Intra-arterial Injection Of Contrast Medium Research Articles

Evaluating the length, diameter, and stenosis of deep circumflex iliac artery and neighboring arteries based on digital subtraction angiography.

The vascularized iliac bone crest flap offers excellent usable bone in terms of volume and quality. Its nourishing vessel, the deep circumflex iliac artery (DCIA), although relatively short, is reliable vessel. Digital subtraction angiography presents still the gold standard for diagnostic purpose. However, computed tomography (CT) and magnetic resonance imaging (MRI) angiography is used for preoperative planning with low morbidity. The purpose of this study is to evaluate the gainable information using digital subtraction angiography (DSA) as compared to other imaging modalities. We evaluated information gainable from standard DSA of 130 consecutive patients (average age was 69.5 years [range 18-90 years]) concerning topography, dimension, and condition of the vessel wall. We looked for differences considering gender and side. DCIA could not be followed in the periphery constantly in all cases due to the small, illustrated field. Arteriosclerotic changes showed to be very low in DCIA as compared to the neighboring vessels. Diabetes mellitus and smoking had a significant impact on vessel condition. DCIA branched off into its main two branches early after 40 mm (11%), after 40-60 mm (30%), or late after 60 mm (59%). DCIA showed to be least affected by different risk factors that reported to affect the vessel condition. We present additional detailed topographic anatomy of DCIA and its variation that can be used intraoperative guide to harvest the flap and teaching purpose. Standard DSA delivers valuable preoperative data regarding stenosis in addition to the topographic anatomy of the flap pedicle. However, imaging of the distal parts of the DCIA, nourishing the skin paddle is limited by the detector field used. For a full imaging of both DCIAs from the origin to the perforators, the intraarterial injection of contrast medium, as applied in DSA, could be combined with different imaging modalities like CT-angiography.

Effects of Remote Ischemic Pre-Conditioning to Prevent Contrast-Induced Nephropathy after Intravenous Contrast Medium Injection: A Randomized Controlled Trial.

ObjectiveWe aimed to assess the effects of remote ischemic pre-conditioning (RIPC) on the incidence of contrast-induced nephropathy (CIN) after an intravenous (IV) or intra-arterial injection of contrast medium (CM) in patient and control groups.Materials and MethodsThis prospective, randomized, single-blinded, controlled trial included 26 patients who were hospitalized for the evaluation of the feasibility of transcatheter aortic valve implantation and underwent investigations including contrast-enhanced computed tomography (CT), with Mehran risk scores greater than or equal to six. All the patients underwent four cycles of five minute-blood pressure cuff inflation followed by five minutes of total deflation. In the RIPC group (n = 13), the cuff was inflated to 50 mm Hg above the patient's systolic blood pressure (SBP); in the control group (n = 13), it was inflated to 10 mm Hg below the patient's SBP. The primary endpoint was the occurrence of CIN. Additionally, variation in the serum levels of cystatin C was assessed.ResultsOne case of CIN was observed in the control group, whereas no cases were detected in the RIPC group (p = 0.48, analysis of 25 patients). Mean creatinine values at the baseline, 24 hours after injection of CM, and 48 hours after injection of CM were 88 ± 32 µmol/L, 91 ± 28 µmol/L and 82 ± 29 µmol/L, respectively (p = 0.73) in the RIPC group, whereas in the control group, they were 100 ± 36 µmol/L, 110 ± 36 µmol/L, and 105 ± 34 µmol/L, respectively (p = 0.78). Cystatin C values (median [Q1, Q3]) at the baseline, 24 hours after injection of CM, and 48 hours after injection of CM were 1.10 [1.08, 1.18] mg/L, 1.17 [0.97, 1.35] mg/L, and 1.12 [0.99, 1.24] mg/L, respectively (p = 0.88) in the RIPC group, whereas they were 1.11 [0.97, 1.28] mg/L, 1.13 [1.08, 1.25] mg/L, and 1.16 [1.03, 1.31] mg/L, respectively (p = 0.93), in the control group.ConclusionThe risk of CIN after an IV injection of CM is very low in patients with Mehran risk score greater than or equal to six and even in the patients who are unable to receive preventive hyperhydration. Hence, the Mehran risk score may not be an appropriate method for the estimation of the risk of CIN after IV CM injection.

Immediate and delayed hypersensitivity after intra-arterial injection of iodinated contrast media: a prospective study in patients with coronary angiography

While hypersensitivity reactions (HSR) to intravenously administered iodinated contrast media (ICM) have been well studied, not much is known about HSR to intra-arterially administered ICM. A prospective observational study was performed to evaluate coronary angiography (CAG)-induced ICM hypersensitivity in patients who underwent CAG using ICM including ioversol, a low-osmolar non-ionic monomer, and iodixanol, an iso-osmolar non-ionic dimer. The HSR were investigated through in-patient monitoring after CAG and telephone interview after discharge. A total of 714 patients were enrolled during the observation period, of whom 26 (3.6%) showed immediate HSR and 108 (15.1%) showed delayed HSR. With regard to severity, proportion of immediate HSR grades 1, 2, and 3 was 57.7%, 38.5%, and 3.8%, respectively, whereas that of delayed HSR grades 1, 2, and 3 was 85.2%, 13.9%, and 0.9%, respectively. Multivariate analysis revealed that previous intra-arterial exposure to ICM was an independent risk factor for immediate HSR (odds ratio (OR) 2.92, 95% confidence interval (CI) 1.22-6.96; p = 0.015). Iodixanol was a significant risk factor for delayed HSR (OR 1.61, 95% CI 1.07-2.43; p = 0.024) and correlated with a higher incidence of delayed HSR within 24-h post-ICM administration compared to ioversol. The incidence rate of immediate and delayed HSR in intra-arterially administered ICM was 3.6% and 15.1%, respectively. Previous exposure to intra-arterially administered contrast media was a significant risk factor for immediate HSR. Compared to ioversol, iodixanol was associated with relatively earlier and more frequent delayed HSR. • In this prospective study, the incidence of immediate and delayed hypersensitivity in intra-arterial injection of contrast media during coronary angiography was 3.6% and 15.1%, respectively. • Delayed hypersensitivity reactions were more common but less severe than immediate hypersensitivity reactions during coronary angiography. • Previous exposure to ICM via intra-arterial route was a significant risk factor for immediate hypersensitivity to intra-arterial contrast medium.

Patient Discomfort during Carotid Artery Stenting: A Comparison Study between Iodixanol versus Iopamidol

The aim of this study was to compare the adverse effects of iodixanol and iopamidol in terms of patient's discomfort in subjects undergoing carotid artery stenting (CAS). We retrospectively analyzed data of all successful CAS procedures performed in our department during a 15-year period study. All patients judged to be collaborative were included. From December 2000 to December 2005, we adopted iopamidol as contrast media (CM), thereafter iodixanol. Any transient unpleasant sensation of bitter taste or warmth perceived by the patient after intra-arterial injection of CM was recorded. Injection-associated discomfort was assessed by visual analog scale (VAS) score. Comparison between the 2 CMs with regard to the overall discomfort was carried out by using the Mann-Whitney test. Spearman correlation was performed to assess the correlation among discomfort, age, and CM used. A univariate analysis was performed for slightly bitter taste and warmth sensation to compare these clinical outcomes and CM used; subsequently, a logistic multivariate analysis regression was performed with the "backward elimination." Data from 1,633 patients were evaluated. A total of 608 patients underwent CAS procedure using iopamidol, and 1,025 using iodixanol. The total amount of CM used during a single procedure was 85±17mL/patient (range 60-135). The median VAS value was statistically significantly lower in the iodixanol group than in the iopamidol group (P<0.001). A significant Spearman correlation coefficient was found between age and discomfort for both CMs used (Spearman rho 0.18 for iodixanol, 0.17 for iopamidol). The univariate analysis showed that patients undergoing CAS with iopamidol had an odds ratio (OR) of 8.48 (P<0.001) to perceive warmth sensation. When adjusted for age and gender, the multivariate analysis still showed an OR of 8.03. For slightly bitter taste sensation, the crude analysis showed an OR of 1.31 (P=0.018); adjusting for age and gender, OR became 1.15 and the difference was not statistically significant (P=0.257). During CAS, less overall discomfort was reported in patients receiving iodixanol than iopamidol; in terms of warmth sensation, patients undergoing procedure using iopamidol as CM have a higher risk to perceive this clinical symptom than iodixanol. Slightly bitter taste seems to have a statistically significant relation with age and gender, and not with CM used.

Determination of Lower Limb Microvasculature by Intrafemoral Arterial Injection Using Computed Tomography-Assisted Angiography

Computed tomography-assisted angiography (CTA) for lower limb vasculature can identify perforators only as small as 1mm in diameter. The technique does not clearly show the microvascularity in subdermal layers of the skin. This study investigated a novel method of CTA using intrafemoral injection of contrast medium instead of intravenous injection to display the vascular anatomy of small perforators with a diameter less than 1mm in the lower extremities of rabbits. Posterior thigh perforator surgery was performed for 15 New Zealand rabbits weighing 2.5 to 3.5kg. Five rabbits underwent anatomic dissection to determine the vascular anatomy of the posterior thigh perforator and its location relative to adjacent structures. Of the remaining 10 rabbits, 5 were subjected to CTA scanning after injection of iodine contrast through a microcatheter inserted into the femoral artery, and 5 were subjected to CTA scanning through venous injection of contrast media. The latter group was designated as the control group (10 extremities). Images were viewed using a dedicated workstation. Postoperative outcomes and complications were monitored for 7days after the procedure. All the CTA images of intraartery administration clearly showed that the posterior thigh perforators originated from the popliteal artery. Injection of contrast agent through the femoral artery improved resolution of the CTA, enabling visualization of perforator arteries with diameters in the range of 0.3 to 0.4mm. The images of the control group indicated the course of the perforator in the muscle of only six legs. The images of the remaining four legs did not display the perforator. The CTA-treated animals recovered without any complications. The anatomic dissection matched the CTA mapping. Computed tomography-assisted angiography using intraarterial injection of contrast media enables visualization of vessels smaller than 1mm in diameter. The described animal model also showed the presence of vascular branches in the subdermis. This imaging technique may help in the preoperative design of perforator flaps for use in clinical practice. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Comparison of Semi-automatic Volumetric VX2 Hepatic Tumor Segmentation from Cone Beam CT and Multi-detector CT with Histology in Rabbit Models

The purpose of this study was to compare tumor volume in a VX2 rabbit model as calculated using semiautomatic tumor segmentation from C-arm cone-beam computed tomography (CBCT) and multidetector computed tomography (MDCT) to the actual tumor volume. Twenty VX2 tumors in 20 adult male New Zealand rabbits (one tumor per rabbit) were imaged with CBCT (using an intra-arterial contrast medium injection) and MDCT (using an intravenous contrast injection). All tumor volumes were measured using semiautomatic three-dimensional volumetric segmentation software. The software uses a region-growing method using non-Euclidean radial basis functions. After imaging, the tumors were excised for pathologic volume measurement. The imaging-based tumor volume measurements were compared to the pathologic volumes using linear regression, with Pearson's test, and correlated using Bland-Altman analysis. Average tumor volumes were 3.5 ± 1.6 cm(3) (range, 1.4-7.2 cm(3)) on pathology, 3.8 ± 1.6 cm(3) (range, 1.3-7.3 cm(3)) on CBCT, and 3.9 ± 1.6 (range, 1.8-7.5 cm(3)) on MDCT (P < .001). A strong correlation between volumes on pathology and CBCT and also with MDCT was observed (Pearson's correlation coefficient = 0.993 and 0.996, P < .001, for CBCT and MDCT, respectively). Bland-Altman analysis showed that MDCT tended to overestimate tumor volume, and there was stronger agreement for tumor volume between CBCT and pathology than with MDCT, possibly because of the intra-arterial contrast injection. Tumor volume as measured using semiautomatic tumor segmentation software showed a strong correlation with the "real volume" measured on pathology. The segmentation software on CBCT and MDCT can be a useful tool for volumetric hepatic tumor assessment.

Intraprocedural Angiographic CT as a Valuable Tool in the Course of Endovascular Treatment of Direct Sinus Cavernous Fistulas

This investigation aimed to demonstrate the potential of intraprocedural angiographic CT in monitoring complex endovascular coil embolization of direct carotid cavernous fistulas. Angiographic CT was performed as a dual rotational 5 s run with intraarterial contrast medium injection in two patients during endovascular coil embolization of direct carotid cavernous fistulas. Intraprocedural angiographic CT was considered helpful if conventional 2D series were not conclusive concerning coil position or if a precise delineation of the parent artery was impossible due to a complex anatomy or overlying coil material. During postprocessing multiplanar reformatted and dual volume images of angiographic CT were reconstructed. Angiographic CT turned out to be superior in the intraprocedural visualization of accidental coil migration into the parent artery where conventional 2D-DSA series failed to reliably detect coil protrusion. The delineation of coil protrusion by angiographic CT allowed immediate correct coil repositioning to prevent parent artery compromising. Angiographic CT can function as a valuable intraprocedurally feasible tool during complex coil embolizations of direct carotid cavernous fistulas. It allows the precise visualization of the cerebral vasculature and any accidental coil protrusion can be determined accurately in cases where conventional 2D-DSA series are unclear or compromised. Thus angiographic CT might contribute substantially to reduce procedural complications and to increase safety in the management of endovascular treatment of direct carotid cavernous fistulas.

Ｃ‐Ａｒｍ ＣＴを備えた脳血管撮影装置での経動脈的造影剤投与法による脳血液量の計測（Ｎｅｕｒｏ ＰＢＶ）および頭蓋内血流動態評価画像（ｉＦｌｏｗ）の検討

【目的】CアームCTを備えた血管撮影装置での新たなアプリケーションである脳血液量（CBV）の計測（Neuro PBV）と，頭蓋内血流動態画像（iFlow）について報告する．【方法】Neuro PBVはマスク撮影後に造影剤を注入して2度目の撮影を行い，両者の差から組織造影剤濃度分布を得てCBVを算出し，iFlowは造影剤の経時的な血管内移動をカラーマップ表示するものである．それぞれの有効性と適切な撮影方法を検討した．【結果】撮影手順を確立し，両者とも良好な画像を得ることができた．【結論】現状では撮影方法を含めた検討が必要であるが，脳血管内治療において有用な情報を提供するツールになると思われる．

Impact of Intra-Arterial Injection Parameters on Arterial, Capillary, and Venous Time-Concentration Curves in a Canine Model

Recent advances in flat panel detector angiographic equipment have provided the opportunity to obtain physiologic and anatomic information from angiographic examinations. To exploit this possibility, one must understand the factors that affect the bolus geometry of an intra-arterial injection of contrast medium. It was our purpose to examine these factors in a canine model. Under an institutionally approved protocol conforming to Guide for the Care and Use of Laboratory Animals of the National Institutes of Health, 7 canines were placed under general anesthesia with isoflurane and propofol. Through a 5F catheter placed into the right common carotid artery, a series of biplane angiographic acquisitions was obtained to examine the effects caused by variation in the volume of injection, the rate of injection, the duration of injection, the concentration of contrast medium, and the catheter position on arterial, capillary, and venous opacification. The results of each injection protocol were determined from analysis of a time-contrast concentration curve derived from locations over an artery, in brain parenchyma, and over a vein. The curve was generated from 2D digital subtraction angiography acquisitions by using prototype software. The area under the curve, the amplitude of the curve, and the time to peak (TTP) were analyzed separately for each injection parameter. Changes in the injection protocols resulted in predictable changes in the time-concentration curves. The injection parameter that contributed most to maximum opacification was the volume of contrast medium injected. When the injection rate was fixed and the volume was varied, there was an increase in opacification (maximal) proportional to the injected volume. The injected volume also had an indirect (secondary) impact on the temporal characteristics of the opacification. The time-concentration curve became wider, and the peak was shifted to the right as the injection duration increased. The impact of injected volume on maximal opacification was significant (P < .0001), regardless of the site of measurement (artery, tissue, and vein); however, the impact on the temporal characteristics of the time-concentration curve reached statistical significance only in measurements made in the artery and the vein (P < .05), but not in the tissue (P > .1). The impact of injected volume on maximal opacification became nonproportional in the tissue and vein when the volume was very large (>12 mL). Increasing the concentration of contrast medium resulted in a nonproportional increase in the height of the time-concentration curves (P < .05). Injection rate had an impact on both maximal opacification and TTP. The impact on TTP occurred only when the injection rate was very slow (1 mL/s). Changes of concentration had a similar impact on the time-concentration curve. Catheter position did not cause significant alterations in the shape of the curves. There were predictable effects from modification of injection parameters on the contrast bolus geometry and on time-concentration curves as measured in an artery, brain parenchyma, or a vein. The amplitude, TTP, and area under the time-concentration curve depend mainly and proportionally on the amount of iodine traversing the vasculature per second. Other injection parameters were of less importance in defining bolus geometry. These findings mimic those observed in studies of parameters affecting bolus geometry following an intravenous injection.

New Frontiers in the Evaluation of Cardiac Patients for Noncardiac Surgery

New Frontiers in the Evaluation of Cardiac Patients for Noncardiac Surgery

Correlation between the blood supply and grade of malignancy of hepatocellular nodules associated with liver cirrhosis: evaluation by CT during intraarterial injection of contrast medium.

The purpose of this study is to evaluate the correlation between the intranodular blood supply revealed by CT during intraarterial injection of contrast medium, mainly using helical CT, and the grade of malignancy of hepatocellular nodules associated with liver cirrhosis as classified by the International Working Party of the World Congress of Gastroenterology. We studied 201 histologically proven nodules (101 resected and 100 biopsied nodules), including 47 low-grade dysplastic nodules (low-DNs), 56 high-grade dysplastic nodules (high-DNs), 24 well-differentiated hepatocellular carcinomas (wd-HCCs), and 74 moderately or poorly differentiated HCCs (mp-HCCs), in 139 cirrhotic patients. Findings on CT during arterial portography (n = 201) and CT during hepatic arteriography (n = 74) were reviewed and compared with the histologic diagnosis. CT findings were classified into four types relative to the surrounding liver: type A (isodense), type B (slightly hypodense), type C (partially hypodense), and type D (markedly hypodense) on CT during arterial portography and type I (isodense), type II (hypodense), type III (partially hyperdense), and type IV (hyperdense) on CT during hepatic arteriography. On CT during arterial portography, the distributions of each type were low-DN (n = 47 [A, n = 36; B, n = 8; C, n = 3]), high-DN (n = 56 [A, n = 18; B, n = 20; C, n = 10; D, n = 8]), wd-HCC (n = 24; [B, n = 4; C, n = 13; D, n = 7]), and mp-HCC (n = 74 [D, n = 74]). On CT during hepatic arteriography, the distributions were low-DN (n = 26 [I, n = 18; II, n = 7; III, n = 1]), high-DN (n = 19 [I, n = 6; II, n = 7; III, n = 4; IV, n = 2]), wd-HCC (n = 15 [I, n = 1; III, n = 8; IV, n = 6]), and mp-HCC (n = 14 [IV, n = 14]). We found a statistically significant correlation between the four types and the grade of malignancy of these nodules. Findings on CT during arterial portography and CT during hepatic arteriography correlated positively with histologic grading when overlap in appearance between dysplastic nodules and HCCs occurred. The concept revealed in this study can apply to diagnoses made on the basis of Doppler sonography, dynamic CT, and MR imaging.

Sensitivity in detection of hypervascular hepatocellular carcinoma by helical CT with intra-arterial injection of contrast medium, and by helical CT and MR imaging with intravenous injection of contrast medium.

To determine the effectiveness of i.a. contrast-enhanced helical CT and of i.v. contrast-enhanced helical CT and MR imaging, in detecting hypervascular hepatocellular carcinoma (HCC). Fifty patients with 125 hypervascular HCC nodules underwent helical CT both during arterial portography (CTAP) and during hepatic arteriography (CTHA). Helical CT and MR imaging of the entire liver with i.v. administration of contrast medium were also performed. Helical CT images were obtained at 30-33 s (arterial-phase CT) and at 5 min (equilibrium-phase CT) after the initiation of an i.v. bolus injection of contrast medium. After T1- and T2-weighted spin-echo MR imaging, gradient-echo images during breath-holding were obtained prior to and 20 s, 1 min, and 2 min after the bolus administration of 0.1 mmol/kg of gadopentetate dimeglumine (dynamic MR). The sensitivity and positive predictive value of the various techniques were evaluated and compared. In terms of sensitivity for hypervascular HCC nodules of less than 1 cm in diameter, CTAP (90%) and CTHA (88%) were significantly superior to dynamic MR imaging (44%), arterial-phase CT (39%), spin-echo MR imaging (20%), and equilibrium-phase CT (7%) (p < 0.001). However, there was no significant difference in the techniques with regard to the detection of lesions equal to or more than 2 cm in diameter. For detecting small hypervascular HCCs, helical CT with i.a. contrast enhancement is superior to helical CT and MR imaging with i.v. enhancement.

Sensitivity in detection of hypervascular hepatocellular carcinoma by helical ct with intra-arterial injection of contrast medium, and by helical CT and MR imaging with intravenous injection of contrast medium

Sensitivity in detection of hypervascular hepatocellular carcinoma by helical ct with intra-arterial injection of contrast medium, and by helical CT and MR imaging with intravenous injection of contrast medium

Detectability of Hypervascular Hepatocellular Carcinoma by Arterial Phase Images of MR and Spiral CT

The ability of arterial phase images of breath-hold MR imaging and spiral CT to detect hypervascular hepatocellular carcinomas (HCCs) was evaluated. Prior to transcatheter arterial chemoembolization (TACE) with iodized oil, MR images and spiral CT during i.v. bolus injection of contrast medium (IV-MR imaging and IV-spiral CT) and spiral CT during intraarterial injection of contrast media through catheter (IA-spiral CT) of the entire liver were obtained in 24 consecutive patients with 93 HCCs. In the detection of HCCs less than 1 cm in diameter, IA-spiral CT (87.3%) was superior to IV-MR imaging (63.5%) and IV-spiral CT (54.0%) (p&lt;0.001). There was no significant difference in detectability in any tumor size between IV-MR imaging and IV-spiral CT. IA-spiral CT was the best for detecting hypervascular HCCs, and there was no significant difference between IV-MR imaging and IV-spiral CT.

Detectability of Hypervascular Hepatocellular Carcinoma by Arterial Phase Images of MR and Spiral CT

The ability of arterial phase images of breath-hold MR imaging and spiral CT to detect hypervascular hepatocellular carcinomas (HCCs) was evaluated. Prior to transcatheter arterial chemoembolization (TACE) with iodized oil, MR images and spiral CT during i.v. bolus injection of contrast medium (IV-MR imaging and IV-spiral CT) and spiral CT during intraarterial injection of contrast media through catheter (IA-spiral CT) of the entire liver were obtained in 24 consecutive patients with 93 HCCs. In the detection of HCCs less than 1 cm in diameter, IA-spiral CT (87.3%) was superior to IV-MR imaging (63.5%) and IV-spiral CT (54.0%) (p < 0.001). There was no significant difference in detectability in any tumor size between IV-MR imaging and IV-spiral CT. IA-spiral CT was the best for detecting hypervascular HCCs, and there was no significant difference between IV-MR imaging and IV-spiral CT.

Cerebral venography with MR.

The authors describe a two-dimensional time-of-flight magnetic resonance (MR) angiography technique to create projection venograms of the head. The technique was applied to 27 healthy volunteers and 39 patients. The superior sagittal and straight sinuses, the internal cerebral veins, and the Galen vein were visualized in all the volunteers. Other veins were seen in a high percentage of subjects. Systematic comparison of digital subtraction angiography (DSA) after intraarterial contrast medium injection and MR venography in patients showed good correlation between the two techniques. MR venography proved helpful in identifying thrombosis or patency of cerebral veins and sinuses and showed collateral venous drainage and venous drainage from arteriovenous malformations. There was good correlation between conventional contrast angiography and MR venography. In conclusion, MR venography is considered reliable for showing the cerebral venous system and provides information additional to that of conventional spin-echo imaging.

Changes in Atrial Natriuretic Peptide Concentration at Femoral Arteriography in Man

The changes in plasma concentrations of atrial natriuretic peptide were investigated in 10 patients who were examined for peripheral vessel disease by aorto-femoral angiography. All patients received 6 x 40 ml contrast medium (iohexol, 300 mg I/ml) plus an initial test dose of 15 ml, resulting in a total mean dose of 255 ml injected into the abdominal aorta. The contrast medium injections produced a significant increase in plasma atrial natriuretic peptide concentration (p less than 0.02). Furthermore a significant decrease was seen in systolic blood pressure (p less than 0.04). It is concluded that the plasma concentration of atrial natriuretic peptide increases after intraarterial injection of contrast medium, and that atrial natriuretic peptide might play a role in the hemodynamic changes seen after intravascular injections of contrast medium.

Changes in Atrial Natriuretic Peptide Concentration at Femoral Arteriography in Man

The changes in plasma concentrations of atrial natriuretic peptide were investigated in 10 patients who were examined for peripheral vessel disease by aorto-femoral angiography. All patients received 6 x 40 ml contrast medium (iohexol, 300 mg I/ml) plus an initial test dose of 15 ml, resulting in a total mean dose of 255 ml injected into the abdominal aorta. The contrast medium injections produced a significant increase in plasma atrial natriuretic peptide concentration (p less than 0.02). Furthermore a significant decrease was seen in systolic blood pressure (p less than 0.04). It is concluded that the plasma concentration of atrial natriuretic peptide increases after intraarterial injection of contrast medium, and that atrial natriuretic peptide might play a role in the hemodynamic changes seen after intravascular injections of contrast medium.

Digital angiography of erectile failure.

Digital angiography of pudendal and penile arteries was performed in 44 consecutive patients with erectile failure of suspected vascular origin. Intra-arterial injection of contrast medium via selective catheterisation of the hypogastric arteries was used in six cases. In 39 patients, one of whom had already had arterial catheterisation, contrast medium was administered by the intravenous route, using a single, large volume, high speed bolus. In 12/44 cases (27%), digital angiography showed a normal vascular picture at the pudendal and penile level but the remaining 32 patients (73%) had steno-occlusive lesions of different degrees of severity. The pictures obtained after administration of intravenous contrast were diagnostically as good as the studies with selective arterial catheterisation. In addition, the intravenous route allowed the simultaneous representation of the arterial network on both sides and was quicker and less invasive. In 31/44 patients (79%), functional determinations of nocturnal penile tumescence and of penile blood flow with Doppler ultrasonography were performed for comparison. Nocturnal penile tumescence results correlated well with the angiographic picture. Penile blood flow measurements with the Doppler technique were less sensitive than digital angiography.

Detection of renal tubular lesions after abdominal aortography and selective renal arteriography by quantitative measurements of brush-border enzymes in the urine.

Quantitative determination of brush-border enzyme excretion in the 24-hour urine is a much more sensitive index of renal tubular damage after aortography and selective renal arteriography than the conventional renal function tests such as serum creatinine and clearance determinations. Among the five brush-border enzymes which we investigated, alkaline phosphatase (AP) was the most sensitive diagnostic pointer. In 90% of hypertensive patients without detectable pre-existing renal parenchymal damage, abnormal levels of AP excretion in the urine were found on the same day as or on the day after the intra-arterial injection of contrast medium. Measurement of other brush-border enzymes does not provide any further diagnostic information. Provided there is no pre-existing renal parenchymal damage, the lesion caused by the contrast medium is transient and is usually reversed within 48 h. For the early detection of tubular lesions caused by tri-iodinated benzoic acid derivatives, AP excretion in the 24-hour urine should be measured at least twice--on the day of the contrast medium injection and on the following day.