Background Determining the stage of non–small-cell lung cancer often requires multiple preoperative tests and invasive procedures. Whole-body positron-emission tomography (PET) may simplify and improve the evaluation of patients with this tumor. Methods We prospectively compared the ability of a standard approach to staging (computed tomography [CT], ultrasonography, bone scanning, and, when indicated, needle biopsies) and one involving PET to detect metastases in mediastinal lymph nodes and at distant sites in 102 patients with resectable non–small-cell lung cancer. The presence of mediastinal metastatic disease was confirmed histopathologically. Distant metastases that were detected by PET were further evaluated by standard imaging tests and biopsies. Patients were followed postoperatively for six months by standard methods to detect occult metastases. Logistic-regression analysis was used to evaluate the ability of PET and CT to identify malignant mediastinal lymph nodes. Results The sensitivity and sp...

Preoperative staging of non-small-cell lung cancer with positron-emission tomography.

Phase-contrast x-ray imaging (PCI) is an innovative method that is sensitive to the refraction of the x-rays in matter. PCI is particularly adapted to visualize weakly absorbing details like those often encountered in biology and medicine. In past years, PCI has become one of the most used imaging methods in laboratory and preclinical studies: its unique characteristics allow high contrast 3D visualization of thick and complex samples even at high spatial resolution. Applications have covered a wide range of pathologies and organs, and are more and more often performed in vivo. Several techniques are now available to exploit and visualize the phase-contrast: propagation- and analyzer-based, crystal and grating interferometry and non-interferometric methods like the coded aperture. In this review, covering the last five years, we will give an overview of the main theoretical and experimental developments and of the important steps performed towards the clinical implementation of PCI.

http://iopscience.iop.org/article/10.1088/0031-9155/58/1/R1/pdf

X-ray phase-contrast imaging: from pre-clinical applications towards clinics

Magnetic resonance (MR) imaging plays an increasingly important role in the evaluation of patients with liver disease because of its high contrast resolution, lack of ionizing radiation, and the possibility of performing functional imaging sequences. With advances in hardware and coil systems, diffusion-weighted (DW) MR imaging can now be applied to liver imaging with improved image quality. DW MR imaging enables qualitative and quantitative assessment of tissue diffusivity (apparent diffusion coefficient) without the use of gadolinium chelates, which makes it a highly attractive technique, particularly in patients with severe renal dysfunction at risk for nephrogenic systemic fibrosis. In this review, acquisition parameters, postprocessing, and quantification methods applied to liver DW MR imaging will be discussed. The current clinical uses of DW MR imaging (liver lesion detection and characterization, compared and combined with conventional sequences) and the emerging applications of DW MR imaging (tumor treatment response and diagnosis of liver fibrosis and cirrhosis) will be reviewed. Also, limitations, mainly image quality and reproducibility of diffusion parameters, and future directions of liver DW MR imaging will be discussed.

Diffusion-weighted MR imaging of the liver.

In applying diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) technique, DW-MR images are acquired during free breathing, which results in images with high signal-to-noise ratio using relatively thin image sections (4–5 mm). Image acquisition during free breathing is possible because bulk tissue motion, including respiratory motion, may be considered as types of coherent motion, which do not result in significant signal loss unlike intravoxel incoherent motion, which reflects random water motion at a cellular level. The concept of DWIBS allows handling of the acquired images as a volumetric dataset and it exploits both prolonged T2 relaxation time and impeded diffusion that the majority of solid lesions (both benign and malignant) exhibit as mechanisms for image contrast, which is used for clinical evaluation of diseases.

Diffusion-Weighted Whole-Body Imaging with Background Body Signal Suppression (DWIBS)

The updated version of the EFSUMB guidelines on the application of non-hepatic contrast-enhanced ultrasound (CEUS) deals with the use of microbubble ultrasound contrast outside the liver in the many established and emerging applications.

/pdf/the-efsumb-guidelines-and-recommendations-for-the-clinical-7973z9x4vy.pdf

The EFSUMB guidelines and recommendations for the clinical practice of contrast-enhanced ultrasound (CEUS) in Non-Hepatic Applications: Update 2017 (Long Version)

Purpose: To evaluate the ability of the apparent diffusion coefficient (ADC) to help predict response to chemotherapy in patients with colorectal and gastric hepatic metastases. Materials and Methods: Institutional review board approval was obtained; all patients provided informed consent. Standard magnetic resonance (MR) imaging and diffusion-weighted (DW) MR imaging were performed before and 3, 7, and 42 days after initiating chemotherapy for 87 hepatic metastases in 23 colorectal and gastric cancer patients (16 men, seven women; mean age, 55.7 years; range, 33–71 years). Lesions were classified as either responding or nonresponding, according to changes in size at the end of therapy. Linear mixed-effects modeling was applied to analyze change in ADCs and size following treatment. The Pearson correlation test was calculated between those ADC parameters and tumor response. Results: Thirty-eight responding and 49 nonresponding metastatic lesions were evaluated. Pretherapy mean ADCs in responding lesions w...

Apparent diffusion coefficient: potential imaging biomarker for prediction and early detection of response to chemotherapy in hepatic metastases.

One week after beginning chemotherapy and radiation therapy (CRT), a significant increase of mean tumor apparent diffusion coefficients (ADCs) and low pretherapy mean ADCs in rectal carcinomas have the potential to help predict tumor downstaging after CRT.

Locally Advanced Rectal Carcinoma Treated with Preoperative Chemotherapy and Radiation Therapy: Preliminary Analysis of Diffusion-weighted MR Imaging for Early Detection of Tumor Histopathologic Downstaging

The usefulness of diffusion-weighted magnetic resonance (MR) imaging (DWI) for differentiating central lung cancer from postobstructive lobar collapse (POC) was investigated. Thirty-three cases suspected of lung cancer and POC on chest bolus computed tomography (CT) underwent thoracic MR imaging examinations. MR examinations were performed using a 1.5-T clinical scanner. Scanning sequences were T1-weighted imaging, T2-weighted imaging (T2WI) and DWI with b=0, 500 s/mm(2), four excitations and segmented breath-holding. The densities and signals of cancer and postobstructive collapsed lung were compared on bolus-enhanced CT, T2W and DW images. Statistical analyses were performed with chi-square test, paired t-test, non-parameter test and kappa statistics. Differentiation between cancer and POC was possible on bolus CT, T2W and DW images in 14, 21 and 26 patients, respectively. Eight cases that were impossible to differentiate on T2W images were distinguishable on DWI, demonstrating that DWI is complementary to T2WI. Using a combination of T2W and DW images, 88% (29/33) of cases were differentiated on MR imaging. Thus, a combination of T2W and DW imaging is superior to bolus-CT or T2WI alone. The contrast-to-noise ratio of DWI was significantly higher than that of T2WI. Agreement between two independent observers on the differential ability of lung cancer and POC was higher for DWI (kappa=0.474) than for T2WI (kappa=0.339). The degree of consolidation around the cancer was negatively correlated with the degree of artifact and degree of deformation. It is feasible to use DWI to differentiate lung cancer from POC. DWI played a role in confirming and providing complementary information to that obtained from T2WI. Our data indicate that using a combination of the two scanned sequences was the best means of distinguishing between lung cancer and POC.

Using diffusion-weighted MR imaging for tumor detection in the collapsed lung: a preliminary study

Diffusion-weighted MR imaging is a promising technique that may be helpful in predicting responses to targeted therapy in patients with gastrointestinal stromal tumors through the early changes in apparent diffusion coefficients at 1 week after therapy.

Gastrointestinal Stromal Tumors Treated with Imatinib Mesylate: Apparent Diffusion Coefficient in the Evaluation of Therapy Response in Patients

Application of contrast-enhanced ultrasound in the diagnosis of solid pancreatic lesions—A comparison of conventional ultrasound and contrast-enhanced CT

Xiao-Peng Zhang

Papers

Apparent diffusion coefficient: potential imaging biomarker for prediction and early detection of response to chemotherapy in hepatic metastases.

Locally Advanced Rectal Carcinoma Treated with Preoperative Chemotherapy and Radiation Therapy: Preliminary Analysis of Diffusion-weighted MR Imaging for Early Detection of Tumor Histopathologic Downstaging

Using diffusion-weighted MR imaging for tumor detection in the collapsed lung: a preliminary study

Gastrointestinal Stromal Tumors Treated with Imatinib Mesylate: Apparent Diffusion Coefficient in the Evaluation of Therapy Response in Patients

Application of contrast-enhanced ultrasound in the diagnosis of solid pancreatic lesions—A comparison of conventional ultrasound and contrast-enhanced CT