The technique of laparoscopic pelvic ultrasonography for metastatic lymph node

Segmentation of Uterus Using Laparoscopic Ultrasound by an Image-Based Active Contour Approach for Guiding Gynecological Diagnosis and Surgery

In laparoscopic gynecologic surgery, ultrasound has been typically implemented to diagnose urological and gynecological conditions. We applied laparoscopic ultrasonography (using Esaote 7.5~10MHz laparoscopic transducer) on the retrospective analyses of 42 women subjects during laparoscopic extirpation and excision of gynecological tumors in our hospital from August 2011 to August 2013. The objective of our research is to develop robust segmentation technique for isolation and identification of the uterus from the ultrasound images, so as to assess, locate and guide in removing the lesions during laparoscopic operations. Our method enables segmentation of the uterus by the active contour algorithm. We evaluated 42 in-vivo laparoscopic images acquired from the 42 patients (age 39.1 ± 7.2 years old) and selected images pertaining to 4 cases of congenital uterine malformations and 2 cases of pelvic adhesions masses. These cases (n = 6) were used for our uterus segmentation experiments. Based on them, the active contour method was compared with the manual segmentation method by a medical expert using linear regression and the Bland-Altman analysis (used to measure the correlation and the agreement). Then, the Dice and Jaccard indices are computed for measuring the similarity of uterus segmented between computational and manual methods. Good correlation was achieved whereby 84%-92% results fall within the 95% confidence interval in the Student t-test) and we demonstrate that the proposed segmentation method of uterus using laparoscopic images is effective.

A novel ultrasound based approach for lesion segmentation and its applications in gynecological laparoscopic surgery

Laparoscopic ultrasound (LUS) has been widely utilized as a surgical aide in general, urological, and gynecological applications. Our study summarizes the clinical applications of laparoscopic ultrasonography in laparoscopic gynecologic surgery. Retrospective analyses were performed on 42 women subjects using laparoscopic surgery during laparoscopic extirpation and excision of gynecological tumors in our hospital from August 2011 to August 2013. Specifically, the Esaote 7.5 × 10 MHz laparoscopic transducer was used to detect small residual lesions, as well as to assess, locate and guide in removing the lesions during laparoscopic operations. The findings of LUS were compared with those of preoperative trans-vaginal ultrasound, postoperative, and pathohistological examinations. In addition, a novel method for lesion segmentation was proposed in order to facilitate the laparoscopic gynecologic surgery. In our experiment, laparoscopic operation was performed using a higher frequency and more close to pelvic organs via laparoscopic access. LUS facilitates the ability of gynaecologists to find small residual lesions under laparoscopic visualization and their accurate diagnosis. LUS also helps to locate residual lesions precisely and provides guidance for the removal of residual tumor and eliminate its recurrence effectively. Our experiment provides a safer and more valuable assistance for clinical applications in laparoscopic gynecological surgery that are superior to trans-abdominal ultrasound and trans-vaginal ultrasound.

Preoperative ultrasound is not useful for identifying nodal metastasis in melanoma patients undergoing sentinel node biopsy: preoperative ultrasound in clinically node-negative melanoma

BACKGROUND

Sentinel lymph node biopsy (SLNB) is widely used in melanoma. Identifying nodal involvement preoperatively by high-resolution ultrasound may offer less invasive staging. This study assessed feasibility and staging results of clinically targeted ultrasound (before lymphoscintigraphy) compared to SLNB.

METHODS

From 2005 to 2009, a total of 325 patients with melanoma underwent ultrasound before SLNB. We reviewed demographics and histopathologic characteristics, then compared ultrasound and SLNB results. Sensitivity, specificity, and positive and negative predictive value were determined.

RESULTS

A total of 325 patients were included, 58% men and 42% women with a median age of 58 (range 18-86) years. A total of 471 basins were examined with ultrasound. Only six patients (1.8%) avoided SLNB by undergoing ultrasound-guided fine-needle aspiration of involved nodes, then therapeutic lymphadenectomy. Sixty-five patients (20.4%) had 69 SLNB positive nodal basins; 17 nodal basins from 15 patients with positive ultrasounds were considered truly positive. Forty-five SLNB positive basins had negative ultrasounds (falsely negative). Seven node-positive basins did not undergo ultrasound because of unpredicted drainage. A total of 253 patients with negative SLNBs had negative ultrasounds in 240 nodal basins (truly negative) but falsely positive ultrasounds occurred in 40 basins. Overall, sensitivity of ultrasound was 33.8%, specificity 85.7%, positive predictive value 36.5%, and negative predictive value 84.2%. Sensitivity and specificity improved somewhat with increasing Breslow depth. Sensitivity was highest for the neck, but specificity was highest for the groin.

CONCLUSIONS

Routine preoperative ultrasound in clinically node-negative melanoma is impractical because of its low sensitivity. Selected patients with thick or ulcerated lesions may benefit. Because of variable lymphatic drainage patterns, preoperative ultrasound without lymphoscintigraphic localization will provide incomplete evaluation in many cases.