In vivo diagnostics of human knee cartilage lesions using delayed CBCT arthrography

Abstract

The aim of this study was to investigate the feasibility of delayed cone beam (CBCT) arthrography for clinical diagnostics of knee cartilage lesions. Knee joints with cartilage lesions were imaged using native radiography, MRI, and delayed CBCT arthrography techniques in vivo. The joints were imaged three times with CBCT, just before, immediately after (arthrography) and 45 min after the intra-articular injection of contrast agent. The arthrographic images enabled sensitive detection of the cartilage lesions. Use of arthrographic and delayed images together with their subtraction image enabled also detection of cartilage with inferior integrity. The contrast agent partition in intact cartilage (ICRS grade 0) was lower (p < 0.05) than that of cartilage surrounding the ICRS grade I-IV lesions. Delayed CBCT arthrography provides a novel method for diagnostics of cartilage lesions. Potentially, it can also be used in diagnostics of cartilage degeneration. Due to shorter imaging times, higher resolution, and lower costs of CT over MRI, this technique could provide an alternative for diagnostics of knee pathologies. However, for comprehensive evaluation of the clinical potential of the technique a further clinical study with a large pool of patients having a wide range of cartilage pathologies needs to be conducted. Keywords: cartilage lesions; contrast agent diffusion; computed tomography; delayed CBCT arthrography; osteoarthrosis Cartilage lesions are common and can lead to progressive joint degeneration at high cost for the healthcare system. Early diagnosis and grading of cartilage lesions could improve the early selection of treatment, enable monitoring the effect of new treatments and therefore reduce the risk for post traumatic osteoarthritis (OA).Detection of acute cartilage lesions or early OA is challenging since cartilage is not visible in X-ray imaging. Resolution of magnetic resonance imaging (MRI) is limited, and queuing times are long, but it is still the routine method used in cartilage lesion diagnostics and in clinical decision making for or against arthroscopy. In planar X-ray imaging the Xray attenuation of the cartilage is similar with that of the surrounding soft tissues and therefore cartilage is not visible in the images. For this reason diagnosis is mainly based on decreased joint separation and changes in subchondral bone. On the other hand, MRI is not based on ionizing radiation and can be used to visualize soft tissues enabling detection of cartilage defects. Cone beam computed tomography (CBCT) utilizes a conical X-ray beam, covering a large volume with a single rotation about the patient. Due to differences in imaging geometry and collimation of X-rays the radiation dose of CBCT is much smaller than that of spiral CT.1 MRI is especially useful for diagnostics of meniscal tears and lesions of anterior cruciate ligament (ACL) with accuracies of 81% to 98% and specificities of 69% to 98%, respectively, 2 but in the diagnostics of cartilage lesions its sensitivity and specificity ha...

Quantitative Evaluation of the Mechanical Risks Caused by Focal Cartilage Defects in the Knee

“…1c). Similarly as in a previous study17, a delayed image was acquired at 45 min after the injection of contrast agent. Here, due to lower concentration of contrast agent, the delayed image was utilized in the approximation of volumetric bone mineral densities (vBMDs) in order to minimize errors caused by beam hardening artefact often present in CBCT images.…”

“…In addition to segmentation of the damaged tissue, a mask representing completely healthy tissue was created by manually interpolating the intact tissue surface over the defect. Other tissue areas were segmented manually or by using a combination of thresholding and morphological operations17.…”

“…Novel magnetic resonance imaging (MRI) and cone beam computed tomography (CBCT) arthrography techniques can help to estimate in vivo deformation of articular cartilage under simple loading configurations1516. Particularly, CBCT arthrography has shown a great clinical potential for joint diagnostics, especially for the detection of cartilage defects17. Over clinical MRI, the benefits of CBCT arthrography include shorter imaging times, higher resolution and lower costs.…”

Osteoarthritis year in review 2015: imaging

“…Baseline ultrasound detected gray-scale synovitis and power Doppler signals predicted radiographic progression of hand OA after 5 years 62 . Another study showed that ultrasound detected inflammatory features, including synovial thickening, effusion and power Doppler signal, especially when persistently 3 Radiography Hip and pelvic geometry are associated with the risk of compartment-specific knee OA Thomas GE, et al 49 Radiography Cam-type FAI and acetabular dysplasia predict development of hip OA and joint replacement High bone mineral density is associated with knee and hip OA Hardcastle SA, et al 4e6 Radiography High BMD Z scores are associated with increased prevalence of hip and knee OA, specifically osteophytosis Potential new approaches to examining joint structures Turunen M, et al 7 CT CBCT can measure volumetric BMD of cortical, trabecular, and subchondral trabecular bone Kokkonen HT, et al 8 CT Arthrographic images enables sensitive detection of cartilage lesions Riecke BF, et al 10 US Ultrasound score is reliable and valid in detecting knee OA Abraham AM, et al 14 US US demonstrates higher prevalence of osteophytes in hand and hip OA than radiographic studies Liukkonen J, et al 15 US Arthroscopic ultrasound imaging quantitatively evaluates articular cartilage Hirata Y, et al 16 Kobayashi N, et al 17 PET 18F-fluoride uptake is associated with mechanical stress in hip OA and can detect bone abnormalities earlier than MRI Ultrasonographic abnormalities correlate with clinical endpoints Hall M, et al 11 US Effusion and synovial hypertrophy are more common in knee OA, with severity correlating with radiographic severity of knee OA Birn J, et al 12 US Large joint effusions correlates with rapidly destructive hip OA Malas FU, et al 13 US Meniscal bulging is associated with radiographic joint space narrowing and KL grades What is new in magnetic resonance imaging? Morphological structural abnormalities predict clinical endpoints Sharma L, et al 19 MRI Cartilage damage, BMLs, meniscal tears, and meniscal extrusion are associated with prevalent frequent knee symptoms and/or incident persistent symptoms Roemer FW, et al 21 MRI Cartilage damage, BMLs, meniscal damage, synovitis and effusion predicted short-term need for knee joint replacement Eckstein F, et al 22 MRI Accelerated cartilage thickness loss is greatest closest to the time of knee replacement Composition of cartilage influences morphometry Crema MD, et al 25 MRI Poorer dermis endpoints are associated with increased cartilage thickness, potentially representing "cartilage swelling" Ukiah T, et al 26 MRI Diffusion tensor imaging can distinguish early cartilage damage Wyatt C, et al …”

“…Arthrographic images enabled sensitive detection of cartilage lesions. The contrast agent partition in intact cartilage (International Cartilage Repair Society, ICRS, grade 0) was lower than that of cartilage surrounding the ICRS grade IeIV lesions 8 . Another study used contrast enhanced CBCT to image contrast agent diffusion in isolated human menisci and found that shorter delay between injection and imaging (e.g., 40 min) could be feasible in clinical diagnostics of meniscal pathologies 9 .…”