AIM:

To determine the frequency, time course and sites of recurrence following surgical resection of gastrointestinal stromal tumours (GIST) and to evaluate the performance of a risk-based surveillance protocol in detection of recurrence.

METHODS:

Eighty-one patients on surveillance following complete resection of GIST were included. Patients were stratified into risk groups according to accepted histopathological criteria. Computed tomography (CT) examinations were retrospectively reviewed to determine rates, sites and imaging characteristics of recurrence and to assess compliance with the local follow-up protocol.

RESULTS:

The median time of follow-up was 41 months. Nineteen patients suffered recurrence, all of whom were in the high-risk group. Fifty-eight percent of relapses occurred within 1 year and 84% within 3 years. Even within the high-risk group, patients with relapse had significantly larger (mean 15 versus 10.4 cm, p < 0.05) and more mitotically active primary tumours (mean 33.7 versus 5.6 mitoses per 50 high-power fields; p < 0.05) than those with no relapse. Relapse was to the liver in 12 cases (63%) and to the omentum and mesentery in nine cases (47%), and was asymptomatic in three-quarters of patients.

CONCLUSIONS:

The high incidence of GIST recurrence in the high-risk group in the first 3 years after surgery supports the use of intensive imaging surveillance in this period. Relapse is often asymptomatic and commonly occurs to the liver, omentum and mesentery. Stratification by tumour factors may enable improved tailoring of surveillance protocols within the high-risk group in the future.

AIM:

To elucidate the natural history of dot-like or "black spot" cavernomas.

MATERIALS AND METHODS:

Data of 18 children with black spot cavernomas were analysed retrospectively.

RESULTS:

Eleven boys and seven girls presented 187 black spot cavernomas during a mean observation period of 5.5 years. Mean and median age at diagnosis of the 187 cavernomas was 9.6 years. There were 70 de novo black spot cavernomas. Boys presented significantly more cavernomas than girls. There were three KRIT1 mutation carriers and four PDCD10 mutation carriers. Children with a PDCD10 mutation presented significantly more lesions than those children with a KRIT1 mutation (mean number of lesions per patient: 23.3 versus 3.3, respectively). There were 10 radiological haemorrhagic events caused by 10 black spot lesions. Two of these events were symptomatic. The haemorrhage rate of black spot cavernomas was 0.7% per lesion-year.

CONCLUSIONS:

A mean bleeding rate of 0.7% per lesion-year is lower than the overall haemorrhage rates provided in the literature. Nonetheless, black spot cavernomas are not purely benign lesions. Furthermore, genetic mutations may play a role in the natural history of black spot cavernomas.

A variety of benign conditions can affect the oesophagus, both primarily and secondarily. Traditionally fluoroscopic oesophagography and endoscopy have formed the mainstay for investigating oesophageal diseases. Increasing use of cross-sectional imaging means that many such diseases and their thoracic complications are now detected at computed tomography (CT), which is very often the first imaging tool. This review describes the CT manifestations of a range of benign oesophageal conditions and discusses the role of CT in their evaluation.

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.

AIM:

To evaluate ascites enhancement during abdominal oncological endovascular intervention (IVR) without iatrogenic extravasation and the factors associated with enhancement of ascites.

METHODS AND MATERIALS:

CT images were obtained using an IVR-CT system for 73 patients with chronic liver disease and ascites. The CT images were obtained at least twice during each IVR. Radiodensity values of ascites at CT were measured for the first and last CT images in each procedure. The factors evaluated for their association with elevated ascitic fluid density were age, interval from the first to the last CT scan, Child-Pugh score, albumin level, total bilirubin level, prothrombin activity, the need for transcatheter arterial chemoembolization (TACE), estimated glomerular filtration rate, total amount of contrast material (CM) per square metre of body surface area (/m(2)), amount of ascitic fluid, and the amount of CM entering the superior mesenteric artery (SMA) or coeliac artery/m(2).

RESULTS:

The average ascitic radiodensity values for the first and last CT images were 18 and 51 HU, respectively. The percentage of patients with "significantly elevated" ascitic fluid density (≥10 HU) was 92%. Multivariate analysis showed that the total amount of CM/m(2) and the amount of ascitic fluid were significantly correlated and inversely correlated, respectively, with elevated ascitic fluid density.

CONCLUSIONS:

Ascites enhancement without extravasation frequently occurs during abdominal oncological endovascular intervention in patients with chronic liver disease.

This article will review the uncommon locations and morphological features of meningiomas, which are important to recognize in order to avoid misdiagnosis. Uncommon locations will be demonstrated at the cerebellopontine angle, pineal, optic, intraventricular, and intradiploic regions. Unusual imaging features including cysts, metaplastic changes, and peritumoural oedema will also be discussed.

AIM:

To assess diffusion changes in the remote white matter and areas of white matter with cerebral artery obstruction without magnetic resonance imaging (MRI) evidence of brain parenchymal abnormalities using high b-value diffusion tensor imaging (DTI).

MATERIALS AND METHODS:

A total of 34 patients with severe unilateral stenosis (≥75%) or occlusion of the middle cerebral artery (MCA) without abnormal brain parenchymal signals at MRI underwent DTI with a b value of 2200 s/mm(2) at 3 T. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), axial diffusivity (eigenvalue λ1) and radial diffusivity (eigenvalue λ23) were measured at the bilateral corona radiata, anterior and posterior limbs of the internal capsule, cerebral peduncle, and pons.

RESULTS:

The mean FA was significantly lower at the ipsilateral corona radiata and anterior and posterior limbs of the internal capsule than at the contralateral corona radiata and anterior and posterior limbs of the internal capsule (p < 0.05). The mean ADC, λ1 and λ23 were significantly higher at the ipsilateral corona radiata than at the contralateral corona radiata (p < 0.01). The mean λ23 were significantly higher at the ipsilateral anterior and posterior limb of the internal capsule than at the contralateral anterior and posterior limb of the internal capsule (p < 0.05). The mean ADC, λ1 and λ2 3were not significantly different between the ipsilateral cerebral peduncle and pons.

CONCLUSIONS:

High b-value DTI could sensitively reveal diffusion changes in white matter in regions of cerebral artery obstruction without abnormal anisotropy and diffusivity of the remote white matter of patients with severe MCA stenosis or occlusion without MRI evidence of brain parenchymal abnormalities.

AIM:

To evaluate the clinical impact and cost-effectiveness of a multidisciplinary team (MDT) meeting in a large hospital in the UK.

MATERIALS AND METHODS:

A management plan for colorectal cancer patients was recorded by the supervising surgical consultant prior to the MDT meeting using the available clinical information and the available reports for imaging and histopathology. The recorded outcomes were then compared with the outcomes documented at the subsequent MDT meeting. The cost of the MDT meeting was calculated based on the salaries of individuals involved plus relevant overheads. A range of opportunity costs were considered, the most significant of which was the expenditure required to re-provide direct clinical care displaced by the MDT.

RESULTS:

Over a 3 month period a sample of 47 random cases were reviewed from the colorectal MDT. In three patients, there were significant differences between the preliminary consultant decision and the MDT recommendation: in one case management was changed based on further information about patient co-morbidity and performance status. In only one case was there a material alteration to a CT report, which altered management. The annual costs of running this colorectal local MDT alone were estimated at £162,734+ per annum with opportunity costs of at least twice that.

CONCLUSION:

The costs of MDT meetings are very high producing a small clinical impact. At a time of increasing financial and capacity pressure in healthcare systems, the use of scarce resources may be better deployed elsewhere.

Implant rupture is a common late complication of breast implant procedures. Ruptures are often silent and difficult to diagnose clinically. This review demonstrates normal appearances and sonographic signs of implant rupture. Breast sonologists should be aware of these signs and pitfalls in interpretation when imaging breast implants.

AIM:

To describe the sequential appearance of healing rib fractures on initial and follow-up radiographs using published guidelines in approximating the age of rib fractures in infants with the aim of establishing a more objective method of dating rib fractures by measuring the thickness of the callous formation.

MATERIALS AND METHODS:

This was a retrospective analysis of initial and follow-up digital skeletal surveys of infants less than 12 months of age performed between January 2008 and January 2012 at the University of California Davis Children's Hospital. Six radiological features of rib fractures evaluating the appearance of the callous formation (C stage) and fracture line (F stage) were assessed. Patients with osteogenesis imperfecta, known vitamin D deficiency, and skeletal or metabolic dysplasia were not included in the study. Thereafter, callous thickness was measured and recorded for each stage.

RESULTS:

Sixteen infants (age range 1-11 months, seven males and nine females) with 23 rib fractures were analysed. The thickness of the callous formation follows a predictable pattern advancing one stage after a 2-week follow-up with progressive callous thickening starting from stage 2, peaks at around stage 4, and then tapers and remodels until it almost disappears when the fracture is healed at stage 6.

CONCLUSION:

It appears that rib fractures in infants follow a predictable pattern of healing. Measuring the thickness of the callous formation is a more objective way of guiding the radiologist in estimating the age of the fracture.