L. Kivisaari

MAGNETIC RESONANCE IMAGING OF CLINICALLY LOCALIZED PROSTATIC CANCER

PURPOSE We assess the accuracy of endorectal coil magnetic resonance imaging (MRI) for detecting tumor localization, capsular penetration and seminal vesicle invasion in clinically organ confined prostate cancer. We also evaluate intra-observer and interobserver agreement in interpreting MRI studies. MATERIALS AND METHODS MRI studies of 51 consecutive patients a mean of 61 years old with biopsy proved prostate cancer were retrospectively read twice by 2 radiologists in random order. Both radiologists marked tumor localization, capsular penetration and seminal vesicle invasion on standard tumor maps. These findings were compared with the histopathological results of radical prostatectomy specimens. RESULTS The overall accuracy of detecting cancer localization was 61%. The detection rate for cancer foci less than 5 mm. was only 5% but for lesions greater than 10 mm. it was 89%. There was 91 and 80% accuracy for detecting capsular penetration and seminal vesicle invasion, respectively. Sensitivity and specificity were 60 and 63, 13 and 97, and 59 and 84% for localization, capsular penetration and seminal vesicle invasion, respectively. Intra-observer and interobserver agreement ranged from fair to good (kappa coefficient 0.240 to 0.647). CONCLUSIONS Endorectal MRI seems to be better than previously reported for detecting seminal vesicle invasion and tumor foci in the anterior half of the prostate. Sensitivity in detecting minor capsular penetration of the tumor was low, which can probably be improved by methodological development. MRI may be useful for locating cancer foci in patients with high prostate specific antigen values but repeatedly negative biopsy findings.

Computed tomography screening for lung cancer in asbestos-exposed workers

We conducted a computed tomography (CT) screening for lung cancer in a high-risk population. Six hundred and two workers (38-81 years, 97% smokers) with asbestos-related occupational disease were screened using spiral CT and chest radiography. The national cancer registry was checked for possible false negative cases. The screening detected 111 patients with non-calcified nodules >0.5 cm in diameter and 66 of them were referred for further hospital examination. We found five lung cancers (106 false positive cases) with a histological spectrum similar to the national, natural occurrence of the disease (two adeno, one squamous cell, one anaplastic and one metastatic carcinoma) and one peritoneal mesothelioma. Three cases were potentially operable (stage I-II). Unfortunately there was one false negative fine-needle aspiration biopsy (FNAB) with misinterpretation of the follow-up CT scan and another patient who refused further investigations after an inadequate FNAB. In the end only one patient with adenocarcinoma underwent surgery. After 3 years of follow-up two new lung cancers were reported to the cancer registry with no evidence of tumour in the retrospective analysis of the screening CT scan. The sensitivity of CT screening was 100%. CT was capable of detecting early lung cancer in asbestos-exposed patients with a lot of confusing pulmonary and pleural pathology. Due to the high number of positive findings attention should be paid to patient compliance and the follow-up protocols and patient selection in future screening programmes.

Computerized Tomography and Transrectal Ultrasound in the Assessment of Local Extension of Prostatic Cancer Before Radical Retropubic Prostatectomy

The value of computerized tomography and transrectal ultrasound in the demonstration of local extension of prostatic cancer was evaluated in 38 patients undergoing radical retropubic prostatectomy. Transrectal ultrasound proved to be reliable for the demonstration of local extension of cancer beyond the prostatic capsule (sensitivity 86 per cent, specificity 94 per cent and accuracy 90 per cent). Invasion of the seminal vesicles was demonstrated by ultrasound, with a sensitivity of 29 per cent, specificity 100 per cent and accuracy 77 per cent. The addition of transrectal ultrasound scanning to clinical evaluation increased sensitivity in relation to detection of extraprostatic involvement from 15 to 92 per cent. When computerized tomography scanning was added to clinical examination, the sensitivity increased from 15 to only 46 per cent. Transrectal ultrasound is valuable for the preoperative evaluation of patients in whom radical prostatectomy is being considered as treatment for clinically localized prostatic cancer.

Early Detection of Acute Fulminant Pancreatitis by Contrast-Enhanced Computed Tomography

Twenty-eight consecutive patients with a first attack of acute alcohol-induced pancreatitis were examined by computed tomography (CT). After a survey scan of the abdomen a rapid contrast bolus (400 mg I/kg) was given intravenously, and the contrast enhancement of the pancreatic parenchyma was measured from a consecutive series of pancreatic scans. Nine patients with a fulminant course of the disease were operated on, and haemorrhagic necrotizing pancreatitis was found in eight. In all of these the contrast enhancement was decreased or absent. Patients recovering by conservative treatment showed normal or increased enhancement. The contrast enhancement seems to constitute a useful criterion for the early differentiation of acute fulminant pancreatitis from less severe forms of the disease.

Prostatic MR imaging: Accuracy in differentiating cancer from other prostatic disorders

Purpose: We assessed the accuracy of MR imaging in differentiating between cancer and other prostatic disorders, and evaluated the diagnostic criteria for various prostatic diseases. Material and Methods: A total of 74 endorectal coil MR studies were performed on 72 patients. Twenty patients had prostatic cancer, 20 benign prostatic hyperplasia (BPH), 4 acute bacterial prostatitis, 5 chronic bacterial prostatitis (2 also belonging to the previous category), 19 chronic non-bacterial prostatitis/chronic pelvic pain syndrome, and 6 were symptomless voluntary controls. All studies were interpreted by two experienced radiologists in random order. Radiologists were blinded to all clinical data including the age of the patients. Based on MR findings, both radiologists filled in a form covering diagnostic criteria and diagnosis. Results: Accuracy in diagnosing prostate cancer was 74%. Sensitivity was 50% and specificity 83%, and positive and negative predictive values were 53 and 82%, respectively. Bacterial prostatitis showed some features similar to carcinoma. Abundant BPH rendered cancer detection more difficult. No diagnostic criterion was clearly better than the others. Interobserver agreement on the MR diagnosis ranged from moderate to good. Conclusion: Without knowledge of accurate clinical data, MR seems to be too insensitive in detecting prostate cancer to be used as a primary diagnostic tool.

Diagnostic evaluation and aggressive surgical approach in bleeding pseudoaneurysms associated with pancreatic pseudocysts

Hemorrhage is an uncommon but serious complication of pancreatic pseudocysts. When gastrointestinal bleeding or intra-abdominal hemorrhage is associated with a pancreatic pseudocyst and the usual sources of bleeding are not detected by endoscopy, the rupture of a pseudoaneurysm inside the pseudocyst should be suspected. We present 13 cases, 11 associated with chronic and 2 with late complications after acute necrotizing pancreatitis. On the basis of sonographic findings, bleeding site was suspected in 8 of 11 patients (73%). Computed tomography (CT) was performed on 10, and bleeding was suspected in 8 (80%). The pseudoaneurysm itself was detected by CT in one and by ultrasonography in none. Visceral angiography was performed on five patients, and the pseudoaneurysm was evident in all. External drainage with arterial ligation was done as a primary operation in five patients; four of them later underwent pancreatic resection because of rebleeding. In eight cases pancreatic resection was the initial operation; none of these patients continued to bleed or needed reoperation because of the same pseudoaneurysm. There were no intraoperative deaths, but one patient died postoperatively. Aggressive diagnostic evaluation and surgical approach are associated with a reduction in mortality and morbidity in this serious complication of pancreatic pseudocysts.

Endorectal magnetic resonance imaging of prostatic cancer: comparison between fat-suppressed T2-weighted fast spin echo and three-dimensional dual-echo, steady-state sequences

Abstract The aim of this study was to develop an endorectal MRI strategy for prostatic cancer. We evaluated the MR images from 44 consecutive prostatic cancer patients treated by radical prostatectomy. Each sequence from every examination was assessed separately with a specific tumor map drawn. Tumor localization, capsular penetration, and seminal vesicle invasion were marked on maps on the basis of T2 and DESS (dual-echo steady-state) sequences. Thirty patients also had T1-weighted images, and these were assessed with regard to possible tumor outgrowth. The maps were compared with histopathological findings from radical prostatectomy specimens. According to our study, DESS equaled T2 in every respect. No statistically significant differences between the sequences were found with respect to detecting either tumor localization, outgrowth, or seminal vesicle invasion. DESS is a potential new sequence in prostatic MRI as it has been proven to parallel the routinely used T2-weighted imaging.

A new method for the diagnosis of acute hemorrhagic-necrotizing pancreatitis using contrast-enhanced CT

Twenty-eight consecutive patients with a first attack of alcohol-induced pancreatitis were studied using contrast-enhanced CT. The findings on CT were then related to the course of the disease. The patients with acute hemorrhagic-necrotizing pancreatitis showed significantly lower enhancement values of the pancreatic parenchyma than those with milder forms of the disease.The next 20 patients with severe pancreatitis were scanned using a slightly modified procedure. The enhancement values were calculated and plotted on the graphs for the 2 former groups.Two categories of pancreatic enhancement were found: “low enhancement” and “high enhancement.” In all 10 patients with “low-enhancement” values surgery revealed hemorrhagic-necrotizing pancreatitis. In the 10 patients with “highenhancement” values conservative treatment was continued, and the clinical course was nonfulminant in all of them.

MRI abnormalities of foot and ankle in asymptomatic, physically active individuals.

Abstract Objective. To assess MRI changes in the ankle and foot after physical exercise. Design and patients. Nineteen non-professional marathon runners and 19 age- and sex-matched controls volunteered for the study. All had ankle and foot MR images (1.5 T) taken in three perpendicular planes (STIR, T2F and T1FS sequences) within 3 h of running a full-length marathon (42.125 km). Three radiologists independently analysed the groups on a masked basis using a predefined form. Results. Severe bone marrow oedema was seen in one and slight bone marrow oedema in three marathon runners. Slight bone marrow oedema was found in three control subjects. Signal alteration within the soleus muscle, consistent with a grade 1 strain, was found in one marathon runner. Small punctate hyperintensities within the Achilles tendon were seen in 26% of the marathon runners and in 63% of controls (P=0.016). An increased amount of fluid in the retrocalcaneal bursa was found in one control and in none of the marathon runners. Small amounts of fluid in the retrocalcaneal bursa were seen in 68% of marathon runners and in 53% of controls. Grade 1 or 2 peritendinous joint fluid was found around 22% of tendons, among both marathon runners and controls, most often involving the tendon sheath of the flexor hallucis longus muscle. An increased amount of joint fluid was noted in 34% of the joints of the marathon runners, and in 18% of the controls. Conclusion. MRI shows several abnormalities in the ankle and foot both after marathon races and in asymptomatic physically active individuals without any preceding extraordinary strain. Recreational sports may lead to a number of positive MRI findings without correlation with clinical findings.

Structural Changes in the Renal Proximal Tubular Cells Induced by lodinated Contrast Media

The renal morphologic changes induced by intravenously injected contrast media (CMs) were studied in 40 Wistar rats which had been deprived of water 24 h before the CM injection. In the first part of the investigation, the kidneys were fixed by perfusion for light and electron microscopy 2 h after injection of 3 g iodine/kg of iopamidol, iobitridol or iohexol. Control animals received physiologic saline. In the second part of the study, the fixation was performed 48 h after the injection of the corresponding dose of iobitridol or iohexol. The structural changes were semiquantitatively evaluated by two independent observers unaware of the agent injected. The lysosomes of the proximal convoluted tubular cells showed moderate changes 2 h after the iopamidol injection. Iobitridol and iohexol induced prominent lysosomal alterations with signs of cytoplasmic injury. After 48 h, the changes induced by iobitridol had almost disappeared, whereas the iohexol group still showed a statistically significant vacuolization. Although the general physicochemical properties of iobitridol and iohexol appear similar in vitro, the different lysosomal alteration might reflect differences in their characteristics in vivo.