Acute colonic pseudo-obstruction post-cesarean section is not a benign entity: A case series and review of the literature

Acute colonic pseudo-obstruction (ACPO) is an infrequent occurrence after cesarean section. Anecdotal evidence suggests that the clinical course of ACPO in the obstetric setting is different to that seen in non-pregnant adult patients with ACPO secondary to alternative causes, such as systemic illnesses, the use of certain medications, and after non-abdominal surgery. The risk of progression to ischemia and perforation, as well as the need for emergency surgery, appears to be higher after cesarean section. Here we describe the clinical course of ACPO in four patients after cesarean section from our institution, followed by a review of the literature and a discussion of the important issues surrounding this condition in the postpartum time period. The findings from our cohort of patients and the reports from the medical literature support a hands-on combined approach from a group of specialists including obstetricians, surgeons, radiologists, and enterostomal therapists. Immediate imaging followed by regular observation is mandatory for any patient being managed conservatively. Early use of endoscopic decompression should be considered for patients who are not resolving with a conservative approach. Clinical signs of peritonism or radiological signs of ischemia or perforation in patients with ACPO mandate immediate surgical intervention. Appropriate postoperative care is necessary to deal with the complex physiological and psychological consequences of emergency surgery and potential stoma formation so soon after cesarean section.

Radiomics-based prediction of FIGO grade for placenta accreta spectrum

BACKGROUND

Placenta accreta spectrum (PAS) is a rare, life-threatening complication of pregnancy. Predicting PAS severity is critical to individualise care planning for the birth. We aim to explore whether radiomic analysis of T2-weighted magnetic resonance imaging (MRI) can predict severe cases by distinguishing between histopathological subtypes antenatally.

METHODS

This was a bi-centre retrospective analysis of a prospective cohort study conducted between 2018 and 2022. Women who underwent MRI during pregnancy and had histological confirmation of PAS were included. Radiomic features were extracted from T2-weighted images. Univariate regression and multivariate analyses were performed to build predictive models to differentiate between non-invasive (International Federation of Gynecology and Obstetrics [FIGO] grade 1 or 2) and invasive (FIGO grade 3) PAS using R software. Prediction performance was assessed based on several metrics including sensitivity, specificity, accuracy and area under the curve (AUC) at receiver operating characteristic analysis.

RESULTS

Forty-one women met the inclusion criteria. At univariate analysis, 0.64 sensitivity (95% confidence interval [CI] 0.0-1.00), specificity 0.93 (0.38-1.0), 0.58 accuracy (0.37-0.78) and 0.77 AUC (0.56-.097) was achieved for predicting severe FIGO grade 3 PAS. Using a multivariate approach, a support vector machine model yielded 0.30 sensitivity (95% CI 0.18-1.0]), 0.74 specificity (0.38-1.00), 0.58 accuracy (0.40-0.82), and 0.53 AUC (0.40-0.85).

CONCLUSION

Our results demonstrate a predictive potential of this machine learning pipeline for classifying severe PAS cases.

RELEVANCE STATEMENT

This study demonstrates the potential use of radiomics from MR images to identify severe cases of placenta accreta spectrum antenatally.

KEY POINTS

• Identifying severe cases of placenta accreta spectrum from imaging is challenging. • We present a methodological approach for radiomics-based prediction of placenta accreta. • We report certain radiomic features are able to predict severe PAS subtypes. • Identifying severe PAS subtypes ensures safe and individualised care planning for birth.

Use of an aortic balloon to achieve uterine conservation in a case of placenta accreta spectrum: A case report

Placenta accreta spectrum (PAS) is a rare complication of pregnancy associated with a high risk of massive haemorrhage and caesarean hysterectomy. This is a case report of abdominal aortic balloon occlusion, using intravascular ultrasound, to achieve uterine conservation in a case of severe PAS. The patient was a 34-year-old woman, G2P1, with one prior caesarean section. Antenatal imaging, consisting of transabdominal and transvaginal ultrasound, and magnetic resonance imaging, showed features of PAS. The risk of caesarean hysterectomy with PAS was explained, but the patient declared a desire to retain fertility. Following multi-disciplinary discussion, it was considered appropriate to attempt uterine conservation using en-bloc myometrial and placental resection. An elective caesarean delivery was performed at 36 weeks of gestation. An aortic balloon was inserted prior to surgery using intravascular ultrasound, which allowed for radiation-free, point-of-surgery, accurate balloon sizing, by measuring the aortic diameter, and correct placement of the balloon in the abdominal aorta below the renal vessels. Intraoperative findings confirmed PAS, and a myometrial resection was performed. There were no intraoperative complications. Estimated blood loss was 1000 mL and the patient had an uncomplicated postoperative course. This case demonstrates how the use of an intravascular intraoperative aortic balloon can facilitate uterine conservation in a case of severe PAS.

MR imaging of acute abdominal pain in pregnancy

Abdominal pain in pregnancy is a diagnostic challenge with many potential aetiologies. Diagnostic imaging is a valuable tool in the assessment of these patients, with ultrasound commonly employed first line. MRI is an excellent problem-solving adjunct to ultrasound and has many advantages in terms of improved spatial resolution and soft tissue characterisation. This pictorial review aims to outline the role of MRI in the work up of acute abdominal pain in pregnancy and provide imaging examples of pathologies which may be encountered.

Comparing three-dimensional models of placenta accreta spectrum with surgical findings

OBJECTIVE

Placenta accreta spectrum (PAS) is associated with significant maternal morbidity mainly related to blood loss. Pre-operative planning is aided by antenatal ultrasound and magnetic resonance imaging. We sought to assess whether three-dimensional (3D) models from MR images were accurate when compared with surgical and pathological findings.

METHODS

Digital Imaging and Communications in Medicine files containing MR images with varying severity of PAS (n = 4) were modeled using 3D Slicer. Placenta, bladder, and myometrial defects were modeled. Myometrial defects at three different uterine locations were included-anterior, lateral and inferior. 3D models were used to identify the relationship between the myometrial defect and the internal cervical os. Findings were validated in a larger series of PAS cases (n = 14) where patterns of invasion were compared with estimated blood loss and distance from defect to the internal os.

RESULTS

The defect illustrated in the four 3D models correlates to both surgical and pathological findings in terms of depth and pattern of invasion, location of defect, bladder involvement. Blood loss and topography of the defect from 3D modeling were examined in 14 further cases. Inferior defects were associated with increased blood loss compared with anterior defects. Increased distance from cervix was associated with reduced blood loss (R²  = 0.352, P = 0.01).

CONCLUSION

Three-dimensional models of PAS provide an accurate preoperative description of placental invasion and should be investigated as a tool for selecting patients for uterine-conserving surgery. Accurate 3D models of placenta accreta spectrum are achievable and may provide additional information, such as distance of the defect from the internal os.

Natural growth pattern of sporadic renal angiomyolipoma

BACKGROUND

Surveillance of sporadic renal angiomyolipomas is a growing issue for physicians and radiologists. Current treatment recommendations favor active surveillance. However, the evidence underlying these is based on small case series, which also typically include angiomyolipomas associated with tuberous sclerosis.

PURPOSE

To evaluate the natural growth pattern of sporadic renal angiomyolipomas in patients without tuberous sclerosis.

MATERIAL AND METHODS

A retrospective review was performed in three separate tertiary referral centers. A keyword search of each institutions PACS history was performed. Inclusion criteria were angiomyolipomas > 1 cm in size, three years of follow-up, and lesions requiring treatment before reaching three years of follow-up. Exclusion criteria included a diagnosis of tuberous sclerosis, pregnancy, prior treatment with embolization without any prior imaging, and lesions which were treated on presentation. Growth of the angiomyolipomas was evaluated on the basis of maximum dimension on initial and follow-up images.

RESULTS

Sixty-three patients were identified in total, with 64 lesions eligible for inclusion. The majority of patients were women (55/63). The mean age at which the angiomyolipomas discovered was 56.4 years. Mean total growth was 0.085 mm and mean follow-up was 65.5 months. At initial measurement, the mean maximum dimension of the lesions in our cohort was 2.08 cm. After follow-up, this was 2.16 cm. The average rate of growth was 0.015 cm per year.

CONCLUSION

Sporadic angiomyolipomas exhibit minimal, if any, natural growth. Current surveillance strategies could be relaxed.

Single-institution experience with selective internal radiation therapy (SIRT) for the treatment of unresectable colorectal liver metastases

BACKGROUND

Liver metastases are the commonest cause of death for patients with colorectal cancer. Growing evidence supports the use of selective internal radiation therapy (SIRT) in combination with conventional chemotherapy regimens for liver-only or liver-dominant unresectable metastatic colorectal cancer.

AIMS

To measure and evaluate outcomes of the first 20 consecutive patients with unresectable colorectal liver metastasis selected for SIRT in addition to their chemotherapy at a single Irish institution.

METHODS

Retrospective case series was performed. Patient charts and medical records were reviewed.

RESULTS

All 20 patients (100%) selected for angiographic workup were subsequently successfully treated with radioembolization. All patients were discharged 1 day post-SIRT. At initial imaging evaluation, 12 (60%) had a partial response in their liver, 2 (10%) had stable disease, and 6 (30%) had liver-specific progressive disease. Median follow up was 10 months (range 6-26). At last follow up, 14 (70%) patients were alive and 6 (30%) deceased. Most recent imaging demonstrated 2 (10%) with a complete response, 7 (35%) had a partial response, 2 (10%) had stable disease, and 9 (45%) had progressive disease within their liver. One patient was downstaged to hepatic resection, and one with a complete hepatic response had his primary sigmoid tumor resected 11 months post-SIRT.

CONCLUSIONS

SIRT is a safe and effective therapy for certain patients with unresectable colorectal liver metastases. This case series supports our opinion that selected patients should be offered SIRT in concert with their medical oncologist, concomitant with their chemotherapy. Larger multi-center studies are required to more clearly define the patient groups that will derive most benefit from SIRT.

The effect of beam purity and scanner complexity on proton CT accuracy

PURPOSE

To determine the dependence of the accuracy in reconstruction of relative stopping power (RSP) with proton computerized tomography (pCT) scans on the purity of the proton beam and the technological complexity of the pCT scanner using standard phantoms and a digital representation of a pediatric patient.

METHODS

The Monte Carlo method was applied to simulate the pCT scanner, using both a pure proton beam (uniform 200 MeV mono-energetic, parallel beam) and the Northwestern Medicine Chicago Proton Center (NMCPC) clinical beam in uniform scanning mode. The accuracy of the simulation was validated with measurements performed at NMCPC including reconstructed RSP images obtained with a preclinical prototype pCT scanner. The pCT scanner energy detector was then simulated in three configurations of increasing complexity: an ideal totally absorbing detector, a single stage detector and a multi-stage detector. A set of 15 cm diameter water cylinders containing either water alone or inserts of different material, size, and position were simulated at 90 projection angles (4° steps) for the pure and clinical proton beams and the three pCT configurations. A pCT image of the head of a detailed digital pediatric phantom was also reconstructed from the simulated pCT scan with the prototype detector.

RESULTS

The RSP error increased for all configurations for insert sizes under 7.5 mm in radius, with a sharp increase below 5 mm in radius, attributed to a limit in spatial resolution. The highest accuracy achievable using the current pCT calibration step phantom and reconstruction algorithm, calculated for the ideal case of a pure beam with totally absorbing energy detector, was 1.3% error in RSP for inserts of 5 mm radius or more, 0.7 mm in range for the 2.5 mm radius inserts, or better. When the highest complexity of the scanner geometry was introduced, some artifacts arose in the reconstructed images, particularly in the center of the phantom. Replacing the step phantom used for calibration with a wedge phantom led to RSP accuracy close to the ideal case, with no significant dependence of RSP error on insert location or material. The accuracy with the multi-stage detector and NMCPC beam for the cylindrical phantoms was 2.2% in RSP error for inserts of 5 mm radius or more, 0.7 mm in range for the 2.5 mm radius inserts, or better. The pCT scan of the pediatric phantom resulted in mean RSP values within 1.3% of the reference RSP, with a range error under 1 mm, except in exceptional situations of parallel incidence on a boundary between low and high density.

CONCLUSIONS

The pCT imaging technique proved to be a precise and accurate imaging tool, rivaling the current x-rays based techniques, with the advantage of being directly sensitive to proton stopping power rather than photon interaction coefficients. Measured and simulated pCT images were obtained from a wobbled proton beam for the first time. Since the in-silico results are expected to accurately represent the prototype pCT, upcoming measurements using the wedge phantom for calibration are expected to show similar accuracy in the reconstructed RSP.

Operation of the Preclinical Head Scanner for Proton CT

We report on the operation and performance tests of a preclinical head scanner developed for proton computed tomography (pCT). After extensive preclinical testing, pCT is intended to be employed in support of proton therapy treatment planning and pre-treatment verification in patients undergoing particle-beam therapy. In order to assess the performance of the scanner, we have performed CT scans with 200 MeV protons from both the synchrotron of the Loma Linda University Medical Center (LLUMC) and the cyclotron of the Northwestern Medicine Chicago Proton Center (NMCPC). The very high sustained rate of data acquisition, exceeding one million protons per second, allowed a full 360° scan to be completed in less than 7 minutes. The reconstruction of various phantoms verified accurate reconstruction of the proton relative stopping power (RSP) and the spatial resolution in a variety of materials. The dose for an image with better than 1% uncertainty in the RSP is found to be close to 1 mGy.

Novel Use of a Pneumatic Compression Device for Haemostasis of Haemodialysis Fistula Access Catheterisation Sites

PURPOSE

Transradial pneumatic compression devices can be used to achieve haemostasis following radial artery puncture. This article describes a novel technique for acquiring haemostasis of arterio-venous haemodialysis fistula access sites without the need for suture placement using one such compression device.

MATERIALS AND METHODS

A retrospective review of fistulograms with or without angioplasty/thrombectomy in a single institution was performed. 20 procedures performed on 12 patients who underwent percutaneous intervention of failing or thrombosed arterio-venous fistulas (AVF) had 27 puncture sites. Haemostasis was achieved using a pneumatic compression device at all access sites. Procedure details including size of access sheath, heparin administration and complications were recorded.

RESULTS

Two diagnostic fistulograms, 14 fistulograms and angioplasties and four thrombectomies were performed via access sheaths with an average size (±SD) of 6 Fr (±1.12). IV unfractionated heparin was administered in 11 of 20 procedures. Haemostasis was achieved in 26 of 27 access sites following 15-20 min of compression using the pneumatic compression device. One case experienced limited bleeding from an inflow access site that was successfully treated with reinflation of the device for a further 5 min. No other complication was recorded.

CONCLUSIONS

Haemostasis of arterio-venous haemodialysis fistula access sites can be safely and effectively achieved using a pneumatic compression device. This is a technically simple, safe and sutureless technique for acquiring haemostasis after AVF intervention.

Asymptomatic Renal Pseudoaneurysm Following Laparoscopic Partial Nephrectomy

A 66-year-old-woman underwent a laparoscopic left partial nephrectomy for a 3 cm partially exophytic tumor arising from the posterior interpolar region of the left kidney. Follow-up surveillance computed tomography 6 months following the surgery found an incidental 4 cm lesion in the left kidney that is avidly enhanced in the arterial phase, consistent with a renal pseudoaneurysm. She was completely asymptomatic. Renal pseudoaneurysm is a rare complication following minimally invasive nephron-sparing surgery and typically presents in the early postoperative period with gross hematuria. However, a large renal pseudoaneurysm may also present as an asymptomatic incidental finding and is amenable to angioembolization.

Fabrication and assessment of 3D printed anatomical models of the lower limb for anatomical teaching and femoral vessel access training in medicine

For centuries, cadaveric dissection has been the touchstone of anatomy education. It offers a medical student intimate access to his or her first patient. In contrast to idealized artisan anatomical models, it presents the natural variation of anatomy in fine detail. However, a new teaching construct has appeared recently in which artificial cadavers are manufactured through three-dimensional (3D) printing of patient specific radiological data sets. In this article, a simple powder based printer is made more versatile to manufacture hard bones, silicone muscles and perfusable blood vessels. The approach involves blending modern approaches (3D printing) with more ancient ones (casting and lost-wax techniques). These anatomically accurate models can augment the approach to anatomy teaching from dissection to synthesis of 3D-printed parts held together with embedded rare earth magnets. Vascular simulation is possible through application of pumps and artificial blood. The resulting arteries and veins can be cannulated and imaged with Doppler ultrasound. In some respects, 3D-printed anatomy is superior to older teaching methods because the parts are cheap, scalable, they can cover the entire age span, they can be both dissected and reassembled and the data files can be printed anywhere in the world and mass produced. Anatomical diversity can be collated as a digital repository and reprinted rather than waiting for the rare variant to appear in the dissection room. It is predicted that 3D printing will revolutionize anatomy when poly-material printing is perfected in the early 21st century.

Fabrication and assessment of 3D printed anatomical models of the lower limb for anatomical teaching and femoral vessel access training in medicine

For centuries, cadaveric dissection has been the touchstone of anatomy education. It offers a medical student intimate access to his or her first patient. In contrast to idealized artisan anatomical models, it presents the natural variation of anatomy in fine detail. However, a new teaching construct has appeared recently in which artificial cadavers are manufactured through three-dimensional (3D) printing of patient specific radiological data sets. In this article, a simple powder based printer is made more versatile to manufacture hard bones, silicone muscles and perfusable blood vessels. The approach involves blending modern approaches (3D printing) with more ancient ones (casting and lost-wax techniques). These anatomically accurate models can augment the approach to anatomy teaching from dissection to synthesis of 3D-printed parts held together with embedded rare earth magnets. Vascular simulation is possible through application of pumps and artificial blood. The resulting arteries and veins can be cannulated and imaged with Doppler ultrasound. In some respects, 3D-printed anatomy is superior to older teaching methods because the parts are cheap, scalable, they can cover the entire age span, they can be both dissected and reassembled and the data files can be printed anywhere in the world and mass produced. Anatomical diversity can be collated as a digital repository and reprinted rather than waiting for the rare variant to appear in the dissection room. It is predicted that 3D printing will revolutionize anatomy when poly-material printing is perfected in the early 21st century.

Loss of renal India ink artifact-a useful radiological sign for obstructive hydronephrosis in pregnancy

Magnetic resonance imaging is a useful tool for investigating causes of abdominal pain in pregnancy. Differentiating between physiologic hydronephrosis of pregnancy and pathologic hydronephrosis can be challenging for clinicians and radiologists. This report describes loss of the India ink artifact around the obstructed kidney as a novel and potentially useful radiological sign, which may be of value in the evaluation of abdominal pain and hydronephrosis in pregnancy.

Transvaginal oocyte retrieval complicated by life-threatening obturator artery haemorrhage and managed by a vessel-preserving technique

We report the case of a 36-year-old woman with secondary infertility who underwent routine transvaginal oocyte retrieval as part of IVF treatment. Four days following the procedure she presented with life threatening haemorrhagic shock. She underwent surgical laparotomy followed by CT and selective angiography, which demonstrated haemorrhage from a pseudoaneurysm of the obturator artery. The haemorrhage was successfully managed endovascularly with a vessel preserving covered stent.

Percutaneous antegrade ureteric stent removal using a rigid alligator forceps

To evaluate the safety and efficacy of percutaneous antegrade ureteric stent removal using a rigid alligator forceps. Twenty patients were included in our study. Indications for ureteric stent insertion included stone disease (n = 7), malignancy (n = 8) and transplant anastomotic strictures (n = 5). Stent retrieval was carried out for proximal stent placement/migration in seven patients and encrustation in the remaining 13. Twenty-two stents were successfully retrieved in 20 patients. There was one technical failure (5%). There were no major complications. We had four minor complications, which included nephrostomy site pain (n = 2), periprocedural sepsis (n = 1) and a small urinoma (n = 1). All patients settled with conservative management. Percutaneous radiologically guided antegrade ureteric stent removal with an alligator forceps is safe and effective, particularly when initial surgical removal has failed.

Ultrasound-guided removal of Implanon devices

Our study has shown that ultrasound-guided localisation and removal of Implanon rods is safe, practical and highly successful. Over a 4-year period, 119 patients had successful, uncomplicated removal of their subdermal devices.The technique is particularly useful for removal of the device when it is not palpable or when an attempt at removal of a palpable device has not been successful.

Imaging of adenomyomatosis of the gall bladder

Adenomyomatosis is a relatively common abnormality of the gall bladder, with a reported incidence of between 2.8 and 5%. Although mainly confined to the adult study group, a number of cases have been reported in the paediatric study group. It is characterized pathologically by excessive proliferation of the surface epithelium and hypertrophy of the muscularis propria of the gall bladder wall, with invagination of the mucosa into the thickened muscularis forming the so-called 'Rokitansky-Aschoff' sinuses. The condition is usually asymptomatic and is often diagnosed as an incidental finding on abdominal imaging. The radiological diagnosis is largely dependent on the visualization of the characteristic Rokitansky-Aschoff sinuses. As the condition is usually asymptomatic, the importance of making a correct diagnosis is to prevent misinterpretation of other gall bladder conditions such as gall bladder cancer, leading to incorrect treatment. In the past, oral cholecystography was the main imaging method used to make this diagnosis. In most institutions, oral cholecystography is no longer carried out, and the diagnosis is now more commonly seen on cross-sectional imaging. In this review article, we describe the manifestations of adenomyomatosis on the various imaging methods, with an emphasis on more modern techniques such as magnetic resonance cholangiopancreatography. A brief section on oral cholecystography to aid readers familiar with this technique in understanding the comparable imaging features on more modern imaging techniques is included.

Emergency embolization of multiple splenic artery pseudoaneurysms associated with portal hypertension complicating cystic fibrosis

Cystic fibrosis (CF) is the most common potentially lethal genetic disease in the white population. Improvements in life expectancy have led to an increasing recognition of hepatobiliary complications from CF. Splenic artery aneurysms are a rare complication of portal hypertension with a high mortality due to their significant potential for rupture, resulting in life-threatening i.p. haemorrhage. The optimum treatment of ruptured splenic artery aneurysms is controversial. This case describes the successful emergency embolization of multiple splenic artery pseudoaneurysms associated with portal hypertension complicating cystic fibrosis.

Vesicoureteric reflux in the adult

Vesicoureteric reflux (VUR) is a well-recognized entity in the paediatric population, but is not well described or understood in the adult population. This is partly explained by the fact that its incidence declines with advancing age. Its diagnosis is, however, still important, with VUR accounting for at least 10% of adult patients with end-stage renal disease. With early detection and careful management, the secondary complications of VUR such as renal failure can be prevented. Imaging plays a major role in the detection and evaluation of VUR in the adult patient. Conventional techniques such as micturating cystourethrograms have now been supplemented by cross-sectional imaging with CT and MRI. In this review article, we comprehensively review the up to date status of imaging the adult patient with VUR and discuss important subgroups of patients such as pregnant and transplant patients.

99mTc bone scintigraphy superscans: a review

Whole-body bone scintigraphy (bone scan) using a (99m)Tc-labelled pharmaceutical is one of the most commonly performed radionuclide examinations. In the normal patient, both the osseous components of the skeletal system as well as the kidneys and bladder are visualized. A superscan is defined as a bone scan which demonstrates markedly increased skeletal radioisotope uptake relative to soft tissues, in association with absent or faint genito-urinary tract activity. While a superscan is relatively uncommon, its recognition is important, as it is associated with a number of important underlying diseases. The purpose of this review article is to describe the causes and variable features of a superscan and depict patterns which may aid in defining the underlying cause for the scan. In addition, we will discuss other investigations that may help further to identify the underlying disease in such cases.

Does a full bladder aid upper tract visualization in magnetic resonance urography?

The aim of this study was to evaluate whether a full bladder improved the visualization of the upper renal tract during magnetic resonance urography (MRU). Twenty volunteers were recruited into the study. The MRU imaging was carried out on a 1.5-T MR system. Imaging was carried out in the coronal plane using a half-Fourier acquired single-shot turbo-spin-echo technique. All volunteers were examined in two separate MRU studies to visualize the urinary tract. The first study was carried out with a 'full' bladder followed by a study with an 'empty' bladder, leading to a total of 40 examinations. Two radiologists then reviewed maximum intensity projection images from both 'full' and 'empty' studies independently. Both left and right upper tracts were divided into five segments. A three-point grading system was used to evaluate visualization. Excellent visualization = 3, good visualization = 2 and poor visualization = 1. Maximum score per patient was 30. Results were tabulated and analysed using an Excel database. The average score for visualization for the 'full' bladder group was 22.1/30 (73.8%) and the average score for the empty bladder was 16.2/30 (54%). Overall improvement in visualization was 5.9/30 (19.8%). There was strong interobserver agreement, with a concordance value of 92.5%. The MRU carried out in healthy young adult volunteers with a full bladder allows improved visualization of the upper tracts.

Imaging and intervention of retroperitoneal fibrosis

Retroperitoneal fibrosis is a rare condition characterized by the development of fibrous plaques in the retroperitoneal space. The fibrous plaques characteristically arise distal to the bifurcation of the abdominal aorta and progress to encase the iliac vessels distally and are defined by the associated encasement of one or both ureters. Imaging plays an important role in not only establishing the diagnosis, but also in monitoring disease progression. Historically, the radiological diagnosis was made predominantly by intravenous urography and retrograde pyelography. More recently, advances in cross-sectional imaging with ultrasound and contrast-enhanced CT have allowed for a more precise diagnosis as well as helping to accurately define the extent of the disease. At our institution, we have found ultra-fast MRI to also play a useful role in establishing the diagnosis. In particular, magnetic resonance urography using HASTE (half Fourier-acquired single shot turbo spin-echo) sequences allow a safe alternative to intravenous urography, particularly in patients with poor renal function. The purpose of this article is to describe the role of the various imaging methods available to the radiologist and to emphasize the important role that the interventional radiologist now plays, not only in obtaining tissue for diagnosis, but also in providing treatment of the disease by percutaneous nephrostomy drainage and subsequent stent placement in select cases.

Gunther Tulip Retrievable Inferior Vena Caval Filters: Indications, Efficacy, Retrieval, and Complications

PURPOSE

We evaluated the Gunther Tulip (GT) retrievable inferior vena cava (IVC) filter with regard to indications, filtration efficacy, complications, retrieval window, and use of anticoagulation.

METHOD

A retrospective study was performed of 147 patients (64 men, 83 women; mean age 58.8 years) who underwent retrievable GT filter insertion between 2001 and 2005. The indications for placement included a diagnosis of pulmonary embolism or deep venous thrombosis with a contraindication to anticoagulation (n = 68), pulmonary embolism or deep venous thrombosis while on anticoagulation (n = 49), prophylactic filter placement for high-risk surgical patients with a past history of pulmonary embolism or deep venous thrombosis (n = 20), and a high risk of pulmonary embolism or deep venous thrombosis (n = 10). Forty-nine of the 147 patients did not receive anticoagulation (33.7%) while 96 of 147 patients did, 82 of these receiving warfarin (56.5%), 11 receiving low-molecular weight heparins (7.58%), and 3 receiving antiplatelet agents alone (2.06%).

RESULTS

Filter placement was successful in 147 patients (100%). Two patients had two filters inserted. Of the 147 patients, filter deployment was on a permanent basis in 102 and with an intention to retrieve in 45 patients. There were 36 (80%) successful retrievals and 9 (20%) failed retrievals. The mean time to retrieval was 33.6 days. The reasons for failed retrieval included filter struts tightly adherent to the IVC wall (5/9), extreme filter tilt (2/9), and extensive filter thrombus (2/9). Complications included pneumothorax (n = 4), failure of filter expansion (n = 1), and breakthrough pulmonary embolism (n = 1). No IVC thrombotic episodes were recorded.

DISCUSSION

The Gunther Tulip retrievable filter can be used as a permanent or a retrievable filter. It is safe and efficacious. GT filters can be safely retrieved at a mean time interval of 33.6 days. The newly developed Celect filter may extend the retrieval interval.

Recurrent pyogenic cholangitis due to chronic infestation with Clonorchis sinensis (2006: 8b)

Recurrent pyogenic cholangitis is a common disease in Southeast Asia, where an association with the liver fluke Clonorchis sinensis is postulated. It is characterised by repeated attacks of cholangitis with multiple recurrences of bile duct stones and strictures. We present a case of recurrent pyogenic cholangitis due to chronic infestation with Clonorchis sinensis in a young Asian immigrant, describing its radiological appearances and also therapeutic strategies with a review of additional examples from the literature.

Imaging of acute pyelonephritis in the adult

The diagnosis of acute pyelonephritis in adults is predominantly made by a combination of typical clinical features of flank pain, high temperature and dysuria combined with urinalysis findings of bacteruria and pyuria. Imaging is generally reserved for patients who have atypical presenting features or in those who fail to respond to conventional therapy. In addition, early imaging may be useful in diabetics or immunocompromised patients. In such patients, imaging may not only aid in making the diagnosis of acute pyelonephritis, but more importantly, it may help identify complications such as abscess formation. In this pictorial review, we discuss the role of modern imaging in acute pyelonephritis and its complications. We discuss the growing role of cross-sectional imaging with computed tomography (CT) and novel magnetic resonance imaging (MRI) techniques that may be used to demonstrate both typical as well as unusual manifestations of acute pyelonephritis and its complications. In addition, conditions such as emphysematous and fungal pyelonephritis are discussed.

Inguinal hernia repair protects testicular function: a prospective study of open and laparoscopic herniorraphy

BACKGROUND

Despite the frequency of open and laparoscopic herniorraphy the effect of the hernia and subsequent repair on testicular function is unknown. Our objective was to determine if there is an association between inguinal hernia and hernia repair on testicular function.

STUDY DESIGN

Thirty-seven men aged 18 to 70 years were enrolled in a prospective internally controlled cohort study. They underwent Doppler ultrasonography and serum testicular hormone analysis pre- and post- either open Lichtenstein's repair or laparoscopic totally extraperitoneal hernioplasty. These surrogates of testicular function were measured up to 6 months postrepair.

RESULTS

Thirty-seven consecutive patients underwent either Lichtenstein (n = 17) or totally extraperitoneal hernioplasty (n = 20) hernia repair as per surgeon preference. Preoperatively there was a significant elevation in the sonographic resistive index (RI) in the affected (hernia) side compared with the normal side (0.601, 0.569; p < 0.001). This elevation in RI was reversed posthernia repair at a median followup of 6.1 months. Inguinal hernia or repair did not affect testicular volume. The choice of either Lichtenstein or totally extraperitoneal hernioplasty hernia did not significantly alter the testicular function.

CONCLUSIONS

Patients with inguinal hernia have an elevated testicular vascular resistance, which is reversed after repair. The choice of laparoscopic or open herniorraphy did not affect reversal of this surrogate of testicular function.

CT-guided bone biopsy: Initial experience with a commercially available hand held Black and Decker drill

PURPOSE

To describe the use of a simple commercially available Black and Decker hand based drill in performing CT-guided bone biopsies.

MATERIALS AND METHODS

Three international institutions were enrolled in the study. In each centre, a fellowship trained musculoskeletal radiologist directed the assessment of a hand based commercial drill for performing CT-guided bone biopsies. A specially designed component was engineered which allowed the connection of a standard bone biopsy set to a commercial drill. The component was distributed to the three centres involved. Over a 3-year period, data from all three institutions was collected. Information regarding technical success, diagnostic data and complication rates were all collated to assess the technical feasibility of this technique.

RESULTS

In total 68 patients underwent bone biopsy using a hand held commercial drill. Technical success was achieved in 65 patients. Diagnostic material was obtained in 53 patients. Non-diagnostic material was obtained in 12 patients. Five out of the 12 patients with non-diagnostic material had repeat biopsies with diagnostic material obtained in 2 of these. No major complications occurred in any patient.

CONCLUSION

CT-guided bone biopsy using a hand held commercial drill has a technically high success rate with minimal complications.

Haemophilic pseudotumour presenting with large bowel obstruction

Osseous haemophilic pseudotumours are uncommon. The commonest sites of involvement are the femur and the pelvis. Trauma is the initiating factor in most reported cases and repeated bleeding into the lesion contributes to their growth. Most lesions grow slowly and are often asymptomatic. Complications include massive haemorrhage, infection and pathological fracture. We present an extremely unusual presentation where a large haemophilic pseudotumour of the pelvis extended to impinge the adjacent colon, resulting in large bowel obstruction.

The usefulness of CT guided drainage of abscesses caused by retained appendicoliths

OBJECTIVES

To determine the utility of percutaneous computed tomography (CT) guided drainage of abscesses formed secondary to retained appendicoliths.

MATERIALS AND METHODS

A retrospective review was conducted over a 5-year period to identify patients who underwent CT guided drainage of abscesses related to retained appendicoliths. Inclusion criteria were a history of prior proven appendicitis treated by laparoscopic appendicectomy, identification of a post-operative abscess related to a visualised retained appendicolith and initial treatment by CT guided drainage. Data regarding initial technical success as well as long-term outcome was recorded in each case.

RESULTS

In total, five patients were identified who underwent CT guided abscess drainage related to retained appendicoliths. There were three males and two females (age range 12-54 years). Initial drainage under CT guidance was technically successful in all cases with successful catheter placement and resolution of the abscess cavity. In all five cases however, there was recurrence of abscess formation following catheter removal. In one case, a second attempt with CT guided drainage was performed. Again this was initially successful with abscess recurrence following catheter removal. In all five cases, formal surgical drainage with removal of retained appendicolith resulted in a successful outcome.

CONCLUSION

CT guided percutaneous drainage of intra abdominal abscess secondary to retained appendicoliths is only successful in the short term. Formal surgical drainage and removal of the appendicolith is required for long-term success.

Valsalva and gravitational variability of the internal jugular vein and common femoral vein: Ultrasound assessment

PURPOSE

Central venous cannulation via the common femoral vein is an important starting point for many interventions. The purpose of this study was to determine the optimum conditions for cannulation of the femoral vein and to compare these with the relative changes in the internal jugular vein.

METHODS

High-resolution 2D ultrasound was utilised to determine variability of the calibre of the femoral and internal jugular veins in 10 healthy subjects. Venous diameter was assessed during the Valsalva manoeuvre and in different degrees of the Trendelenburg position.

RESULTS

The Valsalva manoeuvre significantly increased the size of the femoral and internal jugular veins. There was a relatively greater increase in femoral vein diameter when compared with the internal jugular vein of 40 and 29%, respectively. Changes in body inclination (Trendelenburg position) did not significantly alter the luminal diameter of the femoral vein. However, it significantly increased internal jugular vein diameter.

CONCLUSIONS

Femoral vein cannulation is augmented by the Valsalva manoeuvre but not significantly altered by the gravitational position of the subject.

Pictorial review: magnetic resonance imaging of colonic diverticulitis

Magnetic resonance imaging (MRI) is rapidly emerging as a useful imaging modality for the evaluation of the gastrointestinal tract. Increasingly rapid sequences and improving hardware have significantly improved the visualisation of diseases of the colon. MRI has a major advantage over CT in that there is no ionising radiation. In our institution, MRI has increasingly been used as a complimentary imaging modality to CT in the diagnosis and evaluation of diverticulitis and its complications. In this review article, we illustrate the emerging role of MRI in the diagnosis and evaluation of colonic diverticulitis.

Giant oesophageal fibrovascular polyp (2005:12b)

The authors report a case of a giant fibrovascular polyp of the oesophagus in which CT with multiplanar reformatting gave valuable information as to both location of the lesion as well as size and anatomical attachment proximally, which was pivotal in directing surgery. It was instructive in this case that initial endoscopy was reported to be normal. The lesion was well demonstrated by barium swallow.