Utility of adaptive control processing for the interpretation of digital mammograms.

Background Adaptive control processing for mammography (ACM) is a novel program that automatically sets up appropriate image-processing parameters for individual mammograms (MMGs) by analyzing the focal and whole breast histogram. Purpose To investigate whether ACM improves the image contrast of digital MMGs and whether it improves radiologists' diagnostic performance in reading of MMGs. Material and Methods One hundred normal cases for image quality assessment and another 100 cases (50 normal and 50 cancers) for observer performance assessment were enrolled. All mammograms were examined with and without ACM. Five radiologists assessed the intra- and extra-mammary contrast of 100 normal MMGs, and the mean scores of the intra- and extra-mammary contrast were compared between MMGs with and without ACM in both the dense and non-dense group. They classified 100 MMGs into BI-RADS categories 1-5, and were asked to rate the images on a scale of 0 to 100 for the likelihood of the presence of category 3-5 lesions in each breast. Detectability of breast cancer, reading time, and frequency of window adjustment were compared between MMGs with and without ACM. Results ACM improved the intra-mammary contrast in both the dense and non-dense group but degraded extra-mammary contrast in the dense group. There was no significant difference in detectability of breast cancer between MMGs with and without ACM. Frequency of window adjustment without ACM was significantly higher than that with ACM. Reading time without ACM was significantly longer than that with ACM. Conclusion ACM improves the image contrast of MMGs and shortens reading time.

Relationship between impaired cardiac sympathetic activity and spatial dyssynchrony in patients with non-ischemic heart failure: assessment by MIBG scintigraphy and tagged MRI.

BACKGROUND: Impairment of cardiac sympathetic activity has various detrimental effects on cardiac function. The purpose was to investigate the relationship between left ventricular (LV) dyssynchrony and cardiac sympathetic activity in non-ischemic heart failure (HF). METHODS: Twenty-seven patients with non-ischemic HF were enrolled. Cardiac sympathetic activity was assessed by heart-to-mediastinum ratio (H/M ratio) on (123)I-Metaiodobenzylguanidine scintigraphy. LV dyssynchrony was assessed by cross-correlation analysis of time curves of myocardial circumferential strains delivered from cine-tagging MR images. Temporal dyssynchrony was defined as contraction delay between septal and lateral segments >110 milliseconds. Spatial dyssynchrony was defined as the negative value of the maximum correlation for the two strain time curves. RESULTS: H/M ratio was significantly lower for patients with spatial dyssynchrony compared to patients without (1.8 ± 0.3 vs 2.1 ± 0.3, P < .05). There was no difference between patients with and without temporal dyssynchrony (2.0 ± 0.2 vs 2.0 ± 0.3). The incidence of spatial dyssynchrony was significantly higher in patients with H/M ratio <2.0 than those whose ratios were ≥2.0 (75% vs 20%, P = .001). There was no difference in the incidence of temporal dyssynchrony between the two groups (17% vs 20%). CONCLUSION: Impairment of cardiac sympathetic activity was found to be associated with spatial dyssynchrony in patients with non-ischemic HF.

A Case of Cystic Retroperitoneal Dedifferentiated Liposarcoma Diagnosed by Percutaneous Image-Guided Biopsy.

Introduction: Dedifferentiated liposarcoma (DDLP) was initially defined as a tumor containing differentiated liposarcoma and distinct regions of nonlipogenic spindle cell or pleomorphic sarcoma. Retroperitoneal liposarcomas feature a characteristic appearance with a predominantly fatty component, and cystic liposarcomas are rare. We describe a case of retroperitoneal DDLP predominantly consisting of multilocular cysts. Case Presentation: A 77-year-old man previously visited a doctor because an echo scan unexpectedly revealed an abdominal tumor. Contrast computed tomography (CT) disclosed a large multilocular cystic tumor spanning from the left upper abdomen to the retroperitoneum, and poorly marginated soft tissue structures were present around the abdominal aorta, inferior vena cava, pancreas, mesentery, and left kidney. CT also revealed a right lung mass. The soft tissue structures in the retroperitoneal cystic tumor and right lung mass were strongly enhanced on 2-deoxy-2-[fluorine-18] fluoro-d-glucose positron emission tomography, suggesting a malignant retroperitoneal tumor and lung metastasis. CT-guided percutaneous biopsy targeting the left perirenal soft tissue structure was performed, and the tumor was diagnosed as DDLP. Lung metastasis was present, and the retroperitoneal tumor surrounded multiple organs. Therefore, the tumor was not suitable for surgical resection but it was indicated for chemotherapy based on multidisciplinary discussion. Conclusion: We experienced a case of retroperitoneal cystic DDLP diagnosed by percutaneous image-guided biopsy and treated appropriately based on the pathological diagnosis.

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.

Clinical course and prognosis of patients with lung cancer who develop anticancer therapy-related pneumonitis.

BACKGROUND: Pneumonitis can be triggered by anti-cancer therapies: cytotoxic chemotherapy, tyrosine kinase inhibitors, and immune checkpoint inhibitors. There are few treatment options for patients who develop such pneumonitis and their treatment including chemotherapy is generally difficult thus would limit patient's prognosis. In this study, we investigated the clinical course of patients with lung cancer who developed anti-cancer therapy-related pneumonitis. PATIENTS AND METHODS: We retrospectively examined data of patients who had developed pneumonitis triggered by anti-cancer agents and required hospitalization from January 2014 to March 2019 and analyzed their subsequent clinical course and prognosis. RESULTS: The median age of the 58 study patients was 68 years and 82.8% were men. The median interval between first receiving the responsible agent and drug-induced pneumonitis was 7.4 weeks. Approximately 38% of patients were subsequently able to receive some anti-cancer therapy. The median post-pneumonitis overall survival (OS) from commencement of anti-cancer treatment was 13.2 months. No significant differences were found in survival time between treatment agents. However, patients who received some anticancer therapy after pneumonitis had significantly longer survival times than those did not (HR = 4.11, p = 0.0003) and patients who took longer to develop pneumonitis had a longer survival (HR = 2.28, p = 0.0148). Multivariate analysis revealed that short interval to onset and no post-pneumonitis anticancer therapy were independent predictors of short survival. CONCLUSION: Although patients who developed pneumonitis had relatively short survival times, the interval between initial therapy and pneumonitis had survival impact. Survival can be prolonged by administering further cancer treatment after resolution of pneumonitis.

Rapidly Destructive Coxarthrosis as a Potential Side Effect of Crizotinib in a Patient with ROS1-Positive Lung Adenocarcinoma.

A 75-year-old woman was diagnosed with c-ros oncogene 1 (ROS1)-positive lung adenocarcinoma. She was treated with crizotinib 750 mg/day for 4.5 years, with partial tumor response. However, the patient subsequently presented with right hip pain and difficulty in walking. She underwent magnetic resonance imaging (MRI), which detected T2 prolongation in the right femoral bone head, synovial fluid retention, and bone joint fissure narrowing. The patient was diagnosed with rapidly destructive coxarthrosis (RDC) and received a total hip arthroplasty. This represents a rare case of RDC as a potential side effect of crizotinib in a patient with ROS1-positive lung adenocarcinoma. MRI should therefore be recommended in patients receiving crizotinib who experience continuing severe hip pain and difficulty in walking. Further investigations are warranted to elucidate the pathogenesis of RDC associated with crizotinib treatment.

Brain cavernous hemangioma mimicking radiation-induced necrosis in a patient with non-small cell lung cancer.

In patients with non-small cell lung cancer (NSCLC), stereotactic radiotherapy (SRT) is one of the standard therapies for those suffering with intracranial metastatic NSCLC. Radiation-induced necrosis (RIN) sometimes occurs as the result of the delayed effects of SRT. The magnetic resonance imaging (MRI) of RIN typically shows hypointense and hyperintense lesions on T1- and T2-weighted images, respectively. We herein report a patient with a growing brain cystic lesion mimicking RIN adjacent to a post-radiation brain metastasis from NSCLC harboring anaplastic lymphoma kinase rearrangement. The patient underwent surgical resection of the brain tumor because of the symptoms. The pathological diagnosis was cavernous hemangioma, and the pathological findings were an encapsulated nodular mass composed of dilated, cavernous vascular spaces with no residual tumor or recurrence. Clinicians should be aware of the possibility for the development of a brain cavernous hemangioma following SRT in NSCLC patients.

Detection of axillary node metastasis using diffusion-weighted MRI in breast cancer.

Breast magnetic resonance imagings (MRIs) including diffusion-weighted MRI (DWI) of 110 breast cancers (26 with pathologically proven axillary node metastasis and 84 without metastasis) were retrospectively studied. Axillary nodes were detected as high-signal-intensity areas on DWI in 71 cancers (24 with metastasis and 47 without) and not detected in 39 cancers (2 with metastasis and 37 without). The ADC of metastatic nodes was significantly greater than that of the benign ones (1.08 ± 0.18 × 10(-3) mm(2)/s vs. 0.92 ± 0.22 × 10(-3) mm(2)/s, P=.004). When detectability of axillary nodes on DWI and ADC over 1.05 × 10(-3) mm(2)/s was applied as a threshold, 53.8% sensitivity, 86.9% specificity, and 79.1% accuracy were provided.

Detection of ground-glass opacities by use of hybrid iterative reconstruction (iDose) and low-dose 256-section computed tomography: a phantom study.

The detection of ground-glass opacities (GGOs) is an important issue in lung cancer screening with low-dose CT. The iterative reconstruction (IR) technique has the ability to improve the image quality relative to the filtered back projection (FBP) technique with low-dose CT. Our purpose was to investigate the ability to detect GGO in a chest phantom using a low-dose CT and hybrid IR, named iDose. Simulated GGOs in a chest phantom were scanned with 256-section CT at tube current second products of 20, 50, 100, and 200 mAs. Five radiologists visually assessed the detectability of GGOs in the phantom. The contrast-to-noise ratio (CNR) for GGOs was used as an estimate of image quality. Comparison of the detectability and CNR between standard images with 200 mAs-FBP and low-dose images with 20, 50, and 100-mAs FBP/iDose were performed by ANOVA with Dunnett's and Tukey's test. The detectability was significantly lower at 20-mAs FBP/iDose and 50-mAs FBP than that at 200-mAs FBP (p < 0.05). There was no significant difference between 50-mAs iDose and 200-mAs FBP and between 100-mAs iDose/FBP and 200-mAs FBP. The CNR was significantly higher on iDose images than that on FBP images at each mAs value. The CNR at 200-mAs FBP was the same as that at 50-mAs iDose (CNR:1.8). The hybrid IR technique and low-dose CT imaging with 50 mAs enabled noise and to maintain the detectability for GGOs in a chest phantom that is equivalent to the reference acquisitions of 200 mAs with FBP.

Correlations between apparent diffusion coefficient values and prognostic factors of breast cancer.

PURPOSE: We investigated possible correlations between apparent diffusion coefficient (ADC) values and prognostic factors of breast cancer. METHODS: We retrospectively evaluated 81 patients who underwent magnetic resonance (MR) imaging of the breast and were diagnosed pathologically with invasive ductal carcinoma (IDC) not otherwise specified with invasive foci one cm or larger. We excluded ductal carcinoma in situ and IDC with invasive foci smaller than one cm because small lesions decrease the reliability of signal intensity of diffusion-weighted imaging (DWI). We also excluded special type cancers. We used t-test to compare the mean ADC values of cancers of Stage pT1 (≤2 cm) versus pT2 or 3 (>2 cm), cancers with versus without vascular invasion, axillary lymph node (N)-positive versus N-negative cancers, estrogen receptor (ER)-positive versus ER-negative cancers, and progesterone receptor (PgR)-positive versus PgR-negative cancers. We analyzed correlations between the ADC value with nuclear grade (NG) and human epidermal growth factor receptor 2 (HER2) score by rank test using Spearman's correlation coefficient. RESULTS: The mean ADC value was significantly higher for N-positive (n=28; 0.97 ± 0.20 × 10(-3) mm(2)/s) than N-negative cancers (n=53; 0.87 ± 0.17 × 10(-3) mm(2)/s) (P=0.017); significantly lower for ER-positive (n=63; 0.88 ± 0.15 × 10(-3) mm(2)/s) than ER-negative cancers (n=18; 1.01 ± 0.21 × 10(-3) mm(2)/s) (P=0.005); and significantly lower for PgR-positive (n=47; 0.88 ± 0.16 × 10(-3) mm(2)/s) than PgR-negative cancers (n=34; 0.95 ± 0.18 × 10(-3) mm(2)/s) (P=0.048). Tumor size, vascular invasion, NG, and HER2 status showed no significant correlation with ADC values. CONCLUSION: ADC values were higher for N-positive and ER-negative breast cancers than N-negative and ER-positive cancers.

Evaluation of chronic ischemic heart disease with myocardial perfusion and regional contraction analysis by contrast-enhanced 256-MSCT.

PURPOSE: To investigate myocardial viability in chronic ischemic heart disease by myocardial perfusion and regional contraction analysis using 256-slice MSCT coronary angiography (CCTA). METHODS: In 30 patients with prior myocardial infarction (MI), CCTA with retrospective ECG-gating and stress-redistribution thallium-201 SPECT were performed. Using the same raw data as used for CCTA, myocardial perfusion imaging (CT-MPI) was reconstructed at four phases during the cardiac cycle. Mean myocardial attenuation and wall thickness at end-systole and end-diastole were measured in the MI areas depicted by SPECT, and they were compared between viable and non-viable segments categorized by SPECT. RESULTS: End-systolic thickness was significantly greater for viable than for non-viable segments (12.0 ± 3.2 vs. 9.6 ± 3.5 mm, p = 0.0017). There was no difference in end-diastolic thickness. Myocardial attenuation was significantly higher for viable than for non-viable segments in the subendocardium (62 ± 13 vs. 70 ± 11 HU, p = 0.003) and the epicardium (65 ± 13 vs. 80 ± 15 HU, p = 0.0002). CONCLUSION: The systolic wall thinning and epicardial low-attenuation areas were the indicative findings of CT-MPI for non-viable segments in the prior MI.

Detectability of simulated pulmonary nodules on chest radiographs: comparison between irradiation side sampling indirect flat-panel detector and computed radiography.

OBJECTIVE: To compare the detectability of simulated pulmonary nodules on chest radiographs between an irradiation side sampling indirect flat-panel detector (ISS-FPD) and computed radiography (CR). MATERIALS AND METHODS: This study was an observer performance study. Simulated pulmonary nodules of 8 mm in diameter were superimposed on an anthropomorphic chest phantom. Chest radiographs were acquired under 2 exposure levels (4 and 3.2 mAs) with the ISS-FPD and the CR. Six thoracic radiologists evaluated all 40 images (10 patterns × 2 different exposure doses × 2 different systems) for the presence or absence of a lesion over each of 12 defined areas on a 3-megapixel monochrome liquid-crystal display. Receiver operating characteristic (ROC) curves were obtained for observation in predefined 480 areas. A jackknife method was used for statistical analysis. Differences with a P value of <0.05 were considered significant. RESULTS: The analysis of the observer detection of simulated pulmonary nodules showed larger areas under the ROC curve (AUC) by the ISS-FPD than by the CR. There was a statistically significant difference between the two systems at 3.2 mAs (P=0.0330). CONCLUSION: The ISS-FPD was superior to the CR for the detection of simulated pulmonary nodules at 3.2 mAs.

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.