Radiomics and machine learning for the diagnosis of pediatric cervical non-tuberculous mycobacterial lymphadenitis

Using T2-weighted magnetic resonance imaging-derived radiomics to classify cervical lymphadenopathy in children

BACKGROUND

Cervical lymphadenopathy is common in children and has diverse causes varying from benign to malignant, their similar manifestations making differential diagnosis difficult.

OBJECTIVE

This study aimed to investigate whether radiomic models using conventional magnetic resonance imaging (MRI) could classify pediatric cervical lymphadenopathy.

METHODS

A total of 419 cervical lymph nodes from 146 patients, and encompassing four common etiologies (Kikuchi disease, reactive hyperplasia, suppurative lymphadenitis and malignancy), were randomly divided into training and testing sets in a ratio of 7:3. For each lymph node, 1,218 features were extracted from T2-weighted images. Then, the least absolute shrinkage and selection operator (LASSO) models were used to select the most relevant ones. Two models were built using a support vector machine classifier, one was to classify benign and malignant lymph nodes and the other further distinguished four different diseases. The performance was assessed by receiver operating characteristic curves and decision curve analysis.

RESULTS

By LASSO, 20 features were selected to construct a model to distinguish benign and malignant lymph nodes, which achieved an area under the curve (AUC) of 0.89 and 0.80 in the training and testing sets, respectively. Sixteen features were selected to construct a model to distinguish four different cervical lymphadenopathies. For each etiology, Kikuchi disease, reactive hyperplasia, suppurative lymphadenitis, and malignancy, an AUC of 0.97, 0.91, 0.88, and 0.87 was achieved in the training set, and an AUC of 0.96, 0.80, 0.82, and 0.82 was achieved in the testing set, respectively.

CONCLUSION

MRI-derived radiomic analysis provides a promising non-invasive approach for distinguishing causes of cervical lymphadenopathy in children.

The diagnosis of nontuberculous cervicofacial lymphadenitis: A systematic review

BACKGROUND

Nontuberculous mycobacterial cervicofacial lymphadenitis (NTMCL) is an uncommon condition detected in young immunocompetent children who typically present with a nontender neck mass. Various tests have been proposed to assist in the work-up of suspected NTMCL, with varying diagnostic utility. This systematic review investigates the sensitivity of the various diagnostic methods used in the work-up of pediatric NTMCL.

METHODS

A systematic review in accordance with PRISMA guidelines was performed using the Pubmed, EMBASE, and Web of Science databases. Searches were filtered for English language studies published prior to 05/10/22. Studies meeting criteria included studies featuring 15+ pediatric patients with confirmed or suspected NTMCL. Studies with any reported diagnostic methodology used in the workup of NTMCL were included.

RESULTS

Of 836 abstracts/articles reviewed, 21 studies met inclusion criteria. Diagnostic methods included culture(n = 11 studies), PPD-Tb(Tuberculin)(n = 12), PPD-Scrofulaceum, -Avium, or -Kansasii(n = 6), staining techniques(n = 4), IGRA(n = 3), and ultrasound(n = 2). All studies had an overall low risk of bias. Among patients confirmed to have NTMCL based on PCR and/or culture, the most sensitive tests were PPD-A(0.94, 95 % CI 0.91 to 0.97; n = 210 patients) and PPD-S(0.75, 95 % CI 0.68 to 0.81; n = 171). Auramine and Ziehl-Neelsen staining techniques had moderately high sensitivity(0.85 and 0.60 respectively), though were limited by low patient numbers(n = 20). PPD-Tb(0.45, 95 % CI 0.39 to 0.50; n = 300) and IGRA(0.02; 95 % CI 0 to 0.06; n = 48) demonstrated poor sensitivity. Among patients suspected to have NTM lymphadenitis based on global assessment, the most sensitive tests included combined PPD-S + A + K(0.92, 95 % CI 0.86 to 0.98; n = 85), PCR(0.82, 95 % CI 0.75 to 0.88; n = 136), and PPD-A(0.72, 95 % CI 0.62 to 0.81; n = 84). Culture showed a sensitivity of 0.54(95 % CI 0.50 to 0.58; n = 494). PPD-K, PPD-S, IGRA, and staining techniques demonstrated lower sensitivity.

CONCLUSIONS

This systematic review is the largest study investigating the sensitivity of the various diagnostic methods used in the work-up of pediatric NTMCL. Patients with clinical suspicion for NTMCL and a positive PPD-Tb should first have tuberculous lymphadenitis ruled out with IGRA. Patients with a positive PPD-Tb and negative IGRA and high clinical suspicion for NTMCL can undergo presumptive surgical intervention. Patients with a negative PPD-Tb can undergo NTM antigen skin testing if available, or if high clinical suspicion exists, surgical intervention to reduce tissue burden and elicit additional tissue data.

Current management of cervicofacial nontuberculous mycobacterial infections in the pediatric population

PURPOSE OF REVIEW

The purpose of this review is to analyze and consolidate recently published literature to provide updated guidelines on the diagnosis and management of nontuberculous mycobacterial lymphadenitis (NTM LAD) in the pediatric population and to suggest areas of further research.

RECENT FINDINGS

Diagnosis of NTM LAD relies on a detailed clinical history, physical examination, laboratory tests, and imaging techniques. Treatment strategies vary widely, with a shift towards complete surgical excision being observed due to its higher cure rate, improved aesthetic outcomes, and lower recurrence rates. However, patient-specific factors must be considered. The role of genetic factors, such as Mendelian susceptibility to mycobacterial disease (MSMD), is being increasingly recognized and could lead to targeted therapies.

SUMMARY

Despite strides in the understanding and management of NTM LAD, substantial gaps remain in key areas such as the role of diagnostic imaging, optimal treatment parameters, postoperative care, and surveillance strategies. In this article, we explain our approach to NTM using the most relevant evidence-based medicine while offering directions for future work.

Reproducibility and location-stability of radiomic features derived from cone-beam computed tomography: a phantom study

OBJECTIVES

This study aims to determine the reproducibility and location-stability of cone-beam computed tomography (CBCT) radiomic features.

METHODS

Centrifugal tubes with six concentrations of K2HPO4 solutions (50, 100, 200, 400, 600, and 800 mg ml-1) were imaged within a customized phantom. For each concentration, images were captured twice as test and retest sets. Totally, 69 radiomic features were extracted by LIFEx. The reproducibility was assessed between the test and retest sets. We used the concordance correlation coefficient (CCC) to screen qualified features and then compared the differences in the numbers of them under 24 series (four locations groups * six concentrations). The location-stability was assessed using the Kruskal-Wallis test under different concentration sets; likewise, the numbers of qualified features under six test sets were analyzed.

RESULTS

There were 20 and 23 qualified features in the reproducibility and location-stability experiments, respectively. In the reproducibility experiment, the performance of the peripheral groups and high-concentration sets was significantly better than the center groups and low-concentration sets. The effect of concentration on the location-stability of features was not monotonic, and the number of qualified features in the low-concentration sets was greater than that in the high-concentration sets. No features were qualified in both experiments.

CONCLUSIONS

The density and location of the target object can affect the number of reproducible radiomic features, and its density can also affect the number of location-stable radiomic features. The problem of feature reliability should be treated cautiously in radiomic research on CBCT.

Promoting the application of pediatric radiomics via an integrated medical engineering approach

Radiomics is widely used in adult tumors but has been rarely applied to the field of pediatrics. Promoting the application of radiomics in pediatric diseases, especially in the early diagnosis and stratified treatment of tumors, is of great value to the realization of the WHO 2030 "Global Initiative for Childhood Cancer." This paper discusses the general characteristics of radiomics, the particularity of its application to pediatric diseases, and the current status and prospects of pediatric radiomics. Radiomics is a data-driven science, and the combination of medicine and engineering plays a decisive role in improving data quality, data diversity, and sample size. Compared with adult radiomics, pediatric radiomics is significantly different in data type, disease spectrum, disease staging, and progression. Some progress has been made in the identification, classification, stratification, survival prediction, and prognosis of tumor diseases. In the future, big data applications from multiple centers and cross-talent training should be strengthened to improve the benefits for clinical workers and children.

Evaluation of radiomics feature stability in abdominal monoenergetic photon counting CT reconstructions

Feature stability and standardization remain challenges that impede the clinical implementation of radiomics. This study investigates the potential of spectral reconstructions from photon-counting computed tomography (PCCT) regarding organ-specific radiomics feature stability. Abdominal portal-venous phase PCCT scans of 10 patients in virtual monoenergetic (VM) (keV 40-120 in steps of 10), polyenergetic, virtual non-contrast (VNC), and iodine maps were acquired. Two 2D and 3D segmentations measuring 1 and 2 cm in diameter of the liver, lung, spleen, psoas muscle, subcutaneous fat, and air were obtained for spectral reconstructions. Radiomics features were extracted with pyradiomics. The calculation of feature-specific intraclass correlation coefficients (ICC) was performed by comparing all segmentation approaches and organs. Feature-wise and organ-wise correlations were evaluated. Segmentation-resegmentation stability was evaluated by concordance correlation coefficient (CCC). Compared to non-VM, VM-reconstruction features tended to be more stable. For VM reconstructions, 3D 2 cm segmentation showed the highest average ICC with 0.63. Based on a criterion of ≥ 3 stable organs and an ICC of ≥ 0.75, 12-mainly non-first-order features-are shown to be stable between the VM reconstructions. In a segmentation-resegmentation analysis in 3D 2 cm, three features were identified as stable based on a CCC of > 0.6 in ≥ 3 organs in ≥ 6 VM reconstructions. Certain radiomics features vary between monoenergetic reconstructions and depend on the ROI size. Feature stability was also shown to differ between different organs. Yet, glcm_JointEntropy, gldm_GrayLevelNonUniformity, and firstorder_Entropy could be identified as features that could be interpreted as energy-independent and segmentation-resegmentation stable in this PCCT collective. PCCT may support radiomics feature standardization and comparability between sites.

Ultrasound-Based Radiomics Can Classify the Etiology of Cervical Lymphadenopathy: A Multi-Center Retrospective Study

Medical diagnostic imaging is essential for the differential diagnosis of cervical lymphadenopathy. Here we develop an ultrasound radiomics method for accurately differentiating cervical lymph node tuberculosis (LNTB), cervical lymphoma, reactive lymph node hyperplasia, and metastatic lymph nodes especially in the multi-operator, cross-machine, multicenter context. The inter-observer and intra-observer consistency of radiomics parameters from the region of interest were 0.8245 and 0.9228, respectively. The radiomics model showed good and repeatable diagnostic performance for multiple classification diagnosis of cervical lymphadenopathy, especially in LNTB (area under the curve, AUC: 0.673, 0.662, and 0.626) and cervical lymphoma (AUC: 0.623, 0.644, and 0.602) in the whole set, training set, and test set, respectively. However, the diagnostic performance of lymphadenopathy among skilled radiologists was varied (Kappa coefficient: 0.108, *p < 0.001). The diagnostic performance of radiomics is comparable and more reproducible compared with those of skilled radiologists. Our study offers a more comprehensive method for differentiating LNTB, cervical lymphoma, reactive lymph node hyperplasia, and metastatic LN.