Current Issue : January - March Volume : 2014 Issue Number : 1 Articles : 7 Articles
Background: We previously demonstrated that superparamagnetic iron oxide (SPIO)-enhanced MR imaging is\r\npromising for the detection of metastases in sentinel nodes localized by CT-lymphography in patients with breast\r\ncancer. The purpose of this study was to determine the predictive criteria of the size of nodal metastases with\r\nSPIO-enhanced MR imaging in breast cancer, with histopathologic findings as reference standard.\r\nMethods: This study included 150 patients with breast cancer. The patterns of SPIO uptake for positive sentinel\r\nnodes were classified into three; uniform high-signal intensity, partial high-signal intensity involving =50% of the\r\nnode, and partial high-signal intensity involving <50% of the node. Imaging results were correlated with\r\nhistopathologic findings.\r\nResults: Thirty-three pathologically positive sentinel nodes from 30 patients were evaluated. High-signal\r\nintensity patterns that were uniform or involved =50% of the node were observed in 23 nodes that contained\r\nmacro-metastases and no node that contained micro-metastases, while high-signal intensity patterns involving\r\n<50% of the node were observed in 2 nodes that contained macro-metastases and 8 nodes that contained\r\nmicro-metastases. When the area of high-signal intensity was compared with the pathological size of the\r\nmetastases, a pathologic >2 mm sentinel node metastases correlated with the area of high-signal intensity,\r\nhowever, a pathologic =2 mm sentinel node metastases did not.\r\nConclusions: High-signal intensity patterns that are uniform or involve =50% of the node are features of nodes\r\nwith macro-metastases. The area of high-signal intensity correlated with the pathological size of metastases for\r\nnodes with metastases >2 mm in this series....
Background: The recently developed model-based iterative reconstruction (MBIR) enables significant reduction of\r\nimage noise and artifacts, compared with adaptive statistical iterative reconstruction (ASIR) and filtered back\r\nprojection (FBP). The purpose of this study was to evaluate lesion detectability of low-dose chest computed\r\ntomography (CT) with MBIR in comparison with ASIR and FBP.\r\nMethods: Chest CT was acquired with 64-slice CT (Discovery CT750HD) with standard-dose (5.7 �± 2.3 mSv) and\r\nlow-dose (1.6 �± 0.8 mSv) conditions in 55 patients (aged 72 �± 7 years) who were suspected of lung disease on\r\nchest radiograms. Low-dose CT images were reconstructed with MBIR, ASIR 50% and FBP, and standard-dose CT\r\nimages were reconstructed with FBP, using a reconstructed slice thickness of 0.625 mm. Two observers evaluated\r\nthe image quality of abnormal lung and mediastinal structures on a 5-point scale (Score 5 = excellent and score\r\n1 = non-diagnostic). The objective image noise was also measured as the standard deviation of CT intensity in\r\nthe descending aorta.\r\nResults: The image quality score of enlarged mediastinal lymph nodes on low-dose MBIR CT (4.7 �± 0.5) was\r\nsignificantly improved in comparison with low-dose FBP and ASIR CT (3.0 �± 0.5, p = 0.004; 4.0 �± 0.5, p = 0.02,\r\nrespectively), and was nearly identical to the score of standard-dose FBP image (4.8 �± 0.4, p = 0.66). Concerning\r\ndecreased lung attenuation (bulla, emphysema, or cyst), the image quality score on low-dose MBIR CT (4.9 �± 0.2)\r\nwas slightly better compared to low-dose FBP and ASIR CT (4.5 �± 0.6, p = 0.01; 4.6 �± 0.5, p = 0.01, respectively).\r\nThere were no significant differences in image quality scores of visualization of consolidation or mass, ground-glass\r\nattenuation, or reticular opacity among low- and standard-dose CT series. Image noise with low-dose MBIR CT\r\n(11.6 �± 1.0 Hounsfield units (HU)) were significantly lower than with low-dose ASIR (21.1 �± 2.6 HU, p < 0.0005),\r\nlow-dose FBP CT (30.9 �± 3.9 HU, p < 0.0005), and standard-dose FBP CT (16.6 �± 2.3 HU, p < 0.0005).\r\nConclusion: MBIR shows greater potential than ASIR for providing diagnostically acceptable low-dose CT without\r\ncompromising image quality. With radiation dose reduction of >70%, MBIR can provide equivalent lesion\r\ndetectability of standard-dose FBP CT....
Background: Fine needle aspiration biopsy is usually performed to evaluate thyroid lesions. The purpose of this\r\nstudy was to evaluate the usefulness of diffusion weighted imaging to differentiate malignancy of thyroid lesions.\r\nMethods: The study was approved by ethics committee of Shanghai Changzheng Hospital.Forty-two patients,\r\n10 men and 32 women (range: 20ââ?¬â??72 years, mean age 42.4 years) with thyroid lesions were included in the study.\r\nRoutine neck MR and diffusion-weighted MR imaging was performed using multiple b-values. ADC values were\r\ncomputed for the different b-values. Histological results of the thyroidectomy samples were obtained for all the\r\npatients. ADC values of benign and malignant thyroid lesions were compared with the pathology results. Logistic\r\nregression analysis was used to detect independent parameters for differentiating benign and malignancy of lesions.\r\nResult: Based on the histology results there were 28 benign and 14 malignant cases. The difference of ADC value\r\nbetween benign and malignant thyroid lesions was significant for ADC values obtained using b-values of 0 and 300 s/\r\nmm2 (p < 0.001). The ADC values were significantly higher in benign lesions (benign ADC: 2.37 Ã?± 0.47 Ã?â?? 10-3 mm2/s vs.\r\nmalignant: 1.49 Ã?± 0.60 Ã?â?? 10-3 mm2/s). ADC values obtained with b-values of 0 and 300 mm2/s and max nodular diameter\r\nwas regarded as the two most discriminative parameters for differentiating malignancy. Using the pathology results as a\r\nstandard reference, area under ROC curve was found to be 0.876 for an ADC cutoff value of 2.17 Ã?â?? 10-3 mm2/s that\r\ncorresponded to an acquisition with b-values of 0 and 300 mm2/s.\r\nConclusion: Diffusion-weighted MR imaging is a promising non-invasive method to differentiate malignancy in thyroid\r\nlesions....
Background: Tubal and uterine cavity diseases commonly compromise female fertility. At the present time,\r\nhysteroscopy, laparoscopy with chromopertubation and RX-Hysterosalpingography (RX-HSG) are widely accepted\r\nscreening procedures enabling the effective assessment of both tubal patency and uterine cavity. Nevertheless,\r\nconsistent evidence supports the reliability of Hysterosalpingocontrast sonography (HyCoSy) in uterine cavity and\r\ntubal patency investigation, as a part of the standard infertility work-up. This prospective study was aimed at\r\nevaluating the tolerability of the technique as well as the incidence of related side effects and complications in a\r\nlarge series of infertile patients.\r\nMethods: Pain perception of 632 infertile women was measured by means of an 11-point numeric rating scale.\r\nSide effects and late complications were also recorded.\r\nResults: The mean numeric rating scale was 2.15 Ã?± 2.0 SD. Most of the patients (374/632, 59.17%) rated HyCoSy as a\r\nnon-painful procedure, whereas 24.36% (154/632) women reported mild pelvic pain and 9.96% (63/632) classified\r\nthe discomfort as ââ?¬Å?moderateââ?¬Â. Only 6.48% (41/632) of the patient population experienced severe pelvic pain. Fifteen\r\n(2.37%) patients required drug administration for pain relief. Twenty-six patients (4.11%) showed mild vaso-vagal\r\nreactions that resolved without atropine administration. No severe vaso-vagal reactions or late complications were\r\nobserved.\r\nConclusions: HyCoSy is a well-tolerated examination and the associated vagal effects are unusual and generally\r\nmild. Consequently, we support its introduction as a first-line procedure for tubal patency and uterine cavity\r\ninvestigation in infertile women....
Background: To investigate the imaging features of primary sarcomas of the great vessels in CT, MRI and 18 F-FDG\r\nPET/CT.\r\nMethods: Thirteen patients with a primary sarcoma of the great vessels were retrospectively evaluated. All available\r\nimages studies including F-18 FDG PET(/CT) (n = 4), MDCT (n = 12) and MRI (n = 6) were evaluated and indicative\r\nimage features of this rare tumor entity were identified.\r\nResults: The median interval between the first imaging study and the final diagnosis was 11 weeks (0ââ?¬â??12 weeks).\r\nThe most frequently observed imaging findings suggestive of malignant disease in patients with sarcomas of the\r\npulmonary arteries were a large filling defect with vascular distension, unilaterality and a lack of improvement\r\ndespite effective anticoagulation. In patients with aortic sarcomas we most frequently observed a pedunculated\r\nappearance and an atypical location of the filling defect. The F-18 FDG PET(/CT) examinations demonstrated an\r\nunequivocal hypermetabolism of the lesion in all cases (4/4). MRI proved lesion vascularization in 5/6 cases.\r\nConclusion: Intravascular unilateral or atypically located filling defects of the great vessels with vascular distension,\r\na pedunculated shape and lack of improvement despite effective anticoagulation are suspicious for primary\r\nsarcoma on MDCT or MRI. MR perfusion techniques can add information on the nature of the lesion but the\r\nfindings may be subtle and equivocal. F-18 FDG PET/CT may have a potential role in these patients and may be\r\nconsidered as part of the imaging workup....
Background: Activity of disease in patients with multiple sclerosis (MS) is monitored by detecting and delineating\r\nhyper-intense lesions on MRI scans. The Minimum Area Contour Change (MACC) algorithm has been created with\r\ntwo main goals: a) to improve inter-operator agreement on outlining regions of interest (ROIs) and b) to\r\nautomatically propagate longitudinal ROIs from the baseline scan to a follow-up scan.\r\nMethods: The MACC algorithm first identifies an outer bound for the solution path, forms a high number of\r\niso-contour curves based on equally spaced contour values, and then selects the best contour value to outline the\r\nlesion. The MACC software was tested on a set of 17 FLAIR MRI images evaluated by a pair of human experts and a\r\nlongitudinal dataset of 12 pairs of T2-weighted Fluid Attenuated Inversion Recovery (FLAIR) images that had lesion\r\nanalysis ROIs drawn by a single expert operator.\r\nResults: In the tests where two human experts evaluated the same MRI images, the MACC program demonstrated\r\nthat it could markedly reduce inter-operator outline error. In the longitudinal part of the study, the MACC program\r\ncreated ROIs on follow-up scans that were in close agreement to the original expert�s ROIs. Finally, in a post-hoc\r\nanalysis of 424 follow-up scans 91% of propagated MACC were accepted by an expert and only 9% of the final\r\naccepted ROIS had to be created or edited by the expert.\r\nConclusion: When used with an expert operator''s verification of automatically created ROIs, MACC can be used to\r\nimprove inter- operator agreement and decrease analysis time, which should improve data collected and analyzed\r\nin multicenter clinical trials....
Background: Magnetic resonance imaging (MRI) guided wire localization presents several challenges apart from\r\nthe technical difficulties. An alternative to this conventional localization method using a wire is the radio-guided\r\noccult lesion localization (ROLL), more related to safe surgical margins and reductions in excision volume. The\r\npurpose of this study was to establish a safe and reliable magnetic resonance imaging-radioguided occult lesion\r\nlocalization (MRI-ROLL) technique and to report our initial experience with the localization of nonpalpable breast\r\nlesions only observed on MRI.\r\nMethods: Sixteen women (mean age 53.2 years) with 17 occult breast lesions underwent radio-guided localization\r\nin a 1.5-T MR system using a grid-localizing system. All patients had a diagnostic MRI performed prior to the\r\nprocedure. An intralesional injection of Technetium-99m macro-aggregated albumin followed by distilled water was\r\nperformed. After the procedure, scintigraphy was obtained. Surgical resection was performed with the help of a\r\ngamma detector probe. The lesion histopathology and imaging concordance; the procedure�s positive predictive\r\nvalue (PPV), duration time, complications, and accuracy; and the rate of exactly excised lesions evaluated with MRI\r\nsix months after the surgery were assessed.\r\nResults: One lesion in one patient had to be excluded because the radioactive substance came back after the\r\ninjection, requiring a wire placement. Of the remaining cases, there were four malignant lesions, nine benign\r\nlesions, and three high-risk lesions. Surgical histopathology and imaging findings were considered concordant in all\r\nbenign and high-risk cases. The PPV of MRI-ROLL was greater if the indication for the initial MR examination was\r\nactive breast cancer. The median procedure duration time was 26 minutes, and all included procedures were\r\ndefined as accurate. The exact and complete lesion removal was confirmed in all (100%) patients who underwent\r\nsix-month postoperative MRI (50%).\r\nConclusions: MRI-ROLL offers a precise, technically feasible, safe, and rapid means for performing preoperative MRI\r\nlocalizations in the breast....
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