Diseases that simulate acute appendicitis on ultrasound.
Ripolles T. Martinez-Perez MJ. Morote V. Solaz J.
Department of Radiology, Dr Peset Hospital, Valencia, Spain.
Ultrasound is useful in the assessment of patients with possible appendicitis. A diagnosis of appendicitis can be made in patients with persistent right lower quadrant pain when a non-compressible appendix greater than 6 mm in diameter is shown. When a normal appendix is affected by an adjacent lesion, reactive inflammation can cause secondary enlargement of the appendix. This article reviews ultrasound findings in conditions which can clinically mimic acute appendicitis. Examples of Crohn's disease, tuboovarian abscess, typhilitis, sigmoid diverticulitis, perforated sigmoid neoplasm, perforated peptic ulcer, perforated acute cholecystitis, caecal carcinoma and appendiceal tumours are included.
Estimation of effective dose in some digital angiographic and interventional procedures.
Ruiz Cruces R. Garcia-Granados J. Diaz Romero FJ. Hernandez Armas J.
Radiology and Medical Physics Department, School of Medicine, University of Malaga, Spain.
In general, effective dose values for similar interventional vascular radiology (IVR) procedures are different. This is due to problems with the classification of radiological procedures, which make comparisons difficult. Patient size, examination technique and clinical condition as well as the skill of the medical radiologists also affect effective dose. Currently, there is a broad agreement on the classification of similar procedures so that effective dose estimates can be made from measurements of the dose area product (DAP). Thus, reference dose values may be established and comparative studies between different services and hospitals can be made. The objective of this study is to provide dose data for some digital angiographic and interventional procedures. Values of measured DAP for 143 patients for five types of procedures are presented. Procedures investigated were abdominal angiography, arteriography of lower limbs, biliary drainage, embolization of spermatic vein and nephrostomy. All the procedures were performed using digital equipment. Values of DAP and effective dose were 30 Gy cm2 and 6.2 mSv for arteriography of lower limbs and 150 Gy cm2 and 38.2 mSv for biliary drainage. In each one of these procedures, effective dose values per minute of fluoroscopy and per radiography film have been calculated. It is possible to use this information for the rapid estimation of effective dose.
Dual phase spiral CT in the detection of small insulinomas of the pancreas.
King AD. Ko GT. Yeung VT. Chow CC. Griffith J. Cockram CS.
Department of Diagnostic Radiology and Organ Imaging, Faculty of Medicine, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong.
Dual phase contrast enhanced spiral computed tomography (DPSCT) has the potential to improve detection of small insulin secreting islet cell tumours of the pancreas. Seven patients with biochemically proven insulinoma, who had previously undergone a range of negative radiological procedures, were referred for DPSCT. Images of the pancreas were obtained using 3 mm collimation in the arterial and arteriovenous perfusion phase following the rapid injection of contrast medium. Six tumours were localized in seven patients. The six insulinomas identified on DPSCT ranged in size from 6 mm to 18 mm and were located in the uncinate process (2), head (1), neck (2) and body (1). All six tumours were detected in the arterial phase and four in the arteriovenous phase. The four insulinomas detected on both perfusion phases were more conspicuous in the arterial phase in three patients and more conspicuous in the arteriovenous phase in one patient. In conclusion, high resolution arterial phase acquisition of the pancreas is very valuable in the detection of small insulinomas.
Hydatid cysts of the liver: two cautionary signs.
Lewall DB. Nyak P.
Department of Medical Imaging, King Fahad National Guard Hospital, Riyadh, Kingdom of Saudi Arabia.
The purpose of this paper is to evaluate the significance of two CT findings: evidence of an exophytic component of part of a hydatid cyst and dilated ducts in the vicinity of a cyst. The CT scans and clinical records of 63 patients were reviewed. There was evidence that cysts with an exophytic component are probably unstable and unsuitable for treatment by percutaneous drainage or prolonged medical treatment. Dilated pericystic ducts are a relative contraindication to nonsurgical treatment because of the danger of complicating biliary obstruction. Surgery should not be delayed unduly when either sign is encountered.
Three-dimensional spiral CT angiography in pancreatic surgical planning using non-tailored protocols: comparison with conventional angiography.
Blomley MJ. Albrecht T. Williamson RC. Allison DJ.
Department of Imaging, Hammersmith Hospital, London, UK.
The aim of this study was to investigate three-dimensional spiral computed tomography (3DCT) as an adjunct to routine pancreatic CT scanning, with particular regard to the identification of surgically important hepatic arterial anomalies, correlated with conventional visceral angiography. 32 patients underwent spiral CT scans prior to pancreatic surgery using established protocols. Oral contrast medium was used throughout. 150 ml of intravenous contrast medium was given at 3 ml s-1 with a 24 s spiral CT sequence starting 35 s after the start of infusion. Two protocols were employed, both with a pitch of 1:3 mm table feed/collimation (n = 17) and 5 mm table feed/collimation (n = 15). Overlapping (1 mm minimum) axial reformats were reconstructed. 3DCT shaded-surface displays of the visceral arteries were assessed for visceral arterial anomalies. Visceral angiography (n = 23) was independently correlated. Satisfactory 3D angiograms were performed in all but one patient, in whom the coeliac axis was missed. (i) 3 mm protocol: 3DCT (n = 17) showed three anomalous right hepatic arteries (ARHA), one trifurcation anomaly and one splenic artery with an aortic origin. Angiography (n = 11) confirmed these findings, although one patient with an ARHA did not have angiography. A left gastric arterial supply to the left liver was not detected. (ii) 5 mm protocol: 3DCT (n = 15) showed two cases of ARHA. While confirming these findings, angiography (n = 12) showed a third case of ARHA, in which the coeliac and superior mesenteric artery had very close origins. A left gastric supply to the left liver was also missed. It is concluded that satisfactory 3DCT is possible without changing existing scanning protocols, although narrow sections are required for the confident assessment of right hepatic arterial anomalies, and any left hepatic supply via the left gastric artery was poorly assessed in this series.
In vivo assessment of neovascularization of liver metastases using perfusion CT.
Miles KA. Leggett DA. Kelley BB. Hayball MP. Sinnatamby R. Bunce I.
Centre for Functional Imaging, Wesley Research Institute, Auchenflower, Brisbane, Australia.
Neovascularization of tumours produces a high microvessel density. Although diagnostic imaging is unable to visualize microvessels directly, it is possible to demonstrate associated changes in tissue perfusion. The aim of this study was to use the quantitative functional information and high spatial resolution of perfusion computed tomography to study neovascularization of hepatic metastases. Perfusion CT was performed in 13 patients with hepatic metastases from various primary tumours. Arterial perfusion was measured in the metastasis; both arterial and portal perfusion were measured in a small rim of liver tissue immediately adjacent to the metastasis. Perfusion measurements were correlated against survival of the patient in nine cases. Arterial perfusion was increased above normal values, both in the metastasis (median: 0.62 ml min-1 ml-1; range: 0.26-3.05 ml min-1 ml-1) and in the adjacent liver (median: 0.51 ml min-1 ml-1; range: 0.14-1.60 ml min-1 ml-1). Portal perfusion of adjacent liver was highly variable (median: 0.30 ml min-1 ml-1; range: 0.05-1.85 ml min-1 ml-1). Arterial perfusion was positively correlated with portal perfusion within liver tissue adjacent to metastases (p < 0.05, r = 0.58), a reversal of the normal situation. Survival of the patient correlated with arterial perfusion within the metastasis (p < 0.05, r = 0.69) but more closely with arterial perfusion in the adjacent liver (p < 0.02, r = 0.78). In conclusion, alterations in perfusion within metastases and adjacent liver are in accordance with the histological features of neovascularization. Perfusion CT offers a method for studying neovascularization in the living patient and offers prognostic information.
An unusual form of pneumatosis intestinalis associated with appendicitis.
Parra JA. Acinas O. Bueno J. Madrazo C. Farinas C.
Department of Radiology, Hospital Sierrallana, Cantabria, Spain.
A rare case of pneumatosis intestinalis is described in a patient with appendicitis. Gas in the colonic wall, epiploic appendices and mesentery caused a new appearance not previously reported on plain radiography or CT. The relevance of an associated redundant right colon is also discussed.
Magnetic resonance imaging of fistula-in-ano: STIR or SPIR?
Halligan S. Healy JC. Bartram CI.
Intestinal Imaging Centre, St Mark's Hospital, Harrow, UK.
Patients with clinically suspected anorectal sepsis were studied using MRI in order to determine if T2 weighted sequences with fat suppression conveyed any additional benefit over conventional short tau inversion recovery (STIR) sequences. 23 consecutive patients (16 male) undergoing MRI for suspected perianal sepsis were studied prospectively using a 1.0 T whole body system and body coil. Axial and coronal T1 weighted turbo spin echo sequences were obtained, followed by STIR and T2 weighted spectral fat saturation inversion recovery (SPIR) sequences. Images were assessed for the presence of sepsis or fistula, and information provided by the sequences compared. Active disease was diagnosed in 17 patients, 14 of whom had fistula-in-ano; one intersphincteric, 10 transsphincteric and three extrasphincteric. Internal openings were identified in all of these 14 patients; anal in 10, rectal in two, and both in two. Diagnosis and fistula classification was possible in all of these 14 subjects on the basis of STIR sequences alone. The anal sphincters and pelvic floor musculature were better resolved by STIR than SPIR, leading to easier and more confident determination of fistula anatomy in eight of the 14 (57%). In no case did STIR sequences fail to resolve inflammation seen subsequently on SPIR, despite reduced track intensity. T1 weighted sequences were generally non-contributory. Both STIR and SPIR sequences are adequate to classify fistula-in-ano, but classification was easier with STIR due to superior resolution of pelvic floor structures.
Pancreatic cancer as a second tumour following treatment of Hodgkins disease.
Lambert C. Benk V. Freeman CR.
Department of Oncology, McGill University, Montreal, Quebec, Canada.
Over the past 30 years, the life expectancy in patients with Hodgkin's disease has greatly improved. However, adverse long-term side-effects are now well recognized and development of second malignancies is one of the most important. We report the case of a patient who developed pancreatic cancer 9 years after treatment, with chemotherapy and radiation, for Hodgkin's disease. The increasing number and variety of solid tumours after curative treatment of Hodgkin's disease points to a need for new, less toxic regimens.