Utility of positron emission tomography/CT in the evaluation of small bowel pathology.

We describe the management principles and different roles of positron emission tomography (PET)/CT in the evaluation of patients with small bowel tumours (adenocarcinoma, gastrointestinal stromal tumour, lymphoma, metastases) from initial staging, monitoring response to treatment, to detection of recurrent disease. We also discuss the various non-malignant aetiologies of small bowel fludeoxyglucose (FDG) PET uptake, and other pitfalls in FDG PET/CT interpretation. Awareness of the imaging appearances of small bowel tumours, patterns of disease spread and potential PET/CT interpretation pitfalls are of paramount importance to optimise diagnostic accuracy.

18-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Management of Aggressive Non-Hodgkin's B-Cell Lymphoma.

18-Fluorodeoxyglucose (FDG-PET/CT) is an established imaging modality that has been proven to be of benefit in the management of aggressive B-cell non-Hodgkin's lymphoma, such as diffuse large B-cell lymphoma and advanced stage follicular lymphoma. The combination of anatomic and functional imaging afforded by FDG-PET/CT has led to superior sensitivity and specificity in the primary staging, restaging, and assessment of response to treatment of hematological malignancies when compared to FDG-PET and CT alone. The use of FDG-PET/CT for posttreatment surveillance imaging remains controversial, and further study is needed to ascertain whether this modality is cost effective and appropriate for use in this setting.

Abundant macroscopic fat in intra-abdominal lymph nodes involved in the course of a patient with chronic lymphocytic leukaemia: presentation of imaging findings with biopsy correlation.

The presence of a small amount of macroscopic fat is not unusual in the hilar region of normal lymph nodes. However, abundant replacement of the lymph node with fat is highly unusual and may appear as metastatic lymph node disease in the course of fat-predominant liposarcomas or in the case of coeliac disease complicated by cavitating lymph node syndrome. In this case report, a patient with chronic lymphocytic leukaemia/small lymphocytic lymphoma who demonstrated an increasing abundance of macroscopic fat in the diseased lymph nodes is presented. To the best of our knowledge, the imaging findings of abundant fat in lymph nodes in the course of lymphoma have not been reported before. The presence of macroscopic fat may be seen in the presence of actively involved lymph nodes in the presence of chronic lymphocytic leukaemia.

Radiological evaluation of adrenal incidentalomas: current methods and future prospects.

Incidental adrenal lesions are very common. Computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) all have a role to play in characterizing adrenal lesions. The purpose of this review is to discuss the rationale behind both established and emerging imaging techniques. We also discuss how to follow up incidentally found lesions.

Laparoscopic scar: a mimicker of Sister Mary Joseph's nodule on positron emission tomography/CT.

Positron emission tomography/CT is an established imaging method in the diagnosis and staging of cancers. (18)F-fluoro-2-deoxy-d-glucose (FDG) is the most commonly used radiotracer in positron emission tomography/CT. It is a tumour viability agent and usually its uptake within a lesion reflects the presence of a viable tumour tissue. However, false-positive FDG uptake is known to occur in benign processes of either inflammatory or infectious aetiology. We describe FDG uptake at the site of laparoscopic scar that mimicked Sister Mary Joseph's nodule in a patient with gastric adenocarcinoma. Here, the knowledge of the patient's history and subtle imaging findings helped in accurate staging of the patient. In this case report, we emphasize the value of the knowledge of the patient history and awareness of different pitfalls of FDG to achieve a correct diagnosis on positron emission tomography/CT.

Halo sign: useful CT sign for differentiating benign from malignant colonic disease.

AIM: To evaluate the halo sign for accurately distinguishing benign from malignant colonic wall thickening. MATERIALS AND METHODS: Computed tomography (CT) examinations of 92 patients (70 men; 22 women; mean age 57 years) with pathologically proven colonic wall thickening (51 benign and 41 malignant) were retrospectively reviewed in a blinded fashion. The affected segment was assessed for presence of the halo sign, degree and uniformity of thickness and density of the intramural stratum. RESULTS: The halo sign was present in 74.5% (38/51) patients with benign and 7.3% (3/41) patients with malignant bowel disease. The presence of the halo sign was 75.4% sensitive and 92.5% specific for benign bowel wall thickening. All 38 benign halos showed uniform, continuous stratification; only one of three malignant halos met the strict criteria for benign halo. CONCLUSION: The halo sign is a moderately sensitive and highly specific sign for distinguishing benign from malignant bowel wall thickening. However, it is not pathognomonic for benign disease. Detailed analysis of halo characteristics is necessary to improve the usefulness of this finding.

Infectious waste surveys in a Saudi Arabian hospital: an important quality improvement tool.

OBJECTIVES: To analyze the composition by weight of the infectious waste stream, better segregate waste, reduce disposal costs, reduce the load on the hospital incinerator, identify inappropriate items having significant cost or safety implications, and provide a safer work environment for housekeepers. METHODS: Four infectious waste surveys were conducted between 1991 and 1999 that involved opening a total of 7364 bags of infectious waste. The contents of each infectious waste bag were separated into 20 different components and weighed. Inappropriately discarded items were removed and tagged with the date and hospital unit of origin. SETTING: Dhahran Health Center, a 410-bed hospital operated by the Saudi Arabian Oil Company (Saudi Aramco) in Dhahran, Saudi Arabia. RESULTS: The surveys show a continuing trend in a higher percentage of plastics and a decrease in paper due to increased use of disposables. Much of the infectious waste consisted of plastic intravenous bottles, intravenous lines, and paper wrappers for sterile instrument sets that were not infectious. Dhahran Health Center was producing a total of 1163 kg of infectious waste per day before the first survey. This was reduced to 407 kg per day after implementation of a waste segregation program in 1991 (a reduction of 65%). Incineration operation was reduced from daily to 3 days per week, with a corresponding reduction in incinerator emissions. Infectious waste from inpatient, surgical, and obstetric areas was reduced by a total of 70% between 1991 and 1999, from 2.8 kg (6.1 lb) to 0.85 kg (1.9 lb) per patient per day. This is in the range of 2 to 4 lb per patient per day that is generally reported. Numerous inappropriately discarded items were discovered during the surveys with cost or safety implications. Each survey, including the latest one of November-December 1999, has shown that further improvements are possible in the hospital's waste management program. Specific educational efforts and changes in procedures are described. CONCLUSIONS: We believe this is the first report of such an extensive analysis of a hospital's infectious waste. Many hospitals do not have the resources to conduct such detailed surveys of their waste streams. However, regardless of the method of treatment and disposal, such surveys are valuable quality improvement tools because all health care facilities want to reduce disposal costs, identify high-value items mistakenly discarded, and improve safety.

Virtual colonoscopy and colorectal cancer screening.

Colorectal cancer (CRC) is the leading cause of cancer related death in the United States. Virtual colonoscopy is a new method for imaging the colon and has produced promising early results for polyp and cancer detection. The challenge remains to reproduce these favorable results in clinical practice and to evaluate the use of virtual colonoscopy in a purely screening population. Virtual colonoscopy may dramatically improve population participation in screening programs and play a major role in minimizing the impact of CRC.

Embolotherapy for massive upper gastrointestinal haemorrhage secondary to metastatic renal cell carcinoma: report of three cases.

Three cases are reported in which angiographic embolisation therapy was effective in arresting upper gastrointestinal bleeding secondary to metastatic hypernephroma. Each patient had histologically confirmed disseminated renal cell carcinoma and presented with recurrent haematemeses with a successful outcome following palliative embolisation therapy.

Indications for surgical intervention for gastrointestinal emergencies in children receiving chemotherapy.

BACKGROUND: Abdominal pain in children receiving chemotherapy for cancer presents the clinician with unique problems due to the altered immunity of these patients or to the oncologic setting. The major clinical decisions regarding these patients are to determine if and when operative intervention is indicated. METHODS: A retrospective study was done to examine the clinical, radiographic, and laboratory findings that indicate the need for surgical intervention. Sixty-eight of 1090 children who underwent treatment for cancer from October 1982 to December 1990 developed abdominal complaints requiring them to be hospitalized. Nineteen of these patients underwent exploratory laparotomy (operative), and the other 49 were observed (nonoperative). RESULTS: No significant differences were observed in the phase of chemotherapy, treatment with vincristine or corticosteroids, or the hematologic indices between the operative and nonoperative groups. Eighteen of nineteen patients survived their surgeries. Seventeen (89%) of these laparotomies were positive based on the surgical pathology and the operative report. Peritoneal signs on physical examination (P < 0.001) or pneumatosis intestinalis on abdominal radiographs correlated with positive laparotomies (P = 0.001). CONCLUSIONS: Peritoneal signs on physical examination or pneumatosis intestinalis on abdominal X-rays were associated with and specific for the presence of acute surgical disease of the abdomen in immunocompromised pediatric oncology patients.

Intermittent combination chemotherapy with or without bacillus Calmette-Guérin for treatment of acute lymphoblastic leukemia of childhood.

Seventy-four children ranging in age from 6 months to 17.5 years with acute lymphoblastic leukemia newly diagnosed between 1976 and 1979 were entered on a study incorporating intermittent chemotherapy with or without the addition of bacillus Calmette-Guérin (BCG). The chemotherapy program consisted of induction with vincristine, dexamethasone, and intrathecal methotrexate, intensification with adriamycin and asparaginase, central nervous system treatment with cranial irradiation and intrathecal methotrexate, and continuation treatment with 5-day courses of combination chemotherapy administered every three weeks. The first phase of continuation therapy incorporated vincristine, adriamycin, 6-mercaptopurine, and dexamethasone. In the second phase, oral methotrexate was substituted for the adriamycin in non-T-cell patients; in T-cell patients, cytosine arabinoside or cyclophosphamide and methotrexate in alternating cycles were substituted for the adriamycin and asparaginase was added. Total duration of therapy was approximately 2.5 years. Connaught BCG was administered by Heaf gun on days 8 and 15 of each 3-week cycle for the first 8 months of treatment in approximately one-third of the patients. Actuarial disease-free survival with a median follow-up of 59 months shows no difference in outcome between the BCG and non-BCG poor-risk patients. However, there is an improvement in disease-free survival of BCG-treated good- and average-risk girls (P = 0.04). While patients were actively receiving BCG there was also a trend toward the development of fewer significant infections than when patients were not receiving BCG (P = 0.85). Toxicities from BCG administration included satellite rashes, local tenderness, lymphadenopathy, secondary infection, and residual scars. Overall disease-free survival by actuarial analysis is 60% at 6 years; for patients with unfavorable prognostic features it is 40%. In this trial the addition of BCG prolonged the disease-free survival of girls with good- and average-risk prognostic features and also may have decreased the susceptibility to infection while it was being administered. However, the benefit does not appear sufficient to warrant its routine use, especially in view of the toxicities encountered.