iPads in Breast Imaging - A Phantom Study.

Introduction: Modern tablet PCs as the iPad are becoming more and more integrated into medicine. The aim of this study was to evaluate the display quality of iPads regarding digital mammography. Materials and Methods: Three experienced readers compared the display quality of the iPad 2 and 3 with a dedicated 10 megapixel (MP) mammography liquid crystal display (LCD) screen in consensus using the standardized Contrast Detail Mammography (CDMAM) phantom. Phantom fields without agreement between the readers were classified as "uncertain", correct 2 : 1 decisions were classified as "uncertain/readable". In a second step display quality of the three reading devices was judged subjectively in a side by side comparison. Results: The 10 MP screen was superior to both iPads in 4 (phantom-)fields and inferior in 2 fields. Comparing the iPads, version 3 was superior in 4 fields and version 2 was superior in 1 field. However these differences were not significant. Total number of "uncertain" fields did not show significant differences. The number of "uncertain" fields was 15 with the 10 MP screen, 16 with the iPad 2 and 17 with the iPad 3 (p > 0.05), the number of "uncertain/readable" fields was 4, 7 and 8, respectively. Subjective image quality of the iPad 3 and the 10 MP screen was rated superior to the iPad 2. Conclusion: The evaluated iPads, especially in version 3, seem to be adequate to display mammograms in a diagnostic quality and thus could be useful e.g. for patient consultation, clinical demonstration or educational and teaching purposes. However primary mammogram reading should still be performed on dedicated large sized reading screens.

Dose reduction in computed tomography of the chest: image quality of iterative reconstructions at a 50% radiation dose compared to filtered back projection at a 100% radiation dose.

PURPOSE: The aim of this study was to evaluate the potential of iterative reconstruction (IR) in chest computed tomography (CT) to reduce radiation exposure. The qualitative and quantitative image quality of standard reconstructions with filtered back projection (FBP) and half dose (HD) chest CT data reconstructed with FBP and IR was assessed. MATERIALS AND METHODS: 52 consecutive patients underwent contrast-enhanced chest CT on a dual-source CT system at 120 kV and automatic exposure control. The tube current was equally split on both tube detector systems. For the HD datasets, only data from one tube detector system was utilized. Thus, FD and HD data was available for each patient with a single scan. Three datasets were reconstructed from the raw data: standard full dose (FD) images applying FBP which served as a reference, HD images applying FBP and IR. Objective image quality analysis was performed by measuring the image noise in tissue and air. The subjective image quality was evaluated by 2 radiologists according to European guidelines. Additional assessment of artifacts, lesion conspicuity and edge sharpness was performed. RESULTS: Image noise did not differ significantly between HD-IR and FD-FBP (p = 0.254) but increased substantially in HD-FBP (p < 0.001). No statistically significant differences were found for the reproduction of anatomical and pathological structures between HD-IR and FD-FBP, subsegmental bronchi and bronchioli. The image quality of HD-FBP was rated inferior because of increased noise. CONCLUSION: A 50 % dose reduction in contrast-enhanced chest CT is feasible without a loss of diagnostic confidence if IR is used for image data reconstruction. Iterative reconstruction is another powerful tool to reduce radiation exposure and can be combined with other dose-saving techniques. KEY POINTS: • Iterative reconstructions allow for image noise and artifact reduction.• Comparable image data can thus be attained even at 50 % radiation dose.• Diagnostic confidence remains unaffected.

Advancement of physical process by mental activation: a prospective controlled study.

According to the literature, patients who are significantly impaired by physical mobility limitations can be rehabilitated if the patient's working memory is used to capacity. The conclusion that periodic mental activity improves physical rehabilitation should be evaluated. This is a prospective, controlled, and randomized open study of patients who underwent a total hip arthroplasty (THA). Sixteen patients who played the video game Dr. Kawashima's Brain Training: How Old Is Your Brain? were compared in terms of rehabilitation progress to 16 individuals who did not play. Harris Hip and Merle d'Aubigné scores were evaluated 1 d preoperation and again 12 +/- 1 d postoperation. Preoperation, no significant differences in hip scores between the gaming and control groups were found (median Harris Hip score: 39 vs 33, respectively, p = 0.304; median Merle D'Aubigné score: 12 vs 9, respectively, p = 0.254). Postoperation, there were significant differences between the gaming and control groups (median Harris Hip score: 76.0 vs 56.5, respectively, p = 0.001; median Merle D'Aubigné score: 16.0 vs 13.5, respectively, p = 0.014). Within both groups, the posttest scores significantly improved; however, the increase for the gaming group was greater for both measures. Because the influence of age, sex, and level of education can be excluded, it can be assumed that mental activities can improve physical rehabilitation after THA.

[A useful tool for routine radiological examinations : the iPhone application "KM Helper"]. / Sinnvoller Einsatz neuer elektronischer Medien bei radiologischen Untersuchungen : Die iPhone-Applikation "KM Helper"

Since Apple's iPhone revolutionized the smartphone market, numerous software application features (apps) for portable devices have been developed. Amongst many others, a broad range of medical assistance software, such as anatomic books or medical encyclopedias is now available. We developed an app which helps to identify patients who need medical treatment before intravenous or intra-arterial administration of iodinated contrast media. The purpose of this article is to show that novel techniques such as smartphone applications can be a useful tool in medicine.

Magnetic resonance image segmentation using semi-automated software for quantification of knee articular cartilage---initial evaluation of a technique for paired scans.

PURPOSE: Software-based image analysis is important for studies of cartilage changes in knee osteoarthritis (OA). This study describes an evaluation of a semi-automated cartilage segmentation software tool capable of quantifying paired images for potential use in longitudinal studies of knee OA. We describe the methodology behind the analysis and demonstrate its use by determination of test-retest analysis precision of duplicate knee magnetic resonance imaging (MRI) data sets. METHODS: Test-retest knee MR images of 12 subjects with a range of knee health were evaluated from the Osteoarthritis Initiative (OAI) pilot MR study. Each subject was removed from the magnet between the two scans. The 3D DESS (sagittal, 0.456 mm x 0.365 mm, 0.7 mm slice thickness, TR 16.5 ms, TE 4.7 ms) images were obtained on a 3-T Siemens Trio MR system with a USA Instruments quadrature transmit-receive extremity coil. Segmentation of one 3D-image series was first performed and then the corresponding retest series was segmented by viewing both image series concurrently in two adjacent windows. After manual registration of the series, the first segmentation cartilage outline served as an initial estimate for the second segmentation. We evaluated morphometric measures of the bone and cartilage surface area (tAB and AC), cartilage volume (VC), and mean thickness (ThC.me) for medial/lateral tibia (MT/LT), total femur (F) and patella (P). Test-retest reproducibility was assessed using the root-mean square coefficient of variation (RMS CV%). RESULTS: For the paired analyses, RMS CV % ranged from 0.9% to 1.2% for VC, from 0.3% to 0.7% for AC, from 0.6% to 2.7% for tAB and 0.8% to 1.5% for ThC.me. CONCLUSION: Paired image analysis improved the measurement precision of cartilage segmentation. Our results are in agreement with other publications supporting the use of paired analysis for longitudinal studies of knee OA.

Increase in NADPH-diaphorase-positive and neuronal NO synthase immunoreactive neurons in the rat spinal trigeminal nucleus following infusion of a NO donor--evidence for a feed-forward process in NO production involved in trigeminal nociception.

Nitric oxide (NO) donors, which cause delayed headaches in migraineurs, have been shown to activate central trigeminal neurons with meningeal afferent input in animal experiments. Previous reports indicate that this response may be due to up-regulation of NO-producing cells in the trigeminal brainstem. To investigate this phenomenon further, we determined nitric oxide synthase (NOS)-containing neurons in the rat spinal trigeminal nucleus (STN), the projection site of nociceptive trigeminal afferents, following infusion of the NO donor sodium nitroprusside (SNP). Barbiturate anaesthetized rats were infused intravenously with SNP (50 microg/kg) or vehicle for 20 min or 2 h, and after periods of 3-8 h fixed by perfusion. Cryostat sections of the medulla oblongata containing the caudal STN were histochemically processed for detection of nicotineamide adenine dinucleotide phosphate (NADPH)-diaphorase or immunohistochemically stained for NOS isoforms and examined by light and fluorescence microscopy. The number of neurons positive for these markers was determined. Various forms of neurons positive for NADPH-diaphorase or immunoreactive to neuronal NOS (nNOS) were found in superficial and deep laminae of the STN caudalis and around the central canal. Neurons were not immunopositive for endothelial (eNOS) or inducible (iNOS) NOS isoforms. The number of NADPH-diaphorase-positive neurons increased time dependently after SNP infusion by a factor of more than two. Likewise, the number of nNOS-immunopositive neurons was increased after SNP compared with vehicle infusion. Around the central canal the number of NADPH-diaphorase-positive neurons was slightly increased and the number of nNOS+ neurons not changed after SNP treatment. NO donors increase the number of neurons that produce NO in the STN, possibly by induction of nNOS expression. Increased NO production may facilitate neurotransmitter release and promote nociceptive transmission in the STN. This mechanism may explain the delayed increase in neuronal activity and headache after infusion of NO donors.

Longitudinal evaluation of the occurrence of MRI-detectable bone marrow edema in osteoarthritis of the knee.

BACKGROUND: Bone marrow edema (BME) is a condition detectable with magnetic resonance imaging (MRI) and is present in different stages of osteoarthritis (OA). Its pathogenesis is still not completely known. PURPOSE: To evaluate the longitudinal occurrence and persistence of BME in early OA of the knee. MATERIAL AND METHODS: Twenty-three patients (eight females, 15 males; mean age 55.5+/-10.3 years) were scanned with a 1.5T MR imaging unit (sagittal fat-suppressed intermediate-weighted fast spin echo; 4-mm section thickness, 1-mm intersection gap, 256 x 192 matrix, 120-mm field of view). Images were obtained in all 23 patients at two time points (TPs) and in 12 patients at three TPs. Images were evaluated by two readers independently; discrepancies in image grading were reviewed and evaluated in consensus. A four-point image-grading scale was used (absence of BME to severe BME). Four main anatomical regions were evaluated (medial femur, lateral femur, medial tibia, lateral tibia), which were subcategorized into anterior, central, and posterior regions. RESULTS: One hundred five areas of BME in the 23 patients were found at all three TPs. In 16 areas, the BME was consistent at the same location over time, in seven locations the BME became larger, in six areas the BME became smaller, and in 16 locations it could not be detected in follow-up MRIs. In one case, the BME was smaller at TP2 but increased at TP3. In eight cases, only at the last time point could a BME be detected. CONCLUSION: BME is not a static phenomenon but changes over time. Correlation to physical activity and local inflammatory reaction should be evaluated.

Evaluation of low-cost computer monitors for the detection of cervical spine injuries in the emergency room: an observer confidence-based study.

BACKGROUND: To compare the diagnostic value of low-cost computer monitors and a Picture Archiving and Communication System (PACS) workstation for the evaluation of cervical spine fractures in the emergency room. METHODS: Two groups of readers blinded to the diagnoses (2 radiologists and 3 orthopaedic surgeons) independently assessed-digital radiographs of the cervical spine (anterior-posterior, oblique and trans-oral-dens views). The radiographs of 57 patients who arrived consecutively to the emergency room in 2004 with clinical suspicion of a cervical spine injury were evaluated. The diagnostic values of these radiographs were scored on a 3-point scale (1 = diagnosis not possible/bad image quality, 2 = diagnosis uncertain, 3 = clear diagnosis of fracture or no fracture) on a PACS workstation and on two different liquid crystal display (LCD) personal computer monitors. The images were randomised to avoid memory effects. We used logistic mixed-effects models to determine the possible effects of monitor type on the evaluation of x ray images. To determine the overall effects of monitor type, this variable was used as a fixed effect, and the image number and reader group (radiologist or orthopaedic surgeon) were used as random effects on display quality. Group-specific effects were examined, with the reader group and additional fixed effects as terms. A significance level of 0.05 was established for assessing the contribution of each fixed effect to the model. RESULTS: Overall, the diagnostic score did not differ significantly between standard personal computer monitors and the PACS workstation (both p values were 0.78). CONCLUSION: Low-cost LCD personal computer monitors may be useful in establishing a diagnosis of cervical spine fractures in the emergency room.

[Molecular imaging: future uses in arthritides]. / Molekulare Bildgebung: Künftige Anwendungen bei Arthritiden.

Molecular imaging is an upcoming field in radiology as a result of great advances in imaging technology, genetics, and biochemistry in the recent past. Early-stage imaging of molecular pathological changes in cells opens the gates to new methods in medical treatment of diseases that otherwise would only be detected in advanced stages. Methods of imaging biochemical pathways with molecular agents are currently an issue of intensive research. This article reviews current modalities of molecular imaging in arthritis that should offer future perspective on early disease detection, diagnosis, and monitoring of treatment efficiency and how they can pave the way to optimized therapy.