Prospective comparison of MR phase-contrast velocimetry with intravascular doppler US during infrainguinal artery angioplasty

PURPOSE

To evaluate the accuracy of magnetic resonance (MR) velocimetry for quantitative assessment of stenosis in patients undergoing percutaneous transluminal angioplasty (PTA).

MATERIALS AND METHODS

Thirty patients underwent PTA of the infrainguinal region. To assess hemodynamic parameters of lesions, MR phase-contrast velocimetry with a circular-polarized extremity receiver coil and a cardiac gated gradient echo sequence was conducted before and 1 day after PTA. Additionally, all lesions were examined by means of intravascular Doppler flow measurements (0.018-inch wire, 12 MHz). From these data, the degree of stenosis was calculated and a comparison of MR velocimetry with intravascular Doppler US was undertaken.

RESULTS

Correlation between calculated grade of stenosis for MR velocimetry and intravascular Doppler US was good and significant (r = 0.74; P <.001). Calculated luminal stenosis grade were similar for both methods before PTA (intravascular Doppler US: 0.62 +/- 0.18, MR velocimetry: 0.54 +/- 0.19; P =.17 with paired Student t-test) and after PTA (0.25 +/- 0.23 and 0.3 +/- 0.2, respectively; P =.56).

CONCLUSION

MR velocimetry results in reliable noninvasive in vivo flow measurements and allows accurate assessment of stenosis in a clinical setting.

Transient lesion in the splenium of the corpus callosum: three further cases in epileptic patients and a pathophysiological hypothesis

OBJECTIVE

Focal lesions limited to the splenium of the corpus callosum (SCC) are rare and little is known about their aetiology. Three patients were examined for presurgical evaluation in epilepsy with a transient lesion in the SCC and a pathophysiological hypothesis is presented.

METHODS

Three patients were identified with a circumscribed lesion in the centre of the corpus callosum. Follow up MRI was performed, the medical records examined retrospectively, and the literature reviewed.

RESULTS

The patients showed identical lesions in the SCC with reduced T1 and increased T2 signal intensity and an unaffected marginal hemline of a few mm. Patients were asymptomatic and control MRIs showed complete normalisation within 2 months. Patients had been treated with antiepileptic drugs (AEDs) without signs of toxicity. In all patients AEDs were rapidly reduced for diagnostic purposes, but only one had psychomotor seizures, 5 days before imaging.

CONCLUSIONS

A transient lesion in the SCC has so far only been described in 13 patients with epilepsy and has been interpreted either as reversible demyelination due to AED toxicity or transient oedema after secondary generalised seizures. The data confirm neither of these hypotheses. A transient lesion in the SCC seems to be a non-specific end point of different disease processes leading to a vasogenic oedema. This suggests, in these patients, a multifactorial pathology triggered by transient effects of AEDs on arginine vasopressin and its function in fluid balance systems in a condition of vitamin deficiency. The complete and rapid reversibility in all cases without specific intervention is emphasised and any invasive diagnostic or therapeutic approach is discouraged.

Lack of aura experience correlates with bitemporal dysfunction in mesial temporal lobe epilepsy

The diagnostic value of lack of aura experience in patients with temporal lobe epilepsy (TLE) is unclear.

PURPOSE

To evaluate possible factors of bitemporal dysfunction in patients with mesial TLE who did not experience an aura in electroencephalography EEG/video monitoring for epilepsy surgery.

METHODS

Ictal scalp EEG propagation patterns of 347 seizures of 58 patients with mesial temporal lobe sclerosis or non-lesional mesial TLE, interictal epileptiform discharges (IED), presence of unilateral mesial temporal lobe sclerosis in visual magnetic resonance imaging (MRI) analysis, prose memory performance, history or not of an aura, and postictal memory or absence of an aura were analyzed. The ictal EEG was categorized as follows. EEG seizure: (a) remaining regionalized, (b) non-lateralized, (c) showing later switch of lateralization or bitemporal asynchronous ictal patterns.

RESULTS

Absent aura in monitoring was significantly correlated with absence of unitemporal MRI sclerosis (P=0.004), bitemporal IED (P=0.008), and propagation of the ictal EEG to the contralateral temporal lobe (P=0.001). Other historical data and interictal prose memory performance were not significantly correlated with absent aura. Ten of 11 patients without aura in monitoring also had absent or rare auras in their history.

CONCLUSIONS

Lack of aura experience strongly correlates with indicators of bitemporal dysfunction such as bitemporal interictal sharp waves and bitemporal ictal propagation in scalp EEG, and absence of lateralized MRI sclerosis in patients with mesial TLE. The fact that absent auras are not correlated with episodic memory suggests a transient memory deficit, probably because of rapid propagation to the contralateral mesial temporal lobe.

Tracheal rupture caused by blunt chest trauma: radiological and clinical features

The aim of this study was to assess radiomorphologic and clinical features of tracheal rupture due to blunt chest trauma. From 1992 until 1998 the radiomorphologic and clinical key findings of all consecutive tracheal ruptures were retrospectively analyzed. The study included ten patients (7 men and 3 women; mean age 35 years); all had pneumothoraces which were persistent despite suction drainage. Seven patients developed a pneumomediastinum as well as a subcutaneous emphysema on conventional chest X-rays. In five patients, one major hint leading to the diagnosis was a cervical emphysema, discovered on the lateral cervical spine view. Contrast-media-enhanced thoracic CT was obtained in all ten cases and showed additional injuries (atelectasis n = 5; lung contusion n = 4; lung laceration n = 2; hematothorax n = 2 and hematomediastinum n = 4). The definite diagnosis of tracheal rupture was made by bronchoscopy, which was obtained in all patients. Tracheal rupture due to blunt chest trauma occurs rarely. Key findings were all provided by conventional chest X-ray. Tracheal rupture is suspected in front of a pneumothorax, a pneumomediastinum, or a subcutaneous emphysema on lateral cervical spine and chest films. Routine thoracic CT could also demonstrate these findings but could not confirm the definite diagnosis of an tracheal rupture except in one case; in the other 9 cases this was done by bronchoscopy. Thus, bronchoscopy should be mandatory in all suspicious cases of tracheal rupture and remains the gold standard.

Interictal EEG and ictal scalp EEG propagation are highly predictive of surgical outcome in mesial temporal lobe epilepsy

PURPOSE

Surgical outcome in patients with mesial temporal lobe sclerosis (MTS) is worse than that in patients with temporal lobe activity (TLE) with tumors. Previous studies of the ictal EEG focused on ictal EEG onset in scalp EEG or ictal EEG propagation in invasive recordings. Ictal EEG propagation with scalp electrodes has not been reported.

METHODS

Ictal scalp EEG propagation patterns were studied in 347 seizures of 58 patients with MTS or nonlesional TLE. Interictal epileptiform discharges (IEDs) and the presence of unilateral mesial temporal lobe atrophy in magnetic resonance imaging (MRI) also were studied in these 58 patients. Forty-nine patients were operated on (minimal follow-up of 1 year).

RESULTS

Postoperatively, seizure-free outcome was seen in (a) 82.8% of patients with regionalized EEG seizure without contralateral propagation, but in only 45.5% of patients with contralateral propagation (p = 0.007); (b) 84.6% of patients with 100% IED lateralized to one temporal lobe, but in only 52.2% with <100% unitemporal IED (p = 0.015); (c) 88.9% with 100% unitemporal IED and regionalized ictal EEG combined, 73.7% with one of both variables, and only 33.3% with <100% ipsitemporal IED combined with contralateral ictal EEG propagation (p = 0.007).

CONCLUSIONS

Switch of lateralization or bitemporal asynchrony in the ictal scalp EEG and bitemporal IED are most probably an index of bitemporal epileptogenicity in MTS and are associated with a worse outcome.

EEG predicts surgical outcome in lesional frontal lobe epilepsy

BACKGROUND

Because of the relatively poor results of frontal lobe epilepsy (FLE) surgery, identification of prognostic factors for surgical outcome is of great importance.

METHODS

To identify predictive factors for FLE surgery, we analyzed the data of 61 patients (mean age at surgery 19.2) who had undergone presurgical evaluation and resective surgery in the frontal lobe. Postoperative follow-up ranged from 0.5 to 5 years (mean 1.78). Fifty-nine patients had MRI-detectable lesions. Histopathologic examination showed dysplasia (57.4%), tumor (16.4%), or other lesions (26.2%). Thirty postoperatively seizure-free patients were compared with 31 non-seizure-free patients with respect to clinical history, seizure semiology, EEG and neuroimaging data, resected area, and postoperative data including histopathology.

RESULTS

Three preoperative and two postoperative variables were related to poor outcome: generalized epileptiform discharges, generalized slowing, use of intracranial electrodes, incomplete resection detected by MRI, and postoperative epileptiform discharges. The only preoperative factor associated with seizure-free outcome was the absence of generalized EEG signs. Multivariate analysis showed that only the absence of generalized EEG signs predicts the outcome independently. Moreover, the occurrence of a somatosensory aura, secondarily generalized seizures, and negative MRI was identified as additional independent risk factors for poor surgical results.

CONCLUSIONS

The absence of generalized EEG signs is the most predictive variable for a seizure-free outcome in FLE surgery. Furthermore, nonlesional MRI, somatosensory aura, and secondarily generalized seizures are risk factors for poor surgical results.

Effects of nitinol Strecker stent placement on vascular response in normal and stenotic porcine iliac arteries

PURPOSE

This experimental study was conducted to evaluate neointimal thickness, lumen diameters, and histologic changes in normal and stenotic porcine iliac arteries following placement of self-expanding nitinol Strecker stents.

MATERIALS AND METHODS

Neointimal trauma causing slight vascular stenosis was induced unilaterally within external iliac arteries of 12 swines by means of endothelial abrasion and high cholesterol diet. Nitinol Strecker stents were placed within the stenotic and the normal contralateral vascular segments. For histopathologic evaluation, the pigs were killed 12 or 24 weeks after stent placement and luminal diamters were evaluated angiographically.

RESULTS

Excluding one occlusion, 15% narrowing of the lumen diameter was induced unilaterally (P = .002). Initial luminal gain after stent placement was greater for stenotic than for normal arteries. The amount of neointima thickness was not different between stenotic and normal vessels (P > .05). Comparing vascular diameters before stent placement and at follow-up, luminal loss due to neointima proliferation was 22% within normal arteries (P = .0002), while a luminal gain by 15% was found within the stenotic arteries (P = .008). Maturation of neointima and endothelial coverage were complete after 24 weeks.

CONCLUSIONS

Even though nitinol Strecker stents induce excessive neointimal proliferation, stenotic arteries seem to profit from great early luminal gain resulting in 15% of vascular expansion at follow-up while slight stenosis is induced within normal iliac arteries.

[Epiphyseal injuries of the distal tibia. Does MRI provide useful additional information?]

Plain film radiography often underestimates the extent of injury in children with epiphyseal fracture. Especially Salter-Harris V fractures (crush fracture of the epiphyseal plate) are often primarily not detected. MRI of the ankle was performed in 10 children aged 9-17 (mean 14) years with suspected epiphyseal injury using 1.0-T Magnetom Expert. The fractures were classified according to the Salter-Harris-Rang-Odgen classification and compared with the results of plain radiography. In one case MRI could exclude epiphyseal injury; in four cases the MRI findings changed the therapeutic management. The visualisation of the fracture in three orthogonal planes and the possibility of detection of cartilage and ligamentous injury in MR imaging makes this method superior to conventional radiography and CT. With respect to radiation exposure MRI instead of CT should be used for the diagnosis of epiphyseal injuries in children.

Metastatic RCC arising in a transplant kidney

We report a case of metastatic renal cell carcinoma arising in a cadaver transplant kidney 6 years after transplantation. Due to molecular analysis of the tumor tissue we could prove that the carcinoma originated from the male donor. After tumor resection and interruption of immunotherapy, the concomitant bone and lymph node metastases resolved with alpha-interferon and interleukin-2-based immunotherapy.

[Mortality and morbidity conference in radiology]

PURPOSE

To establish a morbidity and mortality conference in a radiology department as an instrument of quality assurance.

METHODS

Since April 1995 a monthly conference is held in the radiology department. Complications of invasive diagnostic procedures (angiography and biopsy) and minimal invasive interventions are presented. Cases of morbidity (major complications) and mortality (deceased patients, who were examined or treated in the radiology department before) are discussed. The identification of cases was possible due to a data base that included all such procedures prospectively.

RESULTS

Twenty cases of major complications were identified and discussed during 18 morbidity and mortality conferences in 1996 and 1997. Out of the 9 patients who died in our hospital and previously had an interventional procedure in the radiology department, one case was identified as being procedure-related. An analysis of this case was performed.

CONCLUSION

With a formalised structure of case detection, the morbidity and mortality conference becomes a tool of a complete analysis of complications and a meaningful instrument for the solution of problems concerning procedure-related complications.

Correlation of flow velocity measurements by magnetic resonance phase contrast imaging and intravascular Doppler ultrasound

RATIONALE AND OBJECTIVES

The authors compare the magnetic resonance (MR) phase contrast flow velocity measurements in varying concentric stenoses with invasive measurements obtained with a Doppler guidewire.

METHODS

Flow velocity measurements were obtained using a calibrated 0.018 inch 12 MHz Doppler guidewire and a 1.0 T MR imaging system in a pulsatile hydraulic model with variable arterial stenoses. Velocity measurements were performed proximal, intrastenotic, and distal to the stenoses. The cross-sectional area of stenosis was calculated from the data of both methods. For MR imaging measurements, fast low-angle shot two-dimensional phase contrast sequences with different velocity encodings were used.

RESULTS

Phase contrast flow measurements correlated well (r = 0.95, Pearson) with Doppler guidewire-based flow velocity data. Generally, flow velocities obtained with MR imaging were lower when compared with the Doppler-based data (P < or = 0.001, Wilcoxon matched pairs test). However, the ratios and the calculated cross-sectional area of stenoses showed a high correlation (r = 0.96) with the predefined area of stenoses.

CONCLUSIONS

The assessment of flow alterations in vitro due to variable stenoses using MR phase contrast flow measurements is very well correlated with the Doppler guidewire. Consequently, these results required in vivo measurements of atherosclerotic lesions to evaluate the clinical impact.

[Postoperative imaging of synthetic coronary artery bypass graft patency by means of CT angiography]

PURPOSE

CT angiography was performed in 12 patients with insufficient autologous graft situations to evaluate postoperative patency and situation of the proximal, distal and coronary artery anastomoses of synthetic Perma-Flow coronary artery bypass grafts.

METHODS

Bypass grafts were evaluated postoperatively with spiral CT of the mediastinum. At a flow rate of 3 ml/s, 120 ml of contrast material were applied over a cubital vein. Slice thickness was 3 mm, maximum pitch factor 2 and image reconstruction was performed at 2 mm increment. Shaded surface displays were analysed together with axial scans for bypass evaluation.

RESULTS

8 out of 12 synthetic bypasses proved to be patent. One bypass was completely occluded and in three patients the distal portions of the grafts were occluded. Coronary angiography performed in one case confirmed complete bypass occlusion. Due to the occlusions, 8 distal and 12 proximal anastomoses were visible. Only 8 out of 19 side-to-side coronary artery anastomoses could be sufficiently well imaged with this technique.

CONCLUSIONS

CT angiography is suitable for postoperative screening of synthetic coronary bypasses to determine the patency and anastomotic situations. Coronary artery anastomoses however are not sufficiently imaged and coronary angiography continues to be required.

[Pitfalls when using a contrast media injector in MRI]

PURPOSE

Using a power injector to applicate Gd-DTPA we found a contrast enhancement of the pyelo-caliceal system even in the native studies, and hence we analysed pitfalls when using power injectors in MRI.

MATERIAL AND METHODS

We used a power injector Spectris (MedRad, Maastricht, Netherlands). In vitro artifacts were achieved by the mixture of contrast media and saline solution. We substituted contrast media by red water, NaCl by clear water.

RESULTS

Using power injectors in MRI, some pitfalls must be avoided, which can render investigations useless, especially dynamic contrast-enhanced investigations.

CONCLUSION

In our study we showed an easy way to overcome some pitfalls and use a power injector in MRI in a diagnostically helpful way. The simple use of valves inhibits the mixture of contrast media and saline solution.

Localization of epileptic auras induced on stimulation by subdural electrodes

PURPOSE

This study evaluates the localization of stimulation-induced auras (SIA) and tries to determine whether the SIA can help to define the boundaries of resection in epilepsy surgery.

METHODS

Using subdural grid electrodes, 31 patients with drug resistant focal epilepsy were examined in a retrospective and prospective study lasting 2 years.

RESULTS

On stimulation by subdural electrodes, we elicited habitual auras in 16 patients (52%). The zone of SIA overlapped the epileptogenic lesion in 12 patients (75%), the EEG seizure onset zone in 12 patients (75%), and the irritative zone of interictal spikes in eight patients (50%). Postoperative results showed a significant correlation with the complete removal of the epileptogenic lesion (p < 0.001). Because the number of patients in the study was small, we could not find a significant correlation with the complete removal of the SIA zone, EEG seizure onset zone, and irritative zone.

CONCLUSIONS

Our study confirms previous analyses which indicate that complete resection of the epileptogenic lesion is essential to achieve a good outcome. Frequent overlap of the SIA zone with the epileptogenic lesion and the EEG seizure onset zone indicates proximity of the SIA with the epileptogenic zone. Nevertheless, this study does not support the concept that the SIA zone and the EEG seizure onset zone have additional value in defining the boundaries of resection in epilepsy surgery. Three case presentations suggest that SIA result from facilitated pathways between the stimulated cortex, the epileptogenic zone around the lesion, and the symptomatogenic zone. Functional reorganization in the vicinity of the cortical lesion cannot be ruled out but was not seen in our patients. Thus, SIA often do not reflect the normal function of the stimulated underlying cortex.

[CT quantification of pleuropulmonary lesions in severe thoracic trauma]

PURPOSE

Computed quantification of the extent of pleuropulmonary trauma by CT and comparison with conventional chest x-ray--Impact on therapy and correlation with mechanical ventilation support and clinical outcome.

METHOD

In a prospective trial, 50 patients with clinically suspicious blunt chest trauma were evaluated using CT and conventional chest x-ray. The computed quantification of ventilated lung provided by CT volumetry was correlated with the consecutive artificial respiration parameters and the clinical outcome.

RESULTS

We found a high correlation between CT volumetry and artificial ventilation concerning maximal pressures and inspiratory oxygen concentration (FiO2, Goris-Score) (r = 0.89, Pearson). The graduation of thoracic trauma correlated highly with the duration of mechanical ventilation (r = 0.98, Pearson). Especially with regard to atelectases and lung contusions CT is superior compared to conventional chest x-ray; only 32% and 43%, respectively, were identified by conventional chest x-ray.

CONCLUSION

CT allows rapid classification and quantification of pulmonary lesions after thoracic trauma and provides higher sensitivity and reliability. Because of the great correlation with the extent of artificial respiration in respect of duration and pressure, prognosis of the individual patient, as well as a differential therapy, appear possible.

The precise determination of vascular lumen and stent diameters: correlation among calibrated angiography, intravascular ultrasound, and pressure-fixed specimens

PURPOSE

Luminal diameters measured in vivo by calibrated-catheter angiography and by intravascular ultrasound were correlated with those obtained from pressure-fixed histologic cross-sections to determine the accuracy of both methods.

METHODS

Angiographic and endosonographic diameter measurements were performed in the center of stents placed in the iliac arteries of 10 miniature pigs and were compared with luminal and stent diameters in postmortem, pressure-fixed, histologic cross-sections from identical locations.

RESULTS

Compared with histologic diameters, magnification-corrected angiographic measurements still magnified vascular luminal diameters by 0.7 +/- 0.71 mm (r = 0.41, Pearson; p < 0.003, Wilcoxon, matched pairs), whereas intravascular ultrasound measurements proved to be almost identical to the histologic lumina (r = 0.95, Pearson; p > 0. 5, Wilcoxon, matched pairs). Similarly, stent diameters correlated well between endosonographic and histologic measurements (r = 0.91; p = 0.002), and less well between angiographic and histologic diameters (r = 0.62; p = 0.002).

CONCLUSION

Since calibrated angiography still overestimates vascular lumina, endosonography is the preferred technique for accurate in vivo measurements.

Local intraarterial thrombolysis: in vitro comparison of various infusion catheters

PURPOSE

Catheters are compared in vitro to evaluate the efficacy of thrombolysis during urokinase infusion within the thrombus.

METHODS

Six catheters were introduced individually into human thrombus within a stenotic flow model. Urokinase was infused continuously into the thrombus. To quantify the efficacy of thrombolysis, pressure gradients were recorded proximal and distal to the thrombus and during the course of infusion. Uniformity of lysis was assessed radiographically.

RESULTS

The fastest and most homogeneous thrombolysis was achieved with the EDM and the straight-flush catheter, shown by decreasing transthrombotic pressure gradients. All other catheter designs showed less homogeneous and delayed thrombolysis (p </= 0.001, Friedmann-Test, Schaich-Hamerle). There was no significant difference in the efficacy of thrombus dissolution between the EDM and the straight-flush catheter (Wilcoxon, matched pairs, p > 0.7).

CONCLUSION

The EDM catheter and the straight flush catheter achieved the most homogeneous and fastest thrombolysis, apparently due to the best urokinase distribution within the thrombus.

Monitoring of therapy in inoperable lung cancer patients by measurement of CYFRA 21-1, TPA- TP CEA, and NSE

In a series of 381 consecutive patients with lung tumors and benign pulmonary diseases, we examined whether tumor markers CYFRA 21-1 (EIA, Boehringer, Mannheim), TPA-M (IRMA AB Sangtec Medical, Bromma, Sweden), TPS (IRMA, Beki Diagnostics AB, Bromma, Sweden), CEA and NSE (EIA, Roche, Basel) have the potential to contribute to clinical decision-making processes with respect to diagnosis and assessment of response to therapy. The sensitivity values of the marker tests in NSCLC (CYFRA 21-1: 44.4% > 3.9 ng/ml, TPA-M: 39.4% > 200 U/ml, TPS: 13.2% > 230 U/ml, CEA: 37.5% > 8.6 ng/ml), in SCLC (NSE: 61.9% > 14.0 ng/ml) and in pleural mesothelioma (CYFRA 21-1 and TPS: 36.4%) were found to be clearly inferior to the yield of standard cytopathological examinations (85-98%) when using the 95% specificity versus the group with benign pulmonary disease as cut-off values. Therefore, currently available tumor markers are of minor value in the primary diagnosis of lung tumors. After curative surgery (Ro) of NSCLC only CYFRA 21-1 levels dropped to the normal range within one week. The other markers simulated residual tumor mass by displaying elevated marker levels after surgery. During the monitoring of response to chemo-/radiotherapy the changes in marker levels were compared to the clinical assessment according to standard criteria of the WHO. The criteria defined for marker response were a 65% decrease for a partial response and a 40% increase of the marker levels for progressive disease. Concordant results were obtained in 59.4% of the cases for CYFRA 21-1 (TPA-M: 63.3%, TPS: 65.5%, CEA: 54.8%, NSE: 68.9%). Most discordant results were obtained in tumor remission due to an insufficient decrease in the markers. Progressive disease was most effectively indicated by CYFRA 21-1 in NSCLC 60%) and by NSE in SCLC (70.0%). It is concluded that increasing marker levels may contribute to clinical decision making, at least in helping to decide which patients should no longer treated by ineffective and toxic drugs.

[In vitro evaluation of the intravasal Doppler guide wire: determination of hemodynamic effects of stenoses in a flow model]

PURPOSE

In a pulsatile hydraulic model, haemodynamic changes caused by stenoses were assessed using an intravascular Doppler guide wire.

MATERIAL AND METHODS

In defined stenoses (25, 50, 75 and 87.5% diameter ratio), and with and without collateral flow, a 0.018 inch (0.46 mm) 12 MHz Doppler guide wire was assessed. Flow velocity measurements were taken 20 mm proximal, in, and 20 mm distal to the stenoses. Average peak velocity (APV) and ratios of pre-/poststenotic velocities and pre-/intrastenotic velocities of APV were compared with the grade of stenosis. The degree of the stenosis calculated by the ratio of the cross-sectional area, using the pre- and intrastenotic APV, was correlated with the actual stenosis.

RESULTS

The intrastenotic APV increased significantly (APV proximal to the stenosis 15.15 +/- 4.5 cm/s, intrastenotic APV 134.8 +/- 130.9, p < 0.01, Wilcoxon-Mann-Whitney test). The difference between APV pre- and poststenotic was not significant (p > 0.5). Concerning the grade of stenosis the ratio APV pre-/intrastenotic and the consecutively calculated cross-sectional area stenoses was the best predictor (correlation with the known cross-sectional area stenosis r = 0.94 Pearson).

CONCLUSION

Using the Doppler guide wire, APV measurements pre- and intrastenotic enable a reliable quantification of the grade of stenosis. The stenosis calculated via the cross-sectional area correlates significantly with the actual stenosis.

[Must the patient fast before intravascular injection of a non-ionic contrast medium? Results of a controlled study]

PURPOSE

Prospective evaluation of food and fluid restriction before the intravascular injection of a non-ionic contrast medium.

MATERIAL AND METHODS

1000 patients (657 men, 343 women; average age 59 +/- 1/4 5 years) undergoing intravascular contrast injections (CT, phlebography, angiography, urography) were randomly allocated to two groups. Group A had no fluid or solids for at least four hours before the injection (499 cases); group B were allowed unlimited food and fluid (501 cases). Both groups were comparable in all other respects and all were given the non-ionic contrast medium iopamidol (300 mg l/ml).

RESULTS

The incidence of acute complications was 3.5%. There was, however, no statistically significant difference between the two groups (p = 0.29). Late adverse reactions were seen in 3.9% patients. There was again no difference between the two groups (p = 0.33). No serious or life threatening complications occurred.

CONCLUSION

Restriction of food and fluid before intravascular injection of contrast medium does not reduce the number of adverse side effects. For reasons of patient comfort and compliance, and to achieve adequate hydration, the patient should not fast before injection of contrast.