Volume Navigation with Contrast Enhanced Ultrasound and Image Fusion for Percutaneous Interventions: First Results

Percutaneous biopsies and drainages, even of small lesions involving complex access pathways, can be accomplished with a high success rate by using 3D real time image fusion together with real time needle tracking

Patient characteristics.

<p>Patient characteristics.</p

Image fusion (ultrasound and CT) for interventional planning for local radiofrequency ablation.

<p>A 67 years old patient with colorectal carcinoma and several partial liver resections in his history showed a new solitary liver metastasis in segment II of the liver, clearly visible in ceCT. The referring surgeons requested a local radiofrequency ablation of the metastasis. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033956#pone-0033956-g002" target="_blank">Figure 2 A</a>. The metastasis cannot be detected in fundamental B-scan, but in the ceCT on the right side. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033956#pone-0033956-g002" target="_blank">Figure 2 B</a>. For image fusion the contrast enhanced CT scan is color-coded and superimposed onto the fundamental B-scan. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033956#pone-0033956-g002" target="_blank">Figure 2 C</a>. CEUS clearly shows the metastasis, and is therefore used for planning of the radiofrequency ablation. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033956#pone-0033956-g002" target="_blank">Figure 2 D</a>. CEUS control after radiofrequency ablation with point registration shows complete necrosis in the area of the former metastasis with a safety margin of over 1 cm in all directions.</p

Abscess drainage performed with image fusion (ultrasound and CT).

<p>A 45 years old patient presented with elevated infection parameters and fever after partial resection of the stomach. Contrast-enhanced CT showed an abscess. The referring surgeons requested a drainage. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033956#pone-0033956-g003" target="_blank">Figure 3A</a>. Fusion of fundamental B-Scan and contrast-enhanced CT for planning the intervention shows subcapsulary a mostly liquid formation in liver segment VIII (white arrow). <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033956#pone-0033956-g003" target="_blank">Figure 3B</a>. Overlay technique (color-coded CT and fundamental B-Scan) for optimized fusion. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033956#pone-0033956-g003" target="_blank">Figure 3C</a>. CEUS shows a clearly demarcated mostly liquid formation in liver segment VIII and excellent image fusion with ceCT. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033956#pone-0033956-g003" target="_blank">Figure 3D</a>. Planning of needle tracking (V Nav). The virtual puncture line is showing the anticipated end point of the needle in the middle of the formation (green circle). The subcostal cutaneous beginning of the puncture line lies outside the displayed plane (brown square marked ‘N’). <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033956#pone-0033956-g003" target="_blank">Figure 3E</a>. The needle tip now lies in the center of the formation (small green quadrant marked ‘N’) and next to the planned location (green circle). <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033956#pone-0033956-g003" target="_blank">Figure 3F</a>. B-scan control confirms needle tip within the formation (white arrow). <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033956#pone-0033956-g003" target="_blank">Figure 3G</a>. Drainage has been inserted in Seldinger technique. US contrast agent applied over drainage is documented within the abscess formation in parallel imaging (B-scan and contrast mode).</p