Shunya Sunami

Detection of non-palpable breast cancer in asymptomatic women by using unenhanced diffusion-weighted and T2-weighted MR imaging: comparison with mammography and dynamic contrast-enhanced MR imaging

ObjectiveTo compare the detectability of non-palpable breast cancer in asymptomatic women by using mammography (MMG), dynamic contrast-enhanced MR imaging (DCE-MRI) and unenhanced MR imaging with combined diffusion-weighted and T2-weighted images (DWI + T2WI).MethodsForty-two lesions in 42 patients with non-palpable breast cancer in asymptomatic women were enrolled. For the reading test, we prepared a control including 13 normal and 8 benign cases. Each imaging set included biplane MMG, DCE-MRI and DWI + T2WI. Five readers were asked to rate the images on a scale of 0 to 100 for the likelihood of the presence of cancer and the BI-RADS category. Confidence level results were used to construct receiver operating characteristic analysis. Sensitivity and specificity were calculated for each technique.ResultsDWI + T2WI showed higher observer performances (area under the curve, AUC, 0.73) and sensitivity (50%) for the detection of non-palpable breast cancer than MMG alone (AUC 0.64; sensitivity 40%) but lower than those of DCE-MRI (AUC 0.93; sensitivity 86%). A combination of MMG and DWI + T2WI exhibited higher sensitivity (69%) compared with that of MMG alone (40%).ConclusionDWI + T2WI could be useful in screening breast cancer for patients who cannot receive contrast medium and could be used as a new screening technique for breast cancer.

Non–Small Cell Lung Cancer: Detection of Early Response to Chemotherapy by Using Contrast-enhanced Dynamic and Diffusion-weighted MR Imaging

PURPOSE To evaluate the ability of dynamic contrast material-enhanced and diffusion-weighted (DW) magnetic resonance (MR) imaging to help detect early response to chemotherapy in patients with non-small cell lung cancer (NSCLC). MATERIALS AND METHODS This study was approved by the institutional review board, and written informed consent was obtained from all subjects. Twenty-eight patients with stage IIIB or IV NSCLC (17 women, 11 men; mean age, 64.8 years) who underwent chemotherapy were enrolled. All patients underwent MR imaging before and after the first course of chemotherapy. The time to peak enhancement, maximum enhancement ratio, and washout ratio were determined from the time-signal intensity curves of dynamic contrast-enhanced MR images. The apparent diffusion coefficient (ADC) of each lung carcinoma was calculated from DW MR images. The responses of these parameters to the first course of chemotherapy and the pretreatment ADC itself were compared with final tumor size reduction by using the Pearson correlation coefficient. Kaplan-Meier curves of progression-free survival and overall survival were generated, and comparisons between the group with a good response of the significant parameter (upper 50th percentile) and that with a poor response of the significant parameter (lower 50th percentile) were performed by using a two-sided log-rank test. RESULTS Significant correlation was found only between early ADC change and final tumor size reduction rate (r(2) = 0.41, P = .00025). The median progression-free survival for the group with a good increase in ADC was 12.1 months, and that for the group with a stable or decreased ADC was 6.67 months (P = .021), while median overall survival was 22.4 and 12.3 months, respectively (P = .048). CONCLUSION ADC seems to be a promising tool for monitoring the early response to or predicting prognosis after chemotherapy of NSCLC.

Pretreatment Apparent Diffusion Coefficient of the Primary Lesion Correlates With Local Failure in Head-and-Neck Cancer Treated With Chemoradiotherapy or Radiotherapy

PURPOSE This study was performed to evaluate whether the apparent diffusion coefficient (ADC) of a primary lesion correlates with local failure in primary head-and-neck squamous cell carcinoma (HNSCC) treated with chemoradiotherapy or radiotherapy. METHODS AND MATERIALS We retrospectively studied 38 patients with primary HNSCC (12 oropharynx, 20 hypopharynx, 4 larynx, 2 oral cavity) treated with chemoradiotherapy or radiotherapy with radiation dose to gross tumor volume equal to or over 60 Gy and who underwent pretreatment magnetic resonance imaging, including diffusion-weighted imaging. Ten patients developed local failure during follow-up periods of 2.0 to 9.3 months, and the remaining 28 showed local control during follow-up periods of 10.5 to 31.7 months. The variables that could affect local failure (age, tumor volume, ADC, T stage, N stage, dose, treatment method, tumor location, and overall treatment time) were analyzed using logistic regression analyses for all 38 patients and for 17 patients with Stage T3 or T4 disease. RESULTS In univariate logistic analysis for all 38 cases, tumor volume, ADC, T stage, and treatment method showed significant (p < 0.05) associations with local failure. In multivariate analysis, ADC and T stage revealed significance (p < 0.01). In univariate logistic analysis for the 17 patients with Stage T3 or T4 disease, ADC and dose showed significant (p < 0.01) associations with local failure. In multivariate analysis, ADC alone showed significance (p < 0.05). CONCLUSIONS The results suggest that pretreatment ADC, along with T stage, is a potential indicator of local failure in HNSCC treated with chemoradiotherapy or radiotherapy.

Apparent Diffusion Coefficient Calculated with Relatively High b-Values Correlates with Local Failure of Head and Neck Squamous Cell Carcinoma Treated with Radiotherapy

BACKGROUND AND PURPOSE: Few studies have investigated the relationship between ADC and clinical outcome in HNSCC. Our hypothesis has that relatively high pretreatment ADC would correlate with local failure of HNSCC treated with radiation therapy. MATERIALS AND METHODS: This includes prospective and validation studies. Seventeen patients treated with radiation therapy for primary HNSCC completed the prospective study. Variables considered to affect local failure including MR imaging–related parameters such as ADC and its change ratio were compared between patients with local failure and controls, and those showing difference or association with local failure were further tested by survival analysis. Furthermore, variables were analyzed in 40 patients enrolled in the validation study. RESULTS: Relatively high ADC calculated with b-values (300, 500, 750, and 1000 s/mm2) before treatment, high ADC increase ratio, and treatment method (chemoradiotherapy versus radiation therapy alone) revealed significant difference between patients with local failure and controls or association with local failure. In Cox proportional hazard testing, high ADC before treatment alone showed significant association with local failure (P = .0186). In the validation study, tumor volume before treatment, high ADC before treatment, T stage (T12 versus T34), and treatment method showed significance. Tumor volume before treatment (P = .0217) and high ADC before treatment (P = .0001) revealed significant association with local failure in Cox proportional hazard testing. High ADC before treatment was superior to tumor volume before treatment regarding association with local failure. CONCLUSIONS: These results suggest pretreatment ADC obtained at high b-values as well as tumor volume correlate with local failure of HNSCC treated with radiation therapy.

Diagnostic performance in differentiation of breast lesion on digital mammograms: comparison among hard-copy film, 3-megapixel LCD monitor, and 5-megapixel LCD monitor

We compared observer performance of digital mammography among hard-copy readings and soft-copy readings using 3-megapixel (3M) and 5-megapixel (5M) liquid crystal display (LCD) monitors. Five experienced radiologists assessed 80 mammograms of 40 cancers and 40 benign lesions. There were no significant differences among the average A(z) of three modalities and among the κ values for intra- and interobserver agreement. The soft-copy reading using the 3M LCD monitor took a slightly longer time, although there were no significant differences.

Evaluation of the extent of ground-glass opacity on high-resolution CT in patients with interstitial pneumonia associated with systemic sclerosis: Comparison between quantitative and qualitative analysis

AIM To verify whether quantitative analysis of the extent of ground-glass opacity (GGO) on high-resolution computed tomography (HRCT) could show a stronger correlation with the therapeutic response of interstitial pneumonia (IP) associated with systemic sclerosis (SSc) compared with qualitative analysis. MATERIALS AND METHODS Seventeen patients with IP associated with SSc received autologous peripheral blood stem cell transplantation (auto-PBSCT) and were followed up using HRCT and pulmonary function tests. Two thoracic radiologists assessed the extent of GGO on HRCT using a workstation. Therapeutic effect was assessed using the change of vital capacity (VC) and diffusing capacity of the lung for carbon monoxide (DLco) before and 12 months after PBSCT. Interobserver agreement was assessed using Spearmans rank correlation coefficient and the Bland-Altman method. Correlation with the therapeutic response between quantitative and qualitative analysis was assessed with Pearsons correlation coefficients. RESULTS Spearmans rank correlation coefficient showed good agreement, but Bland-Altman plots showed that proportional error could be suspected. Quantitative analysis showed stronger correlation than the qualitative analysis based on the relationships between the change in extent of GGO and VC, and change in extent of GGO and DLco. CONCLUSION Quantitative analysis of the change in extent of GGO showed stronger correlation with the therapeutic response of IP with SSc after auto-PBSCT than with the qualitative analysis.

Joint Position Affects Muscle Proton Diffusion: Evaluation With a 3-T MR System

OBJECTIVE To determine whether joint position affects muscle proton diffusion, fractional anisotropy and primary (lambda(1)), secondary (lambda(2)), and tertiary (lambda(3)) eigenvalues of calf muscles were compared among ankle positions of plantar flexion, intermediate, and dorsiflexion. CONCLUSION In tibialis anterior, fractional anisotropy and lambda(1) decreased, but lambda(2) and lambda(3) increased (p < 0.01) as the joint angle increased. Opposite results were obtained for the gastrocnemius and soleus (p < 0.05). These results indicate that joint position affects muscle proton diffusion.

Anterior mediastinal solid tumours in adults: characterisation using dynamic contrast-enhanced MRI, diffusion-weighted MRI, and FDG-PET/CT.

AIM To find significant parameters to characterise anterior mediastinal solid tumours in adults using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), diffusion-weighted MRI (DWI), and combined 2-[(18)F]-fluoro-2-deoxy-d-glucose positron-emission tomography/computed tomography (FDG-PET/CT). MATERIALS AND METHODS Forty-eight histologically confirmed anterior mediastinal solid tumours in 48 patients (24 men, 24 women; age range 21-83 years, mean 50.7 years) were examined. The parameters analysed were maximal diameter, presence of capsule/septa on T2-weighted images, time-signal intensity curves (TICs), apparent diffusion coefficient (ADC), and maximum standardised uptake value (SUVmax). Also examined was whether any differences between histological types could be seen in these parameters. In a validation study, 42 anterior mediastinal solid tumours in 42 patients were examined consecutively. RESULTS The washout pattern on TIC was seen only in thymic epithelial tumours (20/32). SUVmax of lymphoma (mean, 17.9), malignant germ cell tumours (14.2), and thymic carcinomas (15.6) were significantly higher than that of thymomas (6.1). The mean maximal diameter of thymic epithelial tumours was significantly smaller than that of lymphomas (p<0.01) and malignant germ cell tumours (p<0.05). The validation study also yielded high accuracy (38/42, 91%) in differentiation among the anterior mediastinal solid tumours. CONCLUSION The SUVmax, TIC pattern on DCE-MRI, and maximal diameter might be useful to differentiate anterior mediastinal solid tumours in adults.

Exogenous lipoid pneumonia induced by aspiration of insecticide.

Exogenous lipoid pneumonia is a rare disorder caused by inhalation and/or aspiration of oil-based substances. The confirmed diagnosis of exogenous lipoid pneumonia is difficult, especially in cases for which it is impossible to ascertain a history of inhalation or aspiration. We present a case of exogenous lipoid pneumonia due to aspiration of insecticide, for which the computed tomography findings of fat attenuation within the lesion were helpful in reaching a correct diagnosis.

Correlation between pretreatment or follow-up CT findings and therapeutic effect of autologous peripheral blood stem cell transplantation for interstitial pneumonia associated with systemic sclerosis

PURPOSE To evaluate what is useful among various parameters including CT findings, laboratory parameters (%VC, %DLco, KL-6), patients related data (age, sex, duration of disease) to discriminate between responder and non-responder in patients who received autologous peripheral blood stem cell transplantation (auto-PBSCT) for interstitial pneumonia (IP) with systemic sclerosis (SSc). METHOD Auto-PBSCT and follow-up of at least one year by chest CT, serum KL-6, %VC, and %DLco were performed in 15 patients for IP with SSc. Analyzed CT findings included extent of ground-glass opacity (GGO), intralobular reticular opacity, number of segments that showed traction bronchiectasis, and presence of honeycombing. We regarded the therapeutic response of patients as responders when TLC or VC increase over 10% or DLco increase more than 15%, otherwise we have classified as non-responder. We applied univariate and multivariate analyses to find the significant indicators to discriminate responders from non-responders. P<0.05 was considered statistically significant. RESULTS Univariate and multivariate analyses showed that the significant parameter to discriminate responders from non-responders were pretreatment KL-6, presence of honeycombing, extent of GGO, and early change in extent of GGO. Among them, extent of GGO and early change in extent of GGO were the strongest discriminators between responders and non-responders (P=0.001, 0.001, respectively). CONCLUSION Several CT findings and pretreatment KL-6 may be useful to discriminate between responder and non-responder in patients who received auto-PBSCT for IP with SSc.