anterior versus posterior spinal artery, as in Case 3, is absolutely critical when considering treatment options such as sacrifice of an artery. Ligation of the PSA is usually well tolerated, whereas sacrifice of a major ASA contribution can have devastating effects. Tracing a vascular malformation on 3D reconstructions and the corresponding tomographic MIP reconstructions provides precise localization of the fistulous connection as demonstrated in the case of Case 2. Placed in the context of the soft tissue and bony anato-my, this high-resolution vascular dataset supplies unprec-edented detail while being visually intuitive and therefore easily applicable clinically. Information provided by this advanced imaging tool is likely to improve the planning of endovascular as well as surgical approaches required for lesion obliteration.

ConclusionsIn summary, 3D RA is an advanced imaging tool pro-

ducing extraordinary anatomical detail in the character-ization and delineation of spinal vascular pathology and should become a standard part of the invasive workup of these lesions. Routine use of this tool may improve our understanding and management of SVMs, both for open surgical and endovascular approaches.

Disclosure

The authors report no conflict of interest concerning the mate-rials or methods used in this study or the findings specified in this paper.

Author contributions to the study and manuscript preparation include the following. Conception and design: Frerichs, Ropper, Lin, Thiex. Acquisition of data: Frerichs, Ropper, Lin, Zarzour, Du. Analysis and interpretation of data: Frerichs, Ropper, Lin, Gross, Zarzour. Drafting the article: Frerichs, Ropper, Lin, Gross. Critically revising the article: all authors. Reviewed submitted version of manuscript: all authors. Statistical analysis: Lin. Study supervision: Frerichs.

References

1. Ali S, Cashen TA, Carroll TJ, McComb E, Muzaffar M, Shaibani A, et al: Time-resolved spinal MR angiography: ini-tial clinical experience in the evaluation of spinal arteriove-nous shunts. AJNR Am J Neuroradiol 28:1806–1810, 2007

2. Aminoff MJ, Logue V: Clinical features of spinal vascular malformations. Brain 97:197–210, 1974

3. Behrens S, Thron A: Long-term follow-up and outcome in pa-tients treated for spinal dural arteriovenous fistula. J Neurol 246:181–185, 1999

4. Binkert CA, Kollias SS, Valavanis A: Spinal cord vascular disease: characterization with fast three-dimensional con-trast-enhanced MR angiography. AJNR Am J Neuroradiol 20:1785–1793, 1999

5. D’Ercole L, Mantovani L, Thyrion FZ, Bocchiola M, Azza-retti A, Di Maria F, et al: A study on maximum skin dose in cerebral embolization procedures. AJNR Am J Neuroradiol 28:503–507, 2007

6. Eddleman CS, Jeong H, Cashen TA, Walker M, Bendok BR, Batjer HH, et al: Advanced noninvasive imaging of spinal vascular malformations. Neurosurg Focus 26(1):E9, 2009

7. Gilbertson JR, Miller GM, Goldman MS, Marsh WR: Spinal dural arteriovenous fistulas: MR and myelographic findings. AJNR Am J Neuroradiol 16:2049–2057, 1995

8. Hanel RA, Nakaji P, Spetzler RF: Use of microscope-integrat-ed near-infrared indocyanine green videoangiography in the surgical treatment of spinal dural arteriovenous fistulae. Neu-rosurgery 66:978–985, 2010

9. Heinemann MK, Brassel F, Herzog T, Dresler C, Becker H, Borst HG: The role of spinal angiography in operations on the thoracic aorta: myth or reality? Ann Thorac Surg 65:346–351, 1998

10. Hirai T, Korogi Y, Suginohara K, Ono K, Nishi T, Uemura S, et al: Clinical usefulness of unsubtracted 3D digital angiogra-phy compared with rotational digital angiography in the pre-treatment evaluation of intracranial aneurysms. AJNR Am J Neuroradiol 24:1067–1074, 2003

11. Hochmuth A, Spetzger U, Schumacher M: Comparison of three-dimensional rotational angiography with digital sub-traction angiography in the assessment of ruptured cerebral aneurysms. AJNR Am J Neuroradiol 23:1199–1205, 2002

12. Hurst RW, Grossman RI: Peripheral spinal cord hypointen-sity on T2-weighted MR images: a reliable imaging sign of venous hypertensive myelopathy. AJNR Am J Neuroradiol 21:781–786, 2000

13. Jellema K, Tijssen CC, van Gijn J: Spinal dural arteriovenous fistulas: a congestive myelopathy that initially mimics a pe-ripheral nerve disorder. Brain 129:3150–3164, 2006

14. Jiang L, Huang CG, Liu P, Yan B, Chen JX, Chen HR, et al: 3-Dimensional rotational angiography for the treatment of spinal cord vascular malformations. Surg Neurol 69:369–374, 2008

15. Karakama J, Nakagawa K, Maehara T, Ohno K: Subarachnoid hemorrhage caused by a ruptured anterior spinal artery aneu-rysm. Neurol Med Chir (Tokyo) 50:1015–1019, 2010




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16. Kern M, Naeini R, Lehmann TN, Benndorf G: Imaging of a thoracic spinal nerve haemangioblastoma by three-dimensional digital angiography. J Clin Neurosci 13:929–932, 2006

17. Kim LJ, Spetzler RF: Classification and surgical manage-ment of spinal arteriovenous lesions: arteriovenous fistulae and arteriovenous malformations. Neurosurgery 59 (5 Suppl 3):S195–S201, 2006

18. Lai PH, Pan HB, Yang CF, Yeh LR, Hsu SS, Lee KW, et al: Multi-detector row computed tomography angiography in di-agnosing spinal dural arteriovenous fistula: initial experience. Stroke 36:1562–1564, 2005

19. Matsubara N, Miyachi S, Izumi T, Ohshima T, Tsurumi A, Hososhima O, et al: Usefulness of three-dimensional digital subtraction angiography in endovascular treatment of a spinal dural arteriovenous fistula. Report of 2 cases. J Neurosurg Spine 8:462–467, 2008

20. Mull M, Nijenhuis RJ, Backes WH, Krings T, Wilmink JT, Thron A: Value and limitations of contrast-enhanced MR an-giography in spinal arteriovenous malformations and dural arteriovenous fistulas. AJNR Am J Neuroradiol 28:1249–1258, 2007

21. Narvid J, Hetts SW, Larsen D, Neuhaus J, Singh TP, McSwain H, et al: Spinal dural arteriovenous fistulae: clinical features and long-term results. Neurosurgery 62:159–167, 2008

22. Ohmori Y, Hamada J, Morioka M, Yoshida A: Spinal aneu-rysm arising from the feeding pedicle of a thoracic perimed-ullary arteriovenous fistula: case report. Surg Neurol 64: 468–470, 2005

23. Oldfield EH, Di Chiro G, Quindlen EA, Rieth KG, Doppman JL: Successful treatment of a group of spinal cord arteriove-nous malformations by interruption of dural fistula. J Neuro-surg 59:1019–1030, 1983

24. Prestigiacomo CJ, Niimi Y, Setton A, Berenstein A: Three-dimensional rotational spinal angiography in the evaluation and treatment of vascular malformations. AJNR Am J Neu-roradiol 24:1429–1435, 2003

25. Saladino A, Atkinson JL, Rabinstein AA, Piepgras DG, Marsh WR, Krauss WE, et al: Surgical treatment of spinal dural arteriovenous fistulae: a consecutive series of 154 pa-tients. Neurosurgery 67:1350–1358, 2010

26. Sharma AK, Westesson PL: Preoperative evaluation of spinal vascular malformation by MR angiography: how reliable is the technique: case report and review of literature. Clin Neu-rol Neurosurg 110:521–524, 2008

27. Steinmetz MP, Chow MM, Krishnaney AA, Andrews-Hinders D, Benzel EC, Masaryk TJ, et al: Outcome after the treatment of spinal dural arteriovenous fistulae: a contemporary single-institution series and meta-analysis. Neurosurgery 55:77–88, 2004

28. Symon L, Kuyama H, Kendall B: Dural arteriovenous malfor-mations of the spine. Clinical features and surgical results in 55 cases. J Neurosurg 60:238–247, 1984

29. Zozulya YP, Slin’ko EI, Al-Qashqish II: Spinal arteriovenous malformations: new classification and surgical treatment. Neurosurg Focus 20(5):E7, 2006

Manuscript submitted September 17, 2011.Accepted January 27, 2012.Please include this information when citing this paper: DOI:

10.3171/2012.1.FOCUS11254. Address correspondence to: Kai U. Frerichs, M.D., Department

of Neurosurgery, Brigham and Women’s Hospital, 75 Francis Street, Boston, Massachusetts 02115. email: [email protected].


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