A comparison of MR elastography and 31P MR spectroscopy with histological staging of liver fibrosis.

OBJECTIVES: Conventional imaging techniques are insensitive to liver fibrosis. This study assesses the diagnostic accuracy of MR elastography (MRE) stiffness values and the ratio of phosphomonoesters (PME)/phosphodiesters (PDE) measured using (31)P spectroscopy against histological fibrosis staging. METHODS: The local research ethics committee approved this prospective, blinded study. A total of 77 consecutive patients (55 male, aged 49 ± 11.5 years) with a clinical suspicion of liver fibrosis underwent an MR examination with a liver biopsy later the same day. Patients underwent MRE and (31)P spectroscopy on a 1.5 T whole body system. The liver biopsies were staged using an Ishak score for chronic hepatitis or a modified NAS fibrosis score for fatty liver disease. RESULTS: MRE increased with and was positively associated with fibrosis stage (Spearman's rank = 0.622, P < 0.001). PME/PDE was not associated with fibrosis stage (Spearman's rank = -0.041, p = 0.741). Area under receiver operating curves for MRE stiffness values were high (range 0.75-0.97). The diagnostic utility of PME/PDE was no better than chance (range 0.44-0.58). CONCLUSIONS: MRE-estimated liver stiffness increases with fibrosis stage and is able to dichotomise fibrosis stage groupings. We did not find a relationship between (31)P MR spectroscopy and fibrosis stage. KEY POINTS: Magnetic resonance elastography (MRE) and MR spectroscopy can both assess the liver. MRE is superior to ( 31 ) P MR spectroscopy in staging hepatic fibrosis. MRE is able to dichotomise liver fibrosis stage groupings. Gradient-echo MRE may be problematic in genetic haemochromatosis.

The forgotten appearance of metastatic melanoma in the small bowel.

BACKGROUND: Melanoma is the most aggressive form of skin cancer, with a tendency to metastasise to any organ of the human body. While the most common body organs affected include liver, lungs, brain and soft tissues, spread to the gastrointestinal tract is not uncommon. In the bowel, it can present with a multitude of imaging appearances, more rarely as an aneurysmal dilatation. This appearance is classically associated with lymphoma, but it has more rarely been associated with other forms of malignancy. CASE PRESENTATION: We report a case series of three patients with aneurysmal dilatation in the small bowel (SB) confirmed to be due to metastatic melanoma (MM). All patients had non-specific symptoms; most times being attributed initially to causes other than melanoma. On CT the identified aneurysmal SB dilatations were diagnosed as presumed lymphoma in all cases. In two cases, the aneurysmal dilatation was the first presentation of metastatic disease and in two of the cases more than one site of the gastrointestinal tract was concomitantly involved. All patients underwent surgical resection with histological confirmation of MM. CONCLUSIONS: Recognition of unusual SB presentation of MM, such as aneurysmal SB dilatation, is important to expedite diagnosis, provide appropriate treatment, and consequently improve quality of life and likely survival of these patients. As the most common cancer to metastasise to the SB and as a known imaging mimicker, MM should remain in any radiologist's differential diagnosis for SB lesions with aneurysmal dilatation.

The different faces of metastatic melanoma in the gastrointestinal tract.

Melanoma is the most aggressive form of skin cancer, with tendency to spread to any organ of the human body, including the gastrointestinal tract (GIT). The diagnosis of metastases to the GIT can be difficult, as they may be clinically silent for somewhile and may occur years after the initial melanoma diagnosis. CT imaging remains the standard modality for staging and surveillance of melanoma patients, and in most cases, it will be the first imaging modality to identify GIT lesions. However, interpretation of CT studies in patients with melanoma can be challenging as lesions may be subtle and random in distribution, as well as sometimes mimicking other conditions. Even so, early diagnosis of GIT metastases is critical to avoid emergency hospitalisations, whilst surgical intervention can be curative in some cases. In this review, we illustrate the various imaging presentations of melanoma metastases within the GIT, discuss the clinical aspects and offer advice on investigation and management. We offer tips intended to aid radiologists in their diagnostic skills and interpretation of melanoma imaging scans.

Radiology provision in the United kingdom: an overview.

The UK National Health Service (NHS) came into being in 1948, offering health care for all, free at the point of access. Over the past 6 decades, the NHS has grown to become the world's largest publicly funded health service. The authors present an overview of the NHS, from its conception to the present day, with a particular emphasis on how the changing environment of the NHS has affected the provision of radiologic services. The authors review the current landscape of the NHS with regard to radiology provision, from training and research to funding and the private sector, and touch on the likely future of the service.

Pancreatic transplantation: surgical technique, normal radiological appearances and complications.

Pancreas transplantation is a surgical treatment for diabetes mellitus. More than 23,000 pancreas transplants have now been reported to the International Transplant Registry (IPTR). Early diagnosis and therapy for graft-related complications are essential for graft survival. Radiologists must therefore understand the surgical procedure and the potential complications. During the course of this review, we will illustrate the normal post-operative anatomy and the imaging appearances of common potential complications.

The use of computed tomography in the detection and characterisation of large bowel obstruction.

Computed tomography (CT) has become the imaging modality of choice for the investigation of patients with clinico-radiological suspicion of obstruction. Appropriate CT technique is discussed, with recommendations on how to improve diagnostic confidence and to reduce radiation dose. The performance of CT in the investigation of LBO is compared to that of the plain abdominal radiograph and contrast enema. CT is unrivalled in its ability to detect and characterise the cause of large bowel obstruction (LBO), identify complications, and guide appropriate treatment.

Survival of patients with ALS following institution of enteral feeding is related to pre-procedure oximetry: a retrospective review of 98 patients in a single centre.

A retrospective review was carried out on the influence of pre-procedure respiratory assessment on survival of patients with amyotrophic lateral sclerosis (ALS) requiring nutritional support with either a gastrostomy or a nasogastric feeding tube. Over a five-year period 98 patients (49 male, 49 female; median age 61 years, range 26-86 years) with ALS were referred for enteral feeding with either radiological inserted gastrostomy (RIG), percutaneous endoscopic gastrostomy (PEG) or nasogastric tube (NG). Case notes review was performed to record patient age, sex, pre-procedure respiratory assessment, method of enteral feeding and survival post-procedure. Kaplan-Meier survival curves were constructed for each group, with Cox regression analyses performed in order to establish the effect of each variable on outcome. Median survival (with 95% confidence intervals) following RIG, PEG and NG was 6.31 months (4.58-8.04 months), 7.13 months (4.81-9.45 months) and 0.95 months (0.00-2.77 months), respectively. The survival advantage between RIG and PEG was not statistically significant (p = 0.50), but for NG versus RIG and PEG groups combined, there was a significant difference (p = 0.03). For patients with normal overnight oximetry, median survival was 8.54 months (3.88-13.21 months), compared to 4.80 months (1.20-8.39 months) in the abnormal oximetry group (p = 0.03; relative risk 1.97). It is concluded that RIG and PEG are equivalent in terms of post-procedure survival. Abnormal oximetry prior to the procedure is a significant indicator of post-procedure survival.

Comparison of two percutaneous radiological gastrostomy tubes in the nutritional management of ALS patients.

Patient care and minimizing complications post gastrostomy have to date received little attention in ALS patients. We compare the complications associated with pigtail and mushroom type percutaneous radiological gastrostomy tubes in this patient group. Patients requiring PRG received either Wills-Oglesby or the skin level Entristar. Retrospective review of the clinical notes was performed capturing demographic data, peristomal infection, tube displacement, tube failure, nutritional status, site of disease onset, and survival. Thirty-five patients (Group 1) had the Wills-Oglesby tube of which 14 (40%) tubes required replacement. The Entristar tube was inserted in 29 patients (Group 2) where 8 (28%) required replacement (NS). The incidence of infection was significantly lower with the Entristar tube, (p<0.001). The mean time to tube removal in Group 2 was 223 days (SD 147; range 71-494 days) due to 'buried bumper syndrome'. We conclude that the Entristar skin level gastrostomy tube is associated with a reduction in peristomal infection, tube failure and blockage compared with the Wills-Oglesby tube.

Entristar skin-level gastrostomy tube: primary placement with radiologic guidance in patients with amyotrophic lateral sclerosis.

PURPOSE: To retrospectively review the authors' experience with a radiologic method of primary insertion of a skin-level gastrostomy tube (Entristar; Tyco Healthcare, Mansfield, Mass) in patients with amyotrophic lateral sclerosis (ALS). MATERIALS AND METHODS: Over a 12-month period (September 2002 through September 2003), 25 patients with ALS (mean age, 62.4 years; age range, 41-83 years; 15 men, 10 women) who had bulbar impairment and a body mass index of less than 20 kg/m(2) or weight loss of greater than 10% were selected for placement of an enteral feeding tube. Patients with overnight oxygen desaturation or respiratory acidosis were referred for placement of the Entristar tube with radiologic guidance. This procedure was performed with local anesthesia and without sedation by using a modified percutaneous lateral fluoroscopic technique that aided tube insertion in patients with elevation of the hemidiaphragm and a "high" stomach position. Technical success and immediate and delayed procedure complications were recorded. RESULTS: The Entristar tube was successfully inserted in all 25 patients. Pneumoperitoneum as an early complication was documented in one patient, and one patient developed a pelvic abscess that required drainage. Follow-up for a median of 112 days (range, 14-343 days) revealed superficial wound infections in four patients and weight gain in two patients; weight gain necessitated tube replacement in one patient. There were no procedure-related deaths. CONCLUSION: Radiologically guided insertion of the Entristar skin-level gastrostomy tube is a safe procedure in patients with ALS that allows the creation of a permanent feeding gastrostomy without the need for sedation or endoscopy.

Microbubble ultrasound contrast in the assessment of hepatic artery patency following liver transplantation: role in reducing frequency of hepatic artery arteriography.

We prospectively evaluated the role of microbubble ultrasound contrast for detection of hepatic artery thrombosis following liver transplantation. The hepatic artery of adult liver transplant recipients with suspected thrombosis on surveillance Doppler ultrasound (US) were re-examined by a second observer. In patients with no hepatic spectral Doppler signal the microbubble contrast agent Levovist was used. The presence or absence of flow following microbubble contrast was evaluated against arteriography or repeated Doppler US findings. A total of 794 surveillance Doppler US examinations were performed in 231 patients. Hepatic artery flow was demonstrated in 759 of 794 (95.6%) examinations. Microbubble ultrasound contrast was administered in 31 patients (35 studies) with suspected hepatic artery thrombosis. Following microbubble US contrast the hepatic artery could not be demonstrated in 13 of 35 (37.1%) studies (12 patients). Eight patients had arteriography: there was hepatic artery thrombosis in 7 patients and 1 patient had a patent, highly attenuated artery. Detection of a patent hepatic artery increased from 759 of 794 (95.6%) to 781 of 794 (98.4%) with the addition of microbubble contrast. Upon independent reading of the data, the degree of operator confidence in the assessment of the hepatic artery patency prior to microbubble contrast was 4.7 (CI 1.92-7.5) but rose to 8.45 (CI 7.06-9.84) following microbubble contrast ( p<0.0001). In 22 of 35 (62.9%) of studies arteriography could potentially have been avoided. Ultrasound microbubble contrast media may reduce the need for invasive arteriography in the assessment of suspected hepatic artery thrombosis.