Imaging findings

Abstract

Contrast-enhanced CT is the most useful modalities for evaluating urinary tract lesions in IgG4-related disease (IgG4-RD) patients who do not have decreased renal function or iodine allergy. Contrast-enhanced CT findings of renal parenchymal lesions are broadly classified into the following three patterns. Multiple, poorly-enhancing regions of renal parenchyma, is the most typical and frequently noted picture of renal parenchymal lesions. Next, marked swelling and poor enhancement of the entire renal parenchyma are observed in some cases. Finally, a single focal lesion limited to one kidney is rare, but has been reported. Adding to parnchymal lesion, the wall thickening of renal pelvis is also known as a kidney lesion of IgG4-RD. However, when the possible diagnosis of IgG4-RKD is suggested first by imaging studies, the diagnosis must be confirmed through measurements of the serum IgG4 concentration, tissue biopsy, and (most crucially) careful correlation between the clinical data, radiology and pathology findings.