Digital Angiograms Research Articles

Teaching Neuro Images : Seeing double

A 64-year-old woman developed sudden onset of diplopia, headache, and bilateral abducens palsy. MRI revealed no intracranial mass, ischemia, or intraorbital pathology. Magnetic resonance angiography suggested bilateral carotid cavernous fistulas (CCFs, figure 1). Digital substraction angiogram revealed an intercavernous sinus dural arteriovenous fistula (DAVF), which was successfully embolized (figure 2). By 3-month follow-up, her …

QUANTIFICATION OF FLUORESCEIN-STAINED DRUSEN ASSOCIATED WITH AGE-RELATED MACULAR DEGENERATION

Previous studies of age-related macular degeneration have not quantified the number of drusen that accumulate fluorescein. Histopathologic studies have demonstrated druse subregions with different degrees of hydrophobicity, and these subregions might potentially exhibit different degrees of fluorescein uptake. We evaluated macular drusen from 35 age-related macular degeneration patients by measuring druse area in color digital images and fluorescein angiograms, using 2 morphometric methods. Of 828 drusen evaluated, 405 had a corresponding fluorescein angiogram signal. About half of all drusen per eye (49.57%) stained in each participant. Among fluorescein-stained drusen, druse size measured in color images did not differ significantly from the sizes measured in corresponding fluorescein images (P = 0.8105), across the range of druse sizes. These findings indicate that our understanding of drusen subregion staining may not directly correlate to in vivo observations of macular drusen in age-related macular degeneration.

Cystic Artery Localization with a Three-dimensional Angiography Vessel Tracking System Compared with Conventional Two-dimensional Angiography

Purpose During transcatheter hepatic therapy, the cystic artery feeding the gallbladder may inadvertently be exposed to tumor therapy. Localization of the cystic artery may help prevent exposure. The objective of this study was to compare the application of a vessel tracking system software based on three-dimensional (3D) angiography versus standard two-dimensional (2D) angiography for identifying the cystic artery and its origin. Materials and Methods A software system that can rapidly localize the cystic artery from a 3D common hepatic angiogram was applied in 25 patients and was compared with manual localization of the cystic artery with conventional 2D digital subtraction common hepatic angiograms. Results With the vessel tracking software prototype, 28 cystic arteries were retrogradely tracked in 25 of 25 cases. The origin sites were correctly located by the software in 27 of 28 cystic arteries, with one mistracked as a result of streak artifact. By contrast, on standard 2D hepatic angiography, the cystic artery was deemed visible with certainty in 12 of 25 cases ( P < .001). The vessel tracking system revealed a 56% prevalence of extraanatomic distribution by the cystic artery, with the most common supply going to segment 5 liver parenchyma. Conclusions The 3D vessel rapid tracking system has advantages over conventional 2D hepatic angiography in revealing the cystic artery and its origin site. It is also an important tool to identify the complete distribution of the cystic artery without superselective angiography. Supply to adjacent hepatic parenchyma or tumor by the cystic artery is not insignificant and should be considered during hepatic therapies.

Internal carotid artery agenesis: diagnosis, clinical spectrum, associated conditions and its importance in the era of stroke interventions

Background: Internal carotid artery (ICA) agenesis has been usually reported as an asymptomatic condition in association with other congenital anomalies. However, it is less well described in the context of clinical neurological syndromes.Method: Five cases of ICA agenesis are reviewed. The diagnosis of ICA agenesis was based on the absence of bony carotid canal on computed tomography. Brain CT and magnetic resonance image (MRI) scans were done in all the patients and four vessels digital angiograms were obtained in two. Clinical presentation, coexistent radiological findings and associated abnormalities are reviewed.Findings: The initial presentations were pulsatile tinnitus, ischemic stroke, migraine, Horner's syndrome, and subarachnoid hemorrhage. Collateral circulation was supplied via the posterior communicating artery and the anterior communicating artery. Ophthalmic artery was supplied by meningeal arteries. On CT, all cases demonstrated agenesis of the bony carotid canal. Smaller cavernous sinus were detected in all cases, enlargement of the foramen spinosum was found in three patients and hyper-pneumatization of the petrous apex was detected in two cases. In one patient a cerebral aneurysms was detected and treated with an endovascular approach. Other associated vascular abnormalities were aortic origin of the vertebral artery in two patients, ICA coiling in two cases and fenestration of basilar artery in one case.Conclusion: ICA agenesis is usually asymptomatic but occasionally may be associated with ischemic stroke. Collateral supply is usually effective in preventing stroke but may become inefficient leading to ischemia. Associated anomalies such as cerebral aneurysms are commonly depicted on the same side as the ICA agenesis and may represent a potential life-threatening condition.

Cavernous sinus artery - sylvian - Labbé venous fistulae associated with large venous aneurysm: case report and review literatures

Objective To observe the clinical characteristics of the cavernous sinus artery - sylvian -venous remained with surgical resection of venous aneurysm. The literatures of patients with the Cognard Ⅳ DAVF were reviewed. Results There were no neurological deficits in this patient after microsurgical treatment. The digital subtractions angiogram showed that the fistula was completely occluded and venous aneurysm disappeared. The recurrence of DAVF was not found during the five - year follow - up. Among the review of literatures, there were 66% patients with intracranial hemorrhage;the fistulas were occluded completely and permanently through the selective disconnection of venous drainage;in 13 patients with venous aneurysm, 9 patients of them were treated though the surgical resection or coagulation of venous aneurysms. Conclusions Patients with DAVF associated with retrograde cortical venous drainages,especially with venous ectasia or aneurysms, have more often aggressive course. Selective disconnection of venous drainage and resection of venous aneurysm may provide an effective treatment option of this subtype of DAVF. Key words: Arterovenous fistula; Venous aneurysm; Cavernous sinus; Labbe vein; Microsurgery

Detection of the foveal avascular zone on retinal angiograms using Markov random fields

This paper deals with the segmentation of the Foveal Avascular Zone (FAZ) in digital retinal angiograms. Retinal angiography is used for detection and progression in some eye pathologies. The proposed method consists of two-stages: Singular Value Decomposition (SVD) and FAZ segmentation using Markov Random Fields (MRF). The obtained results demonstrate that the method is encouraging as a first approach for location and evolution of FAZ in retinal images.

Efficacy of DynaCT Digital Angiography in the Detection of the Fistulous Point of Dural Arteriovenous Fistulas

Identifying the precise hemodynamic features, including the fistulous point, is essential for treatments of dural arteriovenous fistulas (DAVFs). This study illustrates the efficacy of DynaCT digital angiograms obtained from a 3D C-arm CT to directly visualize the location of the fistulous points in DAVFs. This retrospective study observed 14 consecutive patients with DAVFs, which included 7 cavernous sinuses, 4 transverse-sigmoid sinuses, 2 convexity-superior sagittal sinuses, and 1 tentorial sinus. In the assessment of the practical applicability for the diagnosis of DAVFs, images obtained from 2D digital subtraction angiography (DSA) and DynaCT were comparatively evaluated. In all patients, DynaCT digital angiography could clearly demonstrate the feeding arteries, the fistulous points, and the draining veins. Significant anatomic landmarks for the fistulous points with relationships to osseous structures were also provided. Compared with 2D DSA, DynaCT digital angiograms demonstrated 12 additional findings in 8 patients (57%), including the detection of the fistulous points (n = 7), the feeders (n = 1), the retrograde leptomeningeal drainage (n = 1), the draining veins (n = 1), and the venous anomaly (n = 2). In comparison with 2D DSA, DynaCT may provide more detailed information to evaluate DAVFs. DynaCT digital angiograms have a high contrast and isotropic spatial resolution, allowing a reliable visualization of small vessels and fine osseous structures. Such detailed information, especially for the location of the fistulous points, could be very useful for either the endovascular or the surgical treatments of DAVFs.

Low coronary flow velocity and shear stress predict restenosis after sirolimus-eluting stent implantation

Objectives. This study sought to assess predictive values of coronary flow velocity and an index of shear stress throughout the vessel for angiographic restenosis after sirolimus-eluting stent implantation. Design. The study patients underwent successful implantation of a sirolimus-eluting stent for de novo lesions located in native coronary vessels and underwent follow-up angiography 6–9 months later. The TIMI frame count method and quantitative digital angiographic analysis were performed based on the post-stenting angiogram. Coronary flow velocity and Reynolds number, an index of shear stress, were measured. Results. Post-stenting digital angiograms from 267 patients were analyzed. We divided the study patients into two groups: a Restenosis group with 21 patients and a Non-Restenosis group with 246 patients. The Restenosis group indicated significantly lower coronary flow velocity (137.7±35.6 mm/sec versus 241.1±72.9 mm/sec, p = 0.0001) and lower Reynolds number (107.0±35.8 versus 199.2±67.1, p = 0.0001) than did the Non-Restenosis group. Conclusions. Lowered coronary flow velocity and shear stress after sirolimus-eluting stenting may predict the risk of restenosis.

IDIOPATHIC SUBARACHNOID HEMORRHAGE AND VENOUS DRAINAGE

In the past, several possible explanations for idiopathic subarachnoid hemorrhage (ISAH) have been proposed; however, neuroimaging studies have never provided conclusive data about the structural cause of the bleeding. The aim of this study is to determine whether there are anatomic differences in the deep cerebral venous drainage in patients with ISAH compared with those with aneurysmal subarachnoid hemorrhage (ASAH) and those without intracranial hemorrhage. We reviewed the venous phase of carotid digital angiograms of 100 consecutive patients who had a final diagnosis of ISAH. We also analyzed the angiograms of a control group of 112 patients with ASAH and the angiograms of a nonhemorrhagic group of 25 patients having incidental aneurysms. The anatomic variants of the basal vein of Rosenthal (BVR) on both sides were classified into the following types: Type A (normal continuous), in which the BVR is continuous with the deep middle cerebral veins and drains mainly into the vein of Galen; Type B (normal discontinuous), in which there is discontinuous venous drainage, anterior to the uncal vein and posterior to the vein of Galen; and Type C (primitive), which drains mainly to veins other than the vein of Galen. We calculated the proportions to analyze the differences in the type of venous drainage between patients with ISAH, patients with ASAH, and patients without hemorrhage. chi2 statistics were used to search for differences. Types A and C venous drainage were present in 23.8 and 32.3%, respectively, of patients with ISAH compared with 58.7 and 15.4%, respectively, in the ASAH group and 57.5 and 5%, respectively, in the nonhemorrhagic group (P < 0.001). A primitive variant was present in at least 1 hemisphere in 38 patients with ISAH (41.8% of the cases) compared with 24 patients with ASAH (21.4%) and 2 patients (8%) in the nonhemorrhagic group (P < 0.001). In patients with ISAH, deep cerebral venous drainage more commonly drains directly into dural sinuses instead of via the vein of Galen compared with patients with ASAH and patients without intracranial hemorrhage. The way in which this venous configuration might influence bleeding remains unknown.

Dye Dependent Differences in Arteriovenous Passage Times: A Comparison of Indocyanine Green and Fluorescein Sodium Dye Analysis

To evaluate the difference in arteriovenous passage time calculated from retinal angiograms using indocyanine green and fluorescein sodium dye in healthy individuals. Examinations of eight healthy individuals (mean age +/- standard deviation: 27.3 +/- 4.2 years) who had four consecutive ophthalmic visits that were 2 weeks apart were analyzed. Indocyanine green and fluorescein angiography were performed sequentially (with the indocyanine green angiography occurring first) using scanning laser ophthalmoscopy. Arteriovenous passage times were calculated offline using digital angiogram video analysis. Mean arteriovenous passage times calculated from indocyanine green angiography (1.417 +/- 0.136 seconds) recordings were significantly shorter than fluorescein sodium times (2.539 +/- 0.421 seconds) (P < .0001) and intra-group variability was similar. There were no significant correlations between indocyanine green and fluorescein sodium arteriovenous passage times. Arteriovenous passage times calculated using indocyanine green and fluorescein angiography are not interchangeable.

The prevalence of retinal angiomatous proliferation in age-related macular degeneration with occult choroidal neovascularization

The purpose of the study was to ascertain the prevalence of retinal angiomatous proliferation (RAP) by means of dynamic indocyanine green angiography (d-ICGA) in patients with newly diagnosed fibrovascular pigment epithelium detachment (type 1) or late leakage of undetermined source (type 2) occult choroidal neovascularization (CNV) on fluorescein angiography. We carried out a review of digital fluorescein and ICG angiograms obtained by confocal scanning laser ophthalmoscope (HRA; Heidelberg Engineering GmbH, Dossenheim, Germany) in 253 consecutive patients (270 eyes) with a clinical diagnosis of type 1 or type 2 occult CNV on fluorescein angiography (1998 through 2003). Sixty eyes had type 1 and 210 eyes type 2 occult CNV on fluorescein angiography. Overall, 57 cases of RAP were identified in 54 eyes (20%) with d-ICGA. RAP was present in 6 out of 60 eyes with type 1 (10%) and in 51 out of 210 eyes with type 2 occult CNV (24%). Mean distance of the lesion from the fovea was 682 +/- 304 microm (mean +/- SD). d-ICGA is invaluable for early diagnosis of RAP in exudative age-related macular degeneration (ARMD). In our series, up to one fourth of type 2 occult CNV were in fact RAP.

VARIABILITY AMONG RETINA SPECIALISTS IN EVALUATING FLUORESCEIN ANGIOGRAMS OF PATIENTS WITH NEOVASCULAR AGERELATED MACULAR DEGENERATION

To determine the rate of agreement among five retina specialists in classifying various angiographic features of subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD), as evaluated on printed digital fluorescein angiogram (FA) frames, as well as determination of eligibility for photodynamic treatment (PDT) according to established guidelines. Ninety-two digital FAs demonstrating subfoveal CNV secondary to AMD were evaluated independently by five retina specialists. The pattern of classic component could be classified as no classic component, minimally classic, predominantly classic, or classic only. Each grader was asked to determine eligibility of each case to PDT according to established treatment guidelines, national health insurance guidelines, and one's own personal judgment. The kappa coefficient of concordance calculated for all five observers regarding CNV localization was 0.285, indicating fair overall agreement, and was 0.295, indicating fair agreement, regarding classification of leakage pattern. The kappa coefficient of agreement calculated for all five graders regarding eligibility for treatment according to established international guidelines, national health insurance, and each grader's own personal judgment was 0.163, 0.33, and 0.164, respectively, indicating slight to fair overall agreement. Considerable variability may exist among retina specialists interpreting FAs and should be considered in the assessment of treatment guidelines.

Magnetic resonance angiographic demonstration of carotid-cavernous fistula using elliptical centric time resolved imaging of contrast kinetics (EC-TRICKS)

Magnetic resonance angiographic evaluation of the intracranial vasculature has been predominantly carried out using conventional angiographic techniques such as time of flight and phase contrast sequences. These techniques have good spatial resolution but lack temporal resolution. Newer faster angiographic techniques have been developed to circumvent this limitation. Elliptical centric time-resolved imaging of contrast kinetics (EC-TRICKS) is one such technique which has combined the use of elliptical centric ordering of the k-space with multiphase 3D digital subtraction MR angiogram (MRA) to achieve excellent temporal resolution of the arterial and venous circulations. Its applications have been mainly in the peripheral vasculature. We report the use of this technique in a case of a high-flow, direct carotid-cavernous fistula to demonstrate its potential in intracranial MR angiography.

Impact of catheter sizes and intracoronary glyceryl trinitrate on the TIMI frame count when digital angiograms are acquired at lower frame rates during elective angiography and PCI

The TIMI frame count (TFC) is a useful measure of coronary flow. To be widely applicable, the effect of different catheter sizes and the use of intracoronary glyceryl trinitrate (ICGTN) must be determined when films are acquired at lower acquisition rates (12.5 frames/s, f/s). We compared 6F versus 5F diagnostic catheters (n = 44), 6F versus 7F diagnostic catheters (n = 45) and 6F diagnostic versus 7F guide catheters (n = 44). In the nitrate angiography group (n = 141), coronary angiography was performed before and after 200 micrograms of ICGTN. In the nitrate percutaneous coronary intervention (PCI) group (n = 48), coronary angiography was performed before and after 200 micrograms of ICGTN after the completion of the elective PCI procedure. The mean difference in the uncorrected TFC using 6F and 5F was 0.02 (95 % CI -0.5, 0.6; P = 0.9); using 6F and 7F diagnostic catheters it was 0.3 (95% CI -0.49, 1.1; p = 0.4); and using 6F diagnostic and 7F guide catheters it was 0.4 (95% CI -2.6, 3.4; P = 0.7) respectively. In the nitrate angiography group, the uncorrected TFC before and after ICGTN was 13.1+/-6.2 and 15+/-7.5 (equivalent to 31.4+/-14.9 and 36+/-2 at 30 f/s), with a mean difference of 1.9 (95% CI 1.3, 2.5; P = or <0.0001). In the nitrate PCI group, the uncorrected TFC before and after ICGTN administration was 9.2+/-3.7 and 10.3+/-4.2 (equivalent to 22.6+/-9.6 and 25.2+/-11 at 30 f/s) respectively with a mean difference between the two injections of 1.2 (95% CI -0.4, 1.9; P = 0.003). We have demonstrated that the catheter sizes did not significantly affect the TFC when angiography was performed at 12.5f/s. The use of ICGTN significantly increased the TFC in both normal and diseased coronary arteries. This effect was also observed when ICGTN was administered into the culprit vessels after the completion of the elective PCI procedure. This effect must be considered when investigating the impact of specific treatments or drugs on coronary flow.

Dynamic and Quantitative Analysis of Choroidal Neovascularization by Fluorescein Angiography

In this study, the authors sought to develop and characterize techniques for measuring changes in choroidal neovascularization (CNV) lesion size and fluorescence over time for quantitative analysis of fluorescein angiograms. Initial assessment of the quantitative technique was made by retrospectively analyzing digital fluorescein angiograms taken before and 3 months after photodynamic therapy (PDT) for CNV (6 patients, group 1). The method was then applied prospectively to digital fluorescein angiograms (baseline and day 71) obtained on 12 patients taking part in a clinical trial investigating the effect of vascular endothelial growth factor (VEGF) Trap in CNV (group 2). Two masked observers, with the use of image processing, measured the area of hyperfluorescence and fluorescence intensity above background. Values for each image were plotted against time after dye injection to generate curves, and each area under the curve (AUC) was calculated. The physician who treated the patients in group 1 judged the condition of three patients to be improved and of three to be worse 3 months after PDT. Masked retrospective grading of fluorescein angiograms showed an 11% decrease in AUC for fluorescence area and a 32% decrease in AUC for fluorescence intensity in the three patients whose conditions clinically improved but increases of 131% and 292% in the three patients whose conditions clinically worsened. In group 2, a 38% decrease in AUC for fluorescence intensity and a 19% decrease in AUC for fluorescence area were observed in patients who received VEGF Trap compared with increases of 66% (P = 0.004, Mann-Whitney U test) and 21% (P = 0.07) for patients who received placebo. Macular volume decreased by 11% in VEGF Trap-treated patients and increased by 10% in placebo-treated patients (P = 0.03). This study reports a technique for analysis of change in fluorescence area and intensity over time during fluorescein angiography (FA) using a continuous scale and its application in a clinical setting and a clinical trial. Compared with previous techniques making use of categorical scales, this approach provides an advantage for evaluating responses to treatment that may improve the value of FA as an outcome measure in clinical trials.

Coating the Wall of an Injured Intracranial Carotid Artery During Tumor Removal With N-Butyl-2-Cyanoacrylate: Technical Case Report

Carotid artery injury close to the clinoid process is difficult to repair, and is even more so when the vessel is firmly attached to a calcified tumor. We treated a patient with an intraoperative carotid lesion by coating the vessel wall with n-butyl-2-cyanoacrylate (NBCA). A 7-year-old boy was referred to our clinic with a 3-month history of somnolence, apathy, and headache. Neurological examination revealed bitemporal hemianopsia. The cranial magnetic resonance imaging and computed tomographic scans showed a sellar and suprasellar calcified mass with heterogeneous contrast enhancement, a cyst component in the upper part of the tumor displaced upward and back from the mesencephalic and diencephalic structures. The patient underwent a pterional craniotomy. Using a microsurgical technique, the suprasellar part of the craniopharyngioma was removed. In an attempt to dissect the calcified mass from the carotid artery on the right side, the vessel was unintentionally injured, followed by severe bleeding. Temporary occlusion and suturing of the vessel was impossible because of the overlying hard mass. To avoid a permanent occlusion, we decided to coat the injured artery wall with 100% NBCA. For this, 0.5 ml of NBCA was distributed on the surface of the injured segment and surrounding subarachnoid space by injection through a needle. An excellent hemostasis could be obtained immediately after coating. The patient woke up with no new neurological deficits. A digital cerebral angiogram obtained a few days after the procedure did not show vasospasm, stenosis, or pseudoaneurysm in the supraclinoidal segment of the carotid artery. A magnetic resonance angiogram obtained 3 years later showed a normal shape of the internal carotid artery and a stable residual tumor without inflammatory signs. The child is now attending school and is under hormonal therapy. For hemostatic purposes, the technique of coating an injured arterial wall with NBCA may be useful in cases in which a microsuture is impossible and a permanent artery occlusion is unwanted because of a risk of an ischemic stroke. It could serve as a transitory measure until a microsurgical bypass or the balloon test occlusion tolerance allow the trapping of the affected artery.

Pulmonary Embolism: Radiation Dose with Multi–Detector Row CT and Digital Angiography for Diagnosis

To compare radiation dose delivered at four- and 16-detector row computed tomography (CT) with a dose-modulation program and that delivered at digital angiography for evaluation of pulmonary embolism (PE). The part of the study involving patients (seven women, four men; mean age, 62 years +/- 16 [standard deviation]; range, 41-85 years) was approved by the institutional review board. Patients gave written informed consent. Exposure was performed with an anthropomorphic phantom with thermoluminescent dosimeters for four-detector row CT without the dose-modulation program and 16-detector row CT without and with the dose-modulation program with standard protocols for pulmonary CT angiography (120 kV, 144 mAs, four and 16 detector rows with 1.00- and 0.75-mm section thickness, respectively). Digital angiograms were acquired with four standard projections at 80 kV. For digital angiography, radiation dose was calculated according to phantom measurements and adapted to acquisition and fluoroscopy times. Distribution of dose was compared for CT and digital angiography. During pulmonary CT angiography, mean radiation dose delivered at middle of chest was 21.5, 19.5, and 18.2 mGy for four-detector row CT and for 16-detector row CT without and with dose-modulation program, respectively. At the same level, a mean dose of 91 mGy was delivered with digital angiography. The dose adjusted to clinical conditions was 139.0 mGy for digital angiography and could be reduced after technical adjustment. Ratios of maximum dose to mean dose were 1.15 and 2.96 for CT and digital angiography, respectively. With application of the dose-modulation program at 16-detector row CT, radiation dose was reduced 15%-20% at the upper chest. Multi-detector row CT delivers a lower radiation dose, with better spatial distribution of dose, than does pulmonary digital [corrected] angiography. With 16-detector row CT and a dose-modulation program, radiation dose is decreased during PE work-up.

Pulmonary artery-to-pulmonary artery anastomoses: angiographic demonstration in patients with chronic thromboembolic pulmonary hypertension

To describe direct pulmonary artery-to-pulmonary artery anastomoses seen at pulmonary angiography in patients with chronic thromboembolic pulmonary hypertension and discuss their possible significance. Between 1 August 2000 and 31 July 2004 43 patients (male-to-female ratio 25:18) with a diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH) underwent selective pulmonary angiography to assess the extent of disease and suitability for surgical pulmonary endarterectomy. The mean pulmonary artery pressure ranged from 27-84 mmHg (average of 51 mmHg). Selective bilateral digital subtraction pulmonary angiograms performed in all individuals were reviewed for the presence of intrapulmonary collaterals. In 15 of the 43 patients (male-to-female ratio =7:8) definite (n = 12) or probable (n = 3) pulmonary artery-to-pulmonary artery anastomoses were demonstrated. Of the remaining 28 patients in whom intrapulmonary collaterals were not seen it was felt that in 16 the angiograms were of insufficient diagnostic quality (grades 4-5) to exclude their presence. Twelve patients, eight of whom had angiograms of sufficient diagnostic quality (grades 1-3), demonstrated one or more areas of luxury perfusion but intrapulmonary collaterals were not seen. Direct pulmonary artery-to-pulmonary artery anastomoses were demonstrated in patients with chronic thromboembolic pulmonary hypertension, which to our knowledge have not been previously described. The importance of these collateral vessels is unclear but they may play a role in the maintenance of pulmonary parenchymal viability in patients with chronic pulmonary embolic disease. The rate of development of these collaterals and their prognostic significance in patients with chronic thromboembolic pulmonary hypertension are areas worthy of further study.

Hemangioblastoma of the filum terminale

A 52-year-old man presented with low backache, paraesthesiae and spasticity of both lower limbs. He had urinary retention and constipation. Investigations revealed a vascular intradural cauda equina-conus tumor. MRI scan demonstrated an enhancing mass at the second and third lumbar vertebral levels. There were multiple dilated and tortuous veins draining from both poles of the tumor. Digital subtraction spinal angiogram showed the tumor to be supplied mainly by the radiculo-medullary artery from first lumbar artery and dural branches of the second and third lumbar arteries. At surgery, after pre-operative embolization, a well-defined tumor with an orange hue and fleshy consistency was encountered arising from the filum terminale. The tumor was excised en bloc. A sporadic hemangioblastoma arising from the filum terminale should be considered as a rare cause of back pain and sciatica. Total excision of the tumor offers cure.

Metabolic factors and the foveal avascular zone of the retina in diabetes mellitus

To study the foveal avascular zone (FAZ) of the central retina in diabetic patients with retinopathy having undergone metabolic evaluation. One hundred and ten digital fluorescein angiograms were chosen from our digital image bank after cross matching diabetic patient lists of the ophthalmology and endocrinology departments of our institution. The patients had undergone day visits with systemic, biological and ophthalmologic evaluation, including digital fluorescein angiography. Sex ratio was M 62/F 48. Average age was 52.4 years (+/- 13.8) with 44 type 1 diabetics and 66 type 2. Retinopathy was present in all patients (54 background (BDR), 30 pre-proliferative (PPDR), 26 proliferative (PDR)). Age was positively correlated with FAZ grade (47.3 years +/- 13.2 for normal FAZ, 53.8 years +/- 13.7 for abnormal FAZ, P=0.03). Lipid profile showed a protective tendency of the Apo A1 fraction of cholesterol on macular vascularization (1.7 gr./l in normal FAZ patients vs 1.43 gr./l in abnormal FAZ patients, P=0.004). Body mass index was negatively correlated with macular ischemia (28.11 if FAZ not severely altered, 25.97 if FAZ severely altered, P=0.03). We found possible relations between BMI and Apo A 1 cholesterol and macular vascularization which may warrant further investigation.