| OCR Text |
Show Underdiagnosis of Posterior Communicating Artery Aneurysm in Noninvasive Brain Vascular Studies Valerie I. Elmalem, MD, Patricia A. Hudgins, MD, Beau B. Bruce, MD, Nancy J. Newman, MD, Vale´rie Biousse, MD Background: Expert interpretation of modern noninvasive neuroimaging such as computed tomographic angiogra-phy (CTA) or MRA should detect nearly all aneurysms responsible for an isolated third nerve palsy. Whether a catheter angiogram should still be obtained in cases with negative CTA or MRA remains debated and mostly relies on whether the noninvasive study was correctly performed and interpreted. The aim of our study was to review the diagnostic strategies used to evaluate pa-tients with isolated aneurysmal third nerve palsy at a large academic center. Methods: Retrospective review of all cases with posterior communicating artery (PCom A) aneurysmal third nerve palsies seen at our institution since 2001. Results: We identified 417 cases with third nerve palsy, aneurysm, or subarachnoid hemorrhage, among which 17 presented with an acute isolated painful third nerve palsy related to an ipsilateral PCom A aneurysm (mean age: 52 years; range: 33-83 years). Patients were classified into 3 groups based on the results of the noninvasive imaging obtained at initial presentation. Group I included 4 cases with subarachnoid hemorrhage on initial noncontrast head CT initially obtained in an emergency department for evaluation of their isolated third nerve palsy. Group II included 5 cases with isolated third nerve palsy and normal noncontrast head CT at presentation, immediately correctly diagnosed with a PCom A aneurysm at the re-ferring institution. Group III included the 8 remaining cases who all had aneurysms that were missed on non-invasive studies at outside institutions. Review of these outside studies at our institution showed a PCom A an-eurysm, confirming misinterpretation of these tests by the outside radiologists, rather than inadequate technique. Absence of specific training in neuroradiology and in-accurate clinical information provided to the interpreting radiologist were associated with test misinterpretation at the outside institutions. The average size of PCom A aneurysms causing an isolated third nerve palsy across all 3 groups was 7.3 mm and was similar in each group. Conclusion: Our study suggests that aside from an accurate history, the training and experience of the in-terpreting radiologist is probably the most important factor in determining the reliability of a noninvasive scan in patients with isolated third nerve palsies. Journal of Neuro-Ophthalmology 2011;31:103-109 doi: 10.1097/WNO.0b013e3181f8d985 2011 by North American Neuro-Ophthalmology Society Isolated third nerve palsy can be the sentinel sign of an aneurysm at the junction of the internal carotid artery and posterior communicating artery (PCom A), and eval-uation of isolated third nerve palsies remains one of the most challenging situations in neuro-ophthalmology (1-9). Expert interpretation of modern noninvasive neuroimaging such as computed tomographic angiography (CTA) and MRA should detect nearly all aneurysms responsible for an isolated third nerve palsy (9-12). Most clinicians prefer CT/ CTA for the initial study in this clinical setting because of CTA's easy accessibility and rapid acquisition time, al-though this varies depending on the institution (8,9,11,12). Whether a catheter angiogram should still be obtained in cases of isolated third nerve palsy with negative CTA or MRA remains a difficult decision (8,9). Although recent studies (13) have reported a risk of neurologic complica-tions close to zero for diagnostic cerebral angiographies performed within a high volume neurointerventional practice, the risk of neurologic complications following catheter cerebral angiography was once between 0.9% and 4% (14) and therefore, algorithms trying to avoid routine catheter angiography, especially as a screening test, have Departments of Ophthalmology (VIE, BBB, NJN, VB), Neurology (BBB), Neurological Surgery (NJN), and Neuroradiology (PAH), Emory University School of Medicine, Atlanta, Georgia. Supported in part by a departmental grant (Department of Oph-thalmology) from Research to Prevent Blindness, Inc, New York, NY, and by National Institutes of Health grants KL2-RR025009 and K23-EY019341 (B.B.B.) and UL1-RR025008 (B.B.B. and V.B.). Dr N. J. Newman is the recipient of a Research to Prevent Blindness Lew R. Wasserman Merit Award. The authors report no proprietary or commercial interest in the topics discussed. Address correspondence to Vale´rie Biousse, MD, Neuro-ophthal-mology Unit, Emory Eye Center, The Emory Clinic, 1365-B Clifton Road NE, Atlanta, GA 30322; Email: vbiouss@emory.edu Elmalem et al: J Neuro-Ophthalmol 2011; 31: 103-109 103 Original Contribution Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. been proposed in the past (1,2,5). Recent publications have emphasized the importance of having presumed negative noninvasive vascular imaging studies reviewed by a skilled neuroradiologist before aneurysm is rejected as the cause of the third nerve palsy or before the patient un-dergoes catheter angiography (9,12). The aim of our study was to review the diagnostic strategies used to evaluate patients with isolated third nerve palsy at our tertiary academic center since 2001 and to examine details of those cases with false negative non-invasive neurovascular imaging studies. METHODS We performed a retrospective review of all cases with PCom A aneurysmal third nerve palsy seen at our institution from 2001 to 2010. Cases seen prior to 2001 were excluded from this study because high quality noninvasive vascular imaging was not routinely performed prior to that date. Our data-base was searched for diagnosis codes of third nerve palsy, aneurysm, and subarachnoid hemorrhage, and these charts were reviewed in detail. Reports from outside radiology tests were obtained, and outside films were reviewed with our neuroradiologists whenever possible. We specifically recorded the clinical information provided to the inter-preting radiologist on the initial imaging report. We also inquired whether the interpreting radiologist was specifi-cally trained in neuroradiology or not. We included all cases that initially presented with a nontraumatic isolated third nerve palsy and were later found to have an ipsilateral PCom A aneurysm. Patients who presented initially with symptoms and signs of sub-arachnoid hemorrhage or who developed a third nerve palsy postoperatively were excluded. Aneurysms in locations elsewhere (such as the intracavernous internal carotid artery, basilar tip, or cerebellar arteries) usually presented with other neurological findings and were thus excluded. The study was approved by our institutional review board. RESULTS Four hundred seventeen cases with third nerve palsy, an-eurysm, or subarachnoid hemorrhage were identified. Of the 417 cases reviewed, 17 presented with an acute isolated painful third nerve palsy related to an ipsilateral PCom A aneurysm (mean age: 52 years; range: 33-83 years). The characteristics of these 17 patients are detailed in Table 1. Patients were classified into 3 groups based on the results of the noninvasive imaging obtained at initial presentation. Group I included 4 cases that were found to have evi-dence of subarachnoid hemorrhage on initial noncontrast head CT obtained in an emergency department for evalu-ation of their isolated third nerve palsy (Table 1, Case I-1 to I-4; Fig. 1). The presence of subarachnoid hemorrhage on CT facilitated the immediate correct diagnosis of aneu-rysmal third nerve palsy in all 4 patients. The mean age of these 4 subarachnoid hemorrhage patients was 59.5 years (range: 46-83 years). The size range (greatest dimension, as measured on catheter angiography or intraoperatively) of aneurysms in group I was 5.4-10 mm. Group II included 5 cases with isolated third nerve palsy and normal head CT without contrast at presentation, correctly diagnosed with a PCom A aneurysm (Table 1, Cases II-5 to II-9; Fig. 2). Of these 5 patients, 4 patients required only noninvasive vascular imaging for immediate correct diagnosis of aneurysm (1 CTA and 3 MRI/MRA). The 1 patient diagnosed by direct catheter angiography could not have a brain MRI because of previous history of anterior communicating artery aneurysmal clipping, which also created an artifact, making the CT difficult to interpret. The mean age of these 5 patients was 56.4 years (range: 41-70 years). Aneurysms in group II ranged in size from 5.5 to 10 mm. Group III included the 8 remaining Cases (Table 1, Cases III-10 to III-17; Fig. 3) who all had aneurysms that were missed on noninvasive studies. These 8 patients were all initially evaluated at outside institutions. In 1 Case (III- 15, Table 1), the patient was transferred from an outside hospital because of high clinical suspicion of aneurysm despite ‘‘negative'' noninvasive vascular imaging. The outside studies were not available for review and a catheter angiogram was performed immediately on arrival to our institution, which revealed a PCom A aneurysm. In all 7 other Cases (III-10 to III-14, III-16, and III-17; Table 1), review of the outside noninvasive vascular studies by our institutional personnel, including neuro-ophthalmologists, neurologists, neuroradiologists, or neurosurgeons, allowed identification of a PCom A aneurysm. This confirmed misinterpretation of these tests by the outside radiologists, rather than inadequate technique. Two of these patients had normal appearing reconstructed MRA images, but an aneurysm was detected on the source images. Five of the 7 misread noninvasive imaging studies were performed and read by general radiologists who had no neuroradiology training. In 1 case, the interpreting radiologist had received neuroradiology training 20 years prior but had been prac-ticing mostly as a general radiologist for many years. We could not determine the training of the radiologist in 1 Case (III-11), but the test had been performed at a general radiology center with no special expertise in neuroradiology. Review of the indications for these misinterpreted studies in the patients' medical records revealed that in 6 of 7 cases, the radiologist performing and interpreting the test was given vague, or wrong, clinical history. Misleading clinical indications included ‘‘headache, Horner,'' ‘‘transient is-chemic attack, hypertension,'' ‘‘headache,'' and ‘‘rule out aneurysm'' without mention of the side or location of the suspected aneurysm (Table 1). The mean age for group III was 44.1 years (range: 33-55 years). The size range for the aneurysms that were initially missed (group III) was 3.5 mm (Case III-16) to a bilobed 12 mm aneurysm (Case III-14) (Table 1). 104 Elmalem et al: J Neuro-Ophthalmol 2011; 31: 103-109 Original Contribution Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. TABLE 1. Imaging strategies in 17 patients with isolated third nerve palsy related to an ipsilateral posterior communicating artery aneurysm Case Age (Yrs)/Sex First Imaging Modalities SAH on CT Initial Diagnosis Missed Clinical Indication on Radiology Report Read by Neuroradiologist Initially How Correct Diagnosis Was Made Side and Size of Aneurysm in Millimeters* I-1 60/F Noncontrast CT, then angiogram Yes No Headache No Initial imaging (angiogram) Right and 6 3 5 3 4 I-2 46/M CT/CTA, then angiogram Yes No Right pupil dilation, suspicion of aneurysm Yes Initial imaging (CTA) Right and 5.4 3 3.6 I-3 59/F CT/CTA, then angiogram Yes No Head/retro-orbital paralyzed left eye NA Initial imaging (CTA) Left and 10 3 534 I-4 83/F CT, MRI/MRA, then angiogram Yes No Headache with new right third nerve palsy; evaluate for possible aneurysm Yes Initial imaging (MRI/MRA) Right and 6 3 4.5 3 4.5 II-5 70/F CT/CTA No No Left CN third palsy Yes Initial imaging (CTA) Left and 6.2 3 3 3 2.7 II-6 53/M MRI/MRA No No NA NA Initial imaging (MRI/MRA) Right and 8 3 5 II-7 41/F Noncontrast CT, MRI/MRA No No Stroke, assess for aneurysm Yes Initial imaging (MRI/MRA) Right and 10 3 8 3 7 II-8 64/F Noncontrast CT, MRI/MRA No No Right third nerve palsy Yes Initial imaging (MRI/MRA) Right and 5.5 3 4.5 3 4.45 II-9 54/M Noncontrast CT, then angiogram (artifact from prior surgical clip) No No Headache with history of cerebral aneurysm Yes Angiogram Left and 9.6 3 8.1 3 5.8 III-10 55/F Noncontrast CT, MRI/MRA No Yes (misread) Headache with right Horner No Review of outside MRI/MRA showed aneurysm on source images Right and 5 3 3 3 3 III-11 53/F Noncontrast CT, then MRI/MRA No Yes (misread) NA NA Review of outside MRI/MRA Right and NA (continued on next page) Elmalem et al: J Neuro-Ophthalmol 2011; 31: 103-109 105 Original Contribution Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. TABLE 1. (continued) Case Age (Yrs)/Sex First Imaging Modalities SAH on CT Initial Diagnosis Missed Clinical Indication on Radiology Report Read by Neuroradiologist Initially How Correct Diagnosis Was Made Side and Size of Aneurysm in Millimeters* III-12 50/F CT/CTA, MRI/ MRA No Yes (misread) Headaches, evaluate for possible aneurysm Yes (but mostly performs general radiology) Review of outside CT/CTA; outside MRI poor quality Left and 6 3 3 III-13 39/F Noncontrast CT, MRI/MRA No Yes (misread) R/o aneurysm right eyelid droop and right-sided headache No Review of outside MRI/MRA showed aneurysm on source images Right, bilobed: 9.4 total and 7.1 3 4.4 3 3.6; 2.3 3 2 3 1.8 III-14 40/F Noncontrast CT, then MRI/MRA No Yes (misread) TIA, hypertension No Review of outside MRI/MRA Left, bilobed: 12 total and 3 3 3; 8 x 6 III-15 33/F Noncontrast CT, MRI/MRA No Yes Right-sided headache No Outside MRI/MRA not available for review; diagnosis on angiogram Right and 6 3 3 III-16 46/F MRI, then CT with contrast, then angiogram No Yes (misread) Migraine headache and CVA No Review of initial imaging (contrast CT) Left and 3.5 3 2.5 3 2.5 III-17 37/F CT with and without contrast, MRI/MRA, then CTA No Yes (misread) Headache, Horner syndrome No Review of outside MRI/MRA Left and 7.7 3 4.7 3 4.2 Group I: SAH on initial noncontrast CT; group II: no SAH but aneurysm correctly initially diagnosed; and group III: no SAH and initial diagnosis missed. *Size of aneurysm in millimeters, as measured on catheter angiography (angiogram refers to catheter angiography). CN, cranial nerve; CTA, CT-angiography; CVA, cerebrovascular accident; NA, not available; PCOM, posterior communicating artery; r/o, rule out; SAH, subarachnoid hemorrhage; TIA, transient ischemic attack. 106 Elmalem et al: J Neuro-Ophthalmol 2011; 31: 103-109 Original Contribution Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. The average greatest dimension of the aneurysms in each group was 6.9 mm for group I, 7.9 mm for group II, and 7.1 mm for group III. A 1-way analysis of variance test showed no statistically significant difference of aneurysm size among the 3 groups (P = 0.33). The average size of PCom A aneurysms causing an isolated third nerve palsy across all 3 groups was 7.3 mm. DISCUSSION Our study demonstrates that the interpretation of non-invasive neurovascular imaging is not easy and that a neg-ative result can only be trusted after verifying that the interpreting radiologist is aware of the correct clinical indication for the study and has appropriate training and experience. Many radiology centers in the United States are equipped with the state-of-the-art CT and MRI scanners, but only a few benefit from experienced technologists who are able to appropriately manipulate the raw data and from neuroradiologists specifically trained to interpret non-invasive neurovascular imaging studies (12). In centers without skilled personnel, patients with an isolated non-traumatic third nerve palsy, should likely undergo a catheter angiogram, which remains the gold standard for the diagnosis of intracranial aneurysms. Unfortunately, it is likely that these centers are also the ones with the highest risk of catheter angiography-related complications because of their lack of experience with invasive neurovascular imaging (13,14). Intracranial aneurysms presenting with an isolated third nerve palsy are relatively rare (9-11,15), and only high volume centers with experienced neuro-radiologists, interventional neuroradiologists, and vascular neurosurgeons have enough experience to efficiently ‘‘rule out'' an aneurysm on noninvasive vascular imaging. Even at our highly specialized center, we could only identify 17 cases with isolated aneurysmal third nerve palsy over a pe-riod of 9 years. Many more aneurysmal third nerve palsies presented to our Emergency and Neurosurgery Depart-ments over the same time period, but these were not isolated, manifesting the more typical symptoms and signs of aneu-rysmal rupture. In theory, noninvasive vascular imaging (CTA or MRA) should be sensitive enough to detect nearly all aneurysmal third nerve palsies (9-12). Indeed, the smallest PCom A aneurysm reported to presumably cause a third nerve palsy was 3 mm and was missed initially on MRA (16). With this case and our case, III-16 as very rare exceptions, most reports have maintained that a PCom A aneurysm needs to be at least 4 mm to cause a third nerve palsy, within the range of highest sensitivity for both current MRA and CTA machines (3,4,6,9-11,17,18). The sensitivity of 1.5T MRA for aneurysms larger than 5 mm has improved to at least 95%, whereas the sensitivity of 1.5T MRA has been reported to be much lower (around 50%) for smaller aneurysms (10,19). The latter are unlikely to cause a third nerve palsy. The sensitivity of 3T MRA is only slightly better than with 1.5T MRA (19), and MRA of 7T might not significantly increase the sensitivity over the standard 1.5T MRA in diagnosing smaller aneurysms (20). The availability of 64-section multidetector CTA in recent years, compared with the previously used 4- or 16-section CTA, has dramatically improved the quality of the CTA exami-nation and in turn, the sensitivity of CTA in the detection of small aneurysms (11,21,22). With improved spatial and temporal resolution and reduced slice thickness, the sensi-tivity of CTA for aneurysms above 3 mm is 99%-100% (23). In addition, rapid acquisition time makes CTA practical for emergency evaluation of cerebral aneurysms. However, unless the interpreting physician improves his/her ability for aneurysm detection, these advancements in im-aging will not be beneficial. In 4 of 17 of our cases (group I, Table 1), there was evidence of subarachnoid hemorrhage on the initial non-contrast CT obtained emergently, and the diagnosis of aneurysm was easily made. In the presence of subarachnoid hemorrhage, the index of clinical suspicion for intracranial aneurysm is very high, which improves the chance that the correct sequence of imaging studies will be performed and that the radiologist will meticulously evaluate the images in the search of an aneurysm. The lack of subarachnoid hemorrhage makes the identification of an aneurysm more difficult. The correct diagnosis was immediately made on initial noninvasive vascular imaging in 5 of 13 cases without FIG. 1. Noncontrast head CT showing subarachnoid hemorrhage (arrow) in a patient with an isolated painful right third nerve palsy (group I). Elmalem et al: J Neuro-Ophthalmol 2011; 31: 103-109 107 Original Contribution Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. subarachnoid hemorrhage (group II). Some of these studies were performed at various institutions (including ours), and nothing differentiated these cases fromthose that weremissed. Interestingly, the patients in group II (correctly diagnosed) were older than those in group III (missed) and perhaps should have been less suspected of harboring an aneurysm and more suspected to suffer a microvascular third nerve palsy. The aneurysms' sizes were similar in groups II and III. All 8 patients with an initial misread as negative non-invasive neurovascular study (group III) had studies per-formed at outside institutions. When considering these 8 patients with missed aneurysms, our initial inclination was to find fault with the technical quality of the test obtained. However, we were able to easily identify the missed aneu-rysm on all outside imaging studies (on a CD or plain films, without the ability to reformat the images), confirming that they were of adequate quality. Because of this finding, we chose not to evaluate or report in detail the techniques used to perform the CTAs and MRAs at outside institutions but rather focused on the interpretation of the studies themselves. In detecting intracranial aneurysm on noninvasive neurovascular studies, it is crucial to carefully examine the source data in addition to the postprocessed reconstructed images. Manual alteration of the window levels and widths at an interpreting workstation can also improve aneurysmal detection. To perform these steps correctly, the radiologist must be given the correct clinical history (eg, left or right third nerve palsy). In 6 of 7 cases, with misinterpreted studies, the radiologist was given vague, or incorrect, clinical history including ‘‘headache, Horner,'' ‘‘transient ischemic attack, hypertension,'' and ‘‘headache,'' without mention of an acute third nerve palsy, or ‘‘rule out aneurysm,'' without mention of the side or location of the suspected aneurysm (group III, Table 1). It is not surprising that when the history is vague or inaccurate, the radiologist may not focus as carefully on the expected location of the aneurysm and may miss aneurysms that are sometimes seen only on 1 CTA slice or MRA source image. Aside from an accurate history, the training and expe-rience of the interpreting radiologist is probably the most important factor in determining the reliability interpretation of a noninvasive scan (12). Most (5 of 7) misread noninvasive imaging studies were interpreted by general radiologists who had no formal neuroradiology training. In 1 case, the interpreting radiologist had received neuroradiology training 20 years prior, but had been practicing mostly as a general radiologist for many years. White et al (24) compared the detection of intracranial FIG. 2. CTA demonstrating a left PCom A aneurysm (arrow) in a patient from group II. FIG. 3. A.MRA reformatted image from a patient in group III showing a PCom A aneurysm (arrow). B. MRA source image from the same patient showing the aneurysm (arrow). 108 Elmalem et al: J Neuro-Ophthalmol 2011; 31: 103-109 Original Contribution Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. aneurysms on CTA and MRA by neuroradiologists versus ‘‘observers,'' which included a neurosurgeon, general radi-ologist, and radiographer with experience in looking at the neuraxis but no formal neuroradiology training. Neuroradiologists were consistently more accurate. For aneurysms larger than 5 mm on CTA, accuracy for neu-roradiologists was 100%, whereas accuracy for the observers was 86%-93%. For MRA, accuracy was 93%-100% for neuroradiologists and 86%-100% for the observers. In another study (25) in which neuroradiologists reinterpreted head and neck imaging in a multidisciplinary cancer center, a change in interpretation occurred in 41% of images, altering management in 98% and prognosis in 95%, most with a worse prognosis, confirming that neuroradiology certification dramatically improves interpretation skills of neuroimaging. While technical improvements in non-invasive neurovascular imaging techniques, including CTA and MRA, have increased their sensitivity in detecting intracranial aneurysms, the most important step in imaging remains interpretation, which is entirely dependent on the training, skills, and experience of the radiologist. Appro-priate communication of the correct clinical information and level of suspicion of an aneurysmal third nerve palsy is essential. Previous reports have emphasized the paucity of trained technologists capable of advanced manipulation of the imaging data and of certified neuroradiologists to interpret the study (12). Trobe (9) recently stated that determining whether a negative report is reliable is critical when evaluating a patient with isolated third nerve palsy. Our study suggests that to avoid diagnostic mistakes, all negative noninvasive studies should be reviewed with an experienced neuroradiologist before rejecting aneurysmal compression as the cause of the third nerve palsy or prior to ordering a catheter angiogram.. This is obviously institution dependent, and delays resulting from patient or image transfer to a specialized institution must be balanced against the risks of immediate catheter angiogram. REFERENCES 1. Trobe JD. Isolated pupil-sparing third nerve palsy. Ophthalmology. 1985;92:58-61. 2. Trobe JD. Third nerve palsy and the pupil. Footnotes to the rule. Arch Ophthalmol. 1988;106:601-602. 3. Jacobson DM, Trobe JD. The emerging role of magnetic resonance angiography in the management of patients with third cranial nerve palsy. Am J Ophthalmol. 1999;128:94-96. 4. Lee AG, Hayman LA, Brazis PW. The evaluation of isolated third nerve palsy revisited: an update on the evolving role of magnetic resonance, computed tomography, and catheter angiography. Surv Ophthalmol. 2002;47:137-157. 5. Bruce BB, Biousse V, Newman NJ. Third nerve palsies. Semin Neurol. 2007;27:257-268. 6. Schultz KL, Lee AG. Diagnostic yield of the evaluation of isolated third nerve palsy in adults. Can J Ophthalmol. 2007; 42:110-115. 7. Vaphiades MS, Cure J, Kline L. Management of intracranial aneurysm causing a third cranial nerve palsy: MRA, CTA or DSA? Semin Ophthalmol. 2008;23:143-150. 8. Lee AG, Hayman LA, Brazis PW. The evaluation of isolated third nerve palsy. Expert Rev Ophthalmol. 2009;4:537-545. 9. Trobe JD. Searching for brain aneurysm in third cranial nerve palsy. J Neuroophthalmol. 2009;29:171-173. 10. Kupersmith MJ, Heller G, Cox TA. Magnetic resonance angiography and clinical evaluation of third nerve palsies and posterior communicating artery aneurysms. J Neurosurg. 2006;105:228-234. 11. Mathew MR, Teasdale E, McFadzean RM. Multidetector computed tomographic angiography in isolated third nerve palsy. Ophthalmology. 2008;115:1411-1415. 12. Chaudhary N, Davagnanam I, Ansari SA, Pandey A, Thompson BG, Gemmete JJ. Imaging of intracranial aneurysms causing isolated third cranial nerve palsy. J Neuroophthalmol. 2009;29:238-244. 13. Thiex R, Norbash AM, Frerichs KU. The safety of dedicated-team catheter-based diagnostic cerebral angiography in the era of advanced nonivasive imaging. AJNR Am J Neuroradiol. 2010;31:230-234. 14. Kaufmann TJ, Huston J III, Mandrekar JN, Schleck CD, Thielen KR, Kallmes DF. Complications of diagnostic cerebral angiography: evaluation of 19,826 consecutive patients. Radiology. 2007;243:812-819. 15. Richards BW, Jones FR Jr, Younge BR. Causes and prognosis in 4,278 cases of paralysis of the oculomotor, trochlear, and abducens cranial nerves. Am J Ophthalmol. 1992;113:489-493. 16. Ross JS, Masaryk TJ, Modic MT, Ruggieri PM, Haacke EM, Selman WR. Intracranial aneurysms: evaluation by MR angiography. AJNR Am J Neuroradiol. 1990;11: 449-456. 17. Yanaka K, Matsumaru Y, Mashiko R, Hyodo A, Sugimoto K, Nose T. Small unruptured cerebral aneurysms presenting with oculomotor nerve palsy. Neurosurgery. 2003;52: 553-557; discussion 6-7. 18. Friedman JA, Piepgras DG, Pichelmann MA, Hansen KK, Brown RD Jr, Wiebers DO. Small cerebral aneurysms presenting with symptoms other than rupture. Neurology. 2001;57:1212-1216. 19. Li MH, Cheng YS, Li YD, Fang C, Chen SW, Wang W, Hu DJ, Xu HW. Large-cohort comparison between three-dimensional time-of-flight magnetic resonance and rotational digital subtraction angiographies in intracranial aneurysm detection. Stroke. 2009;40:3127-3129. 20. Mo¨nninghoff C, Maderwald S, Theysohn JM, Kraff O, Ladd SC, Ladd ME, Forsting M, Quick HH, Wanke I. Evaluation of intracranial aneurysms with 7 T versus 1.5 T time-of-flight MR angiography-initial experience. Rofo. 2009;181: 16-23. 21. McKinney AM, Palmer CS, Truwit CL, Karagulle A, Teksam M. Detection of aneurysms by 64-section multidetector CT angiography in patients acutely suspected of having an intracranial aneurysm and comparison with digital subtraction and 3D rotational angiography. AJNR Am J Neuroradiol. 2008;29:594-602. 22. McKinney AM, Truwit CL, Palmer CS, Teksam M. Intracranial aneurysms: is the diagnostic accuracy rate of multidetector CT angiography equivalent to that of three-dimensional rotational conventional angiography? Radiology. 2008;246:982; author reply-3. 23. Li Q, Lv F, Li Y, Luo T, Li K, Xie P. Evaluation of 64-section CT angiography for detection and treatment planning of intracranial aneurysms by using DSA and surgical findings. Radiology. 2009;252:808-815. 24. White PM, Wardlaw JM, Lindsay KW, Sloss S, Patel DK, Teasdale EM. The noninvasive detection of intracranial aneurysms: are neuroradiologists any better than other observers? Eur Radiol. 2003;13:389-396. 25. Loevner LA, Sonners AI, Schulman BJ, Slawek K, Weber RS, Rosenthal DI, Moonis G, Chalian AA. Reinterpretation of cross-sectional images in patients with head and neck cancer in the setting of a multidisciplinary cancer center. AJNR Am J Neuroradiol. 2002;23:1622-1626. Elmalem et al: J Neuro-Ophthalmol 2011; 31: 103-109 109 Original Contribution Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. |
