The Role of Cone-Beam Computed Tomography CT Extremity Arthrography in the Preoperative Assessment of Osteoarthritis

Abstract

Osteoarthritis (OA) is a prevalent disease and the leading cause of pain, disability, and quality of life deterioration. Our study sought to evaluate the image quality and dose of cone-beam computed tomography arthrography (CBCT-A) and compare them to digital radiography (DR) for OA diagnoses. Overall, 32 cases of CBCT-A and DR with OA met the inclusion criteria and were prospectively analyzed. The Kellgren and Lawrence classification (KLC) stage, sclerosis, osteophytes, erosions, and mean joint width (MJW) were compared between CBCT-A and DR. Image quality was excellent in all CBCT-A cases, with excellent inter-observer agreement. OA under-classification was noticed with DR for MJW (p = 0.02), osteophyte detection (<0.0001), and KLC (p < 0.0001). The Hounsfield Unit (HU) values obtained for the cone-beam computed tomography CBCT did not correspond to the values for multi-detector computed tomography (MDCT), with a greater mean deviation obtained with the MDCT HU for Modeled Based Iterative Reconstruction 1st (MBIR1) than for the 2nd generation (MBIR2). CBCT-A has been found to be more reliable for OA diagnosis than DR as revealed by our results using a three-point rating scale for the qualitative image analysis, with higher quality and an acceptable dose. Moreover, the use of this imaging technique permits the preoperative assessment of extremities in an OA diagnosis, with the upright position and bone microarchitecture analysis being two other advantages of CBCT-A.

Keywords: Kellgren and Lawrence classification; X-ray; cone-beam computed tomography arthrography; density; osteoarthritis; radiation.

Figure 1

Diagram of patient recruitment with inclusion criteria.

Figure 2

Upright position in the WB CBCT to investigate the foot, ankle, or knee, (A) and sitting position with arm extended to explore the hand and wrist (B). WB: weight-bearing; CBCT: cone-beam computed tomography.

Figure 3

The CIRS-062MA Phantom comprises nine inserts with different materials corresponding to different electronic densities (A). It is used to calibrate the system in terms of HU for eight different electronic densities corresponding to eight tissues and a standard removable vial for CBCT and MDCT. Example of ROI measurement of each density tunnel (B). HU: Hounsfield unit; CBCT: cone-beam computed tomography; MDCT: multi-detector computed tomography; ROI: region of interest.

Figure 4

The HU numbers of all 32 CBCT-As were analyzed in the coronal plane after the application of MBIR2. Here, an example of a right knee is shown. The HUs for CM, trabecular and cortical sub chondral bone, and for cartilage densities were reported. ROIs were also placed with three measurements for every item (A). The MJW was evaluated with the MJW at the lateral and medial side of the femoro-tibial joint (B). HU: Hounsfield unit; CBCT-A: cone-beam computed tomography arthrography; ROI: region of interest; MJW: mean joint width; CBCT: cone-beam computed tomography; MDCT: multi-detector computed tomography.

Figure 5

Plexiglas phantom (PMMA) used to represent hand or wrist extremities to calculate the absorbed dose of the CBCT and DR imaging modalities, with dimensions of 20 × 15 × 4 cm³ CBCT: cone-beam computed tomography; DR: digital radiography.

Figure 6

CBCT-A of left wrist in coronal (A) and sagittal (B) planes, which showed sub chondral erosion ((A) white arrow) and definite anterior osteophyte of the radial lip ((B) red arrow), grade 3 of the KLC scoring system. The AP DR showed a possible joint space narrowing between the scaphoid and radial styloid ((C) dark dotted circle), grade 2 of KLC scoring system. The KLC scoring based on DR is underestimated compared to CBCT-A. As osteoarthritis was confirmed between the radius and scaphoid bone surfaces, scaphoidectomy was performed for this patient instead of styloidectomy considered initially based on DR analysis. CBCT-A: cone-beam computed tomography arthrography; DR: digital radiography; KLC: Kellgren and Lawrence classification.

Figure 7

CBCT-A of right ankle in coronal (A,B) planes, showing sub chondral erosion ((A) white arrow) and definite medial talo-crural with cartilage loss ((B) dark arrow), grade 3 of KLC scoring system. The AP DR showed a possible joint space narrowing ((C) dark dotted circle) and a small osteophyte ((C) red arrow), grade 2 of KLC scoring system. The KLC grading based on DR under estimated compared to CBCT-A. The presence of material was a limitation to performing MRI in this case. CBCT-A: cone-beam computed tomography arthrography; DR: digital radiography; KLC: Kellgren and Lawrence classification; MRI: Magnetic resonance imaging.