Side Effects Of Contrast Media Research Articles

Diagnostic accuracy of non-contrast abdominopelvic computed tomography scans in follow-up of breast cancer patients.

To evaluate the effectiveness of follow-up with non-enhanced CT (NECT) in patients with breast cancer. The present retrospective study included 1396 patients with breast cancer. Group A included patients with no metastasis to evaluate the diagnostic performance of NECT in detecting newly developed metastasis. Group B included patients with known hepatic metastasis to evaluate the accuracy of NECT for the assessment of hepatic metastasis. Group A included 895 patients (mean age 52.8 years). Among them, 145 patients had 160 metastases. The per-patient sensitivities for diagnosing newly developed metastasis were 68.3 and 53.8% according to the two reviewers, while the per-lesion sensitivities were 89.4 and 85.0%. Sensitivities for bone metastasis were 98.9 and 95.9%, while sensitivities for hepatic metastasis were 73.7 and 68.4%. In group B, the accuracy of hepatic metastasis response evaluation according to the RECIST criteria was 70.8% for reviewer 1 and 63.8% for reviewer 2. NECT showed inadequate diagnostic performance in detecting newly developed metastasis and in evaluating the response of hepatic metastasis. However, NECT can be utilized as a follow-up modality in patients with decreased renal function or hypersensitivity to iodinated contrast media. The risk of side effects of contrast media should be considered as important when NECT can be utilized as a follow-up modality in decreased renal function patients.

Diagnostic Accuracy and Value of Magnetic Resonance Imaging–Ultrasound Fusion Transperineal Targeted and Template Systematic Prostate Biopsy Based on Bi-parametric Magnetic Resonance Imaging

PurposeThe purpose of this study was to investigate the diagnostic value of magnetic resonance imaging (MRI)–ultrasound (US) fusion transperineal targeted biopsy (FTB) and fusion template systematic biopsy (FSB) for prostate cancer (PCa) and clinically significant prostate cancer (csPCa) (intermediate/high grade [Gleason score ≥ 3+4]) based on bi-parametric MRI (bpMRI).Materials and methodsRetrospectively, we analyzed 300 patients with elevated prostate-specific antigen (≥ 4.0 ng/mL) and/or abnormal findings in a digital rectal examination at the Korea University Hospital. All 300 men underwent bpMRI-US fusion transperineal FTB and FSB in the period from April 2017 to March 2019.ResultsPCas were detected in 158 of 300 men (52.7%), and the prevalence of csPCa was 34.0%. CsPCas were detected in 12 of 102 (11.8%) with Prostate Imaging-Reporting and Data System (PI-RADS) 3, 42 of 92 (45.7%) with PI-RADS 4, respectively; and 45 of 62 (72.6%) men with PI-RADS 5, respectively. BpMRI showed a sensitivity of 95.1% and negative predictive value of 89.6% for csPCa. FTB detected additional csPCa in 33 men (12.9%) compared to FSB. Compared to FTB, FSB detected additional csPCa in 10 men (3.9%).ConclusionBpMRI-US FTB and FSB improved detection of PCa and csPCa. The accuracy of bi-parametric MRI is comparable with that of multi-parametric MRI. Further, it is rapid, simpler, cheaper, and no side effects of contrast media. Therefore, it is expected that bpMRI-US transperineal FTB and FSB could be a good alternative to conventional US-guided transrectal biopsy, which is the current gold standard.

Case report: lipid inclusion in glomerular endothelial and mesangial cells in a patient after contrast medium injection

BackgroundIt is well-recognized that injection of iodinated radiographic contrast media (CM) sometimes causes acute renal injury via multiple mechanisms, such as vasoconstriction, toxicity on glomerular endothelium and tubular epithelium and so forth.Case presentationA 51-year-old man developed acute renal injury with proteinuria after CM administration. To our surprise, in his renal biopsy sample the myelin figure like structure was observed in glomerular endothelium and mesangial cells by transmission electron microscopy. However the patient didn’t has any clinic clues of Fabry disease and other lysosomal storage disorders. Moreover in vitro cultured glomerular endothelial and mesangial cells we found CM triggers lipid aggregation along with the increased CD36 and decreased ABCA1 abundance. Thus this patient was administrated statin to correct the aberrant lipid trafficking, 2 months later at his next visit we found his renal function partially recovered with reduced proteinuria.ConclusionsBesides the well-known underlying mechanisms, CM may cause renal impairment by triggering the dysregulated transportation of lipid. Furthermore statin is suggested to be a very promising medicine to decrease side effects of CM.

CT 조영검사 예약환자의 전처치 프로세스 시스템 개발을 통한 환자안전 및 검사 만족도 향상

CT 조영검사 예약환자의 원활한 검사 진행과 조영검사로 인한 부작용을 줄일 수 있는 전처치 프로세스 시스템을 개발 및 적용하여 CT 조영검사 예약환자의 검사 만족도를 높이고자 하였다. 2014년 1월부터 2014년 2월까지 CT 조영검사를 예약하여 추적검사를 시행했던 2,846명의 환자들 중 예약시간에 검사를 시행하지 못하고 지연된 214명의 환자들을 대상으로 지연사유를 분석한 후 전처치 프로세스 시스템을 구상 및 개발하여 2015년 1월부터 2015년 2월까지 전처치 프로세스 시스템을 이용하여 전처치가 필요한 644명을 대상으로 SMS 전송 시행율, SMS 전송내역, 예약시간 준수율, 예약시간 지연 사유, 예약 시간보다 지연된 시간 등을 분석하였다. 2014년 1~2월 외래 CT 조영검사 예약환자는 2,846명이었고, 그 중 예약시간에 검사를 시행하지 못한 환자는 214건으로, 약 7.52%의 비중을 차지하고 있었다. 예약시간보다 지연된 세부적인 사례는 creatinine 미확인이 98건(46%), creatinine 1.3 이상이 40건(19%), 과거조영제부작용이 34건(16%), 금식 등 전처치 미흡이 25건(11%), 메트포민제제 당뇨약 복용이 4건(2%), 기타 이유가 13건(6%)으로 나타났으며, 평균 지연시간은 creatinine 미확인이 120분, creatinine 1.3이상이 30분, 과거조영제부작용이 40분, 금식 등 전처치 미흡이 120분, 메트포민제제 당뇨약 복용이 30분, 기타 사유가 60분으로 나타났다. 2015년 1월~2 월 전처치 프로세스 시스템을 적용하여 전처치가 필요한 대상자 644명중 SMS 전송시행율은 515건(80%)으로 나타났으며, SMS 전송내역을 분석한 결과 당일 검사가 283건(44%), 진료과 방문이 185건(29%), 전처치 불필요가 47건(7%), 외래과에서 전처치 프로세스 시스템 미확인으로 SMS 전송이 안 된 건수가 129(20%)건으로 나타났다. CT 조영검사 예약시간 준수율은 전체 644건 중 560건(87%)이 예약시간 안에 검사를 시행하였으며, 예약시간보다 지연된 세부적인 사례는 creatinine 미확인이 23건(28%), creatinine 1.3이상이 11건(13%), 과거조영제부작용이 7건(8%), 금식 등 전처치 미흡이 30건(36%), 메트포민제제 당뇨약 복용이 6건(7%), 기타 이유가 7건(8%) 이었다. 예약시간보다 평균 지연된 시간은 creatinine 미확인이 90분, creatinine 1.3이상이 20분, 과거조영제부작용이 30분, 금식 등 전처치 미흡이 120분, 메트포민제제 당뇨약 복용이 30분, 기타 사유가 60분으로 나타났다. 조영제 부작용의 효율적인 관리적 측면과 CT 조영검사 예약시간에 검사가 원활하게 진행될 수 있도록 전처치 프로세스 시스템을 적용해본 결과 적용 전에 비해 전처치 준비 시간이 줄어들고 CT실, 진료실, 채혈실, 주사처치실 등의 방문횟수 및 동선이 줄어들어 CT실을 찾는 고객들의 검사만족도와 의료서비스 향상에 기여가 될 것으로 사료된다. This study aims to improve the satisfaction level of the patient who undergoes CT contrast examination by developing and applying pretreatment process system, which not only can reduce the side effects caused by the test but also can help carry out the test smoothly. The subjects were 214 patients who booked CT contrast examination from January 2014 to February 2014 but could not carry out their test on schedule. We analyzed the reasons for the delay and conducted follow-up survey on them. We analyzed the usefulness of pretreatment process system by contemplating and developing pretreatment process system and applying it to the patients for whom follow-up survey was conducted from January 2015 to February 2015. The number of outpatients who came to the hospital form January to February 2014 was 2,846 and the number of patients who could not undergo the test was 214, accounting for 7.52% of the total. The specific reason for the delay includes 214 cases of unknown creatinine 98 with 120 minutes of average delay time, 40 cases of creatinine over 1.3(19%) with 30minutes of average delay time, 34 cases of past contrast media side effect 6% with 40 minutes of average delay time and 25 cases of lack of pretreatment such as fasting, etc. 11% with 120minutes of average delay time. The number of CT scan has been increasing ever since the development of CT and the frequency of using the contrast media is expected to increase. If we can employ pretreatment process system in order to effectively control the side effect of contrast media and help the CT contrast examination to be smoothly conducted on schedule, I'm sure we could improve the quality of our medical service and increase our patients' satisfaction who come to our CT scan room.

Comparison of Intravascular Ultrasound with Conventional Venography for Detection of Extracranial Venous Abnormalities Indicative of Chronic Cerebrospinal Venous Insufficiency

PurposeTo investigate prevalence of extracranial abnormalities in azygos and internal jugular (IJ) veins using conventional venography and intravascular ultrasound (IVUS) in patients with multiple sclerosis (MS) being evaluated for chronic cerebrospinal venous insufficiency, a condition of vascular hemodynamic dysfunction. Materials and MethodsPREMiSe (Prospective Randomized Endovascular therapy in Multiple Sclerosis) is a venous angioplasty study that enrolled 30 patients with relapsing MS. The patients fulfilled two or more venous hemodynamic extracranial Doppler sonography screening criteria. Phase I of the study included 10 patients and was planned to assess safety and standardize venography, IVUS, and angioplasty and blinding procedures; phase II enrolled 20 patients and further validated diagnostic assessments using the two invasive techniques. Venography was considered abnormal when ≥ 50% lumen-diameter restriction was detected. IVUS was considered abnormal when ≥ 50% lumen-diameter restriction, intraluminal defects, or reduced pulsatility was detected. ResultsNo venography-related or IVUS-related complications, including vessel rupture, thrombosis, or side effects of contrast media were recorded among the 30 study patients. IVUS-detected venous abnormalities, including chronic, organized, thrombus-like inclusions were observed in 85% of azygos, 50% of right IJ, and 83.3% of left IJ veins, whereas venography demonstrated stenosis of ≥ 50% in 50% of azygos, 55% of right IJ, and 72% of left IJ veins. Sensitivity of venography for detecting IVUS abnormalities was 52.9%, 73.3%, and 80% for the azygos, left IJ, and right IJ veins, respectively. ConclusionsIVUS assessment of azygos and IJ veins showed a higher rate of venous abnormalities than venography. IVUS provides a diagnostic advantage over conventional venography in detecting extracranial venous abnormalities indicative of chronic cerebrospinal venous insufficiency.

Contrast-induced kidney injury: mechanisms, risk factors, and prevention

In general, iodinated contrast media (CM) are tolerated well, and CM use is steadily increasing. Acute kidney injury is the leading life-threatening side effect of CM. Here, we highlight endpoints used to assess CM-induced acute kidney injury (CIAKI), CM types, risk factors, and CIAKI prevention. Moreover, we put forward a unifying theory as to how CIAKI comes about; the kidney medulla's unique hyperosmolar environment concentrates CM in the tubules and vasculature. Highly concentrated CM in the tubules and vessels increases fluid viscosity. Thus, flow through medullary tubules and vessels decreases. Reducing the flow rate will increase the contact time of cytotoxic CM with the tubular epithelial cells and vascular endothelium, and thereby damage cells and generate oxygen radicals. As a result, medullary vasoconstriction takes place, causing hypoxia. Moreover, the glomerular filtration rate declines due to congestion of highly viscous tubular fluid. Effective prevention aims at reducing the medullary concentration of CM, thereby diminishing fluid viscosity. This is achieved by generous hydration using isotonic electrolyte solutions. Even forced diuresis may prove efficient if accompanied by adequate volume supplementation. Limiting the CM dose is the most effective measure to diminish fluid viscosity and to reduce cytotoxic effects.

Carotid CT-angiography: Low versus standard volume contrast media and low kV protocol for 128-slice MDCT

Availability and utilization of computed tomography angiography has been increasing recently. We aimed to assess the effectiveness of low amount of contrast media and low kV value in order to reduce possible side effects of contrast media and to provide optimization of kV value in the evaluation of the carotid artery with multi-detector computed tomography angiography. Forty one patients were randomized into two groups. Contrast media was administered at a dose of 1ml/kg in group A patients and of 0.5ml/kg in group B patients. kV value of 120 in group A and 100 in group B were chosen. Bolus tracking technique was used. Attenuation values of certain arterial segments were measured, and values over 200HU were considered as significant. North American Symptomatic Carotid Endartherectomy Trial criteria were utilized in the evaluation of stenosis. Image quality in arterial segments of all cases was found to be sufficient for diagnosis. Arterial attenuation values were found to be higher in group B than group A. When compared separately in all arterial segments, there was no statistically significant difference between the groups. For stenosis, 615 arterial segments were evaluated. Moderate stenosis in eight segments and severe stenosis in three segments were identified in group A. Occlusion in three segments, severe stenosis in three segments, and moderate stenosis in 25 segments were detected in group B. Better image quality can be obtained, and the amount of contrast media can be reduced using low kV technique in carotid artery multi-detector computed tomography angiography examination.

Direct Percutaneous Embolization of Renal Pseudoaneurysm

To describe and evaluate a novel method of direct ultrasonography (US)-guided percutaneous embolization of renal pseudoaneurysm. Fourteen patients with severe hematuria were included in this study from February 2005 to February 2006. They included five patients with penetrating renal trauma, two patients after renal biopsy, and seven patients after percutaneous nephrolithotripsy. Diagnostic duplex US of the pseudoaneurysm was performed. The size of the pseudoaneurysm and its neck were determined. A solution of Gelfoam particles was prepared in sterile saline and under US guidance, the tip of the needle was inserted into the aneurysm, and the solution with Gelfoam particles was injected slowly. During injection of Gelfoam, the pseudoaneurysm initially filled with an echogenic thrombus, thereby decreasing the color flow detected by US. The needle was removed when no flow in the pseudoaneurysm was detectable. The patient was kept for 30 minutes in the department and then discharged home. Follow-up by color Doppler US was performed every 2 weeks for 3 months and then every 3 months for 1 year. In 13 patients, bleeding was effectively controlled with direct embolization in a single session and did not need any further intervention, while one patient needed endovascular embolization because of recurrent severe hematuria after 24 hours. The amount of the injected Gelfoam particles (1-2 mm diameter) was 1 to 3 mL, according to the size of the pseudoaneurysm. No complication was observed secondary to the embolization procedure. Rebleeding did not occur in any patient during the follow-up period that ranged from 3 to 12 months. Direct US-guided percutaneous embolization is a new method for managing renal pseudoaneurysm. It avoids the side effects of contrast media, hazards of irradiation, and complications of angiographic catheterization. Moreover, it saves the risk of surgical interference to control bleeding either by partial or total nephrectomy, especially in patients with a solitary kidney. It is rapid, effective, feasible, and tissue preserving, and likely to reduce morbidity and mortality. Therefore, it is recommended as a first-line treatment of actively bleeding renal pseudoaneurysms.

Preventive Effect of <i>N</i>-Acetylcysteine on Contrast-induced Nephropathy Following Coronary Angiography and Angioplasty

Contrast-induced nephropathy (CIN) is one of the serious side effects of contrast media. A few studies have suggested that N-acetylcysteine (NAC) is effective to prevent CIN, but the efficacy remains unclear in Japanese. Therefore, we retrospectively studied the preventive effect of NAC on CIN in Sakakibara Heart Institute. Patients who had been administered NAC for the purpose of preventing CIN before coronary intervention between February 2005 and November 2006 were included in the NAC group. In addition, age- and rate of diabetes mellitus-matched controls were randomly extracted. We retrieved and analyzed patient data including demographics, NAC dosage, and serum creatinine concentrations (Scr). NAC group (n=16) showed significantly higher baseline Scr (p<0.01) and a tendency toward a lower dose of contrast media (p=0.068) compared with controls (n=48). Since the occurrence of CIN was low, there was no significant difference in the proportion of CIN between the groups (NAC: 6%, controls: 4%). NAC group trended toward a decrease in Scr after the use of contrast media, while controls increased (-0.04+/-0.25 versus +0.03+/-0.36 mg/dl, p=0.096). The multivariate analysis showed that the dosage of NAC is inversely correlated with Scr independent of baseline Scr and dosage of contrast media. Despite higher baseline Scr (i.e., high-risk with CIN) in the NAC group, the real Scr value reflected a lower trend on average. In addition, this finding suggests that a larger dose of NAC results in a lower Scr value, we consider that the NAC dosage more likely prevented CIN.

Diagnosis and therapy of acute ureteral colic

Acute ureteral colic presents with a complex of acute and characteristic flank pain that usually indicates the presence of a stone in the urinary tract. Diagnosis and management of renal colic have undergone considerable evolution and advancement in recent years. The application of noncontrast helical computed tomography (CT) in patients with suspected ureteral colic is one major advance in the primary diagnostic process. The superior sensitivity and specificity of helical CT allow ureterolithiasis to be diagnosed without the potential side effects of contrast media. Initial management is based on three key concepts: (A) rational and fast diagnostic process (B) effective pain control (C) and understanding of the impact of stone location and size on the natural course of the disease and definitive urologic management. These concepts are discussed in this review with reference to contemporary literature.

Late adverse reactions to intravascular iodinated contrast media.

Late adverse reactions to intravascular iodinated contrast media are defined as reactions occurring 1 h to 1 week after contrast medium injection. They have received increasing interest over the past decade, but their prevalence remains uncertain and their pathophysiology is not fully understood. The Contrast Media Safety Committee of the European Society of Urogenital Radiology decided to review the literature and to issue guidelines. An extensive literature search was carried out and summarized in a report. Based on the available information, simple guidelines have been drawn up. The report and guidelines were discussed at the 8th European Symposium on Urogenital Radiology in Genoa. Late adverse reactions after intravascular iodinated contrast medium include symptoms such as nausea, vomiting, headache, itching, skin rash, musculoskeletal pain, and fever. A significant proportion of these reactions is unrelated to the contrast medium; however, allergy-like skin reactions are well-documented side effects of contrast media with an incidence of approximately 2%. Late reactions appear to be commoner after non-ionic dimers. The majority of late skin reactions after contrast medium exposure are probably T-cell-mediated allergic reactions. Patients at increased risk of late skin reactions are those with a history of previous contrast medium reaction and those on interleukin-2 treatment. Most skin reactions are self-limiting and resolve within a week. Management is symptomatic and similar to the management of other drug-induced skin reactions.

Endothelin: what does the radiologist need to know?

Endothelin (ET) is a potent endogenous vasoconstrictor peptide. It has been implicated in various pathological states since its discovery in 1988. The cardiovascular system and the kidneys are important sites for the action of this peptide. Two types of ET receptor, ETA and ETB, govern the biological effects of ET. Drugs that can prevent the endogenous synthesis of ET or block its binding to receptors may offer important therapeutic impact to patients with congestive heart failure, pulmonary hypertension and acute renal failure. Areas of particular interest to the radiologist include the role of ET in mediating some of the side effects of contrast media, particularly contrast medium nephropathy, and the involvement of ET in the pathogenesis of restenosis following angioplasty. This review outlines the basic biology of this important mediator and its role in health and disease.

Thrombogenic Potential of Contrast Media in an Experimental Model of Laser-Induced Thrombosis

Controversy still exists about the pro- or antithrombotic side effects of contrast media used in daily medical practice. Recent reports have shown that various contrast media, including ionic compounds, have deleterious prothrombotic actions. A new evaluation of these adverse side effects is reported here, with the study of the dose–effect relationship. Two ionic (ioxaglate and diatrizoate) and two non-ionic contrast media (iopamidol and iohexol) were studied. Experiments were done on 22 groups of 5 Wistar male rats each, using a Laser Argon-induced thrombosis model in mesenteric microvessels. Three parameters were studied: the number of laser beams needed to induce platelet thrombus formation, the number of emboli, and the duration of embolization. Platelet count and platelet aggregation also were determined. Iopamidol and iohexol induced a significant rise in both the number of emboli and the duration of embolization in mesenteric microvessels at doses up to 1 mL/kg. Ioxaglate and diatrizoate also significantly increased these parameters at doses up to 2 mL/kg. All the products tested decreased platelet count, inducing a −17 to −30% variation from control values. Diatrizoate and ioxaglate inhibited platelet aggregation, while iopamidol and Iohexol behaved as activators. All non-ionic, and to a lesser extent, all ionic contrast media demonstrated prothrombotic properties.

造影剤の副作用発現に及ぼすＤｏｍｐｅｒｉｄｏｎｅ，Ｅｔｉｚｏｌａｍおよび電解質補液の予防効果

Our previous studies suggested that menopause and a preexisting abnormal renal function may be risk factors leading to an increased occurrence of adverse reactions to contrast media. The present prospective clinical study was carried out to examine the effect of pretreatment with domperidone, etizolam and fluid replacement on a reduction of adverse reactions induced by contrast media in patients with these risk factors.In 3009 patients undergoing a coronary angiography examination, a randomized and controlled trial was conducted from April 1, 1998 to March 31, 2000. Perimenopausal patients (n=732) were divided into two groups including: a post menopause group within 5 years (n=265) and over 5 years (n=467). Next, these two groups were further individually classified into two groups including: a domperidone and etizolam pretreated patient group (within 5 years; 132 patients, over 5 years; 233 patients) and a non-treated patient group (within 5 years; 133 patients, over 5 years; 234 patients). In addition, patients (n=83) with an abnormal renal function (serum creatinine level of 1.5 mg/mL or greater) were also divided into a pretreatment with fluid replacement group (42 patients) and a non-treatment group (41 patients).The overall incidence of adverse reactions of contrast media was 11.2%, and there were no serve or fatal adverse reactions. In female patients, the predominant adverse reactions included headache, vomiting, dizziness, glow and palpitations. Pretreatment with a combination of domperidone and etizolam suppressed the adverse reactions due to contrast media by 77% in post menopausal patients within five years. On the other hand, in postmenopausal patients (n=467) over five years, the pretreatment (n=233) did not effectively reduce the side effects of contrast media. In addition, in patients with an abnormal renal function, the incidence (16.7%) of adverse reactions in fluid replacement pretreatment-patients was significantly less than that (51.2%) in the non-treated patients.These results indicate that the pretreatment of patients with domperidone, etizolam and fluid replacement was found to successfully reduce the incidence of adverse reactions induced by contract media in patients with risk factors such as menopause and a preexisting abnormal renal function, respectively.

Calcium antagonistic effects of an angiographic contrast medium in vitro. A comparison of the effects of iohexol with the effects of nifedipine in isolated arteries.

Vasodilatation is a well-known side effect of contrast media. Contrast media inhibit the action of vasoconstrictors. The nonionic contrast medium, iohexol, inhibits vasoactive substances to a lesser extent than ionic contrast media. Iohexol inhibited the action of vasoconstrictors in a way that raised suspicion of a calcium antagonistic effect of the medium. The authors test this hypothesis by comparing the inhibitory effect of iohexol with the inhibitory effect of a calcium antagonist (nifedipine). The vasoconstrictors were KCl, which depends on potential-operated calcium channels, and histamine, endothelin-1, and prostaglandin F2 alpha (PGF2 alpha), which depend on receptor-operated calcium channels. Segments of rabbit coronary arteries were mounted between two L-shaped prongs in tissue baths containing calcium-free buffer, calcium-free buffer with 10(-8) M nifedipine, or iohexol. One of the vasoconstrictors, KCl, histamine, endothelin-1, or PGF2 alpha, was added to induce a level of activation. Thereafter, increasing concentrations of CaCl2 were added in a stepwise manner, and the contractile responses of the vessel segments were recorded. Addition of CaCl2 caused concentration-dependent vasoconstrictions in the buffer. The effect of adding CaCl2 was inhibited in the buffer with nifedipine and in iohexol when the vessels were activated with histamine, endothelin-1, or PGF2 alpha. When the vessels were activated with the potential-operated calcium channel-dependent vasoconstrictor, KCl, the effect of adding CaCl2 was inhibited in the buffer with nifedipine but not in iohexol. In vitro, iohexol had the same effect as the calcium antagonist nifedipine on the action of receptor-operated calcium channel-dependent vasoconstrictors. This suggests a calcium antagonistic effect of iohexol on the action of the ROC.

Sodium-Calcium Relationships and Cardiac Function during Coronary Bolus Perfusion

The present review deals with the side-effects of contrast media (CM) on cardiac function during coronary angiography. A physiological approach is used to redefine existing concepts of CM osmotoxicity and chemotoxicity in terms of osmolal, ionic and molecular effects. The main idea conveyed is that purely ionic effects are of central importance during and immediately following the transit of a brief coronary bolus. Ionic effects result largely from rapid transient washout of normal extracellular ions, but are also influenced by ions present in the CM. In particular, the calcium (Ca) and sodium (Na) ions controlling cardiac function are easily affected. The myocardial Na-Ca exchange, which is mainly a physiological mechanism for cellular Ca efflux during cardiac relaxation, is therefore highlighted in detail. The importance of avoiding a potential Na-Ca mismatch is shown by examples from basic physiology, cardiac surgery and coronary angiography and by results of experiments with Visipaque. In the isomolal and isotonic CM Visipaque, which is based on the dimer isodixanol (320 mg I/ml), an available osmolal space is filled with an appropriately balanced supplement consisting of NaCl (19mM) and CaCl2 (0.3 mM).

Effects of vasoconstrictors on rabbit coronary arteries exposed to iohexol with addition of electrolytes (sodium and calcium).

A well-known side effect of contrast media (CM) is vasodilation. Different types of CM in vitro inhibit the action of vasoconstrictors to various degrees. The nonionic CM iohexol inhibits the action less than ionic CM. In this study, the authors investigate whether the addition of electrolytes to iohexol causes less inhibition of the vasoconstrictors. Vasoconstriction dependent on potential-operated calcium channels (POCs) (potassium chloride), or receptor-operated calcium channels (ROCs) (histamine, endothelin-1, and prostaglandin F2 [PGF2 alpha]) was specifically studied. Segments of rabbit coronary arteries were mounted between two L-shaped prongs in tissue baths with buffer solution or solutions of iohexol (140 mg I/mL) with addition of different concentrations of NaCl and CaCl2. The responses of the vessels to increasing concentrations of a vasoconstrictor were examined. Concentration of vasoconstrictor versus contractile response curves were plotted, and the maximal contraction of the vasoconstrictor (Emax) and half maximal constriction were calculated. Addition of 30 mM NaCl and 1.5 mM CaCl2 caused a vasoconstriction to KCl in iohexol almost identical to its vasoconstriction in buffer. Higher concentrations of NaCl caused decreasing Emax of all vasoconstrictors. The inhibition of the ROC-dependent vasoconstrictors could not be normalized by the addition of electrolytes. The inhibition of the POC-dependent vasoconstrictor was caused by "ion toxicity" of iohexol. The inhibition of the ROC-dependent vasoconstrictors was caused by other mechanisms, in a manner compatible with a blocking effect on ROCs.

Effects of Vasoconstrictors on Rabbit Coronary Arteries Exposed to Isotonic Ionic and Nonionic Contrast Media

Vasodilation is a well-known side effect of contrast media (CM) that is primarily explained by the hyperosmolality of the media. Few reports have dealt with the influences of chemotoxicity and ion toxicity on vessel tone. We compared the effects of solutions iso-osmolar to plasma of iohexol (nonionic monomer), ioxaglate (ionic dimer), diatrizoate (ionic monomer), and mannitol on responses to vasoconstrictors (potassium chloride [KCl], histamine, and endothelin-1). The aim of this study was to investigate if differences in chemotoxicity and ion toxicity could contribute to the changes in vessel tone seen clinically during arteriography. Segments of rabbit coronary arteries were mounted between two L-shaped prongs in tissue baths with buffer solution or CM solutions. Their responses to increasing concentrations of a vasoconstrictor were measured. The maximal contraction of the vasoconstrictor (Emax) and the concentration of the vasoconstrictor causing half maximal contraction (EC50) were calculated. Iohexol caused the same changes as the nonionic solution of mannitol. The media reduced the actions of KCl, histamine, and endothelin-1 to 50% to 60% of their action in buffer. The ionic CM, ioxaglate and diatrizoate, caused a more pronounced inhibition of histamine and almost totally inhibited the action of KCl. The action of endothelin-1 was inhibited to a greater extent by iohexol and mannitol than by ioxaglate and diatrizoate. Different types of iso-osmolar CM interact differently with vasoconstrictors. These effects are caused by differences in chemo- and ion toxicity. These interactions might contribute to the differences in vasodilatation found clinically.

Emergency computerized tomography of tracheoesophageal fistula in lung adenocarcinoma : Smulewicz JJ, Guerrero LE, Washington D, Hassani SN. Department of Clinical Radiology, Harlem Hospital Center, New York, NY 10037. J Natl Med Assoc 1988;80:817-21

Malignant tracheoesophageal fistula occurs infrequently in patients with irradiated esophageal and lung cancer, uncommonly in patients with untreated mediastinal malignancies, infection, or trauma, and rarely in primary adenocarcinoma of the lung. The natural progression of this entity leads to rapid deterioration and death from overwhelming pulmonary infection.Definitive treatment depends on the demonstration and localization of the fistula. Computerized tomography (CT) chest scanning with dilute oral contrast is the ideal means of identification of the fistula. CT scanning without contrast may outline sufficiently the pathology to avoid the usage and side effects of contrast media in the lungs.A review of one case of tracheoesophageal fistula due to pulmonary adenocarcinoma is presented where emergency CT scanning without contrast resulted in rapid and accurate diagnosis, leading to prompt and appropriate management.

A general comparison of functional imaging in nuclear medicine with other modalities

New (noninvasive) diagnostic procedures in medicine (ultrasound [US], digital subtraction angiography [DSA], computed tomography [CT], nuclear magnetic resonance [NMR]) create a need for a review of the clinical utility of functional imaging in nuclear medicine. A general approach that is valid for all imaging procedures is not possible. For this reason, an individual assessment for each class of functional imaging is necessary, taking into account the complexity and sophistication of the various imaging procedures. This leads to a hierarchical order: first order functional imaging: imaging of organ motion (heart, lungs, blood); second order functional imaging: imaging of excretory function (kidneys, liver); and third and fourth order functional imaging: imaging of metabolism (except excretory function). First order functional imaging is possible fundamentally, although with limitations in detail, by all modalities. Second order functional imaging is not possible with US. Third and fourth order functional imaging is a privilege of nuclear medicine alone. Up to now, NMR has not proven clinically useful to produce metabolic images in its true sense. This is due to the fact that the signals used are too weak to provide metabolic information with satisfactory local resolution, even after administration of nonradioactive isotopes. First and second order functional imaging of nonradioactive procedures face severe disadvantages, including difficulties in performing stress investigations, which are essential for coronary heart disease, limited capability for true quantitative information (eg, kidney clearance in mL/min), side effects of contrast media and paramagnetic substances, and high costs. Therefore, nuclear medicine functional imaging turns out to be in a favorable clinical position, even in the presence of the competitive diagnostic modalities that have been developed in recent years.