Evaluation of learning and exposure in the undergraduate interventional radiology curriculum (ELIXIR).

AIM: To gauge current final year medical students' exposure to interventional radiology (IR)and assess their perceptions of IR as a prospective career option. MATERIALS AND METHODS: An online questionnaire comprising of questions that gauge final-year medical students' understanding of and exposure to IR based on the recommendations set out by the British Society of Interventional Radiology (BSIR), was sent out to final-year students across 34 UK medical schools. RESULTS: Five hundred and ten responses were collected from 33 out of 34 eligible medical schools. Sixty-four per cent of respondents rated their own IR knowledge as inadequate. On average, only 50% of all subtopics proposed in the BSIR undergraduate curriculum was covered during medical school and 32.7% of respondents were not exposed to any fundamental IR principles and techniques recommended by the BSIR during medical school. Regarding careers, 2.7% of respondents reported a definite interest in pursuing a career in IR. Most respondents (89.8%) felt that there was insufficient undergraduate teaching on IR and that they lacked information to consider pursuing a career in IR (87.5%). CONCLUSION: Insufficient exposure and teaching on IR throughout medical schools have led to a lack of awareness and consideration of IR as a future career choice amongst UK medical students. The re-evaluation of IR teaching in the medical school curricula is needed. In the long-term, such recommendations could provide the much-needed solution to the workforce shortages seen in IR.

A survey of liver ablation amongst UK interventional radiologists.

AIM: To characterise training for, and conduct of, image-guided liver tumour ablation amongst UK interventional radiologists. MATERIALS AND METHODS: A web-based survey of British Society of Interventional Radiology members was carried out between 31 August to 1 October 2022. Twenty-eight questions were designed, covering four domains: (1) respondent background, (2) training, (3) current practice, and (4) operator technique. RESULTS: One hundred and six responses were received, with an 87% completion rate and an approximate response rate of 13% of society members. All UK regions were represented, with the majority from London (22/105, 21%). Seventy-two out of 98 (73%) were either extremely or very interested in learning about liver ablation during training, although levels of exposure varied widely, and 37/103 (36%) had no exposure. Performed numbers of cases also varied widely, between 1-10 cases and >100 cases per operator annually. All (53/53) used microwave energy, and most routinely used general anaesthesia (47/53, 89%). Most 33/53 (62%) did not have stereotactic navigation system, and 25/51(49%) always, 18/51 (35%) never, and 8/51(16%) sometimes gave contrast medium (mean 40, SD 32%) after procedures. Fusion software to judge ablation completeness was never used by 86% (43/55), sometimes used by 9% (5/55), and always used by 13% (7/55) of respondents. CONCLUSION: Although there are high levels of interest in image-guided liver ablation amongst UK interventional radiologists, training arrangements, operator experience, and procedural technique vary widely. As image-guided liver ablation evolves, there is a growing need to standardise training and techniques, and develop the evidence base to ensure high-quality oncological outcomes.

Image-guided ablation of renal cell carcinoma.

This review article aims to provide an overview of image-guided ablation of renal cell carcinoma (RCC) since it was first introduced in 1998. This will cover the background and rationale behind its development; an overview of the evidence for current thermal technology, such as heat-based, e.g., radiofrequency ablation (RFA), microwave ablation (MWA), and cold-based energies, e.g., cryoablation used; and summarise the published evidence regarding its treatment efficacy and oncological outcome. In addition, it aims to provide an insight into the potential role of the new non-thermal ablative technology, e.g., irreversible electroporation (IRE)/Nanoknife in image-guided ablation of RCC, as well as areas of challenge that will require further research and clinical evaluation to ensure delivery of a quality patient-centred interventional oncology (IO) service in image-guided ablation of RCC.

The effects of cryoablation on renal cell carcinoma perfusion and glomerular filtration rate measured using dynamic contrast-enhanced MRI: a feasibility study.

AIM: To assess the effect of cryoablation on renal cell carcinoma (RCC) perfusion and single kidney (SK) glomerular filtration rate (GFR) using dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). MATERIALS AND METHODS: Eighteen patients undergoing percutaneous cryoablation of a solitary RCC between August 2010 and November 2011 were evaluated with DCE-MRI immediately before and 1 month post-cryoablation. DCE-MRI data were acquired with 2 s temporal resolution in a coronal plane during the first pass of a 0.1 mmol/kg bolus dose of Gd-DOTA. Perfusion of the RCC (in ml/min/100 ml tissue) was estimated using a maximum slope technique. An index of SK GFR (SK-GFRi) was assessed using data acquired every 30 s for the following 3 min in the axial plane and analysed using Rutland-Patlak plots. This was compared to the GFR estimated by creatinine clearance (eGFR). RESULTS: Perfusion in the zone of ablation decreased significantly (p<0.001) from a mean of 98.0 ± 37.5 ml/min/100 ml pre-cryoablation to 11.6 ± 4.1 ml/min/100 ml post-cryoablation; a mean decrease of 88.2%. Functional analysis was performed in seventeen patients. eGFR was underestimated by SK-GFRi which decreased significantly in tumour-bearing (-31.7%, p = 0.011), but not in contralateral kidneys (-4.4%, p = 0.14). CONCLUSION: It is feasible to measure RCC perfusion pre- and post-cryoablation using DCE-MRI. The significant decrease within the zone of ablation suggests that this technique may be useful for assessment of treatment response. Further work is required to address the underestimation of eGFR by SK-GFRi and to validate the perfusion findings.

Evaluation of the sensitivity of scout radiographs on unenhanced helical CT in identifying ureteric calculi: a large UK tertiary referral centre experience.

OBJECTIVE: Unenhanced helical CT for kidney, ureter and bladder (CT KUB) has become the standard investigation for renal colic. This study aims to determine the sensitivity of scout radiographs in detecting ureteric calculi using CT KUB as a standard reference. METHODS: A retrospective review of consecutive patients who presented with acute flank pain and were investigated using CT KUB. 201 patients with positive ureteric calculi were included. Two radiologists independently reviewed the scout radiographs with access to CT KUB images. Each observer recorded the presence or absence of calculi, location, size and mean Hounsfield units of each calculus. RESULTS: 203 ureteric calculi were analysed from 201 patients. The overall sensitivity of scout radiographs for Observer A was 42.3% and for Observer B 52.2%, with an interobserver reliability κ-value of 0.78. The significance of mean Hounsfield units and size between two groups of patients with visible stones and those not visible were tested; the p-value for both variables was <0.0001, which is statistically significant. The study found that calculi in the upper ureter and larger than 4 mm are more likely to be seen on the scout radiograph. CONCLUSIONS: Usage of CT scout radiography should be encouraged and reported routinely in conjunction with CT KUB as a baseline for treatment follow-up.

Emergency department imaging protocol for suspected acute renal colic: re-evaluating our service.

OBJECTIVES: The objective of our study is to determine the positive rate for urolithiasis in male and female patients, and evaluate whether there has been any change at our institution in the use and outcome of unenhanced multidetector CT (CT KUB) performed in the emergency department (ER) for patients presenting with suspected acute renal colic. METHODS: A retrospective review of all 1357 consecutive cases between August 2007 and August 2009 admitted to the ER and investigated with CT KUB. RESULTS: The positive rate for urolithiasis was 47.5% and the rate of other significant findings was 10%. Female patients had a significantly lower positive rate than male patients (26.8% vs 61.6%, p<0.001). Urological intervention was required in 37% and these patients had a larger average stone size. In young female patients with a significantly sized ureteric calculus (>4 mm), the presence of hydronephrosis vs no hydronephrosis was 83% vs 17%, respectively. Among them, only three patients required ureteroscopy for stone removal. CONCLUSION: Contrary to other studies there has been no "indication creep" in the use of CT KUB at our institution. However, the young female patient presenting with suspected urolithiasis presents a particular diagnostic problem, and the significant percentage of negative examinations in females implies that an improvement in current practice is needed. The indiscriminate use of CT KUB in all female patients with flank pain should be avoided, and it is suggested that they should be initially evaluated with ultrasound to detect the presence of hydronephrosis.

Is the KUB radiograph redundant for investigating acute ureteric colic in the non-contrast enhanced computed tomography era?

AIM: To establish whether non-contrast enhanced computed tomography (NCCT) renders the kidneys-ureters-bladder (KUB) radiograph redundant as the initial imaging investigation for suspected acute ureteric colic. MATERIALS AND METHODS: The imaging investigations for 120 patients consecutively admitted to an emergency department-led clinical decisions unit (CDU) with suspected acute ureteric colic were retrospectively reviewed. A multidisciplinary meeting reviewed the findings and recommended that KUB radiographs should not be routinely performed prior to NCCT. Prospective assessment of 116 consecutive patients admitted over a comparable period was then undertaken. RESULTS: In the retrospective group, 61 (50.8%) patients had calculi to account for symptoms (positive NCCT) and 59 (49.2%) patients did not have stone disease (negative NCCT). Ninety (75%) patients had a KUB radiograph prior to NCCT. However, in 46 (38% of total) of these patients the NCCT was negative for stones, and therefore, they had been subjected to an unnecessary radiographic examination. These results prompted a change in practice. In the subsequent and prospectively studied group, preliminary KUB radiographs were performed in only 6% of the patients, with no significant change in the positive NCCT rate (50.8 versus 51.7%) or the total number of examinations performed (120 versus 116). CONCLUSION: NCCT should be the initial imaging examination for acute ureteric colic. Up to 50% of patients with clinical suspicion do not have stone disease, and therefore, preliminary KUB radiographs with attendant radiation and cost implications are unjustified. Preliminary KUB radiographs can be omitted from the imaging pathway with no resultant indication creep or increase in demand for NCCT examinations.

Unenhanced multidetector CT (CT KUB) in the initial imaging of suspected acute renal colic: evaluating a new service.

AIM: To evaluate a new imaging pathway for the investigation of patients presenting with suspected acute renal colic. MATERIALS AND METHODS: A retrospective review of 500 consecutive cases of suspected acute renal colic was undertaken to evaluate the initial results of a new imaging pathway introduced at our institution, which completely replaced the intravenous urogram (IVU) with unenhanced multidetector CT (CT KUB). RESULTS: The positive rate for urolithiasis was 44% (221/500), the negative rate 46% (229/500) and the rate of other significant findings was 12% (59/500). Female patients had a low positive rate compared with male patients (27.5 versus 57.5%; p<0.001). Urological intervention was required in 28% (61/221) and these patients had a larger average stone size (6.6 versus 3.7 mm; p<0.001) and the stone was located more proximally. Out-of-hours imaging was performed in 37% (186/500), and these patients had a higher positive rate (52 versus 40%; p<0.001). Other findings included a wide range of acute non-urological conditions. CONCLUSION: The feasibility of replacing the acute IVU with CT KUB in the initial assessment of suspected acute renal colic was demonstrated in the present study. The technique enables rapid diagnosis of urolithiasis, stratification of patients likely to proceed to urological intervention, and prompt diagnosis of a variety of other acute pathological conditions.

Management of renal-vein perforation during a challenging percutaneous nephrolithotomy.

A 54-year-old man with complex urinary anatomy as the result of previous surgery sustained a renal-vein injury during percutaneous nephrolithotomy for a staghorn calculus with a blood loss of 1.5 L. He was managed with antibiotics, bed rest, heparin, and a 28F nephrostomy catheter, which was withdrawn gradually as the tract sealed. This case highlights the importance of early diagnosis of this complication and the possibility of conservative management.

Ureteric catheterization via an ileal conduit: technique and retrieval of a JJ stent.

Retrograde ureteric catheterization of a patient with an ileal conduit is difficult, because guide wires and catheters coil in the conduit. A modified loopogram, using a Foley catheter as a fulcrum through which catheters can be advanced to the ureteric anastomosis, is described. This technique was used to remove a JJ stent, which had been inserted previously across a stricture in one ureter, the stent crossing from one kidney to the other.

Percutaneous nephrostomy insertion: outcome data from a prospective multi-operator study at a UK training centre.

AIM: To determine the success and complication rates of percutaneous nephrostomies (PCNs) performed at a UK training centre over a one-year period by different groups of operators. MATERIALS AND METHODS: During 2002, a total of 276 PCNs were performed in 190 patients by operators of varying experience. We employed two different techniques: (1) a "Seldinger" technique (ultrasound-guided puncture with a 19G sheathed needle followed by guide-wire insertion and track dilatation to accommodate 8-12F nephrostomy catheters), with or without fluoroscopic guidance, and (2) an ultrasound-guided "one-stab" technique using a 6F Bonanno catheter. Selection of technique was according to configuration of the collecting system and whether the procedure was performed out of hours. RESULTS: There were 218 procedures using the Seldinger technique and 62 using the one-stab technique. The Seldinger technique and one-stab technique were compared: primary technical success rate was 98 versus 93%, the major complication rate was 4.1 versus 3.2%, the minor complication rate was 5 versus 13%, and tube complications, such as drainage catheter dislodgement and blockage, were 29.5 versus 17.7%, respectively. The 30-day mortality was 4.3%, none of which were procedure related. CONCLUSION: Based on data from the USA, proposed targets for primary technical success rates are 88-99%, major complications 4-8%, and minor complications 3-15%, and the results were within these target ranges. The ultrasound-guided one-stab technique is a quick and safe procedure in selected cases, and we recommend this method for temporary urinary diversion in cases with moderate to severe degrees of pelvicalyceal system dilatation. These data may help to form a baseline for outcome targets in the UK.

Pulmonary complications following bone marrow transplantation.

Pulmonary complications account for significant morbidity and mortality in patients following bone marrow transplants (BMT). They are distinct from other immunosuppressed patients in that there is a predictable course of immunosuppresion and therefore of likely pulmonary complications. This is important when interpreting abnormal radiology as the predictable time course will enable narrowing the differential diagnoses to certain pulmonary complications that characteristically occur at a particular time following BMT. Early recognition and correct treatment of the pulmonary complications should minimize the significant mortality and morbidity. This review aims to discuss the role of radiology in the diagnosis and management of pulmonary complications following BMT.

Lower moiety pelvic-ureteric junction obstruction (PUJO) of the duplex kidney presenting with pyonephrosis in adults.

The most common congenital abnormality of the urinary tract is a duplex kidney. Pelvic-ureteric junction obstruction (PUJO) is a rare association that can affect the lower moiety of incomplete duplex kidneys. We report two adult cases of PUJO of the lower moiety in a duplex kidney that both presented with pyonephrosis. This late presentation of lower moiety PUJO with pyonephrosis has not been described previously. We describe the imaging appearances of this rare association and highlight this important diagnostic consideration in lower moiety hydronephrosis of the adult patient.

The role of CT in the management of adult urinary tract trauma.

Computed tomography (CT) is now the investigation of choice for evaluating haematuria following major abdominal trauma. This pictorial review provides a logical framework for understanding the classification and features of urinary tract injuries, defines the indications and outlines the techniques for CT imaging in upper and lower urinary tract trauma. The use of other competing imaging modalities is also discussed.