Janis L. Vahldiek

Performance of referral recommendations in patients with chronic back pain and suspected axial spondyloarthritis

Background: Ankylosing spondylitis (AS) and its early form account for up to 5% of all patients with chronic back pain. Interest has recently focused on shortening the delay of 5–10 years between the appearance of first symptoms and the diagnosis of AS, particularly because effective treatments have now become available. Referral parameters that are easy for doctors in primary care to apply to patients presenting with possible AS could contribute to earlier diagnosis. Methods: Orthopaedists and primary-care doctors were requested to refer patients with (1) chronic low back pain (duration >3 months) and (2) onset of back pain before <45 years of age to a specialist rheumatology outpatient clinic for further diagnostic investigation if at least one of the following screening parameters was present: (1) inflammatory back pain, (2) positive human leucocyte antigen B27, and (3) sacroiliitis detected by imaging. The final diagnosis was made according to expert opinion. Results: In total, 350 referred cases were analysed. A diagnosis of definite axial spondyloarthritis (axial SpA), comprising established AS and pre-radiographic axial SpA, could be made in 45.4% of all referred patients (of which 50.3% were classified as AS and 49.7% as preradiographic axial SpA), whereas 45.4% were classified as non-SpA and 9.1% as possible SpA. A diagnosis of definite axial SpA could be made in 34.2% if only one referral parameter was positive, and in 62.6% if there was >1 positive referral parameter. Conclusions: The proposed referral parameters have proven useful when applied in primary care in identifying patients with AS/pre-radiographic axial SpA among young to middle-aged patients with chronic low back pain.

Evaluation of 2 Screening Strategies for Early Identification of Patients with Axial Spondyloarthritis in Primary Care

Objective. To evaluate 2 referral strategies for axial spondyloarthritis (SpA) in patients with chronic low back pain at the primary care level. Methods. Referral physicians (n = 259) were randomly assigned to either Strategy 1 or Strategy 2 in order to refer patients with chronic back pain (duration > 3 months), age at onset of back pain < 45 years, and no diagnosis of axial SpA, to a cooperating rheumatologist (n = 43). According to Strategy 1, suitable patients were referred if at least 1 of the following screening criteria was present: inflammatory back pain, HLA-B27, or sacroiliitis detected by imaging. According to Strategy 2, patients were referred if 2 out of 5 criteria were positive: the same 3 criteria from Strategy 1 and additionally a positive family history of ankylosing spondylitis (AS) or a good treatment response to nonsteroidal antiinflammatory drugs. The final diagnosis of the rheumatologist was used as the “gold standard.” Results. In total, 560 consecutively referred patients were included in the analysis. Among 318 patients referred by Strategy 1, 41.8% (95% CI 36.5%–47.3%) were diagnosed with definite axial SpA. Among 242 patients referred by the second strategy, definite axial SpA was diagnosed in 36.8% (95% CI 31.0%–43.0%) of the cases. Conclusion. Both referral strategies demonstrated comparable performance in identification of patients with axial SpA. Strategy 1 might be preferred as an easy and reliable screening method for axial SpA at the primary care level.

The frequency of non-radiographic axial spondyloarthritis in relation to symptom duration in patients referred because of chronic back pain: results from the Berlin early spondyloarthritis clinic

Objective This study was aimed at investigating the frequencies of non-radiographic axial spondyloarthritis (nr-axSpA) and ankylosing spondylitis (AS) diagnoses and their ratios in relation to symptom duration in patients referred because of chronic back pain and suspicion of axial SpA. Methods In this monocentre study, orthopaedists and primary care physicians were requested to refer patients with chronic low back pain (duration >3 months) and onset of back pain before 45 years of age to a SpA-specialised rheumatology outpatient clinic for further diagnostic investigation, if proposed screening parameters were present. The ratio of nr-axSpA to AS was analysed in relation to the duration of symptoms. Results A diagnosis of definite axial SpA was made in 43.7% of the referred patients (n=522). Axial SpA was diagnosed in a similar percentage of about 50% if back pain duration was <9 years but decreased to 36% if symptom duration was >9 years. Nr-axSpA represented the majority of patients (67.3%) only if duration of back pain was 1 year and less at the time of referral. Between 1 and 6 years of back pain duration the probability of nr-axSpA and AS was nearly equal (1–3 years: 52.5% and 47.5%, respectively; 3–6 years: 53.7% and 46.3%, respectively). In patients with back pain duration of 6–9 years, AS was more likely (61.1%) to be diagnosed than nr-axSpA (38.9%), and this increased further over time. Conclusions Non-radiographic axial SpA represents an important differential diagnosis of back pain, especially in patients with recent symptom onset.

Comparison of bipolar radiofrequency ablation zones in an in vivo porcine model: Correlation of histology and gross pathological findings

BACKGROUND Continuing research ex vivo and in vivo with animal models is performed to advance the oncological safety of radiofrequency ablation (RFA) of liver tumors. In these experiments, frequently imaging modalities (e.g. MRI or CT) or macro-morphological measurements are used to determine the full extent of the different ablation zones inside of RFA lesions. However, no systematic study has been performed so far, which verified the accuracy of the macro-morphological findings. Therefore, the present study aimed to correlate histological and gross pathological findings of bipolar radiofrequency ablation zones of porcine livers with regard to cell viability in vivo. METHODS Bipolar RFA was performed in the liver of anaesthetized female domestic pigs under CT-guidance using an internally cooled 20 mm RFA applicator. Afterwards RFA cross sections of the liver were made in a perpendicular orientation to the applicator. Ablation zones were initially documented by photography and thereafter prepared for histological analysis. Latter was based on HE-staining and NADH-diaphorase cell viability staining. Micro- and macro-morphological sections were digitally analyzed along the cross-section area for statistical correlation. RESULTS Three different RF ablation zones could be differentiated. A central zone showing no cell viability (white zone) was surrounded by a red zone. The red zone could be divided into an inner zone of viable and non-viable cells (red zone 1), followed by a zone of edema with mostly viable cells (red zone 2).Micro- and macro-morphological data showed a strong correlation for the white zone (r = 0.95, p < 0.01), the red zone 1 (r = 0.85, p < 0.01), and the red zone 2 (r = 0.89, p < 0.01). CONCLUSION White zone and red zone could clearly be distinguished in gross pathology and histology after bipolar RFA of porcine liver tissue in vivo. The red zone could be differentiated into an inner zone of viable and non-viable cells and an outer zone with high cell viability and intercellular edema. A strong correlation of micro- and macro-morphology could be shown for all three ablation zones. With this knowledge, gross pathological examination can be used as a reliable indicator of lethally damaged tissue in bipolar RFA of in vivo porcine liver.

Measuring and optimizing results in multipolar RFA: Techniques and early findings in an experimental setting

Radiofrequency ablation (RFA) has shown to be a reasonable alternative for the treatment of hepatic tumors and metastases although multiple limitations remain. Cooling effects due to larger vessels can prevent complete coverage and may lead to early tumor relapse. This preliminary in vivo pig study combines the use of multipolar RFA with three applicators (six electrodes) and interrupted liver perfusion using Pringles maneuver to overcome the most serious limitations. Furthermore, immediate detection of incomplete RFA is important to revise ablation. We used contrast enhanced computed tomography (CECT) to evaluate post ablation results in comparison to macroscopic images in healthy pig liver. We found significantly (p = 0.001) larger ablation zones and no affection by larger vessels with interrupted liver perfusion. This allows effective RFA for larger tumors. Immediate postinterventional CECT provided comparable results (r = 0.985) to macroscopic evaluation.

Incidence of combined cranial and cervical spine injuries in patients with blunt minor trauma: are combined CT examinations of the head and cervical spine justified?

Background The use of computed tomography (CT) scans of the head and cervical spine has markedly increased in patients with blunt minor trauma. The actual likelihood of a combined injury of head and cervical spine following a minor trauma is estimated to be low. Purpose To determine the incidence of such combined injuries in patients with a blunt minor trauma in order to estimate the need to derive improved diagnostic guidelines. Material and Methods A total of 1854 patients were retrospectively analyzed. All cases presented to the emergency department and in all patients combined CT scans of head and cervical spine were conducted. For the following analysis, only 1342 cases with assured blunt minor trauma were included. Data acquisition covered age, sex, and presence of a head injury as well as presence of a cervical spine injury or both. Results Of the 1342 cases, 46.9% were men. The mean age was 65.6 years. CT scans detected a head injury in 116 patients; of these, 70 cases showed an intracranial hemorrhage, 11 cases a skull fracture, and 35 cases an intracranial hemorrhage as well as a skull fracture. An injury of the cervical spine could be detected in 40 patients. A combined injury of the head and cervical spine could be found in one patient. Conclusion The paradigm of the coincidence of cranial and cervical spine injuries should be revised in patients with blunt minor trauma. Valid imaging decision algorithms are strongly needed to clinically detect high-risk patients in order to save limited resources.

Intermittent Pringle maneuver may be beneficial for radiofrequency ablations in situations with tumor-vessel proximity

Abstract Background Radiofrequency ablation (RFA) represents a treatment option for non-resectable liver malignancies. Larger ablations can be achieved with a temporary hepatic inflow occlusion (Pringle maneuver – PM). However, a PM can induce dehydration and carbonization of the target tissue. The objective of this study was to evaluate the impact of an intermittent PM on the ablation size. Methods Twenty-five multipolar RFAs were performed in porcine livers ex vivo. A perfused glass tube was used to simulate a natural vessel. The following five test series (each n=5) were conducted: (1) continuous PM, (2–4) intermittent PM, and (5) no PM. Ablations were cut into half. Ablation area, minimal radius, and maximal radius were compared. Results No change in complete ablation size could be measured between the test series (p>0.05). A small rim of native liver tissue was observed around the glass tube in the test series without PM. A significant increase of ablation area could be measured on the margin of the ablations with an intermittent PM, starting without hepatic inflow occlusion (p<0.05). Conclusion An intermittent PM did not lead to smaller ablations compared to a continuous or no PM ex vivo. Furthermore, an intermittent PM can increase the ablation area when initial hepatic inflow is succeeded by a PM.

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

BACKGROUND To evaluate whether Canons 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 ± 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.

Characterization of benign periablational enhancement following multipolar radiofrequency ablation using perfusion CT in an in-vivo porcine liver model

PURPOSE: Thermal ablation is an important interventional option in the management of liver tumors. Immediate postablational imaging regularly shows periablational enhancement. This peripheral hyperperfusion may induce heat-sink effects which could contribute to incomplete tumor ablation. To reduce the effect of hyperperfusion the feeding vessels source must be known. The aim of this study was to dynamically characterize the type of blood supply of the periablational enhancement zone immediately after hepatic radiofrequency ablation (RFA) using perfusion CT. METHODS: We used an in-vivo porcine liver model. Multipolar RFA was performed in healthy pig livers. Immediate postablational perfusion CT was acquired. The contrast enhancement over time of the peripheral ablation zone, the aorta and the portal vein were recorded. Time differences of the peak periablational enhancement to the peak arterial perfusion and to the peak portalvenous perfusion were calculated and analyzed. RESULTS: The perfusion peak of the periablational enhancement zone always occurred in mean 8.1 s after the arterial peak in the aorta and in mean 16.9 s before the peak in the portal vein. CONCLUSIONS: Benign periablational enhancement is a result of primary arterial and not portalvenous hyperperfusion. In order to reduce heat sink effects, peri-ablational arterial balloon occlusion or transarterial chemoembolization may be beneficial during RFA.

Diagnostic efficacy and safety of gadoteric acid MR mammography in 1537 patients

OBJECTIVES To perform a large-scale multicenter post-marketing surveillance study for analyzing diagnostic effectiveness and safety of intravenous (IV) gadoteric acid (Dotarem®) in magnetic resonance (MR) mammography under daily practice conditions. MATERIALS AND METHODS Patients underwent high-resolution MR mammography with gadoteric acid in 15 German centers. Radiologists used a standardized questionnaire to report data including patient demographics and medical history, characteristics of MR examination and results in terms of diagnosis and safety for the patient. RESULTS A total of 1537 patients were examined. In 99.2% of all patients, a diagnosis was established. In 91.6% of all patients, image quality was excellent or good. Histopathological examinations were performed for 232 of 1537 patients (15.1%) with invasive ductal carcinoma being the most frequent diagnosis (109 patients, 47.0%). Based on histopathology as the standard of reference, IV gadoteric acid-enhanced MR mammography confirmed diagnoses of invasive ductal carcinoma in 93.5% of the patients. Adverse drug reactions occurred in 5 of 1537 patients (0.3%) and were classified as serious in one case (tachycardia, dysphagia, urticaria, rash). All patients with adverse drug reactions fully recovered after the examination. CONCLUSION This noninterventional surveillance study shows IV gadoteric acid to be a safe and effective contrast agent for use in MR mammography.