Assessing the necessity of intravenous contrast for computed tomography in the acute undifferentiated abdomen.

INTRODUCTION: Undifferentiated abdominal pain in the emergency setting is frequently investigated with an intravenous contrast enhanced CT as a first line diagnostic test. However, global contrast shortages restricted the use of contrast for a period in 2022, altering standard practice with many scans performed without intravenous contrast. Whilst IV contrast can be useful to assist with interpretation, its necessity in the setting of acute undifferentiated abdominal pain is not well described, and its use comes with its own risks. This study aimed to assess the shortcomings of omitting IV contrast in an emergency setting, by comparing the rate of CT scans with "indeterminate" findings with and without the use of IV contrast. METHODS: Data from presentations to a single centre emergency department for undifferentiated abdominal pain prior to and during contrast shortages in June 2022 were retrospectively compared. The primary outcome was the rate of diagnostic uncertainty, where the presence or absence of intra-abdominal pathology could not be ascertained. RESULTS: 12/85 (14.1%) of the unenhanced abdominal CT scans provided an uncertain result, compared with 14/101 (13.9%) of control cases performed with intravenous contrast (P = 0.96). There were also similar rates of positive and negative findings between the groups. CONCLUSION: Omitting intravenous contrast for abdominal CT in the setting of undifferentiated abdominal pain demonstrated no significant difference in the rate of diagnostic uncertainty. There are significant potential patient, fiscal and societal benefits as well as potential improvements to emergency department efficiency with the reduction of unnecessary intravenous contrast administration.

Immune Function After Splenic Artery Embolization for Blunt Trauma: Long-Term Assessment of CD27+ IgM B-Cell Levels.

Splenic artery embolization (SAE) plays a critical role in the treatment of high-grade splenic injury not requiring emergent laparotomy. SAE preserves splenic tissue, and growing evidence demonstrates preserved short-term splenic immune function after SAE. However, long-term function is less studied. Patients who underwent SAE for blunt abdominal trauma over a 10-year period were contacted for long-term follow-up. Sixteen participants (sex: women, 10, and men, 6; age: median, 34 years, and range, 18-67 years) were followed up at a median of 7.7 years (range, 4.7-12.8 years) after embolization. Splenic lacerations were of American Association for the Surgery of Trauma grades III to V, and 14 procedures involved proximal embolization. All individuals had measurable levels of IgM memory B cells (median, 14.30 as %B cells), splenic tissue present on ultrasound (median, 122 mL), and no history of severe infection since SAE. In conclusion, this study quantitatively demonstrated that long-term immune function remains after SAE for blunt abdominal trauma based on the IgM memory B cell levels.

Disseminated intraosseous Kaposi's sarcoma: A rare manifestation of HIV/AIDS.

Kaposi Sarcoma (KS), a mucocutaneous cancer that most frequently occurs in the context of Acquired Immunodeficiency Syndrome (AIDS) secondary to Human Immunodeficiency Virus (HIV), is a relatively benign condition, acting more as a marker of immunodeficiency than directly causing harm itself. However, it has been known to spread both locally and in a metastatic fashion, with reports of KS affecting almost all organ systems. One of the most rarely reported areas of involvement is the musculoskeletal system, with secondary osseous spread representing an even smaller subset of these. We report a case of biopsy proven disseminated intraosseous KS involving the entire imaged skeleton that occurred with HIV/AIDS, despite maximal treatment and normal imaging 8 months prior.

Structural OCT Signs Suggestive of Subclinical Nonexudative Macular Neovascularization in Eyes with Large Drusen.

PURPOSE: To further define the structural OCT features described as the "double-layer sign" suggestive of subclinical, nonexudative macular neovascularization (NE-MNV) in asymptomatic eyes with age-related macular degeneration (AMD). DESIGN: Cross-sectional observational study. PARTICIPANTS: Participants with large drusen (>125 µm) secondary to AMD in at least 1 eye. METHODS: Participants in a "discovery" cohort, with known NE-MNV identified on swept-source (SS) OCT angiography (OCTA) and the "double-layer sign" on structural spectral-domain OCT (SD-OCT) imaging, were used to identify characteristic features of this sign. These features were then assessed by masked grading in an "evaluation" cohort of AMD eyes with large drusen to determine the predictive values for NE-MNV. MAIN OUTCOME MEASURES: Description of OCT features associated with an increased risk of NE-MNV and their diagnostic and predictive performance. RESULTS: The discovery cohort of 4 eyes revealed that in retinal pigment epithelium (RPE) elevations with a greatest transverse linear dimension of 1000 µm or more, an irregular RPE layer with a height of predominantly less than 100 µm, and a nonhomogenous internal reflectivity as characteristic features of the double-layer sign when NE-MNV was present. We term these collective features as a shallow, irregular RPE elevation (SIRE). Features on OCT images from 233 eyes in the evaluation cohort that were associated significantly with NE-MNV when the RPE elevation was more than 1000 µm in length were: height of the RPE elevation, overall flat or variable morphologic features, RPE layer irregularity, and nonhomogeneous reflectivity (all P ≥ 0.032). Twenty-four eyes (10.3%) were identified with a SIRE. On SS-OCTA imaging, 6 of the 233 eyes were found to have definite NE-MNV, and all 6 graded positively for SIRE (sensitivity, 100%). The absence of SIRE was identified in 209 of 227 eyes without NE-MNV (specificity, 92.1%). The positive predictive value for SIRE was 25% and the negative predictive value was 100%. CONCLUSIONS: Eyes whose OCT images display a SIRE sign are at higher risk of having subclinical NE-MNV. SIRE can be used as a screening tool on routine structural OCT imaging. More frequent follow-up and diligent home monitoring is recommended for those with SIRE.