Frequency of extracardiac findings on "negative" CT coronary angiography studies.

AIM: To evaluate the prevalence and nature of extracardiac findings identified on computed tomography (CT) coronary angiography (CTCA) in patients with chest pain but without evidence of coronary artery disease (CAD). MATERIALS AND METHODS: CTCA studies in patients referred to the hospital between January 2017 to February 2021 with chest pain and a suspected diagnosis of CAD were reviewed retrospectively for the presence of extracardiac findings. Consensus review of CTCA studies was performed by two experienced thoracic radiologists. The presence and severity of extracardiac findings, together with the likelihood that chest pain might be attributed to these, was recorded. Patient records were reviewed to ascertain the recording of extracardiac findings on initial CTCA reports and, where applicable, the nature of the follow-up. RESULTS: Extracardiac findings (n=210) were present in 110/180 patients (61%) with a mean of 1.9 findings per patient. Extracardiac findings were more prevalent in patients aged ≥65 years compared to those <65 years (p<0.001). At least one extracardiac finding with the potential to cause chest pain was present in 40 patients (22%): degenerative disc disease (n=23 [13%]) and hiatus hernia (n=6 [3.3%]) were the most common extracardiac findings. Only 37.6% (79) of all retrospectively identified findings had been initially reported and, of these, 12.7% (10) required further follow-up. CONCLUSION: Extracardiac findings are common in patients with no evidence of CAD on CTCA. The entire dataset should be evaluated for the presence of extracardiac findings that could explain chest pain symptoms on wide field of view reconstructions.

Contemporary interventional management of pulmonary embolism.

Minimally invasive interventional techniques are being utilised more frequently in the management of acute and chronic pulmonary emboli; however, robust clinical evidence is only emerging for the utilisation of these techniques. Hence, there is a need for a robust mechanism of patient selection and careful consideration of the benefits and risks of the interventions. In this review, we discuss the risk stratification mechanisms; the role of the multidisciplinary pulmonary embolism response team to support decision-making; and describe the various commonly used interventional techniques and how these can be integrated into treatment strategies for the benefit of our patients.

The safe practice of CT coronary angiography in adult patients in UK imaging departments.

Computed tomography coronary angiography is increasingly used in imaging departments in the investigation of patients with chest pain and suspected coronary artery disease. Due to the routine use of heart rate controlling medication and the potential for very high radiation doses during these scans, there is a need for guidance on best practice for departments performing this examination, so the patient can be assured of a good quality scan and outcome in a safe environment. This article is a summary of the document on 'Standards of practice of computed tomography coronary angiography (CTCA) in adult patients' published by the Royal College of Radiologists (RCR) in December 2014.

Quality assurance in cardiovascular CT: a practical guide.

Cardiovascular computed tomography (CCT) is a cutting-edge imaging technique providing important, non-invasive, diagnostic information. Concerns exist regarding radiation exposure to patient populations, but achieving optimal image quality at the lowest doses can be challenging. This guide provides practical advice about how quality can be assured in any CCT unit or radiology department. Illustrated by real-world vignettes and data analysis from our own experience, we highlight a multidisciplinary team approach to each stage of the patient journey, the effectiveness of regular dose audit overseen by a CT optimisation group, and the importance of underused systolic scanning techniques, in order to drive significant dose reduction without loss of image quality or clinical confidence.

Clinical validation of dual-source dual-energy computed tomography (DECT) for coronary and valve imaging in patients undergoing trans-catheter aortic valve implantation (TAVI).

AIM: To assess the validity of virtual non-contrast (VNC) reconstructions for coronary artery calcium (CACS) and aortic valve calcium scoring (AVCS) in patients undergoing trans-catheter aortic valve implantation (TAVI). MATERIALS AND METHODS: Twenty-three consecutive TAVI patients underwent a three-step computed tomography (CCT) acquisition: (1) traditional CACS; (2) dual-energy (DE) CT coronary angiogram (CTCA); and (3) DE whole-body angiogram. Linear regression was used to model calcium scores generated from VNC images with traditional scores to derive a conversion factor [2.2 (95% CI: 1.97-2.58)]. The effective radiation dose for the TAVI protocol was compared to a standard control group. Bland-Altman analysis and weighted k-statistic were used to assess inter-method agreement for absolute score and risk centiles. RESULTS: CACS and AVCS from VNC reconstructions correlated well with traditional scores (r = 0.94 and r = 0.86; both p < 0.0001). There was excellent agreement between VNC and non-contrast coronary calcium scores [mean difference -71.8 (95% limits of agreement -588.7 to 445.1)], with excellent risk stratification into risk centiles (k = 0.99). However, the agreement was weaker for the aortic valve [mean difference -210.6 (95% limits of agreement -1233.2 to 812)]. Interobserver variability was excellent for VNC CACS [mean difference of 6 (95% limits of agreement 134.1-122.1)], and AVCS [mean difference of -16.4 (95% limits of agreement 576 to -608.7)]. The effective doses for the DE TAVI protocol was 16.4% higher than standard TAVI protocol (22.7 versus 19.5 mSv, respectively) accounted for by the DE CTCA dose being 47.8% higher than that for a standard CTCA [9.9 (5.6-14.35) versus 6.7 (1.17-13.72) mSv; p < 0.01). CONCLUSIONS: CACS and AVCS can be accurately quantified, and patients can be risk stratified using DECT VNC reconstructions. However, the dose from DE CTCA is significantly greater than the standard single-energy CTCA precluding the use of this technology in routine clinical practice.

Maximizing the clinical benefit of high-pitch, single-heartbeat CT coronary angiography in clinical practice.

AIM: To prospectively analyse the occurrence of right coronary artery (RCA) artefact and assess its relationship with patient heart rate (HR) and HR variability (HRV) in order to determine the most appropriate parameters for high-pitch cardiovascular computed tomography (CT) acquisition, minimize the likelihood of artefact, and maximize the clinical benefit in consecutive clinical high-pitch CT coronary angiography (CA) examinations. MATERIALS AND METHODS: One hundred and seventy-three patients undergoing high-pitch CTCA were prospectively assessed for the presence of RCA artefact. Median and maximum HR and the difference in predicted and actual acquisition HR (HR difference, HRD) were correlated from the electrocardiograms recorded at the time of acquisition. RESULTS: Sixty-six percent of the cohort was male, with a median age of 54 (range 16-84 years). There were 53 cases of RCA artefact (30.6%); 26 (49.1%) of these required further imaging to fully delineate the RCA. Of the 53 cases with artefact, 81.1% affected the distal RCA and 18.9% were more proximal. Gender was not associated with an increased likelihood of the artefact (p = 0.14). RCA artefact decreased by 2% with each year of increasing age (p = 0.04). When compared with a reference HR of >70 beats/min, univariate analysis demonstrated RCA artefact significantly increased with both increasing median and maximum HR, whilst the incidence of RCA artefact increased for all HRD >1, with a greater likelihood of artefact with increasing HRD. CONCLUSION: The present results highlight the importance of optimizing patient HR in order to reduce the likelihood of RCA artefact. In addition to aggressive HR control to a median HR of ≤60 beats/min, the present results suggest limiting high-pitch acquisition to patients with HR variability of <3 beats/min. Therefore, use of beta-blockers is of crucial importance to both reduce HR and HR variability to optimize use of high-pitch single-heartbeat CTCA.

Embolization of uterine arteriovenous malformations associated with cyanotic congenital heart disease.

Uterine arteriovenous malformation (AVM) is a rare cause of vaginal bleeding and miscarriage. We report two cases of uterine AVMs in patients with a history of complex congenital heart disease, an association that has not been previously described. Both patients were treated by selective uterine artery embolization, a minimally invasive therapy that has revolutionized the management of uterine AVMs, thus offering an alternative to conventional hysterectomy.

Considerations when introducing a new cardiac MDCT service. Avoiding the pitfalls.

The widespread introduction of multidetector computed tomography (MDCT) into mainstream imaging departments has enabled many centres to undertake cardiac MDCT and, in particular, MDCT coronary angiography. This review highlights the areas that need consideration when introducing a new cardiac MDCT service and covers both technical and non-technical aspects. This includes equipment requirements, personnel, training, patient selection and preparation, cardiac CT protocols and post-processing techniques, and potential pitfalls.

Primary ciliary dyskinesia in the paediatric population: range and severity of radiological findings in a cohort of patients receiving tertiary care.

AIM: To investigate the clinical range and severity of radiological findings in a cohort of patients with primary ciliary dyskinesia (PCD) receiving tertiary care. MATERIALS AND METHODS: The case notes and clinical test results of 89 children attending the paediatric respiratory disease clinic at our institution were retrospectively analysed. Demographic details including age at diagnosis and common presenting signs and symptoms were studied. Results of chest radiographs, microscopy, and high-resolution computed tomography (HRCT) for quantification of lung damage were analysed. RESULTS: In a cohort of 89 children with PCD, a presentation chest radiograph was available in 62% of patients (n=55), with all but one demonstrating changes of bronchial wall thickening. HRCT of the lungs, available in 26 patients, were scored using the system described by Brody et al. analysing five specific features of lung disease, including bronchiectasis, mucus plugging, peribronchial thickening, parenchymal changes of consolidation, and ground-glass density, and focal air-trapping in each lobe. Peribronchial thickening was observed using HRCT in 25 patients, while 20 patients had bronchiectasis. Severity scores were highest for the middle and the lingular lobes. CONCLUSION: The radiographic findings of the largest reported cohort of patients with PCD are presented, with associated clinical findings. Dextrocardia remains the commonest finding on chest radiography. HRCT demonstrates peribronchial thickening and bronchiectasis, which is most marked in the lower zones. Radiological scoring techniques developed for assessment of cystic fibrosis can also be applied for the assessment of disease severity in this patient population.

Computed tomography findings in fibrosing mediastinitis.

AIM: To describe the CT features of fibrosing mediastinitis. MATERIALS AND METHODS: The clinical notes, histology, and CT images from 12 patients with fibrosing mediastinitis were reviewed. Clinical data regarding the presentation and suspected aetiology were correlated with location of mediastinal disease, calcification, effect on mediastinal structures, and additional pulmonary findings on computed tomography (CT). RESULTS: The mean age was 40.5 years, with seven female and five male patients. The most common presenting symptom was shortness of breath. Fibrosing mediastinitis diffusely infiltrated the mediastinum in five patients and was localized in seven. Calcification was present in two cases. Eleven of 12 cases had narrowing of mediastinal structures, including five with pulmonary artery narrowing, five with superior vena cava obstruction, four with bronchial narrowing, three with tracheal narrowing, and one with narrowing of the pulmonary vein. The disease was considered idiopathic in seven cases with a demonstrable aetiology in five cases. Eight out of 12 patients had additional pulmonary findings, including all patients with a known aetiology. CONCLUSIONS: In the present series of patients, fibrosing mediastinitis more commonly presented as a localized mediastinal mass than as diffuse mediastinal disease, with the anterior mediastinal compartment most frequently involved. Most cases were idiopathic compared with the majority of previous cases at this institution being ascribed to tuberculosis. There is a high incidence of concomitant pulmonary findings, in particular when an identifiable aetiology is present. Obstruction of vital structures frequently gives rise to complications.

Assessment of adult congenital heart disease with multi-detector computed tomography: beyond coronary lumenography.

Adult congenital heart disease is an increasingly prevalent condition with more than 135,000 patients affected in England alone. With this increased patient population and an increase in interventional procedures being performed on them, traditional imaging techniques such as cardiac magnetic resonance (CMR) may be unavailable locally or contra-indicated. Cardiac multidetector computed tomography (MDCT) is rapidly emerging as an alternative imaging method for the investigation of these patients and this review highlights the broad application of cardiac MDCT to this population and makes recommendations on the standardized reporting of complex congenital heart disease.

The radiology of IRIS (immune reconstitution inflammatory syndrome) in patients with mycobacterial tuberculosis and HIV co-infection: Appearances in 11 patients.

AIM: To determine the radiological manifestations of IRIS (immune reconstitution inflammatory syndrome) in patients with HIV and mycobacterium tuberculosis co-infection, in the context of their demographic and clinical data. MATERIALS AND METHODS: The radiological imaging, demographic and clinical data of 11 patients diagnosed with IRIS associated with HIV and mycobacterial tuberculosis co-infection were studied retrospectively. Where available, follow-up imaging studies were also reviewed. RESULTS: The most common radiological feature of IRIS was lymph node enlargement (73%), with central low attenuation centres, in keeping with necrosis, present in most of these cases (88%). Most commonly affected were intra-abdominal nodes (70%), followed by axillary (40%) and mediastinal lymph nodes (36%). Within the lung parenchyma, diffuse, bilateral pulmonary nodules were seen in 55% of cases. Unilateral small volume pleural effusions were seen in two cases with associated parenchymal changes seen in only one. Small volume ascites was seen in two cases. Thirty-six percent of cases presented with new or worsening abscesses despite treatment. In this context, image-guided radiological drainage proved a useful adjunct to the conventional medical therapy for IRIS. The most common clinical signs of IRIS included fever (64%), abdominal pain (36%) and cough (27%). CONCLUSION: We have described the radiological features that are characteristic in IRIS and the importance of putting these into context with the clinical and pathological findings as part of a multidisciplinary approach in making the diagnosis. The role of the radiologist is central in diagnosis, monitoring of disease progression and management of complications in patients with IRIS.

CT techniques for imaging the lung: recommendations for multislice and single slice computed tomography.

The introduction of multislice computed tomography (MSCT) has provided the thoracic radiologist with a powerful tool with which to image the lungs. Enthusiasm for new protocols should be tempered with concerns over the potential increase in radiation dose, and before older protocols are abandoned there should be good evidence that newer protocols are objectively superior. Ultimately, the best protocol is one that provides the most relevant clinical information at the lowest dose possible.

Imaging features of multicentric Castleman's disease in HIV infection.

AIM: To describe the computed tomography (CT) features of human immunodeficiency virus (HIV)-associated Castleman's disease. MATERIALS AND METHODS: Nine HIV-positive patients with biopsy-proven Castleman's disease were studied. Clinical and demographic data, CD4 count, histological diagnosis and human herpes type 8 (HHV8) serology or immunostaining results were recorded. CT images were reviewed independently by two radiologists. RESULTS: CT findings included splenomegaly (n=7) and peripheral lymph node enlargement (axillary n=8, inguinal n=4). All nodes displayed mild to avid enhancement after intravenous administration of contrast material. Hepatomegaly was evident in seven patients. Other features included abdominal (n=6) and mediastinal (n=5) lymph node enlargement and pulmonary abnormalities (n=4). Patterns of parenchymal abnormality included bronchovascular nodularity (n=2) consolidation (n=1) and pleural effusion (n=2). On histological examination eight patients (spleen n=3, lymph node n=9, lung n=1, bone marrow n=1) had the plasma cell variant and one had mixed hyaline-vascular/plasma cell variant. The majority had either positive immunostaining for HHV8 or positive serology (n=8). CONCLUSION: Common imaging features of multicentric Castleman's disease in HIV infection are hepatosplenomegaly and peripheral lymph node enlargement. Although these imaging features may suggest the diagnosis in the appropriate clinical context, they lack specificity and so biopsy is needed for diagnosis. In distinction from multicentric Castleman's disease in other populations the plasma cell variant is most commonly encountered, splenomegaly is a universal feature and there is a strong association with Kaposi's sarcoma.

HRCT diagnosis of diffuse parenchymal lung disease: inter-observer variation.

BACKGROUND: This study was designed to measure inter-observer variation between thoracic radiologists in the diagnosis of diffuse parenchymal lung disease (DPLD) using high resolution computed tomography (HRCT) and to identify areas of difficulty where expertise, in the form of national panels, would be of particular value. METHODS: HRCT images of 131 patients with DPLD (from a tertiary referral hospital (n = 66) and regional teaching centres (n = 65)) were reviewed by 11 thoracic radiologists. Inter-observer variation for the first choice diagnosis was quantified using the unadjusted kappa coefficient of agreement. Observers stated differential diagnoses and assigned a percentage likelihood to each. A weighted kappa was calculated for the likelihood of each of the six most frequently diagnosed disease entities. RESULTS: Observer agreement on the first choice diagnosis was moderate for the entire cohort (kappa = 0.48) and was higher for cases from regional centres (kappa = 0.60) than for cases from the tertiary referral centre (kappa = 0.34). 62% of cases from regional teaching centres were diagnosed with high confidence and good observer agreement (kappa = 0.77). Non-specific interstitial pneumonia (NSIP) was in the differential diagnosis in most disagreements (55%). Weighted kappa values quantifying the likelihood of specific diseases were moderate to good (mean 0.57, range 0.49-0.70). CONCLUSION: There is good agreement between thoracic radiologists for the HRCT diagnosis of DPLD encountered in regional teaching centres. However, cases diagnosed with low confidence, particularly where NSIP is considered as a differential diagnosis, may benefit from the expertise of a reference panel.

HRCT in small and large airways diseases.

High-resolution computed tomography (HRCT) is being increasingly used in the diagnostic work-up of paediatric patients with large and small airways disease due to its ability to provide valuable information far beyond that of other non-invasive investigations. This article highlights the key HRCT appearances of a range of conditions involving the airways in children, and where relevant, the role of HRCT in assessment of disease severity and monitoring of disease progression.

The effect of khat chewing on gallbladder motility in a group of volunteers.

An increase in the prevalence of gallstones has been reported from the Middle East and the Republic of Yemen. Changing dietary habits and obesity are thought to be responsible but other local factors may contribute such as chewing the leaves of the khat plant (Catha edulis Forsk.) which is a widespread social custom in Yemen. We have studied the effects of khat chewing on gallbladder motility in a group of 10 healthy volunteers. All subjects underwent ultrasound measurements of gallbladder volume after chewing khat leaves or lettuce, which was used as the control. Results were compared after chewing for up to 2h in the fasting state and in response to a fatty meal. There was no significant change in gallbladder volume after chewing khat compared with lettuce in the fasting state (P=0.7) or in gallbladder emptying after a fatty meal (P=0.4) and we conclude that khat chewing has no clinically significant effect on gallbladder motility.