Does intravenous contrast medium administration result in altered renal biomarkers? A study in clinically stable cats with and without azotemia

Objectives The aim of this study was to determine the prevalence of post-contrast acute kidney injury or comparable side effects on kidney function in cats receiving the non-ionic, iodinated agent ioversol and/or paramagnetic agent gadoteric acid. Methods Fifty-two animals were divided into four groups on the basis of contrast medium administration for imaging: ioversol (n = 27), gadoteric acid (n = 12), dual contrast media (n = 4) or control, which received an infusion of isotone intravenous fluids only during anaesthesia (n = 9). Blood and urine samples were obtained three times after contrast administration and compared with values obtained prior to administration of the contrast medium. Creatinine (<1.60 mg/dl), symmetric dimethylarginine (SDMA; ⩽14 μg/dl), urine protein:creatinine ratio (UPC; <0.2) and critical differences for creatinine (<0.3 mg/dl) and SDMA (<5.98 μg/dl) were measured. Results No significant short-term effects on mean creatinine, SDMA and UPC measurements were seen. Borderline proteinuria (UPC, 0.2–0.4) was detected in 11.4% of cases after contrast media administration. A UPC of more than 0.2 in five cases indicated that contrast media may affect kidney function, leading to (transient) proteinuria. Conclusions and relevance This study found no side effect on renal function following the administration of ioversol or gadoteric acid, provided patients were adequately hydrated. However, the clinical relevance of proteinuria in some cats needs to be evaluated in future studies.

Pure muscle tenosynovial giant cell tumor mimicks a metastasis in patient with melanoma

Tenosynovial Giant Cell Tumor (TGCT) is a rare benign synovial tumor arising from the tendon sheath, bursae, synovium or adjacent soft tissue. TGCT typical occurs in intra-articular site but can be rarely extra- articular. A 50-years-old woman already affected by malignant melanoma was submitted to PET/CT scan for routine diagnostic examinations during follow up; an intense FDG focal uptake corresponding to peritrochanteric medial part of right iliopsoas muscle was detected. Corresponding MRI images demonstrated a lesion with well-defined margins, slightly hyperintense in T1, low to intermediate signal intensity in T2 weighted scans, no significant restriction in DWI, and intense enhancement in T1 after intravenous contrast medium administration. There wasn’t evidence of extra-lesional spread. MRI findings oriented for benign lesion, but according to intermediate signal intensity in T2, intense enhancement in T1 after intravenous contrast medium, the presence of intense FDG uptake as well as history of aggressive malignancy, a local excision was done; then the final diagnosis of TGCT has been proven. Our case shows TGCT lesions may reproduce malignant appearance on FDG-PET, while MRI may be useful tool to properly manage affected patients. Keywords: Tenosynovial giant cell tumor; Melanoma metastasis; Diffusion-MRI; FDG-PET/CT.

Non-contrast MRI can accurately characterize adnexal masses: a retrospective study

Objective To determine the accuracy of interpretation of a non-contrast MRI protocol in characterizing adnexal masses. Methods and materials Two hundred ninety-one patients (350 adnexal masses) who underwent gynecological MRI at our institution between the 1st of January 2008 and the 31st of December 2018 were reviewed. A random subset (102 patients with 121 masses) was chosen to evaluate the reproducibility and repeatability of readers’ assessments. Readers evaluated non-contrast MRI scans retrospectively, assigned a 5-point score for the risk of malignancy and gave a specific diagnosis. The reference standard for the diagnosis was histopathology or at least one-year imaging follow-up. Diagnostic accuracy of the non-contrast MRI score was calculated. Inter- and intra-reader agreement was analyzed with Cohen’s kappa statistics. Results There were 53/350 (15.1%) malignant lesions in the whole cohort and 20/121 (16.5%) malignant lesions in the random subset. Good agreement between readers was found for the non-contrast MRI score (к = 0.73, 95% confidence interval [CI] 0.58–0.86) whilst the intra-reader agreement was excellent (к = 0.81, 95% CI 0.70–0.88). The non-contrast MRI score value of ≥ 4 was associated with malignancy with a sensitivity of 84.9%, a specificity of 95.9%, an accuracy of 94.2% and a positive likelihood ratio of 21 (area under the receiver operating curve 0.93, 95% CI 0.90–0.96). Conclusion Adnexal mass characterization on MRI without the administration of contrast medium has a high accuracy and excellent inter- and intra-reader agreement. Our results suggest that non-contrast studies may offer a reasonable diagnostic alternative when the administration of intravenous contrast medium is not possible. Key Points • A non-contrast pelvic MRI protocol may allow the characterization of adnexal masses with high accuracy. • The non-contrast MRI score may be used in clinical practice for differentiating benign from malignant adnexal lesions when the lack of intravenous contrast medium precludes analysis with the O–RADS MRI score.

DYNAMIC FOLLOW-UP AND PROVING THROUGH COMPUTED TOMOGRAPHY AND MAGNETIC RESONANCE IMAGING OF CHANGES IN SECONDARY MENINGOENCEPHALITIS FROM SUPPURATIVE LEFT MAXILLARY SINUSITIS

Infections of the nervous system and its belonging structures have often been reported as life-threatening conditions. Purpose: the results of dynamic follow-up and proving of changes in secondary meningoencephalitis from suppurative left maxillary sinusitis are presented using the imaging methods - CT and MRI. Methods: diagnostic imaging (CT, MRI), of acute disease in a 13-year-old child with progressive development and proving of secondary bacterial meningoencephalitis. Result: the control CT after two days showed dynamics in the imaging CT finding with the appearance of changes in the type of brain oedema and development of pansinusitis. The MRI data described corresponded to changes as at meningoencephalitis in progress.Conclusion: The extension of the diagnostic algorithm with MRI, with the administration of intravenous contrast medium, clearly demonstrated changes characteristic of meningoencephalitis.

Transient neonatal hypothyroidism secondary to postnatal maternal exposure to contrast medium

We report a preterm breastfed infant who developed a transient hypothyroidism after his lactating mother had a CT scan with iodinated contrast medium, despite the advised 24 hours’ pause in breast feeding. The aetiological assessment did not show any other cause for this hypothyroidism. Transient neonatal hypothyroidism after the use of topical iodine is well known, but it has not been described as a complication of intravenous contrast medium administration to a lactating mother. This case highlights the possibility of transient neonatal hypothyroidism secondary to contrast medium exposure to a lactating mother. When imaging is needed in the lactating mother, a longer break in breast feeding might be needed to prevent transient hypothyroidism in the preterm infant.