Citations

Background Carotid-cavernous fistulas (CCFs) are commonly misdiagnosed on computed tomography angiography (CTA). Purpose This study sought to identify the most sensitive and specific imaging features of CCFs on CTA. Material and Methods A retrospective review identified 18 consecutive patients suspected of having a CCF on CTA and subsequently underwent digital subtraction angiography (DSA). Two blinded reviewers assessed multiple findings on CTA: cavernous sinus asymmetry/enlargement; arterial-phase contrast in the cavernous sinus; proptosis; pre- or post-septal orbital edema; and dilated regional vasculature. Each was graded as positive, possible, and negative; “possible” was counted as positive. A third blinded reviewer served as a tiebreaker. Results Of 18 patients, nine were true-positive and nine were false-positive. Superior ophthalmic vein early enhancement and dilatation had 100.0% sensitivity (95% confidence interval [CI] 40.0–100.0) and 77.8% specificity (95% CI 44.4–100.0); arterial-phase contrast in the cavernous sinus had 88.9% sensitivity (95% CI 44.4–100.0) and 66.7% specificity (95% CI 18.5–90.1); peri-orbital edema had 88.9% sensitivity (95% CI 35.5–100.0) and 77.8% specificity (95% CI 22.2–100.0). The most specific markers of CCF were superior petrosal sinus and inferior ophthalmic vein dilatation/enhancement (100.0%, 95% CI 88.8–100.0 and 88.9%, 95% CI 44.4–100.0, respectively); the specificity of asymmetric cavernous enlargement was 44.4% (95% CI 11.1–77.7). Conclusions Among patients in whom a CCF is suspected on CTA, superior ophthalmic vein dilatation/enhancement and arterial-phase contrast within the cavernous sinus are the most sensitive findings. Asymmetric cavernous sinus enlargement has poor specificity and may result in false-positive diagnoses of CCFs. False positive cases were less likely to have an optimally timed contrast bolus.

Background Clot perviousness in large vessel occlusion has been shown to be associated with improved recanalization outcomes with mechanical thrombectomy and intravenous thrombolysis. Objective To evaluate the association between clot perviousness based on thrombus attenuation increase (TAI) on CT, and histologic composition of clots in acute ischemic stroke (AIS). Methods A retrospective review was completed of patients with AIS secondary to large vessel occlusion, non-contrast CT (NCCT) and CT angiography (CTA) images, and histologic analysis of the retrieved clot. TAI was measured by subtracting clot attenuation on NCCT from the attenuation on CTA. Up to 3 regions of interest (ROIs) were evaluated on each clot; the average attenuation was used for analysis if multiple ROIs were assessed. Pervious clots were defined as TAI ≥10 Hounsfield units (HUs); impervious clots had TAI <10 HU. Histopathologic analyses of clots were assessed for relative compositions of red blood cells (RBCs), white blood cells (WBCs), fibrin, and platelets/other. Results 57 patients were included. Pervious clots were more likely to be RBC rich (p=0.04); impervious clots were more likely to be fibrin and WBC rich (p=0.01 for both). Pervious clots also had greater RBC density than impervious clots (49.8% and 33.0%, respectively; p=0.006); fibrin density of pervious clots was lower than that of impervious clots (17.8% and 23.2%, respectively; p=0.02). Conclusion Clot perviousness, assessed on NCCT and CTA imaging, is associated with higher RBC density and lower fibrin density, offering a possible explanation for the higher rates of successful thrombectomy and favorable clinical outcome seen in such patients.

Purpose Radiology descriptions of intracranial metastases following radiotherapy are often imprecise. This study sought to improve such reports by creating and disseminating a structured template that encourages discrete categorization of intracranial lesions. Methods Following initiation of the structured template, a retrospective review assessed patients with intracranial metastases that underwent radiotherapy, comparing ‘pre-template’ with ‘post-template’ reports. A total of 139 patients were included; 94 patients (67.6%) were imaged pre-template, 45 (32.4%) post-template. Reports were assessed for discrete versus non-specific descriptions of lesions: ‘(presumed) new metastases’, ‘treated metastases’, and ‘indeterminate lesions’. Non-specific language was subdivided based on the type of lesion(s) described: e.g. ‘stable enhancing foci’ was deemed a non-specific description of ‘treated metastases’. Results Non-specific descriptions of lesions were used in 25/94 reports (26.6%) pre-template, and eight reports (17.8%) post-template. No significant difference was found in the frequency of inappropriate/ambiguous descriptions of intracranial lesions following template initiation ( P = 0.52). However, only 27/45 (60.0%) of the reports in the post-template time period used the structured report; the other reports were written as free prose. Of the reports that did use the structured template, the authors used significantly less ambiguous language structured template ( P = 0.02). Conclusion When utilized, a structured report template resulted in decreased non-specific descriptions and improved discrete characterization of intracranial metastases in patients treated with radiation. However, the frequency of non-specific language usage before and after template initiation was unchanged, probably due to poor compliance with template utilization.

The content of either D2O or Na24 has been measured in the intestinal lymph, portal venous blood, and femoral arterial blood of unanesthetized hydrated rats after administration of the isotope into the stomach, duodenum, or peripheral or portal vein. Little, if any, water or sodium ion is delivered to the body by a lymphatic pathway after absorption from the small intestine. At least 99% is carried in portal venous blood. The amount of isotope found in intestinal lymph was proportional to lymph volume whatever the route of administration, and derived mainly from the arterial blood. Even during absorption of water or sodium ion from the small intestine the arterial circulation is the principal source of the water and sodium of the lymph.