Dynamic MRI of Solitary Pulmonary Nodules: Comparison of Enhancement Patterns of Malignant and Benign Small Peripheral Lung Lesions

Kono, Rei; Fujimoto, Kiminori; Tazaki, Hiroshi; Müller, Néstor L.; Kato, Seiya; Sadohara, Junko; Hayabuchi, Naofumi; Takamori, Shinzo

doi:10.2214/ajr.05.1446

Cited by 109 publications

(111 citation statements)

References 37 publications

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“…And overlap of early enhancement characteristics between lung cancer and active in‰am-matory nodules by dynamic MR imaging or CT is reported. [6][7][8] However, our prospective assessment showed overlap of nodular kinetic parameters, which include peak rate, peak time, and steepest slope, between benign pulmonary nodules and lung cancer/active in‰ammatory nodules. This is partly because benign pulmonary nodules may have some of the characteristics of active in‰ammation.…”

Section: Discussionmentioning

confidence: 78%

“…As described in previous studies, we selected a large ROI to incorporate solid-appearing parts of a nodule and to exclude obvious necrotic, cystic, and cavitary areas. 2,7,8 We selected the most enhanced area within the nodules as the ROI and made the ROI as large as possible to include at least half the lesion to minimize noise. We evaluated morphologic enhancement patterns on the image at the time of peak enhancement and classiˆed its pattern as either homogeneous (enhancement uniform throughout the nodule), heter-ogeneous (irregularly enhanced), peripheral (clear enhancement of the nodule periphery), or rim (thin layer [capsule] of enhancement limited to the outer margin of the nodule).…”

Section: Mr Imaging Analysismentioning

confidence: 99%

“…7 From the time-signal intensity curve, we categorized the degree of washout for each nodule. We deˆned washout as reduced contrast after peak enhancement with a 10z or more decrease in signal intensity of peak enhancement during the designated period, 8 no washout as either no delayed washout or minimal washout with less than a 10z decrease in signal intensity during that period. Absence of signiˆcant enhancement was diˆned as enhancement of less than 1.5 times of the peak rate.…”

Section: Mr Imaging Analysismentioning

confidence: 99%

“…4 Tuberculomas were distinguished from active tuberculosis on the basis of absence of change for more than 2 years after the initiation of antituberculosis therapy and classiˆed as benign pulmonary nodules. 6,8 …”

Section: Final Diagnosismentioning

confidence: 99%

“…1 Dynamic evaluation with CT or magnetic resonance (MR) imaging has demonstrated stronger enhancement of malignant neoplasms than benign nodules, [2][3][4][5] and the overlap of early enhancement characteristics between malignant neoplasms and active in‰ammatory nodules by dynamic MR imaging or CT is recently reported. [6][7][8] More recently, researchers using MR imaging reported the absence of washout in most active in‰ammatory and benign nodules at the second or fourth minute from initiation of contrast injection. 9,10 However, these dynamic studies were retrospective, and washout characteristics after 4 min were unclear.…”

Section: Introductionmentioning

confidence: 99%

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Evaluation of Indeterminate Pulmonary Nodules with Dynamic MR Imaging

et al. 2013

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Purpose: We prospectively assessed whether enhancement characteristics on dynamic magnetic resonance (MR) imaging could distinguish indeterminate pulmonary nodules.Methods: We evaluated 51 pulmonary nodules in 51 consecutive patients (11 female, 40 male; mean age, 64 years) using dynamic MR images acquired at 0,10, 20, 30, 40, 50, 60, 70, 80, 90, 120, 150, 180, 210, 240, 360, 480, 600, 720, and 840 s following injection of contrast material. We prospectively evaluated morphologic enhancement patterns, peak rate, time to peak enhancement, steepest slope, and washout of nodules and analyzed statistics to determine any diŠerences between MR parameters, patient age, tumor size, andˆnal diagnosis.Results: We found 25 malignant, 12 active in‰ammatory, and 14 benign nodules. Nodule diameter was signiˆcantly larger for malignant than nonmalignant, and benign nodules (PÃ0.01). Patients with malignant nodules were signiˆcantly older than those with nonmalignant (P＝0.01) and active in‰ammatory (P＝0.02) nodules. However, morphologic enhancement patterns, peak rate, time to peak enhancement, steepest slope, and washout characteristics at 2, 4, 8, and 12 min showed no signiˆcant diŠerence between malignant and nonmalignant nodules and among malignant, active in‰ammatory, and benign nodules.Conclusion: Prospective assessment of dynamic MR images demonstrated their inadequacy for distinguishing indeterminate pulmonary nodules.

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Section: Discussionmentioning

confidence: 78%

Section: Mr Imaging Analysismentioning

confidence: 99%

Section: Mr Imaging Analysismentioning

confidence: 99%

Section: Final Diagnosismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Evaluation of Indeterminate Pulmonary Nodules with Dynamic MR Imaging

et al. 2013

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Dynamic contrast‐enhanced MR imaging for differentiation of rounded atelectasis from neoplasm

Horn

Oechsner

Gardarsdottir

et al. 2010

Magnetic Resonance Imaging

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Purpose: To characterize rounded atelectasis (RA) with dynamic contrast-enhanced MRI in the differential diagnosis of solitary peripheral pulmonary neoplasm. Materials and Methods:Twenty-four patients with diagnostically equivocal peripheral pulmonary nodules were examined with dynamic contrast-enhanced MRI. 13 patients had a total of 16 rounded atelectases and 11 had a neoplasm. The final diagnosis was made either by histology (n ¼ 14) or follow-up examinations of at least 24 months (n ¼ 10). The peripheral nodules were evaluated concerning their morphology and contrast-enhancement dynamics. Curves for signal intensity (SI) versus time were produced and the relative increase in SI, slope of SI during wash-in, and slope of SI during wash-out calculated. Additionally, SI time curves were evaluated using a two compartment model where the ratio for the SI of the fast and the slow component were calculated. Mean values from different tissues of interest were compared by an unpaired two-sided t-test.Results: Analysis of the SI-time curves of the RAs revealed a curve shape similar to the pulmonary artery, but a magnitude in SI between artery and normal lung tissue. Linear curve fit showed a significantly steeper slope during wash-in and wash-out, and higher relative signal increase in atelectases as compared to neoplasms. Results from the two compartment model showed increased flow and a high ratio of the slow to the fast components with a long mean transit time in neoplasms.Conclusion: Three parameters, slope of SI during washin and wash-out, and the slow/fast ratio can be used as diagnostic tools for discrimination of RA and neoplasm.

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Recent technological and application developments in computed tomography and magnetic resonance imaging for improved pulmonary nodule detection and lung cancer staging

Sieren

Ohno

Koyama

et al. 2010

Magnetic Resonance Imaging

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This review compares the emerging technologies and approaches in the application of magnetic resonance (MR) and computed tomography (CT) imaging for the assessment of pulmonary nodules and staging of malignant findings. Included in this review is a brief definition of pulmonary nodules and an introduction to the challenges faced. We have highlighted the current status of both MR and CT for the early detection of lung nodules. Developments are detailed in this review for the management of pulmonary nodules using advanced imaging, including: dynamic imaging studies, dual energy CT, computer aided detection and diagnosis, and imaging assisted nodule biopsy approaches which have improved lung nodule detection and diagnosis rates. Recent advancements linking in vivo imaging to corresponding histological pathology are also highlighted. In vivo imaging plays a pivotal role in the clinical staging of pulmonary nodules through TNM assessment. While CT and positron emission tomography (PET)/CT are currently the most commonly clinically employed modalities for pulmonary nodule staging, studies are presented that highlight the augmentative potential of MR. LUNG CANCER remains a challenging disease to effectively identify, diagnose, and treat, as reflected by the 5-year survival rate, which remains similar to that of 15 years ago at 13%. Lung cancer frequently manifests as a peripheral lung nodule or mass. Radiologically identified lesions in the lung that are less than 30 mm in diameter are defined as pulmonary nodules, while those greater than 30 mm are termed masses (1). Both pulmonary nodules and masses present specific challenges in the evaluation of suspected lung cancer; however, the greatest impact of x-ray computed tomography (CT) and magnetic resonance imaging (MRI) developments have been on the detection and characterization of pulmonary nodules. Hence, the scope of this review will focus on the recent advances in CT and MRI of pulmonary nodules and lung cancer staging, highlighting the respective strengths and weaknesses of these modalities. X-ray chest radiography (CXR) is the most widely utilized modality for pulmonary abnormalities and disease screening, although sonography has been utilized in limited situations in the chest. In addition, positron emission tomography (PET) or PET/CT with 2-deoxy-2-[18F]fluoro-D-glucose (FDG) is currently widely utilized for differentiation of malignant lesions from benign lesions, staging of malignant tumors, and assessment of therapeutic effects after conservative therapy. The value of CT and MR for depicting structural anatomy is widely appreciated and applied clinically to noninvasively identify abnormalities and/ or disease. Recent developments of imaging techniques and processing have expanded the potential of these modalities to include combined structure and function. Recent exciting work for the detection, monitoring, characterization, and staging of pulmonary cancer nodules using imaging of both CT and MR modalities will be summarized in this review.While the overall...

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Dynamic MRI of Solitary Pulmonary Nodules: Comparison of Enhancement Patterns of Malignant and Benign Small Peripheral Lung Lesions

Abstract: Dynamic contrast-enhanced MRI is helpful in differentiating benign from malignant solitary pulmonary nodules. Absence of significant enhancement is a strong predictor that a lesion is benign.

Cited by 109 publications

References 37 publications

Evaluation of Indeterminate Pulmonary Nodules with Dynamic MR Imaging

Evaluation of Indeterminate Pulmonary Nodules with Dynamic MR Imaging

Dynamic contrast‐enhanced MR imaging for differentiation of rounded atelectasis from neoplasm

Recent technological and application developments in computed tomography and magnetic resonance imaging for improved pulmonary nodule detection and lung cancer staging

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