Multiparametric MRI in differentiating pulmonary artery sarcoma and pulmonary thromboembolism: a preliminary experience

Abstract

M agnetic resonance imaging (MRI) is a widely used diagnostic tool for breast imaging in daily practice, with its high sensitivity to detect primary, recurrent, and residual breast cancer. Breast MRI serves as a reliable problem-solving tool in case of inconclusive mammography and ultrasonography (US) findings. It can be used to monitor the results of neoadjuvant chemotherapy and it may also contribute to preoperative evaluation of known lesions. With increasing use of MRI, number of breast lesions visible only on MRI and need for MRI-guided breast biopsy have increased (1). Second-look US can also be used for re-evaluation of these lesions; because US-guided biopsy is an easier, cheaper, and faster method if these lesions are visible on second-look US. According to a recently published meta-analysis, lesion detection rates with second-look US are variable in the literature (22.6%-82.1%). Mass lesions and malignant lesions were more likely to be detected at second-look US; average detection rates were 66% for masses, 29% for non-mass-like enhancement (NME) (2, 3). However, focal or NME lesions, which are less detectable than masses on second-look US, require MRI-guided biopsy in the majority of cases. According to the MRI-guided biopsy series in the literature, approximately 25%-35% of these lesions are diagnosed as malignant (4-9).Within this context, the aim of the present study is to assess the effectiveness of MRI-guided 10 Gauge (G) vacuum-assisted breast biopsies (VABB) performed at our institution and to examine the relationship between lesion characteristics and histopathologic results. B R E A S T I MAG I N G O R I G I N A L A R T I C L E PURPOSEWe aimed to assess the effectiveness of magnetic resonance imaging (MRI)-guided vacuum-assisted breast biopsy (VABB), evaluate and compare the characteristics and histopathologic findings of lesions, and overview the follow-up results of benign lesions. METHODSMRI findings and histopathologic results of breast lesions biopsied by MRI-guided VABB between 2013 and 2016 were retrospectively analyzed. MRI findings closely related with malignancy were investigated in particular. Follow-up results of benign lesions were evaluated. RESULTSMRI-guided VABB was applied to 116 lesions of 112 women. Of the lesions, 75 (65%) were benign, while 41 (35%) were malignant. Segmental (94%), clustered (89%), and clustered ring (67%) nonmass-like enhancement patterns were found to be more related with malignancy. False-negative rate of MRI-guided VABB was 12%, underestimation rate was 21%. One of the 54 followed-up benign lesions had a malignant result. CONCLUSION MRI-guided VABB is a reliable method for the diagnosis of breast lesions that are positive only on MRI. Follow-up results show that cancer detection rate is low for radio-pathologically concordant lesions. Further multicenter studies with larger patient population are needed to elucidate these results.You may cite this article as: Taşkın F, Soyder A, Tanyeri A, Öztürk VS, Ünsal A. Lesion characteristics, histopathologic r...

Building blocks for thoracic MRI: Challenges, sequences, and protocol design

“…DCE MRI involves the acquisition of sequential MR datasets at multiple timepoints before, during, and after the injection of intravenous contrast . These data can be used to obtain time intensity curves (TICs), which can be assessed for different enhancement patterns.…”

“…In thoracic MRI examinations, DCE data are most often obtained using 3D T 1 ‐weighted spoiled fast GRE sequences, but older studies used 2D and spin echo sequences for this purpose . To improve the temporal resolution of a sequence used for DCE, the imaged volume can be limited to the specific tissue being evaluated.…”

“…While temporal resolution is variable, depending on the desired application and the sequences used, temporal resolution of ≤3 seconds is required to reliably obtain quantitative parameters for estimating neoangiogenesis . Motion correction software may be needed, particularly for high temporal resolution applications . Ultimately, DCE data can be used with DWI for a "multiparametric" approach, which allows for characterization of lesions before and after treatment …”

“…DCE MRI involves the acquisition of sequential MR datasets at multiple timepoints before, during, and after the injection of intravenous contrast. 13,27,[57][58][59][60] These data can be used to obtain time intensity curves (TICs), which can be assessed for different enhancement patterns. While standard dynamic pre-and postcontrast acquisitions with low temporal resolution can generate TICs for rough qualitative analysis, higher temporal resolution applications are "perfusion-weighted" and allow more complex analysis of DCE data, which can determine the true multicompartment perfusion model kinetics.…”

“…In thoracic MRI examinations, DCE data are most often obtained using 3D T 1 -weighted spoiled fast GRE sequences, but older studies used 2D and spin echo sequences for this purpose. 10,[58][59][60][61][62][63] To improve the temporal resolution of a sequence used for DCE, the imaged volume can be limited to the specific tissue being evaluated. Newer techniques allowing for faster imaging, including those using a radial acquisition of k-space and compressed sensing (eg, GRASP for Siemens), provide an improved means of obtaining images suitable for DCE in the thorax by increasing temporal resolution and decreasing the effects of motion.…”