RESUMO
The kinetics of iopamidol, a new nonionic radiocontrast agent, were evaluated in 10 patients undergoing lumbar myelography. The doses of iopamidol administered intrathecally were 11 and 15 ml of a 200-mg iodine per ml solution in one and nine patients, respectively. Radiographs were made within 30 to 40 min and CTs were taken at about 1, 6, and 23 hr after iopamidol administration. The diagnostic quality and usefulness of the conventional and CT myelograms were considered excellent. In the lumbosacral subarachnoid space, the densitometry CT readings were maximal at 1 hr, whereas in the cervical subarachnoid space, peak CT values were reached at 6 hr. Plasma and urine samples were taken at frequent intervals up to 48 hr after the contrast agent was administered. Peak plasma levels of iopamidol were observed at 2.9 hr and were no longer detectable at 48 hr. The 48-hr urinary recovery for all patients averaged 66 +/- 8% of the dose. In all but one patient, iopamidol was cleared almost completely from the CSF within 24 hr. Side effects after iopamidol administration were transient and minor, and were not related to the CT readings or its systemic clearance.
Assuntos
Meios de Contraste/metabolismo , Iopamidol/metabolismo , Adulto , Meios de Contraste/administração & dosagem , Meios de Contraste/efeitos adversos , Meios de Contraste/sangue , Meios de Contraste/urina , Densitometria , Feminino , Humanos , Injeções Espinhais , Iopamidol/administração & dosagem , Iopamidol/efeitos adversos , Iopamidol/sangue , Iopamidol/urina , Cinética , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Systemic absorption of iodinated contrast material occurs during endoscopic retrograde cholangiopancreatography (ERCP), the clinical significance of which has not yet been determined. METHODS: Urinary iodine excretion was measured before and after coronary angiography (n = 20) and ERCP (n = 12). Thyroid hormone levels were determined before iodine load and after 6 and 24 weeks. RESULTS: Before coronary angiography, iodine excretion was 101 +/- 38.3 micromol/mol creatinine and increased to 865. 10(5) +/- 721. 10(5) micromol/mol on the next day (p = 0.001). After 6 weeks, it was still elevated (167 +/- 88.8 micromol/mol, p < 0.01). Before ERCP, iodine excretion was 115 +/- 60.3 micromol/mol and reached a peak of 5.3. 10(5) +/- 4.9. 10(5) micromol/mol (p < 0.001). Six weeks later, it had returned to baseline. Two patients in the coronary angiography group but none in the ERCP group had suppressed thyrotropin after 6 weeks. CONCLUSIONS: The systemic iodine load during ERCP is approximately 0.6% of the iodine load during coronary angiography. Therefore routine measurement of thyroid hormones before ERCP is not recommended.