"Triple low" free-breathing CTPA protocol for patients with dyspnoea.

AIM: To assess the performance of a "triple-low" free-breathing protocol for computed tomography pulmonary angiography (CTPA) evaluated on patients with dyspnoea and suspected pulmonary embolism and discuss its application in routine clinical practice for the study of the pulmonary parenchyma and vasculature. MATERIAL AND METHODS: This study was conducted on a selected group of dyspnoeic patients referred for CTPA. The protocol was designed using fast free-breathing acquisition and a small, fixed volume (35 ml) of contrast agent in order to achieve a low-exposure dose. For each examination, radiodensity of the pulmonary trunk and ascending aorta, and the dose-length product (DLP) were recorded. A qualitative analysis was performed of pulmonary arterial enhancement and the pulmonary parenchyma. RESULTS: This study included 134 patients. Contrast enhancement of the pulmonary arteries (409 ± 159 HU) was systematically >250 HU. The duration of acquisition ranged from 0.9 to 1.3 seconds for free-breathing imaging. The mean DLP was in the range of low-dose chest CT acquisitions (145 ± 73 mGy·cm). The analysis was deemed optimal in 90% (120/134) of cases for the pulmonary parenchyma. Sixty-nine per cent (92/134) of cases demonstrated homogeneous enhancement of the pulmonary arteries to the subsegmental level. Only 6% (8/134) of examinations were considered uninterpretable. CONCLUSION: The present "triple-low" CTPA protocol allows convenient analysis of the pulmonary parenchyma and arteries without hindrance by respiratory motion artefacts in dyspnoeic patients.

The accuracy of standard multiple sclerosis MRI brain sequences for the diagnosis of optic neuropathy.

BACKGROUND: Detection of optic neuropathy on MRI has potential implications for the diagnosis and management of Multiple Sclerosis (MS). OBJECTIVE: This study assessed the accuracy of T2 sagittal MRI brain for detection of optic neuropathy, compared to coronal STIR orbit. METHODS AND MATERIALS: Retrospective single-center blinded diagnostic accuracy study of 100 consecutive patients who underwent both T2 sagittal brain and coronal STIR orbit MRI. All were performed on 1.5T scanners. T2 sagittal slice thickness was 4 mm for the first 50 patients (group1) and 3 mm for the second 50 (group2). The MRIs were reviewed in a blinded fashion to determine the presence of optic neuropathy. Coronal STIR orbit sequences were considered the diagnostic reference standard. RESULTS: The sensitivity of T2 sagittal brain imaging for ON was 44% in group 1 and 85% in group 2 (p = 0.007). The specificities were 98% and 97% respectively (p = 0.9). Sensitivity was poorest for evaluation of the intraorbital nerve segment (56% grp1, 69% grp2, p = 0.4). CONCLUSION: T2 sagittal MRI brain has high specificity for the detection of optic neuropathy when compared to coronal STIR orbit. Sensitivity is increased when slice thickness is reduced, but remains poor for evaluation of the intraorbital segment.

The Diagnostic Accuracy of Contrast-Enhanced CT of the Neck for the Investigation of Sialolithiasis.

BACKGROUND AND PURPOSE: Sialolithiasis is a common benign pathology affecting the salivary glands but it is unclear if contrast-enhanced CT, which is commonly used for investigation of head and neck pathology, can identify calculi as accurately as noncontrast CT. The aim of this study was to assess the diagnostic accuracy of contrast-enhanced CT of the neck in the diagnosis of sialolithiasis compared with noncontrast CT of the neck used as the criterion standard. MATERIALS AND METHODS: This was a retrospective, case-control study of 92 consecutive cases in 90 patients who underwent both noncontrast CT of the neck and contrast-enhanced CT of the neck in 2 tertiary referral centers from January 2011 to December 2015 for investigation of sialolithiasis. Axial 3-mm-section images were assessed by a fellowship-trained diagnostic neuroradiologist and diagnostic neuroradiology fellow in consensus. Blinded assessment of the contrast-enhanced CT of the neck was performed first, followed by noncontrast CT of the neck after a 2-week interval. The presence or absence of a stone and stone location and size were documented. Statistical analysis was undertaken to assess the agreement between CT protocols and calculate the sensitivity and specificity of contrast-enhanced CT of the neck. RESULTS: Fifty calculi were identified on noncontrast CT of the neck in 31 cases; and 48 calculi, in 31 cases on contrast-enhanced CT of the neck. No calculi were identified in the remaining 61 cases. The sensitivity and specificity of contrast-enhanced CT of the neck in the detection of sialolithiasis was 96% (95% CI, 86.3%-99.5%) and 100% (95% CI, 94.1%-100%), respectively. The positive predictive value of contrast-enhanced CT of the neck was 100% (95% CI, 92.6%-100%), and the negative predictive value was 96.8% (95% CI, 89%-99.6%). The accuracy of contrast-enhanced CT of the neck in diagnosing the presence or absence of salivary calculi was 98%. CONCLUSIONS: Contrast-enhanced CT of the neck is accurate in the detection of sialolithiasis, with no difference in diagnostic accuracy compared with noncontrast CT of the neck.

Which is the best current guideline for the diagnosis and management of cystic pancreatic neoplasms? An appraisal using evidence-based practice methods.

BACKGROUND AND AIM: Cystic pancreatic neoplasms (CPNs) are an increasingly diagnosed entity. Their heterogeneity poses complex diagnostic and management challenges. Despite frequently encountering these entities, particularly in the context of the increased imaging of patients in modern medicine, doctors have to rely on incomplete and ambiguous published literature. The aim of this project was to review the guidelines relating to CPNs using evidence-based practice (EBP) methods. METHODS: A search of both the primary and secondary literature was performed. Five sets of guidelines were identified which were then methodologically appraised by the AGREE II instrument, a validated and widely utilised tool for guideline development assessment. RESULTS: The 2014 'Italian consensus guidelines for the diagnostic work-up and follow-up of cystic pancreatic neoplasms' were found to be the most methodologically sound guidelines, on the basis of both the overall score and average weighted domain score. CONCLUSIONS: The current best guidelines were identified. The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument can be used for retrospective review of published guidelines or as a roadmap for guideline-writing groups. All guidelines found were methodologically limited. Further longitudinal/prospective studies are required to improve the level of evidence. KEY POINTS: • Cystic pancreatic neoplasms (CPNs) are an increasingly encountered entity in modern medicine. • Clinical uncertainty remains with regard to optimal diagnostic and management strategies. • The Italian consensus guidelines for cystic pancreatic neoplasms are currently the best guidelines.

Should abdominal sequences be included in prostate cancer MR staging studies?

OBJECTIVES: Prostate cancer staging MR examinations commonly include abdominal sequences to assess for non-regional (common iliac or para-aortic) nodal metastasis. In our experience the diagnostic yield of this is limited, but incidental findings are frequent, often necessitating further investigations. The aim of this study is to assess the diagnostic utility of abdominal sequences in routine prostate cancer MR staging studies. METHODS: Findings on abdominal sequences of consecutive MRI prostate studies performed for staging newly diagnosed prostate cancer between September 2011 and September 2013 were reviewed with respect to adenopathy and additional incidental findings. Results were correlated with Gleason grade and serum prostate-specific antigen (PSA) level in each case. RESULTS: 355 MRI prostate examinations were reviewed. 4 (1.1%) showed enlarged non-regional lymph nodes. Incidental findings were found in 82(23.1%) cases, neccessitating further investigation in 45 (12.7%) cases. Enlarged non-regional nodes were associated with higher PSA level and Gleason grade (p=0.007, p=0.005 respectively). With a combined threshold of PSA > 20 ng/mL and/or Gleason grade ≥ 8 the sensitivity, specificity, PPV and NPV were 100, 60, 3 and 100% respectively for predicting the presence of non-regional adenopathy. CONCLUSIONS: Routine abdominal sequences are of very low yield in routine prostate cancer MR staging, frequently resulting in incidental findings requiring further work-up and should be reserved for high-risk cases. Our experience supports the use of an abdominal staging sequence in high-risk cases only.