A case of strangulated bowel obstruction in which transabdominal ultrasound was useful for preoperative diagnosis.

A 74-year-old man presented to the emergency department with the chief complaint of abdominal pain. A computed tomography scan showed paralytic ileus. An ileostomy tube was placed, but the symptoms of bowel obstruction did not improve. Two days after admission, the patient's renal function deteriorated. Transabdominal ultrasound (TUS) showed linear high-intensity echoes consistent with a fibrotic band and microbubbles suggestive of circulatory disturbance in the dilated intestinal tract. Subsequent contrast-enhanced ultrasound revealed circulatory disturbance of the small bowel wall. Emergency surgery was performed under the diagnosis of strangulated ileus. Intraoperative examination revealed that the terminal ileum was strangulated by a fibrotic band from the retroperitoneum, which was confirmed by TUS. The fibrotic band was resected, the strangulation was released, and ileocecal resection was performed. Postoperatively, intestinal peristalsis was rapidly restored. TUS was able to depict the fibrotic band, which could not be detected by a computed tomography scan, allowing the patient to undergo immediate surgical treatment. We herein report this case of strangulated bowel obstruction in which TUS and contrast-enhanced ultrasound were useful in preoperative assessment of the patient's condition.

Feasibility, safety, and efficacy of artificial carbon dioxide pneumothorax for computed tomography fluoroscopy-guided percutaneous radiofrequency ablation of hepatocellular carcinoma.

PURPOSE: To retrospectively assess the feasibility, safety, and efficacy of artificial carbon dioxide (CO2) pneumothorax for computed tomography (CT) fluoroscopy-guided percutaneous radiofrequency (RF) ablation of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This study included 26 sessions of 24 patients in whom the creation of artificial CO2 pneumothorax was attempted to avoid the transpulmonary route during CT fluoroscopy-guided percutaneous RF ablation of HCC between April 2011 and December 2017. In these 26 sessions, 29 HCCs (mean tumor diameter: 12 mm, range: 6-22 mm) were treated. RESULTS: Adequate lung displacement after induction of artificial CO2 pneumothorax was achieved in 23 of the 26 sessions (88.5%). In the remaining three sessions, transpulmonary RF ablation, transthoracic extrapulmonary RF ablation after switching to an artificial pleural effusion procedure, or RF ablation with electrode insertion in the caudal-cranial oblique direction was performed. No major complications were found. Among the 29 treated tumors, one (3.4%) showed local progression, and the other 28 (96.6%) were completely ablated at the last follow-up (mean follow-up period: 39.3 months, range: 7-78 months). CONCLUSION: Artificial CO2 pneumothorax for CT fluoroscopy-guided percutaneous RF ablation appeared to be a feasible, safe, and useful therapeutic option for HCC.

Temperature imaging of water in a microchannel using thermal sensitivity of near-infrared absorption.

This paper presents a remote and preparation-free method of temperature imaging of aqueous solutions in microchannels of microfluidic chips. The principle of this method is based on the temperature dependency of the near-infrared (NIR) absorption band (ν(2) + ν(3) band) of water. Temperature images were constructed from absorbances in a narrow wavelength range including 1908 nm, the most sensitive to temperature in the band, measured by using an NIR camera and an optical narrow-bandpass filter. Calculation and calibration results demonstrated a linear relationship between the absorption coefficient and temperature with a temperature coefficient of 1.5 × 10(-2) K(-1) mm(-1). Temperature images of 50 µm thick water in a Y-shaped PDMS microchannel locally heated by a neighboring hot wire were obtained, in which thermal diffusion processes in the microchip were visualized. Temperature resolution was estimated to be approximately 0.2 K according to the temperature coefficient and noise level.