Ultrasound evaluation of portal venous gas and its mimics.

Portal venous gas on abdominal ultrasound classically represents an indirect indicator of bowel ischemia, a critical condition which poses a high patient mortality and therefore warrants emergent corrective action. While the classic appearance of portal venous gas on ultrasound is well-described in the literature, the characteristic descriptors are nonspecific and may actually represent other less emergent mimics. Therefore, while radiologists should remain vigilant for the detection of findings corresponding to portal venous gas, they should also be aware of similar-appearing entities in order to provide the most accurate diagnosis. This pictorial essay will open with imaging examples of true portal venous gas attributable to bowel ischemia and describe the classic features which should alert radiologists to this specific diagnosis. Subsequently, this pictorial essay will provide imaging examples of other various other clinical entities which on ultrasound may share similar imaging characteristics. An important objective of this pictorial essay is to highlight distinguishing imaging features along with specific clinical circumstances for each pathological entity which can direct radiologists into identifying the correct diagnosis.

Direct stick embolization of a rectal venous malformation via transanal minimally invasive surgery.

Rectal venous malformations (VMs) are rare clinical entities with variable patterns of presentation. Treatment requires unique, targeted strategies based on the symptoms, associated complications, and location, depth, and extent of the lesion. We present a rare case of a large, isolated rectal VM treated by direct stick embolization (DSE) using transanal minimally invasive surgery (TAMIS). A 49-year-old man had presented with a rectal mass incidentally detected on computed tomography urography. Magnetic resonance imaging and endoscopy revealed an isolated rectal VM. Elevated D-dimer levels concerning for localized intravascular coagulopathy warranted the use of prophylactic rivaroxaban. To avoid invasive surgery, DSE using TAMIS was performed successfully without complications. His postoperative recovery was uneventful, aside from a self-limiting and expected course of postembolization syndrome. To the best of our knowledge, this is the first reported case of TAMIS-assisted DSE of a colorectal VM. TAMIS shows promise for more widespread use in the minimally invasive, interventional management of colorectal vascular anomalies.

Creation of an Ex Vivo Renal Perfusion Model to Investigate Microwave Ablation.

This study hypothesized that an ex vivo renal perfusion model can create smaller microwave ablation (MWA) measurements during perfused states compared with nonperfused states across multiple device settings. Nine bovine kidneys, a fluoroscopic compatible perfusion model, and a commercially-available clinical MWA system were used to perform 72 ablations (36 perfused and 36 nonperfused) at 9 different device settings. Comparing perfused and nonperfused ablations at each device setting, significant differences in volume existed for 6 of 9 settings (P < .05). Collapsed across time settings, the ablation volumes by power were the following (perfused and nonperfused, P value): 60 W, 2.3 cm3 ± 1.0 and 7.2 cm3 ± 2.7, P < .001; 100 W, 5.4 cm3 ± 2.1 and 11.5 cm3 ± 5.6, P < .01; and 140 W, 11.2 cm3 ± 3.7 and 18.7 cm3 ± 6.3, P < .01. Applied power correlated with ablation volume: perfused, 0.021 cm3/W and R = 0.462, P = .004, and nonperfused, 0.029 cm3/W and R = 0.565, P < .001. These results support that an ex vivo perfused organ system can evaluate MWA systems and demonstrate heat sink perfusion effects of decreased ablation size.

Correlation of Glottic Gap and Voice Impairment in Presbyphonia.

OBJECTIVE/HYPOTHESIS: The objective of this study was to investigate the glottic gap area as a significant marker for the severity of presbyphonia as it relates to patient-reported outcome measures (Voice Handicap Index-10 [VHI-10]) and stroboscopic findings. STUDY DESIGN: Retrospective case-control study conducted in an academic tertiary voice center. METHODS: Patients seen at a tertiary voice clinic who were diagnosed with presbyphonia without other organic laryngeal pathology from January 2014 to December 2017 were included. Clinical data and laryngeal videostroboscopy videos were collected. Still images at the point of vocal process approximation during adduction were captured, and the glottic gap area was measured using ImageJ. These were compared to a control cohort. Correlations were made using Wilcoxon rank sum test, Mann-Whitney U test, and Pearson correlation coefficients. RESULTS: Thirty-three patients were included. Inter-rater reliability of glottic area measurement was strong (intraclass correlation coefficient = 0.73, P < .001). Compared to controls, presbyphonia patients had a larger glottic gap area (P < .001) and greater open-phase quotient on laryngeal videostroboscopy (P < .001). Larger glottic gap area did not correlate with patient-reported vocal function as measured by VHI-10 (P = .79) and did not correlate with presence of secondary muscle tension dysphonia (P = .99). In the presbyphonia cohort, the glottic gap area did not correlate with age (P = .29). CONCLUSIONS: Glottic gap area at the point of vocal process approximation during phonation can be reliably measured. Patients with presbyphonia have a larger glottic gap area and greater open-phase quotient on stroboscopy, but these do not correlate with patient-reported voice impairment or the presence of secondary muscle tension dysphonia (MTD). These data suggest that dysphonia severity in presbyphonia is not fully explained by a glottic gap or secondary MTD alone. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:1594-1598, 2021.

18F-Fluciclovine Uptake in a Ureterocele.

A 60-year-old man with prostate adenocarcinoma status post radical prostatectomy and bilateral pelvic lymph node dissection referred for restaging F-fluciclovine PET/CT due to rising serum prostate-specific antigen levels (1.1 ng/mL at that time of imaging). PET/CT images were obtained from the proximal thighs to the vertex of the skull approximately 3 to 5 minutes after the IV administration of 347.8 MBq (9.4 mCi) of F-fluciclovine. PET/CT imaging demonstrated a focus of abnormally increased F-fluciclovine uptake at the right ureterovesical junction. Subsequent MRI of the pelvis revealed that this focus corresponded to a benign ureterocele.

Incidental 18F-Fluciclovine Uptake in a Warthin Tumor of the Parotid Gland in a Patient Undergoing PET/CT Imaging for Biochemical Recurrent Prostate Cancer.

A 67-year-old asymptomatic man with biochemical recurrent prostate cancer underwent F-fluciclovine PET/CT for restaging to determine subsequent treatment strategy. PET/CT images were obtained from the proximal thighs to the vertex of the skull, after the intravenous administration of 362.6 MBq (9.8 mCi) of F-fluciclovine. PET/CT imaging demonstrated a focus of abnormally increased F-fluciclovine uptake corresponding to a small nodularity in the left parotid gland. Subsequent ultrasound-guided fine-needle aspiration biopsy of the lesion revealed histopathology compatible with a benign Warthin tumor.