Amount Of Contrast Medium Research Articles

The EchoMap System:

The EchoMap system allows online integration of intravascular ultrasound (IVUS) and intracoronary Doppler (ICD) images into angiographic images during catheterization, providing exact localization of the IVUS transducer and the ICD wire tip position. Although this is a major advance, the use of the system could lead to more angiographic documentation sequences and enhanced radiation exposure. We investigated the influence of system use on radiation and procedure parameters. During a 22-month period, 794 patients underwent coronary angiography with simultaneous performance of IVUS and/or ICD. The EchoMap system was applied in 392 patients ("EchoMap group"), the remaining 402 patients formed the "No-EchoMap group." Multivariate regression analysis showed no independent association between the use of EchoMap and fluoroscopy time (14.7 +/- 8.5 minutes in the EchoMap group vs 14.5 +/- 10 minutes in the No-EchoMap group, P = NS) or dose area product (7589 +/- 4916 in the EchoMap group vs 7031 +/- 5434 cGy x cm(2), P = NS). EchoMap use was significantly associated with a moderate increase in contrast media amount (392 +/- 162 in the EchoMap vs 356 +/- 155 mL in the No-EchoMap group, P = 0.001). In conclusion, the use of the EchoMap system had no significant influence on radiation exposure during cardiac catheterization, whereas it was associated with a moderate increase in contrast media amount.

Swallowing disorder in patients with myotonic dystrophy type i

Objectives: Swallowing disorder is often seen in patients with myotonic dystrophy type I (DM I) and may cause death from aspiration pneumonia. The purpose of the study was to investigate the incidence and extent of swallowing disorder in DM I. Methods: Twenty-two DM I patients were referred from neurologists for otolaryngologic examination. All the patients were evaluated for vocal cord and pharyngeal movements with laryngeal fiberscopy. Nine patients were additionally evaluated with x-ray fluoroscopy of the hypopharynx and esophagus. The extent of (CTG) expansion of the patients peripheral lymphocytes was determined by Southern blot analysis. Results: Laryngeal fiberscopy showed pooling of saliva in the hypopharynx to some extent in all the 22 patients. X-ray fluoroscopy showed pooling of large amount of contrast media in the hypopharynx of 7 patients after cessation of deglutition. Conclusion: Potential dysphagia and the risk of aspiration pneumonia are frequently seen in DM I patients. The neurologists and even the patients are not aware of this unless notified by otolaryngologists. The otolaryngologist is uniquely qualified to evaluate swallowing function and must continue to play a role in management of swallowing disorder in patients with neurological diseases.

Quand, comment et pourquoi réaliser une imagerie des artères des membres inférieurs ?

Noninvasive screening of lower limb arterial disease has long been performed using color Doppler ultrasonography, whereas surgical or endovascular treatment planning relied on conventional angiography. With continued improvements of noninvasive imaging modalities, it is now possible to image the entire lower limb vasculature without arterial catheterization. Multidetector row helical CT angiography has the advantage of visualizing the arterial lumen and arterial wall calcifications, and nephrotoxicity is reduced by decreasing amounts of contrast medium. Three-dimensional MR angiography is a safe procedure, with high contrast sensitivity, and has recently benefited from step table technology that allows a single injection of contrast medium. The literature shows that both helical CT and MR angiography have high levels of accuracy, but outcome studies of their respective role in the setting of acute and chronic lower limb ischemia are lacking. These noninvasive techniques should play a major role in two main situations: first, in critical ischemia where therapeutic planning should ideally be achieved non invasively; second, in the follow-up of treated patients presenting with recurrent ischemia.

Right-to-Left-Shunts Detected by Transesophageal Echocardiography and Transcranial Doppler Sonography

Background: Transesophageal echocardiography (TEE) and transcranial Doppler sonography (TCD) can identify right-to-left-shunts that predispose to paradoxical embolism. In a large cohort we compared the results of both techniques. Methods: 222 patients were investigated by both techniques using the contrast agent Echovist^®-300 and performing each test once without and once with the Valsalva maneuver (VM). Results: TEE-proven right-to-left-shunts were detected by TCD with a high sensitivity of 94%. In addition, TCD revealed shunts not noted during TEE in about 20% of all patients studied. These shunts are in general smaller than those concordantly identified; however, 9% of the patients without a TEE-proven shunt presented with a shunt that allows a considerable amount of contrast medium to pass. There were 12% more microbubbles detected in the right middle cerebral artery than in the left middle cerebral artery during the TCD test performed with VM, but not during the TCD test performed without VM. Conclusions: Contrast-enhanced TEE and TCD are complementary methods in the assessment of stroke and stroke-prone patients. The side difference of microbubbles may indicate a selective streaming of cardiac emboli during VM.

Effectiveness of theophylline prophylaxis of renal impairment after coronary angiography in patients with chronic renal insufficiency

Contrast media can lead to renal impairment that results in longer hospitalization and increased mortality. Adenosine is a crucial mediator of contrast-induced nephropathy (CIN; an increase in serum creatinine of ≥0.5 mg/dl within 48 hours). Therefore, it was the purpose of our study to investigate whether the adenosine antagonist theophylline reduces the incidence of CIN after coronary angiography. We also characterized risk factors for CIN after coronary angiography. One hundred patients with serum creatinine concentrations of ≥1.3 mg/dl randomly received 200 mg IV theophylline or placebo 30 minutes before coronary angiography (amount of contrast medium ≥100 ml). Patients who received theophylline and the controls were comparable with regard to baseline creatinine levels (means ± SD) (1.65 ± 0.41 vs 1.72 ± 0.69 mg/dl) and the amount of contrast medium received (235 ± 89 vs 261 ± 139 ml). Theophylline significantly reduced the incidence of CIN (4% vs 20%, p = 0.0138). With placebo, creatinine significantly increased at 12 (1.82 ± 0.79 mg/dl, p = 0.0057), 24 (1.90 ± 0.86 mg/dl, p = 0.0001), and 48 hours (1.90 ± 0.89 mg/dl, p = 0.0007) after administration of contrast medium. With pretreatment with theophylline, mean creatinine only increased 24 hours after contrast medium administration (1.70 ± 0.40 mg/dl, p = 0.029), but was stable 12 hours (1.65 ± 0.43 mg/dl, p = 0.99) and 48 hours after contrast medium administration (1.65 ± 0.41 mg/dl, p = 0.99). The following parameters were significantly associated with contrast-induced renal impairment: Cigarroa quotient >5 (contrast medium [milliters] × serum creatinine/body weight [kg]), elevated troponin T, >300 ml of contrast medium, and emergency angiography. In conclusion, theophylline reduces the incidence of CIN in patients with chronic renal insufficiency undergoing coronary angiography. It should be used especially in patients receiving large amounts of contrast medium, and in patients with a Cigarroa quotient of >5 and/or elevated troponin T levels.

Low-tube-current multidetector CT for children with suspected extrinsic airway compression.

The purpose of our study was to review the technical success achieved using low-tube-current multidetector CT for the evaluation of children with suspected extrinsic airway compression and to evaluate the need for sedation during this procedure. We reviewed all CT examinations performed for the evaluation of extrinsic airway compression during the first year after installation of a multidetector CT scanner at a pediatric hospital. We recorded the technical parameters including tube current, kilovoltage, slice thickness, mode of study, sedation technique, and amount of contrast material and noted which postprocessing techniques were applied. Studies were evaluated for timing of contrast bolus, image quality, motion artifact, need for sedation, and the diagnoses made. Fifty-four studies were performed in 50 patients (30 boys, 20 girls; age range, 15 days to 17 years; mean age, 2.4 years). The mean tube current was 52.2 mA (range, 30-140 mA). Thirty-four studies (63%) were performed without sedation: 12 with sedation administered under supervision of the radiologist, six with general anesthesia supervised by an anesthesiologist, and two in patients who arrived in the radiology department already intubated. Imaging quality was excellent in 35 studies (65%), diagnostic in 19 studies (35%), and poor in none. Motion artifact was present on several slices in two examinations (4%). Contrast medium administration was well-timed in 49 studies (91%), early in three studies (5%), and late in two studies (4%). Airway abnormalities were detected in 26 (48%) of the studies and included extrinsic compression by vascular anomalies (n = 14) or nonvascular masses (n = 5) and intrinsic airway disease without extrinsic compression (n = 7). Evaluation for extrinsic compression of the airway in children can be accomplished using a low-tube-current multidetector CT protocol; in most pediatric patients, the examination can be performed without sedation.

Direct stenting application in acute coronary syndromes

Although published reports about direct stenting in treating stable coronary artery disease have been increasing, the number of studies regarding direct stenting for acute coronary syndrome is limited. In this study, we report immediate and mid-term results of patients who underwent direct stenting for treating acute coronary syndrome. The average lesion length was 12.1 ± 3.3 mm. The preprocedure average minimum luminal diameter (MLD) was 0.67 ± 0.33 mm. Post-procedure average MLD was 3.19 ± 0.42 mm. In 35 of the 36 cases (97%), the stent delivery system crossed the lesion and was implanted successfully. In one case, an acute occlusion, which was treated by percutaneous transluminal coronary angioplasty (PTCA), occurred. The rate of procedure success was 94%. The amount of contrast media used was 88 ± 16 ml and duration of radiation exposure was 9 ± 2 min. Control angiography was performed in 28 out of 35 cases (80%). Seven patients who did not consent to coronary angiography were asymptomatic and had negative exercise tests. MLD was 2.66 ± 0.53 mm after a six month follow-up. The clinical and angiographic restenosis rates were 14% (5/35) and 18% (5/28), respectively. Three of the five cases of restenosis were treated by excimer laser coronary angioplasty (ELCA) and PTCA and the other two were treated with PTCA only. Target lesion revascularization rate was 14% (5/35). The rate of major adverse cardiac events (MACE) was 17% (6/35) after the six month follow-up period. Based on these results, we conclude that direct stenting for acute coronary syndrome is safe if the lesion is determined to be suitable.

History of cardiovascular imaging procedures

The value of the four main imaging tools: radiology, magnetic resonance imaging, echocardiography and nuclear cardiology depends in the first place on physical properties which determine the spatial, temporal and density resolution and second on the conditions under which the relevant information can be obtained with respect to the diagnostic or therapeutic problem, the comfort of the investigation, the degree of invasivity and the expenses. For several decades radiology was the only available method that allowed a look into the body. Thereby, all relevant information about diseases amenable to any surgical or conservative therapy could be attained. Parallel to the progress of cardiovascular surgery, angiocardiography could provide the anatomic and functional characteristics of congenital and acquired heart diseases. The basic principles for the measurement of total heart size, volume and shape were established already before contrast injection – initially by hand – showed the internal architecture of the heart cavities and the circulatory system. With the invention of film changers, the fundamental knowledge about all kinds of malformations of the heart and vessels was gained. Further technical progress made the procedures faster by cineangiocardiography, more comfortable by simultaneous biplane operation and easier to handle by videotechniques, allowing electronic data processing, storage and retrieval in bright operating theaters. Computer technology favored flexible image processing which, like digital subtraction and functional angiocardiography, could reduce the amount of contrast material to be injected and thereby improve the compatibility, due to better nonionic contrast material and shorter study times. Finally, computer tomography with cross sectional, or spiral data collection enabled a dynamic three-dimensional reconstruction and visualization of the beating heart and to display selected information in ‘measures and numbers’. Inspite all these successes, the ‘stain’ of invasivity remains. Strong competition arose first in echocardiography, which – after some pioneering activities in Germany in the late 1950s – flourished in the 1970s, after being reimported from the US. Most of the rapidly increasing number of ultrasound technologies – from M-mode, via various 2D linear and sector scanning procedures in combination with continuous, pulsed and/or color Doppler methods, new contrast-echo modalities and finally 3D volume scanning procedures – can be applied without any harm in all age groups and from each competent practitioner with comparably small and cheap equipment. Only oesophageal and intravascular approaches retain a touch of invasivity. Consequently not much room remains for other techniques except those, like MRI, which can differentiate tissue properties better and with higher resolution and give unlimited access to all intrathoracic organs noninvasively. Under these conditions the indications for nuclear cardiology are restricted to the small field of myocardial perfusion and metabolic studies, whereas transit time measurements and radionuclide ventriculography are practically obsolete.

Ventriculography Using ECG-Gated Multiple Diastolic Injection of Contrast Material in Pediatric Angiocardiography

In pediatric patients, the lower body weight limits the volume of contrast medium. Conventionally, angiocardiography is carried out with a single large bolus injection of contrast material. Angiocardiograms are used in pediatric patients with complex congenital heart diseases. In patients with complex congenital heart disease, especially with MAPCA, the volume of contrast medium used may be excessive. This would allow further injection to provide additional information. To reduce contrast medium used in the angiocardiogram in pediatric patients, we decided to use electrocardiogram (ECG)-gated multiple diastolic injection (EMDI). Three small boluses were injected during the diastolic phase of three consecutive cardiac cycles using a commercially-available power injector. Seventy-eight ventriculograms (47 left ventriculograms and 31 right ventriculograms) using EMDI were carried out on 53 patients with congenital heart disease. Total contrast medium volume with EMDI ventriculograms (mean [+/- SD] per body weight: 0.72 [+/- 0.25] ml/kg) was significantly smaller than with conventional injection (1.01 [+/- 0.36] ml/kg) (p <0.001). The grades of ventriculograms with EMDI tended to be slightly better than those with conventional injection (statistically not significant, p = 0.478). No short-run type premature ventricular contraction (PVC)s or intramural injection occurred in the ventriculograms with EMDI. PVCs tended to be less frequent in the ventriculograms with EMDI than in those with conventional injection (statistically not significant, p = 0.131). EMDI may be worthwhile in reducing ventricular ectopy when checking ventricular function by angiography, since hemodynamic conditions are less affected by small quantities of contrast medium and only during the filling phase of the ventricles. In conclusion, EMDI may be a useful method for reducing complications of ventriculography in pediatric angiocardiography.

A study of the influence scan timing and depiction of blood vessel diameter in CE-3DMRA: simulation by pulsatile flow

In imaging using contrast-enhanced three-dimensional magnetic resonance angiography (CE-3DMRA), optimizing the delay time from the start of intravenous injection of contrast medium to the start of scanning has generally been an important concern when obtaining blood vessel images of good contrast. Recent methods of mechanically assessing the attainment of contrast medium injection include Smart-Prep and others. Another method is the Test Bolus, in which a small amount of contrast medium determines the timing of scan start, in quest of the time intensity curve. Because these methods are not necessarily satisfactory, the corrected method is used in clinical cases. In terms of how scan timing affects blood vessel depiction, no study has examined pulsatile flow, which is carried out by simulation. On the other hand, there are reports on data filling of k-space using imitation blood vessels on a computer and simple experimental equipment. This research examined experimentally blood vessel depiction according to scan timing and the diameter of blood vessels by using a systemic circulation simulator that incorporated hemodynamic circulation in which pulsatile flow is the same as that of a human body, using an artificial heart developed especially for MRI. It is thought that scan timing in CE-3DMRA affects the depiction of blood vessels for which the diameter of the blood vessel differs from the experimental result. Phase-encoding k-space data filling is the contrast-to-noise ratio (CNR) of each blood vessel irrespective of sequential and centric k-space ordering. The timing shift phenomenon, in which a blood vessel is so thin that the scan timing is overdue and shows a relatively high value, can occur. Moreover, that scan timing affects not only the diameter of a blood vessel but also depiction of the narrowing of a stenotic blood vessel or a branch blood vessel was demonstrated clinically and experimentally. Therefore, blood vessel depiction changes with scan timing, and it is clinically important to determine the time of arrival of contrast medium and the duration of the enhancement effect in quest of the time intensity curve by test bolus when clearly describing the target blood vessel.

Comparison of cervical vacuum cup cannula with metal cannula for hysterosalpingography

Objective The aim of this study was to compare the use of a cervical vacuum cap cannula with the traditional metal cannula. Design A prospective, randomised, single-blinded comparative study. Sample Fifty consecutive infertile women undergoing hysterosalpingography for evaluation of infertility Methods Hysterosalpingography was performed either with the traditional metal cannula ( n=25) or a cervical vacuum cap cannula ( n=25). Main outcome measures Length of procedure, fluoroscopic time, amount of contrast medium, pain to the patient while applying the cannula and injecting the contrast medium, level of difficulty to the performer, the need to reapply the cannula, complications, and results of the hysterosalpingography. Results Using the cervical vacuum cap cannula, compared with the metal cannula, the duration of the procedure was significantly shorter (5.3 vs 9.3 minutes; P<0.001), less fluoroscopic time was needed (0.9 vs 1.8 minutes; P<0.001), a smaller amount of contrast medium was used (4.6 vs 15.7 mL; P<0.001), the procedure caused less pain to the patient (3.2 vs 6.8, respectively; on a scale of 1–10; P<0.001), and was easier for the physician to perform (1.4 vs 3.4; on a scale of 1–10; P<0.001). No significant differences were encountered between the two groups in the need to reapply the cannula, in the rate of complications or in the results of the hysterosalpingography. Conclusions The cervical cap cannula appears to be superior to the traditional metal cannula for performing hysterosalpingography.

A randomised comparison of the use of 4 and 6 French diagnostic catheters: the limits of downsizing

Background: The use of small catheters for coronary angiography can reduce the risk of vascular complications and allow early ambulation, but excessive downsizing may lead to poor quality imaging. The aim of this study was to assess the feasibility of performing coronary angiography using 4 French (4 F) femoral catheters. Methods: In total, 400 consecutive elective patients were randomised to undergo coronary angiography with 4 F or 6 F catheters. The puncture site was manually compressed and inspected before and after ambulation, and 24 h later. The handling difficulty of the catheters was semi-quantitatively evaluated using a three grade scoring system; angiogram quality was evaluated by two independent physicians. Results: No major procedure-related complications were observed. Coronary arteriography with 4 F catheters was possible in all of the attempted cases. There were no statistical differences between the two groups in terms of procedural or fluoroscopy time, the amount of contrast medium used, or the incidence of vascular complications, while compression time was significantly shorter in the patients studied using the smaller catheter (3.4 vs. 9.9 min; P<0.0001). Catheter stability was similar in the two groups, whereas catheter torque and the quality of the coronary angiograms were statistically better in the patients studied using six French catheters. Conclusions: Coronary angiography with 4 F catheters is technically feasible and permits early ambulation after the procedure. Although the radiological resolution of the images obtained using 4 F catheters was always adequate for clinical decision-making, the angiogram quality and catheter handling were significantly better using the 6 F system.

Extravasation of contrast media in brain parenchyma and cerebrospinal fluid space after CT or DSA of thorax or abdomen

Analysis of clinical and CT findings in patients with signs of disruption of the blood-brain or blood-CSF barrier after i.v. or i.a. administration of non-ionic contrast media. 1. Retrospective analysis of 8 patients with clinical and CT findings of disruption of the blood-brain or blood-CSF barrier after i.v. or i.a. administration of non-ionic contrast media (200-450 ml). 2. Prospective analysis of 30 intensive care patients with sepsis and suspected abscess, who underwent CT of the chest and abdomen with 240 ml of a non-ionic contrast medium followed by cranial CT to rule out septic lesions. The retrospective analysis proved that disruption of the blood-brain barrier may occur in elderly patients with risk factors after injection of higher amounts of contrast media. In the prospective study, equivalent CT phenomena were observed in 3 of 30 patients with sepsis. Hypoxemic and toxics damage to the blood-brain barrier as well as higher amounts of contrast media may result in extravasation of contrast medium into the CSF space, which can be demonstrated by CT. For differential diagnosis, the clinical symptoms and CT patterns of a disruption of the blood-brain or blood-CSF barrier should be known.

Biphasic and discontinuous injection of contrast material for thin-section helical ct angiography of the whole aorta and iliac arteries.

AJR:176, February 2001 s a result of recent developments in technology, helical CT is now used for evaluation of patients with aortic disease [1–4]. However, the imaging area during one scanning session using single-detector helical CT is still limited because of the low scan speed, patient intolerance of long breath-hold time, and overheating of the CT tube. If the slice thickness is reduced to 3 mm to obtain high-quality images from the aortic arch to the iliac arteries, it is impossible to scan the entire area during a single breath-hold. As a result, the patient must rest before the radiologist can continue to scan the abdominal aorta and iliac arteries. We designed a split-bolus injection technique to eliminate wasting contrast material during the pause for respiration between the two scan clusters and to secure optimal aortic enhancement in the abdominal aorta and iliac arteries. With this technique, the amount of contrast material is divided and then injected biphasically.

Contrast media in abdominal computed tomography: optimization of delivery methods.

ObjectiveTo provide a systematic overview of the effects of various parameters on contrast enhancement within the same population, an animal experiment as well as a computer-aided simulation study was performed.Materials and MethodsIn an animal experiment, single-level dynamic CT through the liver was performed at 5-second intervals just after the injection of contrast medium for 3 minutes. Combinations of three different amounts (1, 2, 3 mL/kg), concentrations (150, 200, 300 mgI/mL), and injection rates (0.5, 1, 2 mL/sec) were used. The CT number of the aorta (A), portal vein (P) and liver (L) was measured in each image, and time-attenuation curves for A, P and L were thus obtained. The degree of maximum enhancement (Imax) and time to reach peak enhancement (Tmax) of A, P and L were determined, and times to equilibrium (Teq) were analyzed. In the computed-aided simulation model, a program based on the amount, flow, and diffusion coefficient of body fluid in various compartments of the human body was designed. The input variables were the concentrations, volumes and injection rates of the contrast media used. The program generated the time-attenuation curves of A, P and L, as well as liver-to-hepatocellular carcinoma (HCC) contrast curves. On each curve, we calculated and plotted the optimal temporal window (time period above the lower threshold, which in this experiment was 10 Hounsfield units), the total area under the curve above the lower threshold, and the area within the optimal range.ResultsA. Animal Experiment: At a given concentration and injection rate, an increased volume of contrast medium led to increases in Imax A, P and L. In addition, Tmax A, P, L and Teq were prolonged in parallel with increases in injection time The time-attenuation curve shifted upward and to the right. For a given volume and injection rate, an increased concentration of contrast medium increased the degree of aortic, portal and hepatic enhancement, though Tmax A, P and L remained the same. The time-attenuation curve shifted upward. For a given volume and concentration of contrast medium, changes in the injection rate had a prominent effect on aortic enhancement, and that of the portal vein and hepatic parenchyma also showed some increase, though the effect was less prominent. A increased in the rate of contrast injection led to shifting of the time enhancement curve to the left and upward. B. Computer Simulation: At a faster injection rate, there was minimal change in the degree of hepatic attenuation, though the duration of the optimal temporal window decreased. The area between 10 and 30 HU was greatest when contrast media was delivered at a rate of 2-3 mL/sec. Although the total area under the curve increased in proportion to the injection rate, most of this increase was above the upper threshould and thus the temporal window was narrow and the optimal area decreased.ConclusionIncreases in volume, concentration and injection rate all resulted in improved arterial enhancement. If cost was disregarded, increasing the injection volume was the most reliable way of obtaining good quality enhancement. The optimal way of delivering a given amount of contrast medium can be calculated using a computer-based mathematical model.

Modified hysterosalpingography during infertility work-up: use of contrast medium and saline to investigate mechanical factors

Objective: To evaluate the effectiveness of modified hysterosalpingography using <3 mL amount of contrast medium followed by injection of saline to minimize the adverse effects associated with the procedure. Design: For modified hysterosalpingography, 1–2 mL of water-soluble contrast medium were injected to visualize the uterine cavity, followed by injection of 10 mL of saline to check tubal patency and spillage. A control group of patients underwent hysterosalpingography with undiluted contrast medium. Setting: Teaching hospital. Patient(s): Seventy-eight infertile women [study (n = 40)/control (n = 38) groups]. Intervention(s): Modified and standard hysterosalpingography. Main Outcome Measure(s): Assessment of uterine cavity, tubal patency, and sensation of pain during modified hysterosalpingography was compared with that during standard hysterosalpingography. Result(s): Uterine cavity and tubal patency were properly visualized during modified hysterosalpingography. Saline pushed the contrast medium successfully from the uterine cavity through the open fallopian tubes and into the pelvic cavity. The study group reported significantly less pain than did the control group. Between-group differences were statistically significant when pain perception (no pain vs. minimal pain vs. severe pain; no pain vs. any kind of pain) was analyzed by type of adnexal pathology (bilateral passage or unilateral passage). Conclusion(s): Modified hysterosalpingography was sufficient to diagnose tubal and pelvic mechanical factors. The procedure was associated with a significant reduction in self-reported pain and no medical complications.

Factors influencing vascular and hepatic enhancement at CT: experimental study on injection protocol using a canine model.

The purpose of this work was to evaluate the effects of contrast medium injection parameters on aortic, portal vein, and hepatic enhancement at spiral CT and to assess optimal injection protocol for hepatic CT. Ten 15 kg dogs underwent single level dynamic CT through the hepatic hilum at 5 s intervals just after the injection of contrast medium for 3 min. With use of different volumes (1, 2, and 3 ml/kg), injection rates (0.5, 1, and 2 ml/s), and concentrations (150, 200, and 300 mg/ml), a total of 270 spiral CT scans were performed. In each scan, time-attenuation curves of aorta, portal vein, and liver were obtained. The degree of maximum contrast enhancement (Imax), time to maximum enhancement (Tmax), and time to equilibrium phase (Teq) for to each injection protocol were analyzed. Alterations in contrast material volume, injection rate, and concentration had significant impact on contrast enhancement of the liver. With increasing volume of contrast medium, Imax, Tmax, and Teq of aorta, portal vein, and liver increased (p < 0.005). With increasing rate of injection, on the other hand, Imax of aorta and liver increased (p < 0.05), but Tmax and Teq decreased (p < 0.005). Change of concentration of contrast medium had a significant effect on Imax of vessels (p < 0.05). Maximum contrast enhancement of liver and vessels was influenced mainly by injection volume of contrast medium and the time to peak enhancement by injection rate of contrast medium. Under given amounts of contrast medium, therefore, the strategy of increasing volume by dilution and faster injection might give better Imax values without penalty for the duration of an optimal temporal window (Tmax and Teq).

NEUROLOGIC COMPLICATIONS OF CEREBRAL ANGIOGRAPHY. A retrospective study of complication rate and patient risk factors

Purpose: To evaluate the neurologic complication rate and individual patient risk factors in cerebral angiographies using the digital subtraction angiography (DSA) technique and non-ionic contrast media in a department with many radiologists in training. Material and Methods: A retrospective study of 483 cerebral angiographic examinations in 454 patients was carried out. The following parameters were registered: sex and age of the patient, indication for the angiography, cerebral CT diagnosis, laboratory data, type of anesthesia, type of angiographic procedure, level of training of the angiographer, number of participating angiographers, type of catheters, number of vessels catheterized, number of exposures, use of compression series, total amount of contrast media, diagnosis of the angiogram, complications and duration of complications. Results: The frequency of all neurologic complications was 2.3%, the frequency of persistent neurologic deficits was 0.4%. Non-neurologic complications were observed in 14.7% of the examinations. Of all the parameters studied, the only factor that significantly increased neurologic risk was a normal angiogram, a finding we are inclined to ascribe to chance. Performance of a compression series showed a trend towards increasing the neurologic risk. Conclusion: This study showed a complication rate of persistent neurologic deficits of 0.4% which is in accordance with other recent reports. A compression series should not be performed routinely, but only on special indication. This study confirms the low risk of cerebral angiography when performed in a neuroradiological department using the DSA technique and non-ionic contrast media.

Neurologic complications of cerebral angiography. A retrospective study of complication rate and patient risk factors.

To evaluate the neurologic complication rate and individual patient risk factors in cerebral angiographies using the digital subtraction angiography (DSA) technique and non-ionic contrast media in a department with many radiologists in training. A retrospective study of 483 cerebral angiographic examinations in 454 patients was carried out. The following parameters were registered: sex and age of the patient, indication for the angiography, cerebral CT diagnosis, laboratory data, type of anesthesia, type of angiographic procedure, level of training of the angiographer, number of participating angiographers, type of catheters, number of vessels catheterized, number of exposures, use of compression series, total amount of contrast media, diagnosis of the angiogram, complications and duration of complications. The frequency of all neurologic complications was 2.3%, the frequency of persistent neurologic deficits was 0.4%. Non-neurologic complications were observed in 14.7% of the examinations. Of all the parameters studied, the only factor that significantly increased neurologic risk was a normal angiogram, a finding we are inclined to ascribe to chance. Performance of a compression series showed a trend towards increasing the neurologic risk. This study showed a complication rate of persistent neurologic deficits of 0.4% which is in accordance with other recent reports. A compression series should not be performed routinely, but only on special indication. This study confirms the low risk of cerebral angiography when performed in a neuroradiological department using the DSA technique and non-ionic contrast media.

少量test injection法を用いた選択的腎動脈造影の検討

少量test injection法を用いた選択的腎動脈造影の検討