Ventilation inhomogeneity in obstructive lung diseases measured by electrical impedance tomography: a simulation study

Electrical impedance tomography (EIT) has mostly been used in the Intensive Care Unit (ICU) to monitor ventilation distribution but is also promising for the diagnosis in spontaneously breathing patients with obstructive lung diseases. Beside tomographic images, several numerical measures have been proposed to quantitatively assess the lung state. In this study two common measures, the ‘Global Inhomogeneity Index’ and the ‘Coefficient of Variation’ were compared regarding their capability to reflect the severity of lung obstruction. A three-dimensional simulation model was used to simulate obstructed lungs, whereby images were reconstructed on a two-dimensional domain. Simulations revealed that minor obstructions are not adequately recognized in the reconstructed images and that obstruction above and below the electrode plane may result in misleading values of inhomogeneity measures. EIT measurements on several electrode planes are necessary to apply these measures in patients with obstructive lung diseases in a promising manner.     

Bildgebende Verfahren bei Primärdiagnose und Staging des Prostatakarzinoms

The new S3 guideline on prostate cancer includes imaging modalities applied for early detection, primary diagnosis, and staging of prostate cancer. Detection and primary diagnosis are based on digital rectal examination, serum PSA levels, and prostate biopsy. Among the imaging modalities, MRI shows the highest test quality parameters. Although MRI cannot replace biopsy to prove prostate cancer, its high negative predictive value can help to reduce the number of subsequent biopsies after negative prostate biopsy. For T-staging, MRI also demonstrates the highest test quality parameters. Its clinical application is limited, since therapeutic consequences are restricted. Due to its high specificity, MRI can save unnecessary pelvic lymph node dissections in patients at high risk for lymph node metastasis (N-staging). Risk-adjusted bone scans, complemented by additional radiological examinations if necessary, remain the standard to assess hematogenous metastasis (M staging).     

Radiologische Beckendiagnostik

Prostate cancer, bladder cancer, and pelvic floor weakness are among the most common diseases of the pelvis. Cardinal symptoms include painless macrohematuria in bladder cancer and urinary and fecal incontinence in pelvic floor weakness. Suspicion of prostate cancer currently is most frequently raised when the serum concentration of prostate-specific antigen is pathologically elevated. Besides extensive clinical and invasive diagnosis, clinical imaging is frequently applied for the localization, locoregional staging, and diagnosis of recurrence of prostate cancer and invasive bladder cancer, and in clinically difficult cases of cystocele, enterocele, rectocele, descensus or prolapse of vagina, uterus, and rectum, and rectal intussusception. Magnetic resonance imaging with T2-weighted TSE or FSE images in several planes combined with either axial, T1-weighted images and MR spectroscopy for the prostate, dynamic contrast-enhanced T1-weighted images for the urinary bladder, or dynamic T2-weighted functional images for pelvic floor incontinence are particularly well suited as clinical imaging methods.     

CT urography: definition,indications and techniques. A guideline for clinical practice

The aim was to develop clinical guidelines for multidetector computed tomography urography (CTU) by a group of experts from the European Society of Urogenital Radiology (ESUR). Peer-reviewed papers and reviews were systematically scrutinized. A summary document was produced and discussed at the ESUR 2006 and ECR 2007 meetings with the goal to reach consensus. True evidence-based guidelines could not be formulated, but expert guidelines on indications and CTU examination technique were produced. CTU is justified as a first-line test for patients with macroscopic haematuria, at high-risk for urothelial cancer. Otherwise, CTU may be used as a problem-solving examination. A differential approach using a one-, two- or three-phase protocol is proposed, whereby the clinical indication and the patient population will determine which CTU protocol is employed. Either a combined nephrographic-excretory phase following a split-bolus intravenous injection of contrast medium, or separate nephrographic and excretory phases following a single-bolus injection can be used. Lower dose (CTDIvol 5–6 mGy) is used for benign conditions and normal dose (CTDIvol 9–12 mGy) for potential malignant disease. A low-dose (CTDIvol 2–3 mGy) unenhanced series can be added on indication. The expert-based CTU guidelines provide recommendations to optimize techniques and to unify the radiologist’s approach to CTU. Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users. ESUR:     

Functional imaging in penile cancer: PET/computed tomography, MRI, and sentinel lymph node biopsy

PURPOSE OF REVIEW: The presence and extent of lymph node metastasis and primary tumor are among the most important prognostic factors in penile cancer. While inguinal lymphadenectomy is currently the most accurate means of staging, it is associated with severe morbidity and even mortality. Recent literature was reviewed for alternative means of staging. RECENT FINDINGS: Functional imaging modalities distinguish between inguinal lymph nodes with and without metastasis. The false-negative rate of dynamic sentinel lymph node biopsy has recently improved from approximately 20 to 5% in one study. In 13 patients with penile cancer, (18)F-fluorodeoxyglucose-PET/computed tomography was 80% sensitive and 100% specific for lymph node metastasis, but missed micro-metastasis. In seven patients with penile cancer, MRI with lymphotrophic nanoparticles was 100% sensitive and 97% specific for lymph node metastasis. SUMMARY: Combined PET/computed tomography and sentinel lymph node biopsy may help to detect both inguinal micrometastasis and pelvic and abdominal metastasis. Since MRI is highly accurate for staging of both primary penile cancer and its lymph node metastasis, however, it may turn out to be a powerful tool for a one-stop modality in the staging of penile cancer.