Postoperative omental infarction following colonic resection.

AIM: To illustrate the computed tomography (CT) appearances and natural history of postoperative omental infarction following colonic resection and to highlight the important clinical implications of this radiological diagnosis. MATERIALS AND METHODS: Over a 3 year period, 15 patients with a history of colonic resection were identified as having a CT diagnosis of postoperative omental infarction. Relevant clinical and pathological data were retrospectively collected from the institution's electronic patient records system and all relevant imaging was reviewed, including serial CT images in 10 patients. RESULTS: A diagnosis of postoperative omental infarction was made in symptomatic and asymptomatic patients who had undergone open or laparoscopic colonic resection for benign or malignant disease. CT appearances ranged from diffuse omental stranding to discrete masses, which typically appeared within weeks of surgery and could persist for years. In four (36%) of the patients with colorectal cancer, the CT appearances raised concern for recurrent malignancy, but percutaneous biopsy and/or serial CT allowed a confident diagnosis of omental infarction to be made. Although most cases were self-limiting, three (20%) cases were complicated by secondary infection and required radiological or surgical intervention. CONCLUSION: Postoperative omental infarction is an under-recognized complication of colonic resection. It has the potential to mimic recurrent malignancy and may require radiological or surgical intervention for secondary infection.

Provisional reporting of polytrauma CT by on-call radiology registrars. Is it safe?

AIM: To assess the accuracy of provisional reporting and the impact on patient management. MATERIALS AND METHODS: Over a 6 month period, 137 polytrauma computed tomography (CT) examinations were performed by on-call registrar radiologists at our institution. After exclusions, 130 cases were analysed. Discrepancies between registrar and consultant reports were reviewed and classified as either major or minor dependent on potential impact on patient safety. The relationship between seniority of reporting registrar and likelihood of a missed finding was analysed using the Chi-square test. RESULTS: Of the 130 patients, 46 (35%) had a serious injury, 36 (28%) a minor injury, and 48 (38%) no identifiable injury on CT. There were 32 (25%) patients with discrepancies of which 24 (18%) had missed or significantly under-reported findings and eight (6%) overcalled findings. There were six misses classified as major; the remaining 18 were classified as minor. No association was found between the seniority of reporting registrar and the likelihood of a miss (p=0.96). CONCLUSION: The incidence of major discrepancies between the provisional and final report was low and did not lead to any significant clinical deterioration. Our study provides a reference of the commonly missed injuries. We conclude that registrar provisional reporting of polytrauma is safe; however, note that a large proportion of examinations are normal and that further work is required to produce robust criteria given the radiation risk to a young population group scanned in trauma.

Composite abdominosacral resection for recurrent rectal cancer.

BACKGROUND: En bloc resection of the tumour and adjacent involved organs offers the only realistic curative option for patients with locally recurrent rectal cancer. This study assessed outcomes of composite resection for recurrent tumours involving the sacrum. METHODS: A consecutive series of patients underwent composite abdominosacral resection (abdominal mobilization and stoma construction followed by sacral division and tumour retrieval) for recurrent rectal cancer between 2001 and 2007. Patients were staged with preoperative computed tomography, magnetic resonance imaging and positron emission tomography. Data were collected prospectively. RESULTS: Forty patients (28 men; median age 59 (range 31-77) years) underwent surgery with sacral division at the S2/3 interface in 13, S3/4 level in 20 and S4/5 level in seven patients. One patient died and 24 had complications. An R0 resection was achieved in 20 patients and conferred benefit in disease-free interval over an R1 resection. The mean disease-free interval was 55.6 (95 per cent confidence interval (c.i.) 40.0 to 71.3) months for R0 and 32.2 (95 per cent c.i. 19.7 to 44.7) months for R1 resection (P = 0.048). CONCLUSION: Composite abdominosacral resection of locally recurrent rectal cancer is an effective treatment for a difficult clinical scenario.

Relation of Soil Water Movement and Sulfide Concentration to Spartina alterniflora Production in a Georgia Salt Marsh.

It is proposed that differences in plant height and productivity of the salt-marsh cordgrass Spartina alterniflora are the result of a dynamic interaction among tidal water movement, dissolved iron and sulfide concentrations in marsh soils, and bacterial sulfate reduction. Tidal water movement regulates the input of iron into marsh soils and the drainage of sulfide-containing interstitial water, and thereby controls the concentration of dissolved sulfide formed as a result of bacterial sulfate reduction. Near tidal creeks, where water movement and plant height and production are greatest, sulfide concentrations are lowest; in more elevated regions of marsh, where water movement andplant production are least, sulfide concentrations are highest. Plant height and productivity may be limited by the effects of sulfide on nutrient uptake.

Algorithms for the surgical management of retrorectal tumours.

BACKGROUND: Retrorectal tumours are uncommon and may present a surgical challenge. The aim of this study was to identify a surgical strategy based on information gained from the multidisciplinary management of retrorectal tumours. METHODS: This was a retrospective review of 27 patients who had resection of retrorectal tumours between 1998 and 2006. RESULTS: The tumours included ten cystic lesions, two mature teratomas, four chordomas, seven neurogenic tumours, two sarcomas, one angiomyxoma and one gastrointestinal stromal tumour. The diagnosis was suggested initially by non-specific clinical presentation and palpation of a retrorectal mass on examination (16 patients), pelvic imaging (six), obstructed labour (one), recurrent pilonidal sinus (one), recurrent perianal sepsis (one) and return of symptoms after resection (two). Magnetic resonance imaging (MRI) confirmed the diagnosis and enabled surgical planning. The operative approach was perineal (12 patients), abdominal (11) or combined (four). Factors that influenced the operative approach were tumour position, its neoplastic nature, involvement of the pelvic sidewall or pelvic viscera, and size. The retrorectal tumour recurred in three patients. CONCLUSION: A successful multidisciplinary surgical strategy, based on preoperative localization by MRI, has been developed for the treatment of retrorectal tumours.

An unusual case of ureteric obstruction.

We report a case of a 33-year-old female presenting with right sided abdominal pain, a right iliac fossa mass and right hydronephrosis. The mass was subsequently shown to represent an isolated desmoid tumour compromising the adjacent ureter. The patient had no predisposing factors for this pathology. This is an uncommon occurrence and we discuss the imaging features and differential diagnosis.

The role of imaging in acute pancreatitis.

The roles of ultrasound, computed tomography and magnetic resonance in the evaluation and management of acute pancreatitis are discussed with emphasis on the advantages and disadvantages of each. The importance of imaging in the diagnosis of pancreatic necrosis, acute fluid collections, pancreatic abscess, pseudocysts and vascular complications is reviewed. The use of interventional techniques as opposed to surgical intervention is discussed.

Case report: the demonstration of aortocaval fistulae by helical computed tomography.

We report the helical computed tomography findings in two patients with spontaneous aortocaval fistula (ACF) complicating abdominal aortic aneurysm. The use of overlapping slices produced high quality multiplanar reformats which provided anatomical information about the likely site of the ACF and also the relationship of the renal arteries to the neck of the aneurysm.

Imaging appearances of ileouterine fistula complicating recurrent adenocarcinoma of the rectum.

Enterouterine fistulae are rare and nowadays are most commonly due to pelvic tumours. We review the literature and present the case of a woman who presented with an ileouterine fistula following surgery and radiotherapy for recurrent rectal adenocarcinoma. The presence of tumour within the fistula track may also have been a significant aetiological factor. Magnetic resonance imaging (MRI) is an excellent method to demonstrate the site and size of the track and has not, to date, been used to identify such a fistula.

Renal metastases from a squamous cell carcinoma of the larynx.

Laryngeal squamous cell carcinoma (SCC) tends to exhibit local spread with a low incidence of distal metastases. The majority of distal metastases are to the lungs and renal involvement is extremely rare. We present a case of laryngeal SCC with metastatic spread to the left kidney presenting as a large, mainly cystic mass. The radiological differentiation of renal metastases from primary renal tumours is discussed.

Rapid dynamic contrast-enhanced magnetic resonance imaging of the liver and portal vein.

The purpose of this study was firstly to show the diagnostic value of a rapid acquisition multislice sequence (TurboFLASH) during bolus injection of gadolinium-DTPA by comparing it with the pulse sequences currently used for abdominal studies and secondly to develop improved scanning protocols for the liver. Patients were referred for upper abdominal studies including portal vein assessment. 40 patients were imaged in the coronal plane using a multislice TurboFLASH (TF) sequence (TR = 100; TE = 4) acquired during a breath-hold period of 19 s. The short echo time allows up to 11 slices of 5 mm thickness to be acquired simultaneously. Images were obtained before, during and after bolus administration of Gd-DTPA. The slices from each acquisition were combined using a maximum intensity projection algorithm to include all the vessels on a single image. Initially each patient was scanned using a conventional axial T2 weighted spin-echo sequence (T2W-SE) (TR2000; TE = 45/90) and a coronal T1 weighted spin-echo sequence (TR450; TE = 15). The clarity of the demonstration of vascular anatomy was compared and scored for all sequences by two radiologists. Vessel patency, the conspicuity of mass lesions and the spread of tumour to adjacent structures were also scored. The anatomy of the main portal vein was significantly better shown by coronal TF images after bolus injection than on T2W-SE images or TF before Gd-DTPA. The right and left portal veins were equally well shown by coronal TF with Gd-DTPA and T2W-SE images. There was no significant difference between contrast enhanced TF and T2W-SE imaging in visualization of the hepatic veins. More lesions were demonstrated by post-contrast TF than by T2W-SE imaging. Portal venous occlusion was better appreciated by post-contrast TF. Our results demonstrate that Gd-DTPA TF imaging improves visualization of the main portal vein compared with SE sequences and provides a more accurate assessment of vessel patency. The segmental anatomy of the liver is better appreciated and the demonstration of focal liver lesions compared with T2W-SE images is improved during the non-equilibrium phase of enhancement. TF acquisitions before and after Gd-DTPA are obtained in approximately 5 min; thus a marked reduction in examination time can be achieved.

Dynamic contrast enhanced computed tomography: a precise technique for identifying and localising pancreatic necrosis.

OBJECTIVE: To evaluate dynamic contrast enhanced computed tomography for detecting and localising pancreatic necrosis in acute pancreatitis. DESIGN: Prospective evaluation with blind reporting of scans. SETTING: Single teaching hospital. PATIENTS: 60 Consecutive patients with acute pancreatitis suspected to have pancreatic necrosis because of major organ system failure (13); slow recovery five to seven days after admission with raised scores on the acute physiological and chronic health evaluation (APACHE-II) system (27); or findings on previous ultrasonography or computed tomography (20). MAIN OUTCOME MEASURE: Pancreatic necrosis proved histologically--that is, greater than 30 g necrotic tissue debrided at laparotomy (for life threatening sepsis or peritonitis) or necropsy. RESULTS: Dynamic computed tomography correctly localised pancreatic necrosis in 11 patients (confirmed at laparotomy in nine and at necropsy in two). Of nine patients with low enhancement of peripancreatic tissues alone, eight recovered after conservative management; necropsy confirmed viable pancreas and necrosis of peripancreatic fat in one patient. Of 40 patients with normal contrast enhancement, none required laparotomy to debride pancreatic necrosis. CONCLUSION: Dynamic contrast enhanced computed tomography seems to be a safe and accurate method of identifying and localising pancreatic and peripancreatic necrosis, which cannot be predicted accurately by conventional imaging techniques.

Pre-operative MR assessment of recurrent rectal cancer.

The potential for curative resection of recurrent rectal cancer and the recognized benefits of palliative resection have led to increased numbers of patients being referred for MRI assessment. This study assesses the use of MRI to provide a roadmap of tumour recurrence to allow for appropriate surgical planning. Differentiation of recurrent rectal cancer from post-surgical and post-radiotherapy changes on MR proved particularly problematic when assessing the pelvic sidewalls. Areas of uncertainty on imaging, therefore, need to be discussed on a case by case basis regarding the decision to proceed to curative or explorative surgery.

MRI assessment of the bony pelvis may help predict resectability of rectal cancer.

OBJECTIVE: The outcome after surgical treatment of rectal cancer may be influenced by the technical difficulty of the operation, which is thought to be affected by pelvic size. The aim of this study was to examine the association between bony pelvic dimensions and CRM involvement. PATIENTS AND METHODS: All patients with primary rectal cancer between December 1999 and January 2002 were studied. Staging was performed by pelvic MRI. Nine pelvic dimensions were measured from the MR images on a workstation. Pathology reports were obtained for all patients and the mesorectal specimen was examined. Technical difficulty was assessed by circumferential resection margin (CRM) involvement. RESULTS: Of 126 patients with primary rectal cancer, 88 had staging MRI and rectal excision; there were significant differences between the sexes in all 9 pelvic dimensions (P < 0.05). In females, the interspinous diameter was significantly shorter in patients with CRM involvement compared with patients with a negative CRM. In female patients predicted to have a negative CRM, the anteroposterior diameter of the inlet, the anteroposterior diameter of the midplane and the transverse diameter of the midplane (interspinous distance) were significantly shorter in patients who actually had a positive CRM compared with those in whom the CRM was negative. In male patients, there was no correlation between pelvic dimensions and CRM status. CONCLUSIONS: In certain patients with rectal cancer, CRM positivity may be predicted from pre-operative MRI pelvic measurements. This may influence the choice of adjuvant therapy.

Chest radiography for general practitioners--a low yield investigation.

Of 1,163 chest rediographs requested by general practitioners, 67.5 per cent were normal, 21 per cent revealed an apparently relevant lesion, and 11.5 per cent an apparently irrelevant abnormality. The number of referrals for chest radiography should be reduced to cut costs in an expensive specialty.