Percentage volume of delayed kinetics in computer-aided diagnosis of MRI of the breast to reduce false-positive results and unnecessary biopsies.

AIM: To investigate the best cut-off percentage volume of delayed kinetics using magnetic resonance imaging (MRI) with computer-aided diagnosis (CAD) to reduce unnecessary biopsies in patients with newly diagnosed breast cancer. MATERIALS AND METHODS: Between January 2017 and December 2018, 94 malignant and 56 benign masses were analysed using MRI CAD. All malignant and benign masses measured <2 cm and were confirmed histopathologically. The optimal cut-off values for washout, plateau, and persistent components were determined using the maximum Youden Index. The positive predictive value (PPV) was analysed using morphological descriptors and combining the percentage volume of delayed kinetics. RESULTS: The area under the curve (AUC) was highest at ≤73% persistent component (AUC=0.759). In the subgroup analyses of masses <1 cm, the AUC was highest a plateau of >26% (AUC=0.697). When the persistent ≤73% criterion was applied to the lesions of C4a, the positive predictive value (PPV) increased from 61.9% to 72.44% with reduced false-negative cases and when applied to the lesions of C4a and C4b, the PPV increased from 61.9% to 78.1% with slightly increased false-negative cases. For subcentimetre lesions, the PPV increased from 46.77% to 54.72% with the same number of false-negative cases, when a plateau of >26% was applied to C4a, and the PPV increased from 46.77% to 61.36% with five false-negative cases when applied to C4a and C4b. CONCLUSION: The percentage volume of delayed kinetics has the potential to improve the PPV of breast MRI. When suspicious masses <2 cm do not show ≤73% persistence, follow-up rather than biopsy could be considered; however, to avoid increasing false-negative cases, delayed kinetic information should be used with caution and accurate margin assessment is essential.

Comparison of the diagnostic performance of abbreviated MRI and full diagnostic MRI using a computer-aided diagnosis (CAD) system in patients with a personal history of breast cancer: the effect of CAD-generated kinetic features on reader performance.

AIM: To compare the diagnostic performance of abbreviated magnetic resonance imaging (MRI) and full diagnostic MRI with computer-aided diagnosis (CAD) system in patients with a personal history of breast cancer and to evaluate how the kinetic features affect the performance of two radiologists. MATERIALS AND METHODS: Between 1 January 2014 and 31 December 2017, 3,834 breast MRI examinations in 2,310 patients with a history of breast cancer comprised the study population. MRI images were reviewed retrospectively by two radiologists. First, two radiologists independently reviewed T1-weighted images scanned at 90 seconds after the contrast medium injection and T2-weighted images. After 6 months, the two readers reviewed contrast-enhanced T1-weighted images with five consecutive delayed images using CAD. The diagnostic performance of the abbreviated-sequence and full-sequence MRI were compared. RESULTS: Fifty-one intramammary recurrences were detected with breast MRI in 47 patients. Of the 51 tumour recurrences, 36 (70.6%) lesions occurred >3 years after initial cancer surgery and seven (13.7%) lesions at <2 years after initial surgery. The sensitivity and specificity were 92.2-94.1% and 97.6-98.6% on the abbreviated sequence and 94.1-96.1% and 97.9-98.3% on the full diagnostic MRI. Of 51 malignant lesions, six showed delayed persistent pattern, of which three lesions were non-mass enhancement and three lesions were small enhancing masses <1 cm. CONCLUSION: Overall diagnostic performances of abbreviated MRI and full diagnostic MRI were similar in both readers. The CAD-generated kinetic features could affect reader performance and the sensitivity could be improved or the specificity improved according to the reader.

Evaluation of lymph node status after neoadjuvant chemotherapy in breast cancer patients: comparison of diagnostic performance of ultrasound, MRI and ¹8F-FDG PET/CT.

OBJECTIVE: To evaluate the diagnostic performance of ultrasound, MRI and fluorine-18 fludeoxyglucose positron emission tomography (¹8F-FDG PET)/CT for the diagnosis of metastatic axillary lymph node (ALN) after neoadjuvant chemotherapy (NAC) and to find out histopathological factors affecting the diagnostic performance of these imaging modalities. METHODS: From January 2012 to November 2014, 191 consecutive patients with breast cancer who underwent NAC before surgery were retrospectively reviewed. We included 139 patients with ALN metastasis that was confirmed on fine needle aspiration or core needle biopsy at initial diagnosis. RESULTS: After NAC, 39 (28%) patients showed negative conversion of ALN on surgical specimens of sentinel lymph node (LN) or ALN. The sensitivity of ultrasound, MRI and PET/CT was 50% (48/96), 72% (70/97) and 22% (16/73), respectively. The specificity of ultrasound, MRI and PET/CT was 77% (30/39), 54% (21/39) and 85% (22/26), respectively. The Az value of combination of ultrasound and PET/CT was the highest (0.634) followed by ultrasound (0.626) and combination of ultrasound, MRI and PET/CT (0.617). The size of tumour deposit in LN and oestrogen receptor was significantly associated with the diagnostic performance of ultrasound (p < 0.001 and p = 0.009, respectively) and MRI (p = 0.045 and p = 0.036, respectively). The percentage diameter decrease, size of tumour deposit in LN, progesterone receptor, HER2 and histological grade were significantly associated with the diagnostic performance of PET/CT (p = 0.023, p = 0.002, p = 0.036, p = 0.044 and p = 0.008, respectively). On multivariate logistic regression analysis, size of tumour deposit within LN was identified as being independently associated with diagnostic performance of ultrasound [odds ratio, 13.07; 95% confidence interval (CI), 2.95-57.96] and PET/CT (odds ratio, 6.47; 95% CI, 1.407-29.737). CONCLUSION: Combination of three imaging modalities showed the highest sensitivity, and PET/CT showed the highest specificity for the evaluation of ALN metastasis after NAC. Ultrasound alone or combination of ultrasound and PET/CT showed the highest positive-predictive value. The size of tumour deposit within ALN was significantly associated with diagnostic performance of ultrasound and PET/CT. ADVANCES IN KNOWLEDGE: This study is about the diagnostic performance of ultrasound, MRI, PET/CT and combination of each imaging modality for the evaluation of metastatic ALN after NAC. Of many histopathological factors, only the size of tumour deposit within ALN was an independent factor associated with the diagnostic performance of ultrasound and PET/CT.

Does background parenchymal enhancement on MRI affect the rate of positive resection margin in breast cancer patients?

OBJECTIVE: The purpose of our study was to evaluate whether strong background parenchymal enhancement (BPE) would be a significant independent factor associated with positive resection margin in patients treated initially with breast-conserving surgery (BCS). METHODS: Retrospective evaluation of breast MRI examinations of 314 patients with breast cancer was carried out. Breast cancer was histologically confirmed in all patients who underwent BCS from January 2008 to December 2010. BPE was dichotomized into weak (minimal or mild) and strong (moderate or marked) enhancement for statistical analysis. Histopathological features of attained specimens were evaluated by an experienced pathologist and were also dichotomized for statistical analysis. RESULTS: On univariate analysis, positive extensive intraductal component (p < 0.001), strong BPE (p = 0.001) and human epidermal growth factor receptor 2 (HER2) positivity (p = 0.08) had significant association with positive surgical margin. Tumour size, axillary lymph node metastasis, nuclear grade, histological grade, lymphovascular invasion, oestrogen receptor and progesterone receptor did not show significant correlation with positive surgical margin. On multivariate analysis, the significant independent predictors were extensive intraductal component [odds ratio, 5.68; 95% confidence interval (CI), 2.72-11.82] and strong BPE (odds ratio, 2.39; 95% CI, 1.20-4.78). CONCLUSION: Strong BPE is a significant independent factor for positive resection margin along with positive extensive intraductal component, and performing MRI during the period of lower parenchymal enhancement is needed in patients with strong BPE. ADVANCES IN KNOWLEDGE: As far as we know, this is the first study to reveal that BPE is a significant independent factor associated with positive resection margin.

Diagnostic performance of 18F-FDG PET/CT, ultrasonography and MRI. Detection of axillary lymph node metastasis in breast cancer patients.

UNLABELLED: The aim of this study was to evaluate the diagnostic abilities of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography(PET/CT) compared with those of ultrasonography and magnetic resonance imaging (MRI) for axillary lymph node staging in breast cancer patients. PATIENTS, METHODS: Preoperative 18F-FDG PET/non-contrast CT, ultrasonography and MRI were performed in 215 women with breast cancer. Axillary lymph node dissection was performed in all patients and the diagnostic performance of each modality was evaluated using histopathologic assessments as the reference standard. ROC curves were compared to evaluate the diagnostic ability of several imaging modalities (i. e., ultrasonography, MRI and 18F-FDG PET/CT). RESULTS: In total, 132 patients (61.4%) had axillary lymph node metastasis. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for the detection of axillary lymph node metastasis were 72.3%, 77.3%, 66.7%, 81.6%, 75.3% for ultrasonography, 67.5%, 78.0%, 65.9%, 79.2%, 74.0% for MRI, and 62.7%, 88.6%, 77.6%, 79.1%, 78.6% for 18F-FDG PET/CT, respectively. There was no significant difference in diagnostic ability among the imaging modalities (i.e., ultrasonography, MRI and 18F-FDG PET/CT). The diagnostic ability of 18F-FDG PET/CT was significantly improved by combination with MRI (p = 0.0002) or ultrasonography (p < 0.0001). The combination of 18F-FDG PET/CT with ultrasonography had a similar diagnostic ability to that of all three modalities combined (18F-FDG PET/CT+ultrasonography+MRI, p = 0.05). CONCLUSION: The diagnostic performance of 18F-FDG PET/CT for detection of axillary node metastasis was not significantly different from that of ultrasonography or MRI in breast cancer patients. Combining 18F-FDG PET/CT with ultrasonography or MRI could improve the diagnostic performance compared to 18F-FDG PET/CT alone.

Co-registered spectrally encoded confocal microscopy and optical frequency domain imaging system.

Spectrally encoded confocal microscopy and optical frequency domain imaging are two non-contact optical imaging technologies that provide images of tissue cellular and architectural morphology, which are both used for histopathological diagnosis. Although spectrally encoded confocal microscopy has better transverse resolution than optical frequency domain imaging, optical frequency domain imaging can penetrate deeper into tissues, which potentially enables the visualization of different morphologic features. We have developed a co-registered spectrally encoded confocal microscopy and optical frequency domain imaging system and have obtained preliminary images from human oesophageal biopsy samples to compare the capabilities of these imaging techniques for diagnosing oesophageal pathology.

[Comprehensive assessment of coronary disease using perfusion CT with pharmacologically induced stress]. / Valoración integral de la enfermedad coronaria mediante TC-perfusión con estrés farmacológico.

Technological advances in multidetector computed tomography (MDCT) like second-generation dual source scanners have made it possible to evaluate myocardial perfusion as well as the anatomy of the coronary arteries in patients with suspected coronary disease; until recently, this application was confined to other imaging modalities. In this brief communication, we report a cardiac CT imaging protocol that combines CT coronary angiography with the analysis of ventricular function, perfusion, and myocardial viability in a single examination, thereby enabling a comprehensive assessment of coronary disease.

Effects of delta-aminolevulinic acid and vitamin C supplementation on feed intake, backfat, and iron status in sows.

This study was conducted to evaluate the effect of dietary administered delta-aminolevulinic acid (ALA) and vitamin C on the hematological profiles and performance of sows and sucking pigs and to determine if iron status could be improved by dietary administration of ALA. Seven days before parturition, 120 sows (Landrace x Yorkshire) were randomly assigned within parities to 1 of 4 dietary treatments. The lactation treatments were arranged as a 2 x 2 factorial with 2 ALA concentrations (0 or 10 mg/kg of feed, as fed) and 2 vitamin C concentrations (0 or 500 mg/kg of feed, as fed). After farrowing, daily feed allowance increased gradually, and sows had ad libitum access to feed by wk 2. Sows provided diets with ALA tended to consume more feed (P < 0.10) than sows fed diets that did not contain ALA. Conversely, backfat losses were less in sows that received the diets with ALA compared with those received the nonsupplemented diets (P < 0.05). Supplementation with ALA and vitamin C resulted in improved hematological profiles (total protein, albumin, and IgG) in sows (P < 0.05). The iron status in the blood and milk were also improved by ALA supplementation (P < 0.05). Moreover, the BW at weaning and the ADG during the sucking period increased in response to supplementation of ALA and vitamin C (P < 0.05). The blood iron status of piglets was also improved by ALA supplementation (P < 0.05). In conclusion, dietary supplementation of ALA can increase the blood iron status of sows and sucking pigs, as well as the iron transfer efficiency from sows to piglets through elevated milk iron concentrations.

The A-factor regulatory cascade and cAMP in the regulation of physiological and morphological development in Streptomyces griseus.

In the A-factor regulatory cascade leading to the onset of streptomycin biosynthesis and aerial mycelium formation in Streptomyces griseus, the A-factor receptor protein (ArpA) serves as a DNA-binding repressor and A-factor releases the repression by binding to ArpA and dissociating it from the DNA. Mutants defective in arpA therefore produce streptomycin and aerial hyphae in the absence of A-factor. A gene that inhibits streptomycin production and aerial hyphae formation in an arpA mutant was cloned on a high-copy-number plasmid and found to encode a eukaryotic-type adenylate cyclase (CyaA). Consistent with this, an exogenous supply of cAMP at high concentration almost abolished streptomycin production and aerial hyphae formation. On the other hand, cAMP at lower concentrations stimulated or accelerated these developmental processes. The effects of cAMP were detectable only in arpA mutants, and not in the wild -type strain; an exogenous supply of cAMP or cyaA disruption in the wild-type strain caused almost no effect on these phenotypes. Thus the effects of cAMP became apparent only in the arpA-defective background. cAMP at high concentrations inhibited stringent response factor ppGpp production, which is important for the onset of antibiotic biosynthesis. cAMP also influenced the timing of tyrosine phosphorylation of more than nine proteins. These findings show that a cAMP regulatory relay for physiological and morphological development functions in a concerted and interdependent way with other signal transduction pathways.

c-Fos expression by dopaminergic receptor activation in rat hippocampal neurons.

While dopamine is likely to modulate hippocampal synaptic plasticity, there has been little information about how dopamine affects synaptic transmission in the hippocampus. The expression of IEGs including c-fos has been associated with late phase LTP in the CA1 region of the hippocampus. The induction of c-fos by dopaminergic receptor activation in the rat hippocampus was investigated by using semiquantitative RT-PCR and immunocytochemistry. The hippocampal slices which were not treated with dopamine showed little expression of c-fos mRNA. However, the induction of c-fos mRNA was detected as early as 5 min after dopamine treatment, peaked at 60 min, and remained elevated 5 h after treatment. Temporal profiles of increases in c-fos mRNA by R(+)-SKF-38393 (50 microM) and forskolin (50 microM) were similar to that of dopamine. An increase in [cAMP] was observed in dopamine-, SKF-, or forskolin-treated hippocampal slices. By immunocytochemical studies, control hippocampal cells showed little expression of c-Fos immunoreactivity. However, when cells were treated with dopamine, an increase in the expression of c-Fos immunoreactivity was observed after treatment for 2 h. The treatment of hippocampal neurons with R(+)-SKF38393 (50 microM) or forskolin (50 microM) also induced a significant increase in c-Fos expression. These results indicate that the dopamine D1 receptor-mediated cAMP dependent pathway is associated with the expression of c-Fos in the hippocampal neurons. These data are consistent with the possible role of endogenous dopamine on synaptic plasticity via the regulation of gene expression. Furthermore, these results imply that dopamine might control the process of memory storage in the hippocampus through gene expression.