Injection Of Nonionic Contrast Medium Research Articles

Effect of Nonionic Iodinated Contrast Media on Blood Pressure during Contrast-enhanced Computed Tomography of Abdomen Examination: A Cross-sectional Study

ABSTRACT Introduction: Computed tomography (CT) scan has high sensitivity and specificity for numerous conditions. The images produced by a CT scanner can be enhanced using iodinated contrast media. Significant hemodynamic changes are seen with rapid intravenous contrast media injection. The average acceptable blood pressure (BP) value is 120/80 mmHg. Many studies have related hypertensive crises with high-osmolar contrast media, whereas its relation with low-osmolar contrast media is still unclear. This study aims to evaluate the effect of nonionic iodinated contrast media on BP during contrast-enhanced CT (CECT) of the abdomen. Materials and Methods: A cross-sectional study was conducted from April 2022 to August 2023. A total of 146 subjects (73 males and 73 females were included in the study). Statistical analysis of data was done using SPSS 23.0. A comparison of systolic BP and diastolic BP across the three periods was done using repeated measures of ANOVA. A between-group comparison was performed by unpaired t-test. The level of significance was set as 5%. All subjects underwent a CECT abdomen, including a plain, arterial, and venous phase. A bolus of 80 mL of Ultravist was administered. BP was measured before the contrast injection (baseline value), between the arterial and venous phases, and 3 min after the contrast injection. Results: Injection of nonionic contrast media caused a decrease in BP among subjects. The mean systolic BP readings before contrast injection in males and females were 127.5 ± 8 mmHg and 122.8 ± 8.4 mmHg, respectively. The mean diastolic BP before contrast injection was 79.2 ± 6.4 and 76 ± 6.4 mmHg among males and females, respectively. For systolic, these values decreased to 123 ± 10.3 mmHg in males and in females to 115 ± 14.6 mmHg when measured between arterial and venous phases. Similarly, for diastolic BP, the mean values recorded between the arterial-venous phase reduced to 76.7 ± 9.3 mmHg and 72.3 ± 10 mmHg, respectively. The BP readings, however, increased near baseline value when measured 3 min after the injection. The mean systolic BP measured 126.1 ± 8.5 mmHg and 124.9 ± 11.8 mmHg for males and females at 3 min after injection. Similarly, the mean diastolic BP values taken after 3 min of contrast injection were 78.3 ± 6.5 mmHg and 76.2 ± 7 mmHg in males and females, respectively, P < 0.001. BP in both male and female groups was affected similarly. Conclusion: Bolus administration of 80 mL of Ultravist reduced BP. This reduction was short-term and got back to normal within a few minutes. The contrast media similarly affected both genders. The BP changes had no clinical significance.

Interobserver agreement of computed tomography reporting standards for chronic pancreatitis.

To assess the interobserver agreement of computed tomography (CT) reporting standards for chronic pancreatitis (CP). Retrospective analysis of CT of 47 patients (33 males and 11 females, age range 36 to 56years) with CP who presented with abdominal pain (n = 41), steatorrhea (n = 37), and glucose intolerance (n = 31). The patients underwent CT study using a 16-multidetector CT scanner with a pancreatic protocol including a nonenhanced scan followed by pancreatic phase at 35s and portal venous phase at 65s after intravenous injection of nonionic contrast medium. Image analysis was performed by two radiologists according to reporting standards for CP. There was excellent interobserver agreement (84.8%) between the two reviewers in CT reporting standards for CP (K = 0.80, 95% CI 0.75-0.85, P = 0.001). There was good interobserver agreement for pancreatic duct (PD) caliber (K = 0.71, 95% CI 0.56-0.87, P = 0.001), PD contour (K = 0.76, 95% CI 0.61-0.91, P = 0.001), PD stricture (K = 0.070, 95% CI 0.53-0.88, P = 0.001), and distribution of findings (K = 0.69, 95% CI 0.51-0.86, P = 0.001). There was excellent interobserver agreement for intraductal calculi (K = 0.84, 95% CI 0.68-0.98, P = 0.001), pancreatic calcifications (K = 0.86, 95% CI 0.84-0.98, P = 0.001), and pancreatic diameter (K = 0.87, 95% CI 0.75-0.99, P = 0.001). CT reporting standards for CP is a reliable method for diagnosis of patients with CP.

Concurrent Assessment of Cartilage Morphology and Bone Microarchitecture in the Human Knee Using Contrast-Enhanced HR-pQCT Imaging

Osteoarthritis (OA) is a prevalent articular disease characterized by whole joint degradation, including articular cartilage and bone. Presently, no single imaging modality is well suited to concurrently capture these changes. Recent ex vivo animal studies have demonstrated the efficacy of utilizing contrast agents in conjunction with micro-CT as a means of evaluating cartilage and bone alterations concurrently, though no work as of yet has been performed in large animal models or humans. This study sought to develop and validate a novel joint imaging technique, contrast enhanced high resolution peripheral quantitative computed tomography (CEHR-pQCT), to concurrently assess bone microarchitecture and cartilage morphology in the whole human knee. Fresh frozen cadaveric knees were harvested (n = 10) and scanned using magnetic resonance imaging (MRI), HR-pQCT without contrast, and HR- pQCT following intra-articular injection of nonionic contrast media. Cartilage morphology and bone microarchitecture were evaluated in weight bearing regions of interest in both the tibia and femur. Joints were then disarticulated, and the articular cartilage thickness measured by needle probe. Measures of cartilage morphology, thickness and volume, were found to be significantly less when measured by CEHR- pQCT compared to magnetic resonance imaging in all regions. Compared to needle probing, cartilage thickness measured by CEHR-pQCT was less in the lateral tibia and greater in the medial tibia. Bone microarchitecture was found to be significantly different when measured with CEHR-pQCT compared to HR-pQCT, where cortical bone mineral density (BMD) was depressed, and trabecular bone mineral density was greater. This study demonstrates that CEHR-pQCT can be used to concurrently measure cartilage morphology and bone microarchitecture; however, systematic errors impact both measures. This is the first study using contrast media in combination with HR-pQCT in whole joints. Additionally, all imaging parameters, as well as the contrast media, were selected to be directly transferable to in vivo studies, laying the foundation to perform in vivo scanning of knee cartilage and bone.

Popliteal artery entrapment syndrome evaluation with multislice CT angiography

PurposeThe purpose of this study is to evaluate the use of multislice computed tomography (MCT), Doppler US, and angiography in the diagnosis of popliteal artery entrapment syndrome. Patients and methodsIn a prospective study of 26 patients referred to Doppler ultrasound examination with suspected popliteal artery entrapment syndrome, we have made Doppler study of the popliteal artery of the diseased limb using 7–10MHz probe. Additional multislice CT angiography after bolus injection of non-ionic contrast medium (Ultravist), axial transverse sections and multiplanar reformation reconstruction images were analyzed. Conventional angiography of the diseased limb was performed with the use of pigtail catheter and injection of 60cc Ultravist. ResultsOn 22 of 26 patients, the Doppler study revealed damped flow, biphasic waves and a dramatic decrease in peak velocity. All these signs appeared in the Doppler study of popliteal artery while retaining normal flow and waves in distal tibial vessels.When 26 patients were examined, the conventional angiography revealed sudden attenuated and decreased caliber of popliteal artery with retained average caliber of the distal run-off vessels without showing the surrounding structures.When 26 patients were examined, the CT angiography revealed decreased caliber of popliteal artery, verified the exact diameter of popliteal artery and gave an accurate idea about the wall of the vessels and the surrounding soft tissue structures. These last benefits enable us to differentiate between organic and functional causes of popliteal artery entrapment syndrome. ConclusionIn conclusion, popliteal artery entrapment syndrome can be diagnosed with the use of multislice CT which is as efficient as conventional angiography. However, multislice CT provides detailed information on the wall, diameter of the artery and relation of the artery to adjacent structures by a non-invasive technique.

Prospective Study of Access Site Complications of Automated Contrast Injection With Peripheral Venous Access in MDCT

The purpose of this article is to prospectively assess the frequency and type of IV injection site complications associated with high-flow power injection of nonionic contrast medium in MDCT. Contrast-enhanced (300-370 mg iodine/mL) MDCT examinations with high flow rates (up to 8 mL/s) using automatic CT injectors were performed according to standardized MDCT protocols. The location, type, and size (16-24 gauge) of IV catheters and volumes, iodine concentration, and flow rates of contrast medium were documented. Patients were questioned about associated discomfort, IV catheter sites were checked, and adverse effects were recorded. Prospectively, 4,457 patients were studied. The injection rate ranged from 1-2.9 mL/s (group 1; n = 1,140) to 3-4.9 mL/s (group 2; n = 2,536) to 5-8 mL/s (group 3; n = 781); 1.2% of the patients experienced extravasations (n = 52). Contrast medium iodine concentration, flow rates, and volumes were not related to the frequency of extravasation. The extravasation rate was highest with 22-gauge IV catheters (2.2%; p < 0.05) independently of the anatomic location. For 20-gauge IV catheters, extravasation rates were significantly higher in the dorsum of the hand than in the antecubital fossa (1.8% vs 0.8%; p = 0.018). Extravasation rates were higher in older patients (≥ 50 vs < 50 years, 0.6% vs 1.4%; p = 0.019). Different iodine concentrations did not trigger significant differences in contrast material reactions (p = 0.782). Automated IV contrast injection applying high flow rates (i.e., up to 8 mL/s) is performed without increased risk of extravasation. The overall extravasation rate was 1.2% and showed no correlation with iodine concentration, flow rates, or contrast material reactions. Performing high flow rates with low-diameter IV catheters (e.g., 22-gauge catheters) and a location of IV catheter in the hand is associated with a higher extravasation rate.

Unverträglichkeitsreaktionen auf ionische und nicht-ionische Kontrastmittel in der Herzdiagnostik: Eine randomisierte Doppelblindstudie

Reactions to an ionic and a nonionic contrast medium were compared in a randomized double-blind trial involving 1153 patients (897 men, 256 women; mean age 56 [18-84] years) who underwent left-heart catheterization with coronary angiography. 584 patients (group 1) received the ionic contrast medium meglumine diatrizoate (Urografin 76%), while 569 (group 2) received the nonionic iopromide (Ultravist -370). Reactions of skin and mucosae, heart and circulation, lungs and respiratory tract, as well as of the central nervous system were noted. There was no significant difference between the two groups with respect to age, weight, height, allergic predisposition, left-ventricular ejection fraction, or serum electrolyte concentrations. Mild reactions, not requiring any treatment, occurred in 108 of the 1153 patients (9.4%), 85 (14.6%) in group 1 and 23 (4%) in group 2 (P less than 0.001). Severe reaction requiring treatment occurred in eight patients of group 1 (1.4%) and 14 of group 2 (2.5%)--difference not significant. Ventricular fibrillation was more frequent among group 2 patients (four compared with one in group 1), while two of three asystoles requiring treatment occurred in group 1 patients. The results show that, while mild reactions not requiring treatment were clearly less frequent after nonionic contrast medium injection, the risk of severe reactions was not reduced by their use.

Accessory Left Atrial Appendage

A 69-year-old woman with a history of atypical chest pain was referred for coronary computed tomographic (CT) angiography study with a 64-detector row multidetector CT scanner (LightSpeed VCT, GE Healthcare, Milwaukee, Wis). Imaging was performed after multiphasic injection of nonionic contrast media (Omnipaque 350, GE Healthcare) into the right antecubital vein at a rate of 4.0 mL/s through a 20-gauge needle with a dual-barrel injector (Stellant D; Medrad, Warrendale, Pa). The coronary arteries were patent. However, a cauliflower-like accessory atrial appendage was incidentally noted at the anterior …

Right Ventricular Diverticula

Right Ventricular Diverticula Dr. Srichai and coworkers [1] wrote an interesting article, published in the July 2007 issue of the AJR, describing the findings of contrast-enhanced gated cardiac CT in 15 patients with 23 incidentally noted cardiac ventricular diverticula. The diverticula were all located in the left ventricle in the study. In this letter, we report a case with right ventricular diverticula. A 56-year-old woman with a history of atypical chest pain was referred for coronary CT angiography. CT was performed using a 64-MDCT scanner (LightSpeed VCT, GE Healthcare). Imaging was performed after multiphasic injection of nonionic contrast medium (Omnipaque 350, GE Healthcare) through a 20-gauge needle in the right antecubital vein at a rate of 4.0 mL/s using a dual-barrel injector (Stellant D, Medrad). During the first phase of injection, 44 mL of contrast medium was administered. After the first phase, 40 mL of contrast media–saline mixture (80% contrast media and 20% saline) was injected, and 24 mL of contrast medium–saline mixture (30% contrast medium and 70% saline) was injected during the third phase. A 20-mL saline flush was then administered. The scanning delay was determined by a test bolus. The purpose of this multiphasic injection protocol was to obtain uniform right heart attenuation in addition to coronary artery enhancement [2]. The coronary arteries were patent. However, two small diverticula were incidentally noted in the right ventricle along the inferoseptal wall (Fig. 1A). The diverticula measured 7.5 × 5.6 × 3.2 mm and 4.0 × 2.9 × 2.3 mm, respectively, during diastole (Fig. 2B). The size of the diverticula decreased during systole and measured 4.2 × 2.4 × 1.0 mm and 4.2 × 2.4 × 1.0 mm (Fig. 2C). Right ventricular diverticula might be missed on cardiac CT if the right ventricle is not adequately opacified by contrast medium. Lee WJ, Chen SJ, Wang TD Wen-Jeng Lee Shyh-Jye Chen Tzung-Dau Wang National Taiwan University Hospital National Taiwan University College of Medicine Taipei, Taiwan

Cell-dependent influence on the phagocytosis induced by non-ionic contrast medium injection

Iodinated contrast media (CM) can inhibit phagocytosis. To better understand the importance of this effect upon the elementary defence mechanism, the aim of the study was to compare the in vivo effect of non-ionic CM on the engulfing ability of peripheral blood phagocytic cells from patients undergoing CM-enhanced CT. Neutrophil granulocytes and monocytes from patients' peripheral blood obtained before and 30 min after CM injection were incubated with fluorescent-labelled Escherichia coli bacteria. Both the percentage of cells that engulfed bacteria and the phagocytic activity per cell has been determined by flow cytometry. We found that phagocytosis was greater in neutrophils than in monocytes. CM decreased the percentage of monocytes phagocyting bacteria, both at 4 degrees C (20.3%+/-3.3% versus 16.1%+/-2.0%; p<0.03) and at 37 degrees C (51.6%+/-4.1% versus 47.5%+/-2.6%; p>0.05), and increased the percentage of neutrophils at 4 degrees C (11.8%+/-2.1% versus 14.3%+/-2.2%; p<0.002) and at 37 degrees C (83.1%+/-3.6% versus 85.1%+/-3.2%; p>0.05). The phagocytic activity decreased significantly at 37 degrees C in monocytes (p<0.02), and was not affected in neutrophils. CM injection has different effects on both the percentage of phagocytosing cells and the phagocytic activity in monocytes and neutrophils. The inhibitory effect on monocyte phagocytosis seems to be compensated by neutrophils.

Multidetector Computed Tomography Angiography in Detection of Active Bleeding in Renal and Liver Transplant Recipients

Objectives The aim of this study was to evaluate the effectivity of multidetector computed tomography angiography (MDCT-A) to detect active bleeding in transplant patients. Materials and Methods Between 1999 and 2006, 532 patients underwent renal or liver transplantation. MDCT-A was performed on recipients who displayed decreased hemoglobin levels or who had a hematoma during abdominal ultrasound imaging. The MDCT-A used a 16-detector CT device (Siemens, Sensation) with slices 0.75 mm thick after injection of nonionic contrast media (4 mL per second). A multiple intensity projection (MIP) technique was used to maintain angiographic images in the axial and coronal planes. Results MDCT-A detected active bleeding among 23 posttransplant patients: 10 of arterial origin and 13 venous, as proven either by angiography or during operation. Among 8 of the 11 patients who underwent angiographic imaging the arterial origin was embolized. For three patients the angiographic evaluation was not helpful to find the bleeding point. A cohort of 5 of 12 patients did not undergo angiographic evaluation and were followed by clinical and ultrasonographic findings. Seven patients underwent re-operating. Discussion Management of the patients who were suspected to have active bleeding after renal or liver transplantation was benefitted by MDCT-A as an accurate and feasible screening modality.

Thromboelastographic Changes Following Nonionic Contrast Medium Injection During Transfemoral Angiography in Patients with Peripheral Arterial Occlusive Disease

Patients with peripheral arterial occlusive disease (PAOD) are known to be systemically hypercoagulable and there is concern that exposing them to contrast media during angiography may exacerbate that thrombotic tendency. Many in vitro studies in which blood is exposed to contrast media suggest that nonionic contrast medium (NICM) has a weaker anticoagulant effect than ionic contrast medium (ICM) and some studies suggest that NICM can lead to activation of coagulation thus increasing the risk of thrombotic events where it is employed. We have looked at the changes in coagulation adjacent to the site of contrast injection/potential angioplasty to determine the magnitude of change locally. We measured changes in the coagulability of aortic blood samples immediately before and within 2 min after injection of the last bolus of iohexol (NICM) prior to any intervention procedure in 30 patients with PAOD. Samples were analyzed using thromboelastography (TEG) to identify changes in the coagulability of the aortic blood samples. TEG tracings of samples taken from the aorta after injection of NICM showed a significant increase in R time (time to fibrin formation) (p = 0.036) and in k time (dynamics of clot formation) (p = 0.028) and a reduction in Angle (decreased acceleration of fibrin build-up) (p = 0.013), Maximal amplitude (MA) (reduced ultimate clot strength) (p = 0.018) and Coagulation Index (CI) (p = 0.032). These changes in TEG parameters show that the local effect of NICM is a reduction in coagulation activity rather than the activation suggested by some previous studies.

Assessment of parallel conductance for the trans-cardiac conductance method: can we use the hypertonic saline method with pulmonary artery injections?

The trans-cardiac conductance (TCC) method provides on-line left ventricular (LV) volume signals by determining the electrical conductance of blood in the LV using central venous and epithoracic electrodes. Conductive structures outside the LV cause a ‘parallel conductance’ offset term (Vp) that is determined by bolus injections of hypertonic saline in the pulmonary artery (Vpsaline). Analysis of the increased conductance signal during passage of the bolus through the LV yields Vpsaline. Since TCC signals are picked up by epithoracic electrodes, concern has been raised that hypertonic saline remaining in the lungs might lead to overestimation. The decrease in blood conductivity induced by injection of non-ionic contrast medium during a LV angiogram may also be used to determine Vp (Vpcontrast). Since the contrast is injected directly into the LV, lung conductance should be unaltered. Thus, we compared Vpsaline with Vpcontrast in six anaesthetized sheep during different hemodynamic conditions. Linear regression showed that Vpsaline = 0.99 Vpcontrast + 2.45 ml (r2 = 0.99). Bland–Altman analysis yielded a small non-significant bias (±2SD) of 1.8 (±6.8) ml. We conclude that parallel conductance for TCC can be accurately determined with the conventional hypertonic saline method.

SEVERE LIVER INJURY WITH HEMATOLOGICAL DISORDERS FOLLOWING THE INJECTION OF NON-IONIC CONTRAST MEDIUM. A case report

We describe a dramatic case of severe liver injury and hematological disorders following the injection of non-ionic contrast medium in a 49-year-old woman with endometrial cancer. This case developed into a fulminant hepatitis-like picture that required repeated plasmapheresis and hemodialysis.

３Ｄ‐ＣＴＡ術前診断による破裂脳動脈りゅう手術

Recently, three-dimensional CT angiography (3D-CTA) is routine and useful examination before aneurysmal surgery, coupled with digital subtraction angiography (DSA). We believe 3D-CTA may show enough anatomical information for most ruptured aneurysmal surgeries. In this study, the surgery was performed using 3D-CTA without DSA. Between May 1997 and December 1999, 67 patients of SAH (total 78 aneurysms: 64 ruptured aneurysms, 14 unruptured aneurysms) were explored by 3D-CTA. A helical acquisition was performed for computed tomographic scans obtained with a bolus injection of non-ionic contrast medium on Toshiba X vigor/Real. It took only 15 minutes to get the final 3D films in our system. Examination by 3D-CTA showed 63 cases (94%) clearly developed aneurysms. Three cases were false positive. One of those aneurysms was suspected of being BA top AN. Another was IC-PC AN. The third was AcomA AN. But we could not find those aneurysms in the surgery. We diagnosed those cases as “Unknown SAH.” One case was false negative. The aneurysm located on the distal PICA (1.5%) could not be detected because it was out of the image. In 98.4% of the patients, it was retrospectively though to be possible to perform safe operations with information from 3D-CTA. In 1 case 3D-CTA but not DSA detected MCA aneurysms. In the acute phase of subarachnoid hemorrhage, we could get the information quickly in the severe cases such as Grade IV or V. But 1 aneurysm of MCA reruptured during 3D-CTA due to lack of sedation. 3D-CTA was fast and a mostly safe examination. We concluded that it was possible to perform most ruptured aneurysmal surgeries successfully using 3D-CTA without DSA.

Nonfatal adverse reactions to iodinated contrast media: spontaneous reporting to the U.S. Food and Drug Administration, 1978-1994.

To identify any changes in the frequency of serious, nonfatal adverse drug events (ADEs) reported to the U.S. Food and Drug Administration in 1978-1994 since the introduction of low-osmolality contrast media (LOCM). Reports of ADEs submitted were reviewed for use of iodinated contrast media. The estimated 170 million contrast medium-enhanced radiologic studies performed in 1978-1994 produced 22,785 reports of mild or moderate ADEs, 2,639 reports of serious but nonfatal ADEs, and 920 reports of death. The most common ADEs (urticaria, dyspnea, vomiting, pruritus, facial edema, and hypotension) ranked similarly for ionic and nonionic contrast media. High-osmolality contrast media were associated with 512 serious, nonfatal ADEs reported in 1978-1986; 1,068 were reported in 1987-1994. Nonionic LOCM were associated with 17 serious, nonfatal ADEs reported in 1978-1986; 609 were reported in 1987-1994. Intrathecal injection of nonionic contrast media was associated with 235 reported serious, nonfatal ADEs; intrathecal ionic [corrected] contrast media were associated with 14 such reported ADEs. Reports of serious, nonfatal ADEs are uncommon relative to the use of contrast media. The authors observed no decrease in the number of ADEs reported since the introduction of LOCM but did not consider marketing trends or secular reporting trends.

Fibrinopeptide A, Prothrombin Fragment 1 + 2, Thrombin-Antithrombin Complex and D Dimer before and after Injection of a Nonionic Contrast Medium (lohexol)

The principal aim of this study was to evaluate, on biochemical grounds, whether injection of a low-osmolar nonionic contrast medium (iohexol) can induce a prothrombotic state and/or a change in fibrinolysis. Fifteen patients were submitted to urographic examination and the assays listed below were performed: before the injection (T0), 1 h after (T1), and 24 h after (T24) the injection of the contrast medium. The following assays were performed: fibrinopeptide A (FPA), prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT) and D dimer (D-D). The assays were carried out on 6 of the patients to whom a saline infusion was administered. Only a mild statistically significant increase was found in FPA levels at 1 h after injection of the contrast medium (mean and CI 95%: T0 4.4, 3.7-5.5; T1 6.0, 4.9-9.1; p = 0.003). F1+2, TAT and D-D did not show any significant change after the injection. These findings show that after injection of iohexol, only a mild, though statistically significant, increase in FPA levels was observed as an expression of increased thrombin activity. In the absence of any significant increases in TAT, F 1+2 and D-D, we have no evidence of a prethrombotic state.

Hemodynamic effects of nonionic contrast bolus injection and oxygen inhalation during pulmonary angiography in patients with chronic major-vessel thromboembolic pulmonary hypertension.

Pulmonary angiography is the gold standard for the diagnosis of chronic thromboembolic pulmonary hypertension; however, major complications have been reported. This study evaluates the hemodynamic effects of direct pulmonary nonionic contrast bolus injection and oxygen inhalation in patients with chronic thromboembolic pulmonary hypertension. In 33 patients, hemodynamic parameters were measured after oxygen inhalation and during bolus injection of nonionic contrast medium in a control group (group 1. n = 11), in a group of patients with moderately severe pulmonary hypertension (group 2, n = 9), and in a group with severe pulmonary hypertension (group 3, n = 13). Oxygen inhalation significantly improved oxygen supply. Pulmonary artery pressure and heart rate were reduced, but pulmonary vascular resistance and total pulmonary resistance were not significantly affected. One hundred ninety-eight angiograms were performed selectively on both pulmonary arteries in the posterior-anterior, oblique, and lateral views. Before contrast bolus injection, RAP and PAP significantly increased because of initial inspiration. Contrast bolus injection caused only a minor pressure increase (delta PA systolic, 2.3 +/- 1.4, 2.5 +/- 1.8, and 5.0 +/- 5.2 mm Hg, groups 1, 2, and 3, respectively) without significance between the groups. After the angiography, pulmonary artery pressure was moderately increased, predominantly in group 3, but pulmonary vascular resistance was not significantly changed. Systemic vascular resistance was decreased. Cardiac index increased in groups 1 and 2 but was unchanged in group 3. Systemic pressure therefore decreased in group 3. We concluded that bolus injection of nonionic contrast medium causes no major hemodynamic effects even in patients with severe chronic thromboembolic pulmonary hypertension. Oxygen contributes to safety during the procedure.

Three-dimensional spiral CT for neurosurgical planning.

We carried out 22 examinations to determine the value of three-dimensional (3D) volumetric CT (spiral CT) for planning neurosurgical procedures. All examinations were carried out on a of the first generation spiral CT. A tube model was used to investigate the influence of different parameter settings. Bolus injection of nonionic contrast medium was used when vessels or strongly enhancing tumours were to be delineated. 3D reconstructions were carried out using the integrated 3D software of the scanner. We found a table feed of 3 mm/s with a slice thickness of 2 mm and an increment of 1 mm to be suitable for most purposes. For larger regions of interest a table feed of 5 mm was the maximum which could be used without blurring of the 3D images. Particular advantages of 3D reconstructed spiral scanning were seen in the planning of approaches to the lower clivus, acquired or congenital bony abnormalities and when the relationship between vessels, tumour and bone was important.

Late adverse reactions to non-ionic contrast media: a cohort analytic study

In this cohort study early, intermediate and late reactions after intravenous injection of non-ionic contrast media were evaluated and compared with the nature and incidence of complaints stated by a control group investigated without contrast media. Study A was conducted by means of a questionnaire. In study B a physician interviewed a different group of patients. Early adverse reactions (day 1) occurred in 11.4% of patients to whom contrast (CM) media had previously been administered compared with 6.1% of patients who had not received a CM injection (study A). Late adverse reactions (up to day 7) were observed in 39.1% and 21.1% of the patients respectively. The incidence was 7.0% versus 0.9% on day 1 for the symptom “increased diuresis”. Between days 4 and 7, 4.8% and 2.6% of the patients respectively had this symptom, which is interpreted as an impairment of renal function. In study B the incidence of early adverse reactions was 3% and 1.5% respectively between days 2 and 3 (CM group). The authors conclude that more than half of the adverse reactions after (non-ionic) contrast media are due to the underlying disease and that a (clinically latent) impairment of renal function can be assumed.

Differentiation of central lung tumor from postobstructive lobar collapse by rapid sequence computed tomography

When central lung tumor is associated with lobar collapse, discrimination of tumor from atelectasis is important for determining operability or for field planning should radiation therapy be utilized. Because tumor and collapsed lung have similar attenuation values, they cannot always be distinguished with usual contrast-enhanced CT. The article describes separation of tumor from collapsed lung by means of RSCT with bolus injection of nonionic contrast medium. With this technique collapsed lung is appreciably enhanced, but tumor enhancement is slow and minimal. The difference is most marked from 40 seconds to 2 minutes after scanning begins. This phenomenon is probably related to the marked increase in blood flow per unit area of collapsed lung due to crowding of relatively large pulmonary arteries compared to tumor blood supply through small bronchial arteries. Tumor can also be delineated from atelectasis by differences in internal structure with this technique.