Hampus Eklöf

Limited Tumor Involvement Found at Multiple Endocrine Neoplasia Type I Pancreatic Exploration: Can It Be Predicted by Preoperative Tumor Localization?

Abstract. Radiologically demonstrable pancreatic endocrine tumors are a frequent requirement for exploration in patients with multiple endocrine neoplasia type I (MEN-I). Such delayed intervention is accompanied by a 30% to 50% incidence of pancreatic endocrine metastases. This study explores biochemical tumor markers and operative findings in relation to preoperative pancreatic radiology in 25 MEN-I patients. They underwent pancreatic surgery with (n= 19) or without (n= 6) radiologic signs of primary tumor and absence of metastases upon conventional examination, including OctreoScan testing (n= 10). Biochemical diagnosis required an increasing elevation of at least two independent pancreatic tumor markers. Tumor diameters averaged 1.1 cm (0–5 cm) and 0.9 cm (0.2–1.5 cm) in the patients with and without positive preoperative radiology, respectively. These investigations never displayed more than one of the consistently multiple tumors, and the results were falsely positive in 26%. Preoperatively unidentified regional or hepatic metastases were found at surgical exploration in 26% of patients with radiologic localization and in none of the others. Limited pancreatic tumor involvement necessitated intraoperative absence of metastases and pancreatic lesions ≤ 1 cm in diameter on palpation, intraoperative ultrasonography, and microscopy. It occurred in 37% and 50% of the patients with and without radiologic tumor localization, respectively. The number of positive tumor markers was similar for patients with limited and major disease (2.3 vs. 2.7), whereas four or more such markers were found in all those with malignancies. The mean marker level was higher in patients with radiologically demonstrable tumors and lower in those with limited disease, but with a substantial overlap. OctreoScan testing was negative in all cases with limited disease and was the single most sensitive method (75%) in the others. Limited pancreatic disease could not be identified preoperatively, and the present means of biochemical pancreatic tumor identification invariably involved the presence of at least one lesion ≥ 7 mm in diameter. Conventional pancreatic imaging is insensitive and nonspecific for recognizing even substantial pancreatic tumors associated with MEN-I.

Renal Effects of CO2 and Iodinated Contrast Media in Patients Undergoing Renovascular Intervention: A Prospective, Randomized Study

PURPOSE CO2 gas has been proposed for use instead of iodinated contrast media in angiographic examinations in patients at risk of developing renal failure from contrast media. The influence of intraarterial injection of CO2 with small added amounts of ioxaglate (200 mgI/mL) or ioxaglate alone on renal function in patients with suspected renal artery stenosis was studied in a prospective, randomized study. MATERIALS AND METHODS One hundred twenty-three patients underwent renovascular intervention (n = 83) and/or renal angiography (n = 40) for suspected renal artery stenosis. Patients with a serum creatinine concentration less than 200 micromol/L (n = 82) were randomized prospectively to receive CO2 with small added amounts of ioxaglate (n = 37) or only ioxaglate (n = 45). Patients with serum creatinine levels greater than 200 micromol/L (n = 41) were not randomized and initially received CO2. Serum creatinine concentrations were measured within 1 day before and 1 day, 2 days, and 2-3 weeks after the procedure. RESULTS The amount of injected CO2 did not relate to an increase in serum creatinine level. In the randomized groups, and also when the whole patient sample was considered, the amount of injected iodine was significantly correlated (P = .011) with an increase in serum creatinine level and a decrease in estimated creatinine clearance after 2 days. Among the randomized patients, one in the CO2 group and three in the ioxaglate group had a more than 25% increase in serum creatinine level within the first 2 days after the intervention. CONCLUSION The risk of impairment of renal function is lower after injection of CO2 with small amounts of added ioxaglate compared with injection of a larger amount of ioxaglate alone. The larger the amount of administered iodinated contrast medium, the greater the risk of development of renal failure.

Split Renal Function in Patients with Suspected Renal Artery Stenosis: a Comparison between Gamma Camera Renography and Two Methods of Measurement with Computed Tomography

Purpose: To validate a method for calculating split renal function from computed tomography (CT) compared with gamma camera renography, and to test a new method for the measurement based on a volume-rendering technique. Material and Methods: Thirty-eight patients, aged 65.7±11.6 (range 37.8–82.1) years, who had undergone both CT angiography and gamma camera renography for a suspected renal artery stenosis were included in this study. Split renal function was calculated from the CT examinations by measuring area and mean attenuation in the image slices of the kidneys, and also by measuring volume and mean attenuation from a 3D reconstruction of the kidneys. Gamma camera renography with 99mTc-MAG3 with or without captopril enhancement was used as a reference. Results: The 2D CT method had good correlation with renography (r = 0.93). Mean difference was 4.7±3.6 (0–12) percentage points per kidney. There was also excellent correlation between the two CT methods (r = 1.00). Conclusion: CT is equivalent to renography in determining split renal function, and the measurement from the CT examination can be made more quickly and equally accurately with a 3D technique.

2D inflow MR angiography in severe chronic leg ischemia

Purpose: the aim of this study was to compare 2D inflow MR angiography (MRA) with selective X-ray angiography (XRA) in patients with severe chronic leg ischemia. Material and Methods: In a blinded prospective study, 2D inflow MRA and XRA were compared with regard to evaluation of the arteries distal to the knee in 24 patients (median age 72 years) with severe ischemia; 23 of them had either rest pain or tissue loss. Statistics were calculated with XRA as the reference method. Results: the interpretations of 2D inflow MRA and XRA showed moderate agreement in the calf arteries but poor agreement in the foot arteries. of the discrepancies, two-thirds were observer-related and only one-third method-related. of all the comparable arteries, 9% showed method-related differences between the two methods. An assessment of MRA using only maximum intensity projections (MIP) resulted in 19% of findings being judged inconclusive whereas all the arteries could be classified when the cross-sectional images were studied on the viewing console. Conclusion: the agreement between MRA and XRA was good in the calf but questionable in the foot.

Whole body computed tomography for trauma patients in the Nordic countries 2014 : survey shows significant differences and a need for common guidelines

Background Whole body computed tomography in trauma (WBCTT) is a standardized CT examination of trauma patients. It has a relatively high radiation dose. Therefore, well-defined clinical indications and imaging protocols are needed. This information regarding Nordic countries is limited. Purpose To identify Nordic countries’ WBCTT imaging protocols, radiation dose, and integration in trauma care, and to inquire about the need for common Nordic guidelines. Material and Methods A survey with 23 multiple choice questions or free text responses was sent to 95 hospitals and 10 trauma centers in and outside the Nordic region, respectively. The questions were defined and the hospitals selected in collaboration with board members of “Nordic Forum for Trauma and Emergency Radiology” (www.nordictraumarad.com). Results Two Nordic hospitals declined to take part in the survey. Out of the remaining 93 Nordic hospitals, 56 completed the questionnaire. Arterial visualization is routine in major trauma centers but only in 50% of the Nordic hospitals. The CT scanner is located within 50 m of the emergency department in all non-Nordic trauma centers but only in 60% of Nordic hospitals. Radiation dose for WBCTT is in the range of 900–3600 mGy × cm. Of the 56 responding Nordic hospitals, 84% have official guidelines for WBCTT. Eighty-nine percent of the responders state there is a need for common guidelines. Conclusion Scanning protocols, radiation doses, and routines differ significantly between hospitals and trauma centers. Guideline for WBCTT is presently defined locally in most Nordic hospitals. There is an interest in most Nordic hospitals to endorse new and common guidelines for WBCTT.

Teleradiology Uppsala–Sydney for Nighttime Emergencies: Preliminary Experience

Background: The development of digital imaging systems for radiology in combination with the possibility to transfer large quantities of data over the Internet has increased the interest in teleradiology. Transferring nighttime examinations to an evaluation center in a daytime zone may provide improved patient security, better working hours for radiologists, and reduced costs for emergency radiological services. Purpose: To evaluate the time required for transferring radiological information from Uppsala (Sweden) to Sydney (Australia). Material and Methods: A radiologist in Sydney reported on radiological examinations performed in Uppsala. The time required for downloading 75 examinations and returning 24 reports was registered. Results: Downloading was completed in <60 min for all conventional radiological examinations, but only 44% of computed tomography (CT) examinations with >65 images. Reports were completed in <10 min. Turnaround time was directly related to the time required for downloading the images. The Sydney report was available in Uppsala within 30 min of the in-house report in 79% of examinations. Conclusion: The main challenge for emergency teleradiology is the time required for downloading large volumes of data over the Internet.

Duplex ultrasound for identifying renal artery stenosis: direct criteria re-evaluated.

Background Renal artery duplex ultrasound (RADUS) is an established method for diagnosis of renal artery stenosis (RAS), but there is no consensus regarding optimal RADUS criteria. Purpose To define optimal cutoff values for RADUS parameters when screening for RAS using intra-arterial trans-stenotic pressure gradient measurement (PGM) as reference. Material and Methods The renal arteries of 58 consecutive patients evaluated for renovascular hypertension were examined by RADUS and PGM. Conclusive measurements with both methods were obtained in 76 arteries. Hemodynamically significant RAS was defined as PGM ≥15 mmHg and was found in 43 of the 76 arteries. RADUS parameters included renal artery peak systolic velocity (PSV) and the renal–aortic ratio (RAR) of flow velocities. Receiver operating characteristic curves (ROCs) and Youden’s index were used to calculate optimal RADUS criteria for RAS. Results When traditional RADUS criteria for RAS were used, with a combination of PSV ≥180 cm/s and RAR ≥3.5, the sensitivity was 62% and the specificity was 91%. When RADUS criteria were optimized for sensitivity, then RAR ≥2.6 alone resulted in a sensitivity of 89% and a specificity of 69%. Conclusion The RAR ≥2.6 is a more sensitive criterion than traditional RADUS criteria when screening patients with clinical suspicion of RAS.