Point-of-care lung ultrasound for the assessment of pneumonia: a narrative review in the COVID-19 era.

In the coronavirus disease-2019 (COVID-19) era, point-of-care lung ultrasound (LUS) has attracted increased attention. Prospective studies on LUS for the assessment of pneumonia in adult patients were extensively carried out for more than 10 years before this era. None of these prospective studies attempted to differentiate bacterial and viral pneumonia in adult patients using LUS. The majority of studies considered the LUS examination to be positive if sonographic consolidations or multiple B-lines were observed. Significant differences existed in the accuracy of these studies. Some studies revealed that LUS showed superior sensitivity to chest X-ray. These results indicate that point-of-care LUS has the potential to be an initial imaging modality for the diagnosis of pneumonia. The LUS diagnosis of ventilator-associated pneumonia in intensive care units is more challenging in comparison with the diagnosis of community-acquired pneumonia in emergency departments due to the limited access to the mechanically ventilated patients and the high prevalence of atelectasis. However, several studies have demonstrated that the combination of LUS findings with other clinical markers improved the diagnostic accuracy. In the COVID-19 era, many case reports and small observational studies on COVID-19 pneumonia have been published in a short period. Multiple B-lines were the most common and consistent finding in COVID-19 pneumonia. Serial LUS showed the deterioration of the disease. The knowledge and ideas on the application of LUS in the management of pneumonia that are expected to accumulate in the COVID-19 era may provide us with clues regarding more appropriate management.

MRI features of the nested variant of urothelial carcinoma of the urinary bladder: report of four cases.

We report on four patients with the nested variant of urothelial carcinoma (NVUC) of the urinary bladder and focus on their magnetic resonance imaging (MRI) findings. MRI showed that all lesions had irregular wall thickening with little protrusion into the bladder lumen. All had extravesical invasion, and two had invaded other organs (uterus and seminal vesicle). On T2-weighted images, all tumors mainly showed relatively strong hypointensity similar to that of the muscularis propria, and in three cases there was also a thin hyperintense layer on the tumor surface, suggesting edematous mucosa. Diffusion-weighted images demonstrated different degrees of hyperintensity, which was faint in one case. Dynamic contrast-enhanced MRI was performed in two cases and both showed gradual contrast enhancement. It has been suggested that NVUC may produce unique MRI findings reflecting its pathological features. It would be useful for those who interpret bladder MRI to recognize this rare urothelial carcinoma variant.

MRI features of mucinous adenocarcinoma of the prostate: report of four cases.

CASE REPORTS: We report four patients with mucinous adenocarcinoma of the prostate, focusing on their magnetic resonance imaging (MRI) findings. The lesions appeared hyperintense on T2-weighted images (T2WI) in all four patients. In the two patients in whom the tumors were confined to the peripheral zone (PZ), the lesions were isointense to the surrounding normal PZ, making them difficult to identify. In all three patients who underwent diffusion-weighted imaging (b = 1000), the lesions appeared hyperintense but visually there was little or no decrease in the apparent diffusion coefficient (ADC), with ADC values of 1.02, 1.39, and 1.66 × 10-3 mm2/s, respectively. In the three patients who underwent a dynamic contrast-enhanced MR study, early enhancement was evident in two (partial in one), and gradually increasing enhancement in one. CONCLUSION: In the four cases in this instance, MRI findings of mucinous adenocarcinoma were very different from the appearance of non-mucinous adenocarcinoma. It is suggested that the conventional interpretation method of MRI for prostate cancer is not suitable for mucinous adenocarcinoma. Those who interpret prostate MRI should be aware of this rare and unique subtype of prostate cancer.

Preparation of Transparent Bulk TiO2/PMMA Hybrids with Improved Refractive Indices via an in Situ Polymerization Process Using TiO2 Nanoparticles Bearing PMMA Chains Grown by Surface-Initiated Atom Transfer Radical Polymerization.

Transparent TiO2/PMMA hybrids with a thickness of 5 mm and improved refractive indices were prepared by in situ polymerization of methyl methacrylate (MMA) in the presence of TiO2 nanoparticles bearing poly(methyl methacrylate) (PMMA) chains grown using surface-initiated atom transfer radical polymerization (SI-ATRP), and the effect of the chain length of modified PMMA on the dispersibility of modified TiO2 nanoparticles in the bulk hybrids was investigated. The surfaces of TiO2 nanoparticles were modified with both m-(chloromethyl)phenylmethanoyloxymethylphosphonic acid bearing a terminal ATRP initiator and isodecyl phosphate with a high affinity for common organic solvents, leading to sufficient dispersibility of the surface-modified particles in toluene. Subsequently, SI-ATRP of MMA was achieved from the modified surfaces of the TiO2 nanoparticles without aggregation of the nanoparticles in toluene. The molecular weights of the PMMA chains cleaved from the modified TiO2 nanoparticles increased with increases in the prolonging of the polymerization period, and these exhibited a narrow distribution, indicating chain growth controlled by SI-ATRP. The nanoparticles bearing PMMA chains were well-dispersed in MMA regardless of the polymerization period. Bulk PMMA hybrids containing modified TiO2 nanoparticles with a thickness of 5 mm were prepared by in situ polymerization of the MMA dispersion. The transparency of the hybrids depended significantly on the chain length of the modified PMMA on the nanoparticles, because the modified PMMA of low molecular weight induced aggregation of the TiO2 nanoparticles during the in situ polymerization process. The refractive indices of the bulk hybrids could be controlled by adjusting the TiO2 content and could be increased up to 1.566 for 6.3 vol % TiO2 content (1.492 for pristine PMMA).

Point-of-care ultrasound detection of tracheal wall thickening caused by smoke inhalation.

Smoke inhalation is the leading cause of death due to fires. When a patient presents with smoke inhalation, prompt assessment of the airway and breathing is necessary. Point-of-care ultrasonography (US) is used for the rapid assessment of critically ill or injured patients. We herein present a case report of a 54-year-old male who was transferred to the emergency department with shortness of breath, coughing, carbonaceous sputa, and rhinorrhea after inhaling smoke caused by a fire in his locked bedroom. He had no surface burns on the face and no edema or erosion in the oral cavity. He had hoarseness without stridor. His breath sounds were positive for expiratory wheezes. Laryngoscopy showed light edema and erosive findings on the supraglottic region. Bedside point-of-care US revealed hypoechoic thickening of the tracheal wall. The thickening was confirmed by a computed tomographic scan. The patient was carefully monitored with preparation for emergency airway management and was treated with supplemental oxygen and an aerosolized beta-2 adrenergic agonist in the intensive care unit. The symptoms were subsequently relieved, and reexamination by US after 2 days showed remission of the wall thickening. Point-of-care US may therefore be a useful modality for the rapid diagnosis and effective follow-up of tracheal wall thickening caused by smoke inhalation.

Transabdominal ultrasound-guided urethral catheterization with transrectal pressure.

BACKGROUND: Occasionally, difficulty with standard urethral catheterization is encountered. OBJECTIVE: We conducted a pilot study to evaluate whether transabdominal ultrasound (TAUS) showed the tip of a urethral catheter and whether TAUS-guided catheterization with transrectal pressure is successful in male patients in whom performing standard catheterization is difficult. METHODS: The eligible study participants included adult male patients in whom standard catheterization failed in our emergency department or who were transferred from other facilities after failure of catheterization and subsequent urethral bleeding. The enrolled patients included those in whom the tip of a catheter could not be advanced through the posterior and bulbar urethra judging from the inserted length. First, an emergency nurse advanced a catheter until the progress was obstructed. Next, an emergency physician performed TAUS to detect the tip of the catheter. If the tip was detected, the physician inserted the index finger into the rectum and kept pushing the site of the obstruction. After following these procedures, the nurse again advanced the catheter. RESULTS: Six patients were enrolled. The tip of a catheter was detected in the urethra or the false passage using TAUS in 4 of the 6 patients. In these 4 patients, the curve of the urethra became gentle or the false passage was compressed by transrectal pressure and the tip was advanced smoothly to the bladder. CONCLUSIONS: In some male patients in whom performing standard urethral catheterization is difficult, TAUS reveals the tip of the catheter and TAUS-guided catheterization with transrectal pressure can be safe and useful.

Cross-leg fillet flap for the reconstruction of severe bilateral leg burns.

For a patient with fourth-degree burns involving both legs, we performed an amputation of the right leg at the thigh and covered the left knee joint with the posterior part of the right leg as a cross-leg fillet flap. It is reasonable to use tissue from one leg for reconstruction of the other leg in order to avoid bilateral leg amputation in the treatment of bilateral severe leg injury. We could transfer a sufficient amount of tissue by using this flap without donor site morbidity. Generally, hip or knee joint contracture is a major problem with the cross-leg flap. The long pedicle of this flap allowed the patient some leg movement and there was no contracture at his knee or hip joints. We cannot use this flap as a sensory flap because of pedicle cutting, but inappropriate sensation of the lower extremity is uncomfortable and reduces a patient's quality of life. The cross-leg fillet flap described here avoids donor site morbidity without the use of microsurgery. This flap will become a treatment option for severe bilateral leg injuries when one leg requires amputation.