Dural carotid cavernous fistulas: role of conventional radiation therapy--long-term results with irradiation, embolization, or both

PURPOSE

To evaluate the long-term results of irradiation alone or of embolization with or without irradiation in patients with dural carotid cavernous fistulas (DCCFs).

MATERIALS AND METHODS

Between 1984 and 1996, symptomatic DCCFs in 26 patients were treated by using irradiation alone (protocol 1, n = 12) before April 1988 and by using embolization as an initial treatment (protocol 2, n = 14) during and after April 1988. When angiography showed no improvement after embolization, irradiation was added (n = 6). On the basis of drainage flow speed, DCCFs were classified as fast, medium, or slow.

RESULTS

With irradiation alone, all six patients with slow- to medium-type DCCFs had cure with a mean follow-up of 62 months. Four of six patients with fast-type DCCFs had cure or improvement, but the remaining two had no change. In the embolization group, irradiation was added in six patients with fast-type DCCFs. With a mean follow-up of 24 months, four of the six patients had cures, one had improvement, and one had no clinical change. Those who underwent protocol 2 had cures significantly earlier than those who underwent protocol 1 (P < .05).

CONCLUSION

Conventional radiation therapy resulted in cure of DCCFs in nine (75%) of the 12 patients and in improvement of signs and symptoms in one (8%). Fast-type DCCFs may not always be improved. Radiation therapy may be useful in DCCFs after embolization.

Basic imaging properties of a new screen-film system for chest radiography

To evaluate the potential clinical usefulness of a new screen-film system (advanced screen-film system; AD system) for chest radiography, its fundamental imaging properties compared with a conventional screen-film system (HR-4/HR-S) were investigated. The basic imaging properties were evaluated by measuring characteristic (H&D) curves, relative speeds, MTFs (modulation transfer functions), WS (Wiener spectra), and x-ray attenuations of screens. The detail visibilities and pathological details of various diseases in chest radiographs of patients were evaluated subjectively. The film gradient of the AD system was slightly lower at low radiographic density, and higher at high density, as compared with a conventional screen-film system. The screen speed of the AD system was 212% greater than that of the conventional system, and the film speed was 53% that of the conventional film. As the result, the total speed of the AD system was slightly higher compared with the conventional system. The spatial resolution of the AD system was comparable to or slightly lower than that of the conventional system. The noise level of the AD system was considerably lower than that of the conventional system at low (D = 0.5) and middle (D = 1.0) radiographic density levels. However, it was high at high radiographic density (D = 1.8). The radiographic densities in the underpenetrated areas with the AD system were greater than those of the conventional system when the lung densities are matched comparable. Improvement in noise level with the AD system at low and middle density levels may be useful for detection of various diseases in chest radiographs.

[Percutaneous transluminal angioplasty of the ilio-femoro-popliteal arteries: initial and long-term results]

The initial and long-term results of percutaneous transluminal angioplasty (PTA) were assessed in 254 atherosclerotic lesions of the ilio-femoro-popliteal arteries in 130 patients. There were 122 men and 8 women, aged 36-85 years (average, 68 years). Follow-up periods ranged from 1 to 131 months, with a mean of 42 months. PTA was performed in 6 patients in Fontaine's stage I, 112 patients in stage II, and 12 patients in stage III-IV. We reported initial success rates of 92%, 58%, 83% and 74% for iliac stenosis, occlusion, femoro-popliteal stenosis and occlusion, respectively. Overall, the initial success rate was 82% (203/247). The 5-year patency rates according to Kaplan-Meier analysis were 70%, 69% and 63% for iliac stenosis, occlusion and femoro-popliteal stenosis, respectively. In femoro-popliteal occlusion, the 1-year patency rate was 42%, which was significantly worse than that for stenosis (P < 0.01). The longest patency periods obtained were 131 months in the iliac artery, and 106 months in the femoro-popliteal artery. The recurrence rate within 6 months was significantly higher in patients with diabetes. The recurrence rate between 6 and 12 months was significantly higher in patients with poor run-off, and those of advanced age.

Iotrolan: a blood-isotonic nonionic dimer contrast agent for peripheral angiography

Twenty-four patients undergoing peripheral arteriography with iotrolan 280, a blood-isotonic, nonionic, dimeric contrast medium, were evaluated in a carefully controlled phase III open trial using a variety of objective and subjective tests of discomfort. There was almost no evidence of pain, and the patients reported that they had minimal warm sensation during injection. No abnormalities in blood chemistry or urinalysis were noted in relation to injection of the contrast medium. Opacification of the peripheral arteries was excellent in all patients. Multiple physical examinations, chemical tests, electrocardiograms, and monitoring of the blood pressure showed that iotrolan 280 was a safe and useful contrast agent for peripheral angiography.

[Preliminary clinical applications of asymmetric screen-film systems in chest radiography]

The physical imaging properties of asymmetric systems and a conventional system were evaluated by measuring characteristic curves, resolution properties and noise Wiener spectra. The potential clinical application of asymmetric screen-film systems was studied by evaluating the visibility of the anatomical structures and various types of abnormalities in comparison with those of a conventional screen-film system. The asymmetric systems showed a wider dynamic range than the conventional system. The resolution properties of asymmetric systems depend on the combination of front and back screens used. Chest radiographs obtained with asymmetric systems improved the visibility of the mediastinal area. The visibility of the lung field in the asymmetric systems was slightly inferior to that with the conventional system when the same tube potential was used. However, the image quality and visibility of various abnormalities showed greater improvement with the asymmetric systems when a lower tube potential was applied. We conclude that the selection of radiographic techniques and combination of screens are important for the clinical use of asymmetric systems.

[Percutaneous transluminal angioplasty of the subclavian arteries]

We studied the complications and long-term results of percutaneous transluminal angioplasty (PTA) of subclavian artery stenosis in 11 patients. In all patients but one, the systolic blood pressure before PTA in the arm on the involved side was at least 30 mmHg lower than that in the opposite arm. PTA of 11 left subclavian arteries and one right subclavian artery was attempted. Five of the patients suffered from symptoms of vertebrobasilar insufficiency as well as ischemia of the upper limb, two had only cerebral symptoms, two had only ischemia of the upper limb, and another had no symptoms related subclavian arterial lesion. Standard techniques for PTA were employed, using the femoral route eight times and the axillary route four times. Angioplasty was successful in 11 lesions (92%). In the successfully treated patients, the blood pressure in the ipsilateral arm was significantly increased after PTA. No complications occurred during or after the procedure. The patients were followed for 2-74 months (mean 25.7 months). During this time, no recurrence of the stenosis was observed, although the symptoms of vertebrobasilar insufficiency did not always improve. These results suggest that PTA is useful for treating subclavian artery stenosis.

Evaluation of oil-soluble FUdR ester for transcatheter arterial treatment of hepatomas

From January 1987 to December 1989, we performed a prospective study of transcatheter arterial chemoembolization therapy with iodized oil (Lipiodol) mixed with an anticancer agent. A new oil-soluble modification of FUdR, FUdR-C8 ester, was developed and dissolved in Lipiodol as an embolic material, which was administered to 36 patients with hepatomas. Water-soluble adriamycin emulsified in Lipiodol was used as control in 67 patients with hepatomas. Initial effects on tumors were observed as decrease of tumor size in 25.0% for the FUdR group and 17.9% for the control group. Alpha-fetoprotein decreased more than half in 41.9% of the FUdR group, and 16.1% of the ADM group. Six-month and one-year survivals were 74.2% and 46.8% for the FUdR group (median survival 317 days), whereas the control group yielded 61.0% and 28.3% survivals, respectively (median survival 191 days).

Percutaneous transluminal angioplasty: pain during balloon inflation

The pain during the balloon dilatation of angioplasty was evaluated prospectively to assess its clinical significance. In 54 angioplasties, no pain was observed in 54%, mild pain in 20%, moderate pain in 11% and severe pain in 15%. Moderate or severe pain was observed in 39% of 28 iliac angioplasties and in 7% of 14 femoral angioplasties. There was a significant difference between the two groups. We did not find any significant correlation between the severity of pain and stenotic ratio before angioplasty. Severe pain may be a warning of severe dissection; in our study, all severe dissections were accompanied by severe pain without arterial rupture.

[CT appearance of small renal angiomyolipoma]

Twenty-six small renal angiomyolipomas (AML) in 21-patients, detected incidentally by ultrasonography, were evaluated with CT. Conventional CT findings of AML were classified into three types by the degree of the fatty areas in the mass. Type 1 is a mainly fat density mass like a lipoma observed in 7 lesions (26.9%). Type 2 is a fatty mass intermixed with areas of tissue density and found in 15 lesions (57.7%). Type 3 is a mass without fatty portion and observed in 4 lesions (15.4%). These latter lesions were indistinguishable from renal cell carcinoma on CT. It is important to diagnose a small lesion of the kidney as AML correctly for proper treatment.

Normal and abnormal pituitary glands: gadopentetate dimeglumine-enhanced MR imaging

Dynamic magnetic resonance (MR) imaging with a 1.5-T superconductive unit was used in the evaluation of nine normal pituitary glands and 10 pituitary adenomas, including four microadenomas and six macroadenomas. Seven to 10 images were obtained every 20-30 seconds with use of the spin-echo technique after rapid injection of gadopentetate dimeglumine. The earliest contrast material enhancement of normal structures was seen in the infundibulum and posterior lobe of the pituitary gland at 20 seconds, followed by gradual contrast material enhancement of the anterior lobe of the pituitary gland from the junction of the infundibulum to the peripheral portion of the anterior lobe of the pituitary gland within 80 seconds after gadopentetate dimeglumine injection. The peak enhancement of pituitary adenomas occurred at 60-200 seconds, usually after the most marked enhancement of the normal pituitary gland. Microadenomas are best visualized at earlier phases of gadopentetate dimeglumine-enhanced dynamic imaging, with signal intensity lower than that seen on images of normal pituitary glands.

Development of a ceiling-suspended angiographic unit for interventional neuroradiology

A new neuroangiographic unit was developed with a ceiling-suspended gantry, capable of rotation (110 degrees) and craniocaudal angulation (+/- 45 degrees) along the body axis. The gantry could also be rotated 225 degrees at the ceiling suspension axis and sidetracked away from the angiographic table in case of emergency. Two sets of a twin-focus X-ray tube and a 12-inch image intensifier (II) were mounted on the gantry in the isocentric and cross-firing positions. High resolution 1024 x 1024 matrix digital radiography was obtained with a speed of 30 frames/s, while conventional film-screen radiography was obtained at 4 films/s. Rapid film changers were installed and interchangeable with the IIs. The lateral II and X-ray tube could be positioned from either side of the patient. There was no angulated position of the lateral imaging system during angulated anteroposterior or Towne projection of the frontal imaging system. Automatic repositioning of the gantry was possible to the preset position. Stereoscopic, magnification and stereoscopic magnification radiography could be obtained easily in monoplane or biplane mode. Switching from fluoroscopy to radiography and vice versa was possible rapidly and easily. Neuroangiographic as well as interventional procedures were performed expeditiously with lower complication rates. Suspending the gantry from the ceiling made more space available on the floor for the anesthesiologists.

Digital TV tomography: description and physical assessment

A digital TV tomography system, capable of retrospective reconstruction of multiple digital tomographic images, has been developed and its basic physical characteristics have been evaluated. The multiple tomographic images were formed through retrospective reconstruction of digital data acquired on a linear tomographic x-ray unit and an image intensifier-television system. Digital data were obtained with a series of 30 pulsed exposures during linear motion of the system. A distortion correction algorithm for the convex surface of the image intensifier was developed in order to reduce image distortion. A phantom study showed that the square-wave response at the fulcrum plane was slightly inferior to that in conventional tomography. There was also a slight decrease in the square-wave response away from the fulcrum plane and upon application of a correction algorithm, as compared with the response of the original reconstructed image at the fulcrum plane. The exposure dose for a single image was approximately half that in conventional tomography. Because of many advantages, including low exposure, short examination time, digital image manipulation, and applicability to picture archiving and communication systems, this is likely to become an important method in radiology when further technical refinements have been made.

[Cerebellar infarction; the findings of CT, MRI and cerebral angiography]

The findings of CT, MRI and cerebral angiography were analysed in 18 cases with cerebellar infarction, of which 10 were men and 8 women. The areas of infarction were as follows; PICA in 9 cases, SCA in 8 cases, AICA and diffuse type in one case each. One case had two lesions. CT showed low density areas in 15 cases after 24 hours of the onset, but an abnormality was not demonstrated in one case which had an infarction of PICA area. MRI showed a high-intensity lesion on T2 weighted image during the first and tenth day after the onset, while a low-intensity lesion on T1 weighted image and high-intensity lesion on T2 weighted image were demonstrated after seventh day. MRI revealed the area of infarction better than CT. Vertebral angiography and DSA showed narrowing or poor visualization of the cerebellar arteries in 5 cases but this finding was not shown in 3 cases which were examined by IVDSA.

Intraarterial infusion of 5-fluoro-2-deoxyuridine-C8 dissolved in a lymphographic agent in malignant liver tumors. A preliminary report

The drug 5-fluoro-2-deoxyuridine-C8 (FUdR-C8), one of the lipophilic prodrugs of FUdR, was dissolved in an oily lymphographic agent (Lipiodol Ultra Fluid, Andre Gelbe Laboratory, Paris, France; Ethiodol, Savage Laboratories, Melville, NY) and used for the intraarterial treatment of malignant liver tumors. From August 1985 to June 1988, 33 patients with hepatocellular carcinoma and 13 patients with metastatic liver tumors were treated with this agent at the Kumamoto University Hospital and its affiliated hospitals. The response rate (complete remission [CR] and partial remission [PR]) was 27.6% for hepatocellular carcinomas and 46.1% for metastatic liver tumors. The cumulative 1-year survival rate was 55.1% for hepatocellular carcinomas and 70.0% for metastatic liver tumors. More than a 50% decrease in the tumor marker level was observed in ten of 21 patients with hepatocellular carcinoma and in two of eight patients with metastatic liver tumors. The side effects, which were transient and controlled with conservative treatment, included fever, abdominal pain, nausea, vomiting, and acute gastritis.

[Angiographic positions for thoracic outlet syndrome]

Thirty four patients (18 males and 16 females, 54 lesions) with thoracic outlet syndrome (TOS) were studied with conventional angiography. Angiography in the supine position did not confirm subclavian artery compression in 43.4% of patients. Lordotic position or upright position was useful for demonstration of subclavian artery compression in patients who did not show any findings in conventional techniques.

Balloon-occluded arterial infusion therapy in the treatment of primary and recurrent gynecologic malignancies

Balloon-occluded arterial infusion (BOAI) of bilateral internal iliac arteries produces high drug concentration as well as increased arterial flow of pelvic organs. Twenty-seven patients with primary and locally recurrent gynecologic malignancies were treated with BOAI of cisplatinum. Six of 10 patients with primary advanced uterine cancer and 5 of 11 patients with recurrent cancer showed clinical response. In 6 patients, BOAI was performed as an adjuvant therapy to radiation or other chemotherapy. Toxicity was similar to that seen with systemic treatment using cisplatinum, but its frequency and degree were less severe.

[Percutaneous transluminal renal angioplasty: indication for renovascular hypertension associated with renal atrophy]

The results of clinical studies indicate that percutaneous transluminal renal angioplasty (PTRA) is an effective means for treating renovascular hypertension resulting from renal artery stenosis. However, the indications for the patients with renal failure or renal atrophy are not established on a firm ground. We attempted PTRAs of ten kidneys in nine patients with hypertension associated with renal atrophy. They were followed for an average of 8 months by the methods including blood pressure, angiography or DSA, blood chemistry, and RI-renogram. We also evaluated enlargement of the renal size on an angiogram or on a plain film at DSA. Angiographic follow-up showed persistent relief of the stenosis in all cases. After PTRA, blood pressure reduced to normal or improved in two thirds of the patients for the follow-up period. In the study of three patients with excellent results for blood pressure, two patients showed the renal length to be increased by 1.0 cm or more, and one patient by 0.5 cm. In the same group, RI-renogram also showed good response. These data indicate that PTRA could improve total perfusion on the affected kidneys. On the other hand, in three patients with no change in blood pressure, there was poor response in both the renal size and the data of RI-renograms. We suggest that the irreversible changes might have occurred in these kidneys. It was difficult to predict cure group from no change group before PTRA.

[Localization of spinal tumors by MRI]

Exact localization of the spinal tumors is particularly important for differential diagnosis and surgery. Therefore, it was attempted to evaluate the diagnostic accuracy of MRI in localizing the spinal tumors exactly. Nineteen cases of spinal cord tumors, being localized in the intradural extramedullary, extradural and both intradural and extradural spaces, were studied with MRI. Intradural extramedullary tumors showed small CSF spaces just below and above the tumor which were demonstrated as CSF intensity on T1 and T2 weighted images. Although extradural tumors did not show CSF spaces, there was extradural sign or dural density between the tumor and the spinal cord. Intradural and extradural tumors were outlined as having both characteristics. Signal intensities of the spinal tumors were not characteristic for specific histology. Gd-DTPA was quite useful for accurate localization of the tumors. In comparison with myelography, MRI was superior to myelography in extradural tumors and equally useful for intradural and extradural tumors, but it was less diagnostic in intradural extramedullary tumors. In general, MRI was quite useful in localizing the spinal tumors exactly and the accuracy of MRI was quite high. In the near future this technique will replace myelography and other radiologic methods.

Depth determination on stereoscopic digital subtraction angiograms

The determination of depth on stereoscopic digital subtraction angiographic (DSA) images was evaluated. A "plus" phantom that contained simulated blood vessels of various sizes with various concentrations of contrast medium was used for the study. The vessels ranged in diameter from 0.46 to 1.35 mm, with concentrations of contrast material of 1.6%-25%. The images were evaluated by seven radiologists and six radiologic technologists. The detectability of depth separation increased as the iodine concentration and the vessel size increased. With stereoscopic DSA, correct identification of depth is possible more than 80% of the time for vessels approximately 1 mm in diameter and containing 3.1% contrast medium when the vessels are separated by more than 2.8 mm.

MR visualization and clinical significance of the anterior longitudinal epidural venous plexus in cervical extra-axial lesions

A thin band of intermediate signal intensity behind the cervical vertebral bodies, demonstrated on sagittal MR images, was attributed to the anterior longitudinal epidural venous (AEVP). Percentage visualization and clinical significance of this structure were evaluated in extra-axial lesions of the spinal cord. In review of 50 normal controls, the percentage visualization of this structure at each cervical vertebral level was 25.5% on T1 weighted sagittal SE images, while that of T2 or proton density weighted SE images was 26.0%. AEVP was demonstrated by sagittal MRI in 29 of 128 extra-axial lesions of the cervical cord (22.7%), including cervical spondylosis, ossification of the posterior longitudinal ligament (PLL), herniated disk and spondylosis at a single level. AEVP in these conditions was often thickened compared with normal controls, probably due to venous engorgement and contribution of the dura mater and PLL. Posterior displacement of this structure or "lifted band appearance" indicated herniated disk or posteriorly protruding osteophyte, demonstrating true anteroposterior diameter of the spinal canal. Demonstration of AEVP on sagittal MRI was important in the diagnosis of extra-axial lesions of the cervical cord.

Increased MR signal intensity secondary to chronic cervical cord compression

Magnetic resonance images of 128 patients with compressive lesions of the cervical spinal canal were reviewed to determine whether a high signal intensity lesion within the spinal cord was present on T2 and proton density weighted spin echo images. Such high signal intensity was observed in 24 cases or 18.8%. The incidence was higher in herniated disk (32.4%), atlanto-axial dislocation (28.6%), and ossification of the posterior longitudinal ligament (22.7%), whereas the abnormality was found sporadically in cervical spondylosis and vertebral body tumors. The high intensity lesion on T2 weighted images was generally observed in patients with constriction or narrowing of the spinal cord. The lesion was not demonstrated on T1 weighted spin echo images. Spinal cord constriction or localized narrowing seemed to be the most important predisposing factor in producing such a high signal intensity. The pathophysiologic basis of such an abnormality was presumed to be myelomalacia or cord gliosis secondary to a long-standing compressive effect of the spinal cord.

Percutaneous transluminal angioplasty of the ilio-femoro-popliteal arteries: initial and long-term results

Percutaneous transluminal angioplasty has been widely used for dilatation and recanalization of occluded or stenosed vessels, but clinical experience in Japan is not extensive. Follow-ups of 78 ilio-femoro-popliteal angioplasties were performed for up to 51 months to assess the initial and long-term results. The initial technical success rate was 91%. The three-year cumulative patency rate was 75%. This study demonstrates that the long-term results of PTA of ilio-femoro-popliteal arterial lesions are competitive with reconstructive surgery. PTA should be the treatment of choice in patients with atherosclerotic narrowing or occlusion of the lower extremities.

High resolution DSA: experimental and clinical evaluation

The DSA system has been upgraded for capabilities of slow scan video technique and progressive T.V. read-out of 1024 X 1024 matrix with 10 bits of depth. A square wave test pattern made of lead bar demonstrated moderate improvement in spatial resolution, but imaging of a Burger-Rose phantom revealed no significant increase in contrast resolution. Clinical study of various angiograms with intraarterial injections showed that there was slight improvement in the visibility of the vessels, especially small arterial branches, while there was no increase in visibility of the veins. There were no cases in which diagnoses were altered by application of high resolution DSA. With future improvements of the image intensifiers, DSA with 1024 X 1024 matrix may reveal its potential advantage, especially when coupled to larger image intensifiers such as 12 or 14 in.

Development of a new universal neuroangiographic unit

A new neuroangiographic unit has been developed with use of a "C" type gantry, which is capable of rotation and angulation for various angiographic projections. Two sets of a twin focal X-ray tube and an imaging system are mounted on the gantry. Each imaging system consists of a 9 inch image intensifier and a 14 X 14 rapid film changer, which can be exchanged in position rapidly. Stereoscopic magnification and stereoscopic contact angiography, fluoroscopy and DSA are performed in monoplane and biplane and switched over to each other expeditiously and easily. The detailed angiographic information is obtained with lower complication rate and lower exposure to patients. Interventional neuroradiologic procedures are performed efficiently on this unit.

Cerebral vasculitis secondary to Wegener's granulomatosis: computed tomography and angiographic findings

The central nervous system is rarely involved by Wegener's granulomatosis. A case of Wegener's granulomatosis with involvement of the cerebral arteries was reported. Computed tomography showed extensive brain edema with angiographic demonstration of cerebral vasculitis.

Stereoscopic DSA of the central nervous system

Stereoscopic DSA is performed with alternate exposures from a twin focal X-ray tube (6,5 cm focal separation). Excellent intravenous and intra-arterial DSA images of the cerebral vessels are obtained with separation of overlapping parts of the normal and abnormal vasculature. The clinical value of DSA has been enhanced by use of stereoscopic DSA.

Determination of left ventricular volumes with use of DSA density values

A computer program was developed to obtain left ventricular volumes from the density values of DSA. The highest density value along the horizontal pixel line over the left ventricle in 30 degrees RAO was considered to correspond to the greatest width on the same level of 60 degrees LAO. The left ventricular volume was obtained by converting the density values into the width and integrating these values. This method estimated experimental balloon volumes with considerable accuracy. Clinical evaluation revealed good correlation between DSA and conventional cine left ventriculography.

Stereoscopic technique in digital subtraction angiography

Stereoscopic technique was applied to digital subtraction angiography (DSA) with alternate exposures from twin focus spots (6.5-cm separation) of an x-ray tube. Correct identification of two crossed aluminum wires was obtained more than 90% of the time when there was separation of more than 5 mm. Excellent clinical images of intravenous as well as intraarterial DSA have been obtained, and the clinical value of DSA was enhanced by application of the stereoscopic technique.

Diagnostic accuracy of intravenous digital subtraction angiography for peripheral vascular diseases

Intravenous digital subtraction angiography (IV DSA) was performed on 406 regions of 241 patients with peripheral vascular diseases. The results were compared with conventional angiograms for 167 arteries. There was excellent correlation between conventional angiograms and IV DSA. The diagnostic accuracy was 95 with 97% sensitivity and 94% specificity when more than 60% stenoses were taken into consideration. DSA is a less-invasive procedure which can be performed on out-patients for screening and follow-up evaluation of peripheral vascular diseases.

Intraarterial digital subtraction angiography vs conventional angiography of abdominal diseases

Seventy-five patients with various abdominal diseases were studied by intraarterial digital subtraction angiography (IA DSA) during conventional abdominal angiographic examinations. The image quality, tumor stain, and arterial encasements were evaluated and diameters of vessels visualized by IA DSA were measured. The vessels greater than 2.0 mm or more in diameter were equally well demonstrated on IA DSA. IA DSA demonstrated tumor stains and portal system to good advantage. Real time imaging was also advantageous during an embolization procedure.

Evaluation of the cerebral vasculature by intraarterial DSA--with emphasis on in vivo resolution

Comparative study was performed between IA DSA and stereoscopic magnification angiography in relation to small vessel resolution, image quality of the vessels and image quality of various pathologic lesions. The vessels of various diameters, accurately measured by stereoscopic magnification angiography, were localized on IA DSA and their resolution was carefully assessed. The vessels more than 1 mm in diameter were equally visualized on IA DSA and conventional angiography. The vessels between 1 mm and 0.5 mm showed fair resolution on IA DSA, whereas IA DSA did not resolve the vessels smaller than 0.5 mm in diameter to good advantage. In addition, image quality of the vessels on IA DSA was compared with the conventional methods. Cerebral gyrus, venous sinuses, and intracerebral veins are often shown better on DSA. The small vessels such as lenticulostriate, small cortical, thalamoperforate and meningohypophyseal arteries were not defined on DSA. Equal or better image quality was obtained in more than 85% of cases with pathologic lesions. Examinations were performed faster with lower cost and lower complication rate. Information provided by DSA was often sufficient for managements of patients. Combined use of DSA and conventional angiography will improve diagnostic accuracy and decrease the complication rate.

The value of digital subtraction angiography in peripheral vascular diseases

The iliac and subclavian arteries and their distal branches were studied by digital subtraction angiography (DSA) in 79 patients and the results compared with conventional angiograms for 35 patients. Techniques, results, advantages and disadvantages are described. DSA (both intravenous and intra-arterial) looks very promising in the diagnosis of peripheral vascular disease.