The software myNeedle Guide allows you to plan the routes of needles in the 3D volume. It provides a real-time display of the planned routes in the image and thus serves as a guide for insertion procedures.

One or more needle/puncture paths can be planned, either in the newly purchased 3D volume or in a 3D volume belonging to the same patient but from another exam. XA (DynaCT/3D Angio), MRI, CT, PET, or SPECT volumes can be used.

When planning in a previous 3D volume, from another examination, it is necessary to execute a 3D/3D registration between the planning volume and the examination patient.

Fig 1: Cone-beam CT–guided abdominal abscess drain placement. (A) Initial contrast-enhanced CT scan shows an air-liquid deep pelvic collection in the left side. This could not be visualized with US. Collection is located posterior to a previous surgical drainage, orange arrow. (B) 50% fusion image after 3D/3D registration between the planning volume and the examination patient. (C, D) Needle trajectory (green line) is created from the skin entry site to the fluid collection (arrow), which is shown in axial and sagittal views. The system shows the distance from the skin to the target in millimeters.

Bull's Eye View: At this position in the system, the C-arm of ARTIS pheno system is angled in the same direction as the path of the active needle. Sight is used to determine the point of entry into the skin and align the needle.

Fig 2: (A) Robotic C-arm ARTIS pheno system. (B, C) The system automatically aligns the laser cross with the planned location and angle path. You can monitor the progression of the needles using imaging.

Progression View 1 (Bull's Eye View) and Progression View 2 (Lateral view): These two system positions are automatically calculated and are used to control the progression of the needle. They offer two side views of the planned needle path.

Fig 3: (A) In the Bull's Eye View, the destination is indicated by a circle. (B) In the lateral view, the destination is indicated by an arrow. (C) Real real-time fluoroscopic view allows the operator to track needle progression from the skin entry site to the target site.

Alternatively, the current position of the needle inside the patient can be checked by performing a follow-up scan.

Fig 4: Intermediate follow-up scan to check needle position inside the patient. The tip of the needle is located close to anterior border of the collection, red arrow.

In-Plane View allows to check if Bull's Eye View can be achieved. The three MPR segments and the VRT segment automatically align with the path defined for the needle. To avoid possible damage to critical anatomical structures, check the planned path for the needle in different views.

Fig 5: In-plane view shows correct placement of the needle inside an air-fluid pelvic collection. MPR and VRT reconstructions.

At the end, a control scan can be performed to acquire a current 3D volume. The new 3D volume will be automatically merged with the planning 3D volume, to check and assess the placement of the needle (2).

Fig 6: End control scan to check pig-tail catheter position inside air-liquid pelvic collection. Note iodine contrast filling the collection to confirm correct placement. (A) Cone beam-CT in sagittal view. (B) 50% fusion image after 3D/3D registration between the planning volume and the examination patient.

This technology decreases procedure time (1) and increases safety and effectiveness, as well as potential decreases in radiation dose to the patient, in the treatment of deep pelvic collections.

Conscious sedation and no rigid immobilization of the patient are necessary.

We illustrate this procedure with several cases. Figures

Fig 7: (A) Female 62y with acute diverticulitis and poor evolution post laparoscopic treatment (same patient of figures 1 and 6). Residual air-liquid deep pelvic collection, red arrow. (B, C) Needle trajectory planning is shown in sagittal MPR and VRT fused images. Note two previous surgical drainages catheters located into the pelvis. (D) Final control scan with pig-tail catheter inside the collection, orange arrow. 50% fusion image after 3D/3D registration between the planning volume and the examination patient.

Fig 8: (A) Male 61y urothelial high grade bladder carcinoma treated with radical cystectomy with ileal conduit (Bricker). Pelvic recurrence with abscess. No clear differentiation with near intestinal loops in ultrasonography. Same patient of figure 5. (B) Fused VRT image with planning needle cranio-caudal trajectory, green line. Correct placement of the needle inside the collection in MPR views. Cone-Beam CT (C) and 50% fusion image after 3D/3D registration between the planning volume and the examination patient (D). A pig-tail drainage catheter was placed (not shown).

Fig 9: (A) Female 64y terminal ileitis, orange arrow, and pelvis abscess with gas bubbles, green arrow, which is not visible in echography. (B, C) MPR views fusion images after punction of the collection. Ileal fistula was demonstrated after iodine contrast injection. (D) No leakage of purulent material. Inflammatory bowel disease was suspected, no drainage is left. Good evolution with antibiotic and anti-inflammatory treatment.

In the follow-up, 3D/3D registration can be used to check correct placement of the drainage catheter and monitoring decrease volume collections.