S. Zaïm

PURPOSE: To evaluate the clinical and biologic safety of ultrasmall superparamagnetic iron oxide particles (AMI-227) as a contrast agent for magnetic resonance (MR) lymphography and to assess their efficacy for the differentiation of metastatic and benign nodes in patients with urologic and pelvic cancer. MATERIALS AND METHODS: Thirty adults suspected of having lymph node metastases underwent MR imaging before and 22-26 hours after intravenous infusion of AMI-227 (1.7 mg Fe/kg). Sixty histopathologically proved lymph nodes were analyzed on MR images, and 29 of these nodes were also analyzed quantitatively. RESULTS: AMI-227 was well tolerated with no major side effects. It allowed the detection of 10 additional nodes relative to those detected at MR imaging without AMI-227. None of the 27 metastatic nodes showed a decrease in signal intensity (SI) on AMI-227-enhanced images; nine of 27 metastatic nodes showed an increase in SI on T1-weighted images, probably resulting from altered capillary permeability in the tumor. A visually perceptible reduction in SI, indicating active AMI-227 uptake, was observed on postcontrast T2- and T2*-weighted images in 16 of 21 benign nodes. The SI ratio of benign nodes was lower than that of metastatic nodes on T2- and T2*-weighted images. The sensitivity of AMI-227-enhanced MR lymphography was 100%, and the specificity was 80%. CONCLUSION: AMI-227 is safe and may facilitate the differentiation of metastatic and benign nodes in patients with urologic and pelvic cancers.

OBJECTIVE: Using radiography to assess the efficacy of a disease-modifying osteoarthritis (OA) drug on joint structure is challenging. Subchondral bone marrow abnormalities determined by magnetic resonance imaging (MRI) and urinary excretion of C-terminal crosslinking telopeptide of type II collagen (CTX-II) have recently been shown to be predictors of radiographic progression in patients with knee OA, suggesting that these may represent valuable biomarkers with increased sensitivity compared with findings on radiography. The aims of this investigation were to analyze, in patients with knee OA, whether the values associated with these 2 OA biomarkers can change within 3 months, and to investigate the relationships between bone marrow abnormalities and CTX-II. METHODS: Knee MRI scans were obtained in 377 patients with painful knee OA (76% women, mean age 63 years, mean disease duration 6.6 years) at both baseline and 3 months. The femoral and tibial condyles and the patella were divided into 8 sites for the scoring of bone marrow abnormalities. A bone marrow abnormality was defined as an area of increased signal on T2-weighted images of the subchondral bone. All scans were reviewed centrally and scored by a single trained radiologist using a validated 4-point scoring method. Fasting urine and serum samples were also collected from all patients at baseline, month 1, month 2, and month 3, in order to measure the levels of urinary CTX-II and serum CTX-I, a biochemical marker of bone resorption. RESULTS: At baseline, 82% of patients had MRI evidence of bone marrow abnormalities. Bone marrow abnormality scores correlated significantly with CTX-II levels (P < 0.0001). Within 3 months, the bone marrow abnormality score decreased in 37 patients (9.8%), increased in 71 patients (18.8%), and did not change in the majority of patients (71.4%). Patients with baseline urinary CTX-II levels in the highest tertile had a relative risk of 2.4 (95% confidence interval 1.1-5.0) of worsening bone marrow abnormalities at 3 months compared with patients with levels in the lowest tertile, after adjustment for age, sex, and body mass index. In patients who showed a decrease in the bone marrow abnormality score at 3 months, urinary CTX-II levels decreased significantly (mean -75 ng/mmole creatinine), whereas levels increased (mean +23 ng/mmole creatinine) in patients showing an increase in the bone marrow abnormality score (P = 0.01 between the 2 groups). No significant association between bone marrow abnormalities and serum CTX-I was observed. CONCLUSION: In patients with painful knee OA, bone marrow abnormalities on MRI can change within only 3 months in approximately 30% of patients. Reduction in the extent of bone marrow abnormalities is associated with a decrease in cartilage degradation.

PURPOSE: To evaluate the clinical and biologic safety of superparamagnetic iron oxide (SPIO) as a contrast agent in magnetic resonance (MR) imaging and to assess its efficacy in the detection of liver metastases. MATERIALS AND METHODS: Twenty adults with liver metastases underwent MR imaging at 1.5 T before and 1 hour after infusion of SPIO. Four spin-echo (SE) sequences and one gradient-echo (GRE) sequence were used. RESULTS: There were no adverse reactions. Alterations in serum protein, serum iron, transferrin, and ferritin levels and transferrin saturation coefficient were statistically significant. The mean tumor-to-liver contrast-to-noise ratio (C/N) increased markedly with all sequences. The best postcontrast tumor-to-liver contrast was obtained with the GRE sequence (repetition time msec/echo time msec = 300/15). The mean number of apparent lesions detected after administration of SPIO increased by 12 with the proton-density-weighted SE sequences (800/30 and 2,500/30), four with the T2-weighted SE sequence (2,500/90), and seven with the GRE sequence (300/15). CONCLUSION: SPIO is safe, increases tumor-to-liver C/Ns with some sequences, and improves the detection of liver metastases.