RESUMEN
Vibro-acoustography (VA) uses two or more beams of confocal ultrasound to generate local vibrations within their target tissue through induction of a time-dependent radiation force whose frequency equals that of the difference of the applied frequencies. While VA has proven effective for assaying the mechanical properties of clinically relevant tissue such as breast lesions and tissue calcifications, its application to brain remains unexplored. Here we investigate the ability of VA to detect acute and focal traumatic brain injury (TBI) in-vivo through the use of transcranially delivered high-frequency (2 MHz) diagnostic focused ultrasound to rat brain capable of generating measurable low-frequency (200-270 kHz) acoustic emissions from outside of the brain. We applied VA to acute sham-control and TBI model rats (sham N=6; TBI N=6) and observed that acoustic emissions, captured away from the site of TBI, had lower amplitudes for TBI as compared to sham-TBI animals. The sensitivity of VA to acute brain damage at frequencies currently transmittable across human skulls, as demonstrated in this preliminary study, supports the possibility that the VA methodology may one day serve as a technique for detecting TBI.
Asunto(s)
Lesiones Encefálicas/diagnóstico por imagen , Diagnóstico por Imagen de Elasticidad/métodos , Animales , Diagnóstico por Imagen de Elasticidad/instrumentación , Diseño de Equipo , Masculino , Modelos Estadísticos , Ratas , Ratas Sprague-Dawley , TransductoresRESUMEN
OBJECTIVE: To report the management of urachal anomalies using a robotically assisted approach. PATIENTS AND METHODS: Between January 2005 and February 2006, five patients (mean age 51 years, range 24-68) were diagnosed with urachal anomalies. Two basic robot-assisted surgical approaches were used for excising the urachal anomalies: excision of the urachal remnant via partial cystectomy, and radical cystectomy for excision of urachal adenocarcinoma. RESULTS: All five cases were successful and the excised specimens were assessed histologically. The short-term oncological outcome in the three patients with histologically confirmed moderately differentiated adenocarcinoma showed no evidence of recurrent disease within a median interval of 8 months. Surveillance follow-up cystoscopy in the patients who had a partial cystectomy showed a well-healed bladder mucosa with no evidence of recurrence. CONCLUSIONS: Radical excision of the urachal tract with partial cystectomy or radical cystectomy using the da Vinci robot is safe, effective and technically feasible.