Diagnostic Performance of Diffusion MRI for differentiating Benign and Malignant Nonfatty Musculoskeletal Soft Tissue Tumors: A Systematic Review and Meta-analysis

Soft tissue vascular tumor-like lesions in adults: imaging and pathological analysis pitfalls per ISSVA classification

OBJECTIVES

To compare the magnetic resonance imaging (MRI) and Doppler ultrasound (DUS) findings with the pathological findings of soft tissue vascular tumors (STVTs) according to the 2018 ISSVA (International Society for the Study of Vascular Anomalies) classification to differentiate vascular tumors from vascular malformations.

METHODS

This retrospective study included patients with STVTs who underwent contrast-enhanced MRI and pathological analysis at our hospital between 2010 and 2020. The presumptive diagnosis based on the on-site imaging and histological analysis was compared with imaging and histological analysis conducted off-site utilizing the ISSVA criteria.

RESULTS

This study included 31 patients with 31 vascular tumors located in the head and neck (n = 3), trunk (n = 2), and extremities (n = 26). The off-site pathological analysis confirmed benign vascular tumors in 54.8% of cases (non-involuting congenital hemangioma: 35.5%; epithelioid hemangioma: 13%; pyogenic granuloma: 3%; and spindle cell hemangioma: 3%). Based on the off-site histological analysis, 25.8% were reclassified as having a vascular malformation whereas three had other benign lesions. Only phleboliths were associated with a vascular malformation (p = 0.03). The concordance between off-site MRI and pathological findings was fair (k = 0.3902 (0.0531-0.7274)), whereas that between on-site and off-site pathological analyses was poor (k = -0.0949 (-0.4661 to 0.2763)).

CONCLUSION

Benign vascular tumors have non-specific imaging features on imaging with some overlap with atypical vascular malformations. Therefore, histological analysis is recommended. Imaging and pathological analyses should be performed in accordance with the ISSVA classification to minimize inter-observer discrepancies.

CRITICAL RELEVANCE STATEMENT

Imaging features of benign vascular tumors on MRI are non-specific, leading to discrepancies with pathological findings and potential overlap with atypical vascular malformations. Imaging and histological analyses should be performed in accordance with ISSVA guidelines to improve patient management.

KEY POINTS

The imaging features of benign vascular tumors are non-specific. Histological analysis is recommended for soft tissue vascular tumors in adults. Analyses of soft tissue vascular tumors should be performed in accordance with ISSVA guidelines.

Magnetic Resonance Imaging Biomarkers of Bone and Soft Tissue Tumors

Magnetic resonance imaging (MRI) is essential in the management of musculoskeletal (MSK) tumors. This review delves into the diverse MRI modalities, focusing on anatomical, functional, and metabolic sequences that provide essential biomarkers for tumor detection, characterization, disease extent determination, and assessment of treatment response. MRI's multimodal capabilities offer a range of biomarkers that enhance MSK tumor evaluation, aiding in better patient management.

Diagnostic performance of diffusion-weighted imaging and intravoxel incoherent motion for renal lesions: a meta-analysis

AIM

To compare the diagnostic performance of diffusion-weighted imaging (DWI) and intravoxel incoherent motion (IVIM) parameters, specifically true diffusion coefficient (D), pseudo diffusion coefficient (D∗), and perfusion fraction (f) for quantitatively differentiating benign and malignant renal lesions.

MATERIALS AND METHODS

A comprehensive search was conducted in the EMBASE and PubMed databases before September 2022 to identify studies in English investigating the diagnostic accuracy of DWI and IVIM in renal lesions. The quality of the included studies was assessed using the QUADAS-2 tool. Pooled sensitivity, specificity, and area under the curve (AUC) values were estimated for each parameter.

RESULTS

A total of 19 studies involving 1,860 renal lesions (1,160 malignant and 700 benign), met the inclusion criteria. Among these studies, 15 assessed the apparent diffusion coefficient (ADC), four assessed IVIM, and three evaluated both ADC and IVIM. The pooled sensitivity, specificity, and AUC for ADC were 0.84 (95% confidence interval [Cl], 0.79-0.88), 0.82 (95% Cl, 0.72-0.89), and 0.89 (95% Cl, 0.86-0.92), respectively. The IVIM parameter with the highest diagnostic accuracy was D, with a pooled sensitivity, specificity, and AUC of 0.89 (95% Cl, 0.74-0.96), 0.96 (95% Cl, 0.85-0.99), and 0.98 (95% Cl, 0.96-0.99), respectively. The pooled sensitivity, specificity and AUC for f were 0.67 (95% Cl, 0.55-0.77), 0.81 (95% Cl, 0.30-0.98), and 0.73 (95% Cl, 0.69-0.77), respectively. The pooled sensitivity, specificity, and AUC for D∗ were 0.87 (95% Cl, 0.81-0.91), 0.59 (95% Cl, 0.48-0.70), and 0.82 (95% Cl, 0.78-0.85), respectively.

CONCLUSION

This meta-analysis indicated that both IVIM and DWI had moderate to high diagnostic accuracy for differentiating benign and malignant renal lesions. Among the IVIM parameter, D exhibited the highest diagnostic accuracy, demonstrating higher sensitivity and specificity than ADC, D∗, and f.

Differentiating nasopharyngeal carcinoma from lymphoma in the head and neck region using the apparent diffusion coefficient (ADC) value: a systematic review and meta-analysis

Purpose

This study aimed to assess the applicability of the apparent diffusion coefficient (ADC) for differentiating nasopharyngeal carcinoma (NPC) from lymphomas in the head and neck region.

Material and methods

Four databases, including PubMed, the Cochrane Library, EMBASE, and Web of Science, were searched systematically to find relevant literature. The search date was updated to 8 September 2022, with no starting time restriction. The methodological quality of the studies was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Firstly, a random-effects model was used in a meta-analysis of continuous variables with low heterogeneity to determine the overall effect size, which was reported as the standard mean difference (SMD). Then, bivariate random effects modelling was used to calculate the combined sensitivity and specificity. The area under the curve (AUC) for each diffusion parameter was calculated after constructing summary receiver operating characteristic curves. The presence of heterogeneity was evaluated using subgroup and meta-regression analysis.

Results

Twelve studies involving 181 lymphoma and 449 NPC lesions (N = 630) in the head and neck region were included, of which 5 studies provided sufficient data for pooling diagnostic test accuracy. A meta-analysis of the 12 studies using a random-effects model yielded an SMD of 1.03 (CI = 0.76-1.30; p = 0.00001), implying that NPC lesions had a significantly higher ADC value than lymphoma lesions. By pooling 5 standard DWI studies, the pooled sensitivity and specificity of ADC were 0.90 (95% CI: 0.82-0.95) and 0.63 (95% CI: 0.52-0.72), respectively. The area under the curve (AUC) calculated from the SROC curve was 0.74 (95% CI: 0.70-0.78).

Conclusions

According to this systematic review and meta-analysis, nasopharyngeal carcinoma has a significantly higher ADC value than lymphomas. Furthermore, while ADC has excellent sensitivity for distinguishing these 2 types of tumours, its specificity is relatively low, yielding a moderate diagnostic performance. Further investigations with larger sample sizes are required.

Pitfalls of Diffusion-Weighted Imaging: Clinical Utility of T2 Shine-through and T2 Black-out for Musculoskeletal Diseases

Diffusion-weighted imaging (DWI) with an apparent diffusion coefficient (ADC) value is a relatively new magnetic resonance imaging (MRI) sequence that provides functional information on the lesion by measuring the microscopic movement of water molecules. While numerous studies have evaluated the promising role of DWI in musculoskeletal radiology, most have focused on tumorous diseases related to cellularity. This review article aims to summarize DWI-acquisition techniques, considering pitfalls such as T2 shine-through and T2 black-out, and their usefulness in interpreting musculoskeletal diseases with imaging. DWI is based on the Brownian motion of water molecules within the tissue, achieved by applying diffusion-sensitizing gradients. Regardless of the cellularity of the lesion, several pitfalls must be considered when interpreting DWI with ADC values in musculoskeletal radiology. This review discusses the application of DWI in musculoskeletal diseases, including tumor and tumor mimickers, as well as non-tumorous diseases, with a focus on lesions demonstrating T2 shine-through and T2 black-out effects. Understanding these pitfalls of DWI can provide clinically useful information, increase diagnostic accuracy, and improve patient management when added to conventional MRI in musculoskeletal diseases.

Advances in The Application and Research of Magnetic Resonance Diffusion Kurtosis Imaging in The Musculoskeletal System

Magnetic resonance diffusion kurtosis imaging (DKI) is an emerging magnetic resonance imaging (MRI) technique that can reflect microstructural changes in tissue through non-Gaussian diffusion of water molecules. Compared to traditional diffusion weighted imaging (DWI), the DKI model has shown greater sensitivity for diagnosis of musculoskeletal diseases and can help formulate more reasonable treatment plans. Moreover, DKI is an important auxiliary examination for evaluation of the motor function of the musculoskeletal system. This article briefly introduces the basic principles of DKI and reviews the application and research of DKI in the evaluation of disorders of the musculoskeletal system (including bone tumors, soft tissue tumors, spinal lesions, chronic musculoskeletal diseases, musculoskeletal trauma, and developmental disorders) as well as the normal musculoskeletal tissues. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: 1.

Diffusion-Weighted Magnetic Resonance Imaging: Clinical Potential and Applications

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Features of ophthalmic, magnetic resonance imaging, and histopathology of a feline case of idiopathic sclerosing orbital pseudotumor

In the present report, we describe a case of sclerosing orbital pseudotumor in an 11‐year‐old castrated male American Shorthair cat. Ophthalmic exam showed lagophthalmos, retracted right upper eyelid, and resistant to retropulsion in his right eye. Under magnetic resonance imaging (MRI) scans, increased volume of the extraocular muscles (EOMs) of the right eye was prominent. Immunosuppressive dosage of prednisolone partially ameliorated the clinical signs, but some clinical signs were still gradually progressive or persistent. In the second MRI scan, decreased diameter of the thickened right extraocular muscles was found. After the third MRI scan, enucleation of the right eye was performed due to substantial adverse effects of systemic steroid therapy. Histopathological examination revealed no evidence of neoplastic transformation nor infection. Feline restrictive orbital myofibroblastic sarcoma (FROMS) was therefore excluded, suggesting unknown causes of extensive fibrotic changes in the right orbit of the affected cat.