Intracholecystic papillary neoplasm associated with invasive carcinoma of the remnant gallbladder after subtotal cholecystectomy: a case report.

BACKGROUND: Intracholecystic papillary neoplasm (ICPN) of the gallbladder is a rare tumor and a relatively new concept. Therefore, the natural history and imaging characteristics of ICPN have not yet been fully documented. Moreover, cases who underwent curative resection for remnant gallbladder cancer, including ICPN with associated invasive carcinoma, have been rarely reported. We report a resected case of ICPN of the remnant gallbladder with associated invasive carcinoma for which we could observe a temporal change in imaging findings until malignant transformation. CASE PRESENTATION: A 79-year-old female patient with a surgical history of subtotal cholecystectomy for acute cholecystitis was an ambulatory patient of our institution because of postoperative surveillance for colon cancer. Ultrasonography and computed tomography incidentally detected a small nodule in the cystic remnant gallbladder. The nodule had increased in size 3 months later; thus, additional investigations were performed. Magnetic resonance imaging revealed a 10-mm enhanced nodule without evidence of extraluminal invasion. Diffusion-weighted magnetic resonance imaging revealed restricted diffusion of the lesion, and positron emission tomography revealed marked accumulation in the lesion. The lesion was diagnosed as suspicious for a malignant remnant gallbladder tumor. Therefore, remnant cholecystectomy with gallbladder bed resection was performed. Because preoperative endoscopic retrograde cholangiography revealed a relatively long intact cystic duct, extrahepatic bile duct resection was planned to be omitted. Intraoperatively, the hepatic and duodenal side bile duct where the cystic duct diverged was taped. Using these tapes, which permitted pulling the bile duct, the cystic duct located behind the bile duct could be safely exposed. The lesion was pathologically diagnosed as biliary morphologic ICPN with associated invasive carcinoma. CONCLUSIONS: Because remnant cholecystectomy is an uncommon procedure and technically difficult, accurate preoperative investigation and surgical planning are important to prevent bile duct injury and omit extrahepatic bile duct resection. In the present case, intracystic change could be detected incidentally at an early stage because of previous remnant gallbladder producing (reconstituting) subtotal cholecystectomy and surveillance for other disease. This case suggests the existence of ICPN that can progress to invasive carcinoma during a short period.

Durable response to nivolumab in a lung adenocarcinoma patient with idiopathic pulmonary fibrosis.

The efficacy and safety of immune-checkpoint inhibitors in non-small cell lung cancer patients with idiopathic pulmonary fibrosis (IPF) remain unknown. Herein, we describe the case of a 62-year-old man with multiple pleural tumors and carcinomatous pleurisy. High-resolution computed tomography indicated usual interstitial pneumonia, and a respiratory function test revealed a restrictive disorder and decreased diffusion capacity. He was diagnosed with lung adenocarcinoma and IPF. After failure of initial chemotherapy, he was treated with nivolumab and achieved a complete response without any sign of exacerbation of IPF. The response to nivolumab has persisted for > 1 year. This is the first report of a non-small cell lung cancer patient with IPF who has been treated with immune-checkpoint inhibitors for such a long period and achieved a sustained response.

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.

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.

Diffusion-weighted imaging (b value = 1500 s/mm(2)) is useful to decrease false-positive breast cancer cases due to fibrocystic changes.

BACKGROUND: We aimed to evaluate the application of apparent diffusion coefficient (ADC) values calculated from diffusion-weighted imaging (DWI) (b value = 1500 s/mm(2)) in the breast imaging reporting and data system (BI-RADS). METHODS: For 104 cases of breast lesions with definitive histology diagnosis (45 benign cases, 59 malignant cases) in which breast magnetic resonance imaging was performed, ADC values were compared between benign and malignant cases, between ductal carcinoma in situ (DCIS) and fibrocystic changes, and between DCIS and ductal hyperplasia (one type of fibrocystic change). Diagnostic accuracy was compared for a total of 101 images and for 34 images including only nine DCIS and 25 fibrocystic changes between BI-RADS alone (with categories 4a, 4b, and 5 defined as malignancies) and BI-RADS plus ADC. RESULTS: There were significant differences in mean ADC values between malignant and benign cases (p < 0.0001) and between DCIS and fibrocystic changes (p < 0.002), but not between DCIS and ductal hyperplasia. Positive predictive values were significantly greater for BI-RADS plus ADC than for BI-RADS alone in all cases (70.5% for BI-RADS alone, 81.3% for BI-RADS plus ADC) and in cases of DCIS versus fibrocystic changes (40.9% for BI-RADS alone, 64.3% for BI-RADS plus ADC), resulting in a significant improvement in diagnostic accuracy with the addition of ADC. CONCLUSION: Adding ADC values calculated from DWI (b value = 1500 s/mm(2)) to BI-RADS is a useful way to improve differential diagnostic accuracy for malignant tumors and benign lesions, especially for DCIS versus fibrocystic changes, except in cases of ductal hyperplasia.

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.

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.

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.

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.

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.

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.

OBJECTIVE: To 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). METHODS: Forty-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. RESULTS: DWI+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%). CONCLUSION: DWI+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.

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.