Prophylactic 0.9% saline hydration inhibited high-dose gadodiamide-induced nephropathy in rats.

High doses of gadolinium-based contrast media are reported to induce deterioration of renal function. We assessed whether prophylactic 0.9% saline hydration inhibits high-dose gadodiamide-induced renal damage in rats. Twelve Sprague-Dawley rats were randomly divided into two groups, which are given gadodiamide (5 mmol/kg) with (hydration group) or without (control group) 0.9% saline hydration. The saline (4 mL/kg) was infused as a bolus into the peritoneum every 4 h, starting 12 h before and continuing for 12 h after the gadodiamide injection. Urine was collected to calculate creatinine clearance (Ccr) 24 h before and 48 h after the gadodiamide injection. The kidneys were harvested and stained for pathologic analysis. High-dose gadodiamide induced acute kidney injury as shown by decreased Ccr and renal histology with tubular cell injuries 48 h postinjection in both the groups. However, the extent of Ccr reduction was significantly (p = 0.02) less in the hydrated rats (-15% in the hydration group vs. -39% in the control group). Renal tubular cell injuries characterized by vacuolization, loss of brush borders, sloughing of tubular cells into the lumen, and flattening of the tubular epithelium were less frequently seen in the hydration group; only vacuolization (p = 0.01) and epithelial sloughing (p = 0.02) of the proximal tubules differed significantly between the two groups. We conclude that prophylactic 0.9% saline hydration significantly inhibited high-dose gadodiamide-induced nephropathy.

High Z elements in human sarcomata: assessment by multienergy CT and neutron activation analysis.

"Tumor equivalent" phantoms containing inorganic salts (KH2PO4, CH3COOK, NaCl and Kl) were scanned on an EMI 5005 body scanner at 140 kVp, 28 mA; 120 kVp, 33 mA; and 81 kVp, 42 mA. Significant signal gain for the detection of higher atomic number elements by multiple energy scanning was noted. Certain sarcomas are known to accumulate high Z elements. Accordingly, excised specimens of various histologies of human sarcomata (chondrosarcoma, liposarcoma, and malignant fibrous histiocytoma) were scanned at 140 kVp and 81 kVp. Using selected areas of interest in the computed tomographic (CT) image to direct the in vitro biopsy of various regions of excised tumors, interesting correlations between the CT number variation and the respective, high Z elemental composition variation, as determined by thermal neutron activation analysis were observed. Further investigation with phantoms and excised sarcomata at 62 kVp and 42 mA suggested that dual energy CT scanning (at 140 kVp and 62 kVp) may be a method of monitoring "effective Z" and heavy element compositional changes. The authors are also attempting to develop these same low kilovoltage techniques as a method for the noninvasive clinical monitoring of an antisarcoma chemotherapeutic agent, cis-diammineaichloroplatinum (11).