Splenic findings in patients with acute babesiosis.

PURPOSE: To identify the imaging manifestations of splenic involvement in babesiosis, a potentially fatal tick-borne zoonosis with multi-organ involvement. METHODS: In our single center HIPAA compliant IRB-approved study, we performed a retrospective search of the electronic medical record at our institution to identify all patients with known or suspected acute babesiosis from 2000 to 2017. We then reviewed all abdominal imaging of patients with confirmed disease to identify incidence and characteristics of splenic involvement. Splenomegaly was determined using a height- and gender-adjusted reference. RESULTS: After exclusions, 63 patients with a confirmed diagnosis of babesiosis and contemporaneous imaging of the spleen were included in the final cohort. Within this cohort, 56 (89%) had splenomegaly at a minimum and 13 had splenic infarcts. Splenic rupture was present in eight patients with three having a pseudoaneurysm. In 14 patients with follow-up imaging, the spleen subsequently diminished in size. One additional patient with ruptured spleen underwent emergency splenectomy prior to imaging. CONCLUSION: Although the literature suggests splenic involvement is a rare finding, acute parasitemia with babesiosis commonly affects the spleen. Recognition of this association can aid radiologists diagnosing splenic involvement in babesiosis and can lead to appropriate intervention in the minority with splenic hemorrhage.

Reference range of liver corrected T1 values in a population at low risk for fatty liver disease-a UK Biobank sub-study, with an appendix of interesting cases.

PURPOSE: Corrected T1 (cT1) value is a novel MRI-based quantitative metric for assessing a composite of liver inflammation and fibrosis. It has been shown to distinguish between non-alcoholic fatty liver disease (NAFL) and non-alcoholic steatohepatitis. However, these studies were conducted in patients at high risk for liver disease. This study establishes the normal reference range of cT1 values for a large UK population, and assesses interactions of age and gender. METHODS: MR data were acquired on a 1.5 T system as part of the UK Biobank Imaging Enhancement study. Measures for Proton Density Fat Fraction and cT1 were calculated from the MRI data using a multiparametric MRI software application. Data that did not meet quality criteria were excluded from further analysis. Inter and intra-reader variability was estimated in a set of data. A cohort at low risk for NAFL was identified by excluding individuals with BMI ≥ 25 kg/m2 and PDFF ≥ 5%. Of the 2816 participants with data of suitable quality, 1037 (37%) were classified as at low risk. RESULTS: The cT1 values in the low-risk population ranged from 573 to 852 ms with a median of 666 ms and interquartile range from 643 to 694 ms. Iron correction of T1 was necessary in 36.5% of this reference population. Age and gender had minimal effect on cT1 values. CONCLUSION: The majority of cT1 values are tightly clustered in a population at low risk for NAFL, suggesting it has the potential to serve as a new quantitative imaging biomarker for studies of liver health and disease.