Diagnosing axial spondyloarthritis: estimation of the disease probability in patients with a priori different likelihoods of the diagnosis.

OBJECTIVE: To evaluate the diagnostic value of SpA parameters and their combination for the diagnosis of axial SpA in patients with an a priori different probability of the diagnosis. METHODS: A total of 361 patients with chronic back pain and suspicion of axial SpA (181 referred by primary care physicians or orthopaedists, 180 recruited via an online screening tool) received a structured rheumatologic examination, which resulted into a diagnosis or exclusion of axial SpA. The prevalence of axial SpA indicating the pre-test probability was 40% in the physician-referred subgroup and 20% in the online screening subgroup. Sensitivities, specificities and likelihood ratios for SpA features were determined in both subgroups and the respective post-test probabilities of axial SpA were calculated. RESULTS: The relative diagnostic value of single SpA features varied substantially between the groups with different referral pathways. For instance, HLA-B27 positivity increased the probability of the presence of axial SpA by 35% to 55% in online-screened patients and by 22% to 62% in physician-referred patients. The absence of HLA-B27 resulted in a sharp decrease in the probability of the presence of axial SpA in physician-referred patients (from 40% to 6%). This decrease was less sharp in the online screening group (from 20% to 10%). These differences were especially relevant in patients with a small number (one to two) of positive SpA features. CONCLUSION: The diagnostic value of SpA features varies in different patient populations, which should be considered in the diagnostic approach.

Effect of Different Iodine Concentrations on Patient-Reported Discomfort in Contrast-Enhanced Computed Tomography: A Prospective Comparative Trial.

PURPOSE: Reducing contrast media injection speed while maintaining iodine flux is a promising workaround to lower or avoid contrast media-related discomfort during CT examinations. This approach demands contrast media with a higher concentration to guarantee excellent image quality. It remains unclear whether these concentration changes affect the patient's experience. Thus, the aim of this study was to evaluate the influence of different concentrations of intravenous iodinated contrast media on patient discomfort during and after contrast media delivery. MATERIALS AND METHODS: Patients were randomized to receive either Iomeprol 400 mg/ml (group A) or 300 mg/ml (group B) during routinely scheduled CT examinations at our department. The iodine delivery rate and injection time were kept constant in both groups. After examination, study subjects completed a digital questionnaire on different CM-related sensation items using digital visual analogue scales. RESULTS: 253 consecutive patients were enrolled in a 6-month period. Most of the patients reported heat sensation in both groups (mean VAS: 5.3 mm in group A vs. 5.0 mm in group B, p = 0.5). Taste sensation also did not differ significantly between both groups (2.4 mm vs. 2.0 mm, p = 0.08). Pain sensation was reported to be significantly lower in group B patients (1.3 mm vs. 1.0 mm, p = 0.005), even though pain sensation in general was reported on a very low level. Other injection-related sensations were rarely reported. CONCLUSION: Patient-reported discomfort during intravenous injection of high-concentration contrast media (400 mg/ml) was low and only marginally different when compared to the injection of contrast media with a lower concentration. The injection of highly concentrated contrast media showed comparable overall patient acceptance, allowing a reduction of the injection speed and volume during examinations. KEY POINTS: · Patient-reported, contrast-related discomfort was very low in this study.. · High-concentration contrast media (HCCM) showed comparable overall patient acceptance.. · HCCM allow a reduction of injection speeds while keeping iodine flux constant.. CITATION FORMAT: · Vahldiek JL, Schaafs LA, Niehues BK et al. Effect of Different Iodine Concentrations on Patient-Reported Discomfort in Contrast-Enhanced Computed Tomography: A Prospective Comparative Trial. Fortschr Röntgenstr 2020; 192: 945 - 951.

Periradicular Infiltration of the Cervical Spine: How New CT Scanner Techniques and Protocol Modifications Contribute to the Achievement of Low-Dose Interventions.

PURPOSE: CT-guided periradicular infiltration of the cervical spine is an effective symptomatic treatment in patients with radiculopathy-associated pain syndromes. This study evaluates the robustness and safety of a low-dose protocol on a CT scanner with iterative reconstruction software. MATERIALS AND METHODS: A total of 183 patients who underwent periradicular infiltration therapy of the cervical spine were included in this study. 82 interventions were performed on a new CT scanner with a new intervention protocol using an iterative reconstruction algorithm. Spot scanning was implemented for planning and a basic low-dose setup of 80 kVp and 5 mAs was established during intermittent fluoroscopy. The comparison group included 101 prior interventions on a scanner without iterative reconstruction. The dose-length product (DLP), number of acquisitions, pain reduction on a numeric analog scale, and protocol changes to achieve a safe intervention were recorded. RESULTS: The median DLP for the whole intervention was 24.3 mGy*cm in the comparison group and 1.8 mGy*cm in the study group. The median pain reduction was -3 in the study group and -2 in the comparison group. A 5 mAs increase in the tube current-time product was required in 5 patients of the study group. CONCLUSION: Implementation of a new scanner and intervention protocol resulted in a 92.6 % dose reduction without a compromise in safety and pain relief. The dose needed here is more than 75 % lower than doses used for similar interventions in published studies. An increase of the tube current-time product was needed in only 6 % of interventions. KEY POINTS: · The presented ultra-low-dose protocol allows for a significant dose reduction without compromising outcome.. · The protocol includes spot scanning for planning purposes and a basic setup of 80 kVp and 5 mAs.. · The iterative reconstruction algorithm is activated during fluoroscopy.. CITATION FORMAT: · Elsholtz FH, Kamp JE, Vahldiek JL et al. Periradicular Infiltration of the Cervical Spine: How New CT Scanner Techniques and Protocol Modifications Contribute to the Achievement of Low-Dose Interventions. Fortschr Röntgenstr 2019; 191: 54 - 61.

Impact of Single-Energy Metal Artifact Reduction on CT image quality in patients with dental hardware.

BACKGROUND: To evaluate whether Canon's Single-Energy Metal Artifact Reduction (SEMAR) algorithm can significantly improve subjective and objective image quality of patients with nonremovable dental hardware undergoing CT imaging of the oral cavity and oropharynx. MATERIALS AND METHODS: SEMAR was reconstructed from routine Adaptive Iterative Dose Reduction (AIDR) images in 154 patients (46 females and 108 males; mean age 66.3 ±â€¯10.5 years). Subjective SEMAR and AIDR image quality of the mouth floor, sublingual glands, lymphatic ring and overall impression were evaluated by two independent radiologists on a 6-point scale (1 = very good image quality, 6 = poor image quality) and compared to ratings of an oral and maxillofacial surgeon. Interrater agreement was assessed using the intraclass correlation coefficient (ICC). Objective image analysis was performed by placing regions of interest (ROIs) on the mouth floor and measuring CT attenuation in Hounsfield units (HU) and standard deviation (SD). RESULTS: SEMAR significantly improved subjective image quality in all evaluated structures for all raters (p < 0.001). Furthermore, SEMAR significantly reduced objective metal artifacts and image noise (p < 0.001). CONCLUSION: SEMAR significantly improved diagnostic quality of CT images of the oral cavity and oropharynx by reducing artifacts caused by dental hardware.