A quantitative assessment of dual energy computed tomography-based material decomposition for imaging bone marrow edema associated with acute knee injury

Diagnostic performance of dual-energy computed tomography in detecting anterior cruciate ligament injuries: a systematic review and meta-analysis

OBJECTIVE

Anterior cruciate ligament (ACL) injuries are common and lead to significant physical limitations. While MRI is the diagnostic gold standard, its use is restricted in acute trauma cases due to contraindications and longer imaging times. Dual-energy computed tomography (DECT) has emerged as a potential alternative. This meta-analysis evaluates the diagnostic accuracy of DECT for ACL injuries.

MATERIALS AND METHODS

Following PRISMA guidelines, a comprehensive literature search was conducted using PubMed, Web of Science, Scopus, and Embase for studies published up to June 2024. Studies that provided diagnostic accuracy data for DECT in ACL ruptures were included. Metrics of diagnostic accuracy were aggregated using a bivariate random effects model.

RESULTS

The meta-analysis, which included five studies with a total of 191 patients, found that DECT had a pooled sensitivity of 88.1% (95% CI, 78.0-93.9%) and a specificity of 82.0% (95% CI, 62.0-92.7%) for diagnosing ACL ruptures, with an AUC of 0.92 (95% CI, 0.72-0.96). For complete ruptures, sensitivity was 83.2% (95% CI, 68.2-92.0%), and specificity was 94.9% (95% CI, 92.2-96.7%), with an AUC of 0.96 (95% CI, 0.81-0.98). In acute/subacute settings, sensitivity was 89.4% (95% CI, 76.8-95.6%), and specificity was 82.1% (95% CI, 56.2-94.2%), with an AUC of 0.93 (95% CI, 0.71-0.97).

CONCLUSION

Our findings suggest that DECT is a valuable diagnostic tool for ACL injuries, particularly as an adjunct or alternative when MRI is unavailable or contraindicated, enabling timely and accurate diagnosis.

Extracorporeal shock wave therapy with imaging examination for early osteonecrosis of the femoral head: a systematic review

BACKGROUND

Extracorporeal shockwave therapy (ESWT) is a traditional noninvasive therapy to treat osteonecrosis of the femur head (ONFH). This systematic review aims to investigate whether ESWT can improve the clinical function of ONFH and whether differences in improvement can be observed in radiographic outcomes.

MATERIALS AND METHODS

Two authors independently searched PubMed, Embase, Cochrane Library, and Web of Science for English articles until 21 October 2023. After screening and reading the literature, the two authors independently used corresponding scales to evaluate the quality of the included articles and extracted data. The key data extracted included the Harris Hip Score (HHS), Visual Analog Scale (VAS), changes in lesion size, the change in the Association Research Circulation Osseous (ARCO) stage, and bone marrow edema (BME) stage.

RESULTS

Nine articles included 468 males and 248 females. The average age was 43.29 years and the mean follow-up time was 15.19 months. After receiving ESWT, five studies involving 146 hips showed a higher HHS (MD=-33.38; 95% CI: -46.31, -20.45), and the difference was statistically significant ( P <0.00001). The average VAS before treatment was above 5, but it dropped to 1.2 after ESWT (MD=4.64; 95% CI: 3.63-5.64), and the difference was statistically significant ( P <0.00001). Three studies found no significant differences in the areas of femoral head necrosis before and after treatment with ESWT(MD=9.66; 95% CI: -0.36, 19.67; P =0.06; I2 =84%). Two articles showed that the use of ESWT had no significant effect on the change in the ARCO stage (MD=1.11; 95% CI: 0.76-1.62; P =0.60; I2 =0%). Three studies indicated that using ESWT could improve the BME symptom in the early stage of ONFH (MD=4.35; 95% CI: 1.32-14.37; P =0.02; I2 =62%).

CONCLUSION

Based on the current evidence, ESWT shows promise as a therapy to enhance hip function and alleviate pain in the early stage of ONFH. With the advancement of more precise imaging techniques, ESWT can potentially reduce the area affected by ONFH. However, such reduction was not found to be statistically significant at the imaging level. Additionally, ESWT could improve symptoms of BME in the early stage. However, no significant change in ARCO grade was observed with ESWT treatment.

Image-based finite element model stiffness and vBMD by single and dual energy CT reconstruction kernel

Single-energy quantitative computed tomography (SEQCT) provides volumetric bone mineral density (vBMD) measures for bone analysis and input to image-based finite element models (FEMs). Dual-energy CT (DECT) improves vBMD by accounting for voxel-specific material variations utilizing scans at multiple x-ray energies. vBMD is also altered by reconstruction kernel that cannot be accounted for using calibration phantoms. This study compared vBMD and FEM stiffness derived from SEQCT and DECT images reconstructed with two common kernels. SEQCT and DECT images of cadaveric shoulders (n = 10) were collected using standard (STD) and boneplus (BONE) kernels. Hounsfield Units were converted to vBMD using specimen-specific calibrations. DECT STD and BONE images were generated using an established material decomposition method with 40 and 90 keV simulated monochromatic images. A proximal humerus bone section below the anatomic neck was used for vBMD analysis and FEM generation. FEMs were loaded to 1% apparent strain for stiffness measurements. Between STD and BONE kernel images, average vBMD differed 0.9 mgK2HPO4/cc and 4.1 mg K2HPO4/cc, in SEQCT and DECT images, respectively. Significant differences occurred in DECT images (p = 0.001). BONE reconstructed images produced higher vBMD measures across both SEQCT and DECT images. The difference between STD and BONE in both SEQCT- and DECT-based FEMs persisted, with larger estimated stiffness in BONE models. For six of the models DECT-based had higher stiffness than SEQCT-based models using the same kernel, although these models differed between STD and BONE kernels. Differences in stiffness between STD and BONE derived models were similar across image types (DECT: 17.5 kN/mm; SEQCT: 19.0 kN/mm). Stiffness values were significantly different within SECT kernels and between SEQCT BONE and DECT STD models. This study shows important differences in vBMD and FEM stiffness that occur due to CT-based imaging parameters alone. These results indicate that consistent imaging parameters should be used for vBMD analysis and FEM input to avoid systematic measurement errors.

Application of double-layer detector spectral CT calcicum supression technique in the diagnosis of traumatic bone marrow edema in the knee

Objective

To investigate the accuracy of calcicum supression (CaSupp) technique derived from double-layer detector spectral computed tomography (DSCT) in the diagnosis of traumatic bone marrow edema in the knee.

Methods

Twenty-three patients with trauma in the knee who underwent DSCT and Magnetic Resonance Imaging (MRI) in the Third Hospital of Hebei Medical University from October 2021 to March 2022 were retrospectively collected. To make the evaluation more detailed and accurate, each knee was divided into 10 partitions. Bone marrow edema in each partition of the knee was evaluated by two physicians (physician A and B) using CaSupp images combined with conventional CT-CaSupp fusion false-color images. MRI results were used as the gold standard and the accuracy of the CaSupp technique was analyzed in the diagnosis of traumatic bone marrow edema in the knee. The CaSuppCT values of the normal bone marrow area and the bone marrow edema area were delineated, and receiver operating curve (ROC curve) was drawn to find the optimal cut-off value of CaSuppCT as the quantitative parameter for the diagnosis of bone marrow edema.

Results

The diagnostic sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of physician A were 83.1 %, 98.1 %, 95.5 % and 92.1 %, respectively; those of physician B were 93.5 %, 97.4 %, 94.7 % and 96.8 %, respectively. The CaSuppCT values in the bone marrow edema areas were higher than those in the normal areas, and the difference was statistically significant. The area under the receiver operating characteristic curve (AUC) of the CaSuppCT values was 0.979, and the cut-off value was 7.05Hu*. The corresponding diagnostic sensitivity was 87.0 %, and specificity was 100.0 %.

Conclusion

The CaSupp technique derived from DSCT has high sensitivity and specificity in the detection of traumatic bone marrow edema in the knee, and can provide more imaging information for clinical practice.

Detecting Bone Marrow Edema of the Extremities on Spectral Computed Tomography Using a Three-Material Decomposition

BACKGROUND

Detecting bone marrow edema (BME) as a sign of acute fractures is challenging on conventional computed tomography (CT). This study evaluated the diagnostic performance of a three-material decomposition (TMD) approach for detecting traumatic BME of the extremities on spectral computed tomography (SCT).

METHODS

This retrospective diagnostic study included 81 bone compartments with and 80 without BME. A TMD application to visualize BME was developed in collaboration with Philips Healthcare. The following bone compartments were included: distal radius, proximal femur, proximal tibia, distal tibia and fibula, and long bone diaphysis. Two blinded radiologists reviewed each case independently in random order for the presence or absence of BME.

RESULTS

The interrater reliability was 0.84 (p < 0.001). The different bone compartments showed sensitivities of 86.7% to 93.8%, specificities of 84.2% to 94.1%, positive predictive values of 82.4% to 94.7%, negative predictive values of 87.5% to 93.3%, and area under the curve (AUC) values of 85.7% to 93.1%. The distal radius showed the highest sensitivity and the proximal femur showed the lowest sensitivity, while the proximal femur presented the highest specificity and the distal tibia presented the lowest specificity.

CONCLUSIONS

Our TMD approach provides high diagnostic performance for detecting BME of the extremities. Therefore, this approach could be used routinely in the emergency setting.

MsgeCNN: Multiscale geometric embedded convolutional neural network for ONFH segmentation and grading

BACKGROUND

The incidence of osteonecrosis of the femoral head (ONFH) is increasing gradually, rapid and accurate grading of ONFH is critical. The existing Steinberg staging criteria grades ONFH according to the proportion of necrosis area to femoral head area.

PURPOSE

In the clinical practice, the necrosis region and femoral head region are mainly estimated by the observation and experience of doctor. This paper proposes a two-stage segmentation and grading framework, which can be used to segment the femoral head and necrosis, as well as to diagnosis.

METHODS

The core of the proposed two-stage framework is the multiscale geometric embedded convolutional neural network (MsgeCNN), which integrates geometric information into the training process and accurately segments the femoral head region. Then, the necrosis regions are segmented by the adaptive threshold method taking femoral head as the background. The area and proportion of the two are calculated to determine the grade.

RESULTS

The accuracy of the proposed MsgeCNN for femoral head segmentation is 97.73%, sensitivity is 91.17%, specificity is 99.40%, dice score is 93.34%. And the segmentation performance is better than the existing five segmentation algorithms. The diagnostic accuracy of the overall framework is 90.80%.

CONCLUSIONS

The proposed framework can accurately segment the femoral head region and the necrosis region. The area, proportion, and other pathological information of the framework output provide auxiliary strategies for subsequent clinical treatment.

Diagnostic accuracy of a dual-energy computed tomography-based post-processing method for imaging bone marrow edema following an acute ligamentous knee injury

OBJECTIVE

This study evaluated the ability of a custom dual-energy CT (DECT) post-processing material decomposition method to image bone marrow edema after acute knee injury. Using an independent validation cohort, the DECT method was compared to gold-standard, fluid-sensitive MRI. By including both quantitative voxel-by-voxel validation outcomes and semi-quantitative radiologist scoring-based assessment of diagnostic accuracy, we aimed to provide insight into the relationship between quantitative metrics and the clinical utility of imaging methods.

MATERIALS AND METHODS

Images from 35 participants with acute anterior cruciate ligament injuries were analyzed. DECT material composition was applied to identify bone marrow edema, and the DECT result was quantitatively compared to gold-standard, registered fluid-sensitive MRI on a per-voxel basis. In addition, two blinded readers rated edema presence in both DECT and fluid-sensitive MR images for evaluation of diagnostic accuracy.

RESULTS

Semi-quantitative assessment indicated sensitivity of 0.67 and 0.74 for the two readers, respectively, at the tibia and 0.55 and 0.57 at the femur, and specificity of 0.87 and 0.89 for the two readers at the tibia and 0.58 and 0.89 at the femur. Quantitative assessment of edema segmentation accuracy demonstrated mean dice coefficients of 0.40 and 0.16 at the tibia and femur, respectively.

CONCLUSION

The custom post-processing-based DECT method showed similar diagnostic accuracy to a previous study that assessed edema associated with ligamentous knee injury using a CT manufacturer-provided, built-in edema imaging application. Quantitative outcome measures were more stringent than semi-quantitative scoring methods, accounting for the low mean dice coefficient scores.

Fat Fraction Measurements Using a Three-Material Decomposition Dual-Energy CT Technique Accounting for Bone Minerals: Evaluation in a Bone Marrow Phantom Using MRI as Reference

Conventional two-material dual-energy CT (DECT) decomposition is insufficient to model bone marrow, which contains three materials [bone minerals, red marrow (water), yellow marrow (fat)]. We explore an image-domain three-material decomposition DECT technique accounting for bone minerals in a bone-water-fat phantom. Three-material decomposition fat fraction (FF3MD) exhibited stronger correlation than two-material decomposition fat fraction (FF2MD) with FFMRI (r=0.95 vs r=0.69). With increasing bone minerals, correlation of FF3MD remained stable (r=0.81-1.02), whereas correlation of FF2MD decreased (r=0.21-0.65).