Myocardium Assessment by Relaxation along Fictitious Field, Extracellular Volume, Feature Tracking, and Myocardial Strain in Hypertensive Patients with Left Ventricular Hypertrophy.

Background: Previous research has shown impaired global longitudinal strain (GLS) and slightly elevated extracellular volume fraction (ECV) in hypertensive patients with left ventricular hypertrophy (HTN LVH). Up to now, only little attention has been paid to interactions between macromolecules and free water in hypertrophied myocardium. Purpose: To evaluate the feasibility of relaxation along a fictitious field with rank 2 (RAFF2) in HTN LVH patients. Study Type. Single institutional case control. Subjects: 9 HTN LVH (age, 69 ± 10 years) and 11 control subjects (age, 54 ± 12 years). Field Strength/Sequence. Relaxation time mapping (T 1, T 1ρ , and T RAFF2 with 11.8 µT maximum radio frequency field amplitude) was performed at 1.5 T using a Siemens Aera (Erlangen, Germany) scanner equipped with an 18-channel body array coil. Assessment. ECV was calculated using pre- and postcontrast T 1, and global strains parameters were assessed by Segment CMR (Medviso AB Co, Sweden). The parametric maps of T 1ρ and T RAFF2 were computed using a monoexponential model, while the Bloch-McConnell equations were solved numerically to model effect of the chemical exchange during radio frequency pulses. Statistical Tests. Parametric maps were averaged over myocardium for each subject to be used in statistical analysis. Kolmogorov-Smirnov was used as the normality test followed by Student's t-test and Pearson's correlation to determine the difference between the HTN LVH patients and controls along with Hedges' g effect size and the association between variables, respectively. Results: T RAFF2 decreased statistically (83 ± 2 ms vs 88 ± 6 ms, P < 0.031), and global longitudinal strain was impaired (GLS, -14 ± 3 vs - 18 ± 2, P < 0.002) in HTN LVH patients compared to the controls, respectively. Also, significant negative correlation was found between T RAFF2 and GLS (r = -0.53, P < 0.05). Data Conclusion. Our results suggest that T RAFF2 decrease in HTN LVH patients may be explained by gradual collagen accumulation which can be reflected in GLS changes. Most likely, it increases the water proton interactions and consequently decreases T RAFF2 before myocardial scarring.

Investigating errors in medical imaging: medical malpractice cases in Finland.

OBJECTIVE: The objectives of the study were to survey patient injury claims concerning medical imaging in Finland in 1991-2017, and to investigate the nature of the incidents, the number of claims, the reasons for the claims, and the decisions made concerning the claims. MATERIALS AND METHODS: The research material consisted of patient claims concerning imaging, sent to the Finnish Patient Insurance Centre (PVK). The data contained information on injury dates, the examination code, the decision code, the description of the injury, and the medical grounds for decisions. RESULTS: The number of claims included in the study was 1054, and the average number per year was 87. The most common cause was delayed diagnosis (404 claims, 38.3%). Most of the claims concerned mammography (314, 29.8%), radiography (170, 16.1%), and MRI (162, 15.4%). According to the decisions made by the PVK, there were no delays in 54.6% of the examinations for which claims were made. About 30% of all patient claims received compensation, the most typical reason being medical malpractice (27.7%), followed by excessive injuries and injuries caused by infections, accidents and equipment (2.7%). CONCLUSION: Patient injury in imaging examinations and interventions cannot be completely prevented. However, injury data are an important source of information for health care. By analysing claims, we can prevent harm, increase the quality of care, and improve patient safety in medical imaging.

Justification and active guideline implementation for spine radiography referrals in primary care.

Background Spinal disorders are a major public health problem. Appropriate diagnostic imaging is an essential part in the management of back complaints. Nevertheless, inappropriate imaging increases population collective dose and health costs without improving outcome. Purpose To determine the effects of active implementation of referral guidelines on the number and justification of spine radiography in primary care in one city. Material and Methods Specified guidelines for spine radiography were distributed to referring practitioners altogether three times during the study period. Educational lectures were provided before the guidelines were taken into use. The guidelines were also made available via the intranet. The number of spine radiography referrals during similar 6-month periods in the year preceding the interventions and the following 2 years was analyzed. Justification of 448 spine radiographs was assessed similarly. Results After interventions, the total number of spine radiography examinations decreased by 48% (P < 0.001) and that of cervical spine radiography by 46% ( P < 0.001), thoracic spine by 53% ( P < 0.001), and lumbar spine by 47% ( P < 0.001). The results persisted after 1-year follow-up. Before interventions, 24% of the cervical, 46% of the thoracic, and 32% of the lumbar spine radiography referrals were justified. After interventions, only justification of lumbar spine radiography improved significantly, 64% being justified ( P = 0.005). Conclusion Spine radiography in primary care can be reduced significantly by active referral guideline implementation. The proportion of inappropriate radiography was unexpectedly high. Thus, further education and studies concerning the appropriate use of spinal radiography seems to be needed.

Comparison of Diagnostic Performance of Semi-Quantitative Knee Ultrasound and Knee Radiography with MRI: Oulu Knee Osteoarthritis Study.

Osteoarthritis (OA) is a common degenerative musculoskeletal disease highly prevalent in aging societies worldwide. Traditionally, knee OA is diagnosed using conventional radiography. However, structural changes of articular cartilage or menisci cannot be directly evaluated using this method. On the other hand, ultrasound is a promising tool able to provide direct information on soft tissue degeneration. The aim of our study was to systematically determine the site-specific diagnostic performance of semi-quantitative ultrasound grading of knee femoral articular cartilage, osteophytes and meniscal extrusion, and of radiographic assessment of joint space narrowing and osteophytes, using MRI as a reference standard. Eighty asymptomatic and 79 symptomatic subjects with mean age of 57.7 years were included in the study. Ultrasound performed best in the assessment of femoral medial and lateral osteophytes, and medial meniscal extrusion. In comparison to radiography, ultrasound performed better or at least equally well in identification of tibio-femoral osteophytes, medial meniscal extrusion and medial femoral cartilage morphological degeneration. Ultrasound provides relevant additional diagnostic information on tissue-specific morphological changes not depicted by conventional radiography. Consequently, the use of ultrasound as a complementary imaging tool along with radiography may enable more accurate and cost-effective diagnostics of knee osteoarthritis at the primary healthcare level.

Effect of display type, DICOM calibration and room illuminance in bitewing radiographs.

OBJECTIVES: To compare observer performance in the detection of both anatomical structures and caries in bitewing radiographs using consumer grade displays with and without digital imaging and communications in medicine (DICOM) calibration, tablets (third generation iPad; Apple, Cupertino, CA) and 6-megapixel (MP) displays under different lighting. METHODS: 30 bitewing radiographs were blindly evaluated on four displays under bright (510 lx) and dim (16 lx) ambient lighting by two observers. The dentinoenamel junction, enamel and dentinal caries, and the cortical border of the alveolar crests were evaluated. Consensus was considered as reference. Intraobserver agreement was determined. The proportion of equivalent ratings and weighted kappa were used to assess reliability. RESULTS: The proportion of equivalent ratings with consensus differed significantly between uncalibrated and DICOM-calibrated consumer grade display in enamel caries in upper and lower molars in bright (p = 0.013 and p = 0.003) lighting, and in dentinal caries in lower molars in both bright (p = 0.022) and dim (p = 0.004) lighting. The proportion also differed significantly between DICOM-calibrated consumer grade and 6-MP display in dentinal caries in lower molars in bright lighting (p = 0.039), tablet and consumer grade display in enamel caries in upper molars (p = 0.017) in bright lighting, tablet and 6-MP display in dentinal caries in lower molars (p = 0.003) in bright lighting and in enamel caries in lower molars (p = 0.012) in dim lighting. CONCLUSIONS: DICOM calibration improves the detection of enamel and dentinal caries in bitewing radiographs, particularly in bright lighting. Therefore, a calibrated consumer grade display can be recommended as a diagnostic tool for viewing bitewing radiographs.

Effect of display type and room illuminance in chest radiographs.

OBJECTIVES: To compare diagnostic accuracy in the detection of subtle chest lesions on digital chest radiographs using medical-grade displays, consumer-grade displays, and tablet devices under bright and dim ambient light. METHODS: Five experienced radiologists independently assessed 50 chest radiographs (32 with subtle pulmonary findings and 18 without apparent findings) under bright (510 lx) and dim (16 lx) ambient lighting. Computed tomography was used as the reference standard for interstitial and nodular lesions and follow-up chest radiograph for pneumothorax. Diagnostic accuracy and sensitivity were calculated for assessments carried out in all displays and compared using the McNemar test. The level of significance was set to p < 0.05. RESULTS: Significant differences in sensitivity between the assessments under bright and dim lighting were found among consumer-grade displays in interstitial opacities with, and in pneumothorax without, Digital Imaging and Communication in Medicine-Grayscale Standard Display Function (DICOM-GSDF) calibration. Compared to 6 megapixel (MP) display under bright lighting, sensitivity in pneumothorax was lower in the tablet device and the consumer-grade display. Sensitivity in interstitial opacities was lower in the DICOM-GSDF calibrated consumer-grade display. CONCLUSIONS: A consumer-grade display with or without DICOM-GSDF calibration or a tablet device is not suitable for reading digital chest radiographs in bright lighting. No significant differences were observed between five displays in dim light. KEY POINTS: • Ambient lighting affects performance of consumer-grade displays (with or without DICOM-GSDF calibration). • Bright light decreases detection of pneumothorax on non-medical displays. • Bright light decreases detection of interstitial opacities on DICOM-GSDF-calibrated, consumer-grade displays. • Dim light is sufficient to detect subtle chest lesions from all displays.

Comparison of consumer grade, tablet and 6MP-displays: observer performance in detection of anatomical and pathological structures in panoramic radiographs.

OBJECTIVE: To compare observer performance in the detection of anatomical structures and pathology in panoramic radiographs using a consumer grade display and tablet (3(rd) generation iPad; Cupertino, CA, USA) under suboptimal conditions compared to 6 MegaPixels (6 MP) display under dim lighting conditions. STUDY DESIGN: Thirty panoramic radiographs were selected. All images were blindly evaluated on three displays by two observers with different amounts of experience. Consumer grade display and tablet evaluations were made under approximately 510 lx ambient light and 6MP display evaluations under approx. 16 lx. RESULTS: The observer performance of an experienced observer did not differ between different displays whereas the less experienced observer performed better with 6MP display than with consumer grade display or tablet. CONCLUSIONS: A dentist with less experience in interpreting panoramic radiographs may be more dependent on the high-quality display used under optimal viewing conditions to detect anatomical structures and pathology compared to a more experienced dentist.

[Displays at health centers insufficient for radiological diagnostics]. / Terveyskeskusten työasemanäytöt riittämattömiä röntgendiagnostiikkaan.

BACKGROUND: The quality of workstation displays and viewing conditions affect the diagnostic information visible from digital radiographs. MATERIALS AND METHODS: The image viewing practice at health centers in Northern Finland were surveyed with a questionnaire filled by 91 physicians. The quality of 23 monitors at ten health centers was measured. RESULTS: Display performance and viewing conditions were poor. Sixty percent of radiographic exams remained without a statement from a radiologist. Only few physicians assessed the quality of displays. CONCLUSIONS: Health centers should invest into displays of diagnostic quality, consider the viewing conditions and perform systematic quality assurance of medical displays.