Increased prevalence of pancreaticobiliary maljunction in biliary malignancies.

AIM: The incidence of pancreaticobiliary maljunction is thought to approximate 1:100,000 within Western populations. We aimed to study the significance of pancreaticobiliary maljunction in biliary tract malignancies. METHODS: Medical records and magnetic resonance cholangiopancreatography images of 252 consecutive patients treated for biliary malignancies during 2005-2016 were reviewed. Patients with other known risk factors for biliary cancers (n = 27) were excluded. A common pancreaticobiliary channel measuring ⩾10 mm outside the duodenal wall was defined as pancreaticobiliary maljunction. MAIN RESULTS: Of the 225 patients, a reliably interpretable preoperative magnetic resonance cholangiopancreatography was available for 73 (32%). Sex (47% vs 57% females) and age at diagnosis (67 vs 66 years) were similar among patients with or without an magnetic resonance cholangiopancreatography (p = ns for both). In magnetic resonance cholangiopancreatography, a pancreaticobiliary maljunction with a median length of 20 mm (range 10-23 mm) was identified in four patients (5.5%, 95% confidence interval 1.6-14), while none had evident accompanying biliary tree dilatation. Pancreaticobiliary maljunction patients were significantly more often females (100% vs 43%, p = 0.043), less likely to have intrahepatic bile duct cancer (0% vs 65%, p = 0.019) while more likely to have gallbladder cancer (75% vs 22%, p = 0.044) compared to the others. Age at diagnosis (66 vs 67 years, p = 0.898), extrahepatic bile duct cancer incidence (25% vs 13%, p = 0.453), and survival status at last follow-up (50% vs 42% alive, p = 1.000) were comparable between the subgroups. CONCLUSION: The prevalence of pancreaticobiliary maljunction is substantially higher in adults with biliary malignancies than one would expect based on its incidence, reinforcing the etiologic role of pancreaticobiliary maljunction especially in females with gallbladder cancer.

Spinal canal dimensions affect outcome of adolescent disc herniation.

PURPOSE: Small spinal canal dimensions play a role in symptomatic adult disc herniation, but its role in adolescent disc herniation has not been investigated with MRI. The goal of this study was to examine retrospectively if there is a correlation with dimensions of osseous spinal canal and need of discectomy in an adolescent population suffering from disc herniation. METHODS: A retrospective review of child and adolescent patients who were treated in our institution for back or back--related leg pain was conducted. Patients were divided in three groups; group 1: lumbar disc herniation requiring operative treatment; group 2: lumbar disc herniation treated with observation; and group 3: back pain and no disc herniation on MRI. MRI images and radiographs were studied for spinal canal dimensions and compared between groups. RESULTS: The discectomy group presented considerably smaller spinal canal dimensions measured from the MRI images than the two other groups. CONCLUSION: Adolescent patients requiring operative treatment for symptomatic disc herniation have smaller osseous spinal canals than patients who are managed non-operatively.

Unconscious trauma patients: outcome differences between southern Finland and Germany-lesson learned from trauma-registry comparisons.

PURPOSE: International trauma registry comparisons are scarce and lack standardised methodology. Recently, we performed a 6-year comparison between southern Finland and Germany. Because an outcome difference emerged in the subgroup of unconscious trauma patients, we aimed to identify factors associated with such difference and to further explore the role of trauma registries for evaluating trauma-care quality. METHODS: Unconscious patients [Glasgow Coma Scale (GCS) 3-8] with severe blunt trauma [Injury Severity Score (ISS) ≥16] from Helsinki University Hospital's trauma registry (TR-THEL) and the German Trauma Registry (TR-DGU) were compared from 2006 to 2011. The primary outcome measure was 30-day in-hospital mortality. Expected mortality was calculated by Revised Injury Severity Classification (RISC) score. Patients were separated into clinically relevant subgroups, for which the standardised mortality ratios (SMR) were calculated and compared between the two trauma registries in order to identify patient groups explaining outcome differences. RESULTS: Of the 5243 patients from the TR-DGU and 398 from the TR-THEL included, nine subgroups were identified and analyzed separately. Poorer outcome appeared in the Finnish patients with penetrating head injury, and in Finnish patients under 60 years with isolated head injury [TR-DGU SMR = 1.06 (95 % CI = 0.94-1.18) vs. TR-THEL SMR = 2.35 (95 % CI = 1.20-3.50), p = 0.001 and TR-DGU SMR = 1.01 (95 % CI = 0.87-1.16) vs. TR-THEL SMR = 1.40 (95 % CI = 0.99-1.81), p = 0.030]. A closer analysis of these subgroups in the TR-THEL revealed early treatment limitations due to their very poor prognosis, which was not accounted for by the RISC. CONCLUSION: Trauma registry comparison has several pitfalls needing acknowledgement: the explanation for outcome differences between trauma systems can be a coincidence, a weakness in the scoring system, true variation in the standard of care, or hospitals' reluctance to include patients with hopeless prognosis in registry. We believe, however, that such comparisons are a feasible method for quality control.

Microsurgical technique for previously coiled aneurysms.

Since the introduction of Guglielmi detachable coils to treat intracranial aneurysms in 1991, the number of patients undergoing endovascular coiling has continuously risen as well as the number of those residual and recurrent previously coiled aneurysms that necessitate a microsurgical occlusion. Between July 1995 and August 2009 we retrospectively analyzed 81 patients with 82 previously coiled aneurysms treated microsurgically at two Finnish Neurosurgical University Hospitals, Helsinki and Kuopio. Fifty-eight aneurysms (71%) were located at anterior circulation and 24 (29%) at posterior circulation. Fifteen patients were operated on within the first month (early surgery) after coiling, whereas 66 were treated later (late surgery). Complete or partial removal of coils during surgery may facilitate clipping, but is significantly (P<0.001) more difficult to accomplish in late surgery. Removal of coils may also increase the chance for poor outcome. Chance of poor outcome increased also with intraoperative aneurysm rupture, size of the aneurysm and posterior circulation location. Good clinical outcome, three months after surgery, was achieved in 71 patients (88%); four patients were severely disabled, and six patients died (three of them due to poor clinical condition). Complete microsurgical occlusion of the residual previously coiled aneurysm is a high-risk procedure in large and giant aneurysms, and these patients should be referred to a dedicated neurovascular center to minimize surgical complications. Bypass procedures may be the best option for demanding growing lesions, especially those in posterior circulation.

Cost-effectiveness of decompressive craniectomy in traumatic brain injuries.

BACKGROUND AND PURPOSE: Decompressive craniectomy (DC) is used regularly in traumatic brain injury (TBI). There are, however, no cost-effectiveness studies of the procedure. METHODS: We evaluated the outcomes and treatment costs of all decompressive craniectomies performed between the 2000 and 2006 in a single institution to lower intractable intracranial pressure after TBI. The health-related quality of life was evaluated on the Euroqol (EQ-5D) questionnaire and on the visual-analogue scale (VAS), and cost of a quality-adjusted life year (QALY) was calculated. RESULTS: In this study of 54 patients, the median follow-up time was 5.6 years. Overall mortality rate was 41%. Of the 22 non-survivors, 73% died within 30 days. For 32 survivors, the median EQ-5D index value was 0.85, which is equal to the normal population. The median VAS value was 73, whilst normal population's value is 80. Of the survivors, 81% (26/32) were able to live at home and 31% (10/32) returned to work. The cost of neurosurgical treatment for one QALY was 2400 €. Estimation for all medical costs, including rehabilitation and anticipated future costs, resulted cost of a QALY 17,900 €. CONCLUSION: Mortality after severe TBI leading to DC was high, but amongst the survivors, the health-related quality of life was equal to normal population. Most survivors were able to live at home and were almost as satisfied with their health as in general people are. Cost of neurosurgical treatment was low, and also including all evaluated costs, cost of a QALY gained was acceptable.

Cost-effectiveness of decompressive craniectomy in non-traumatic neurological emergencies.

BACKGROUND: Decompressive craniectomy is used regularly in traumatic brain injury (TBI) and malignant middle cerebral artery infarction. Its benefits for other causes of non-traumatic brain swelling, if any, are unclear, especially after a devastating primary event. METHODS: We evaluated the outcomes as well as treatment costs of all emergency decompressive craniectomies performed between the 2000 and 2006 in a single institution to lower intractable intracranial pressure, excluding the standard indications TBI and malignant middle cerebral infarction. The health-related quality of life (HRQoL) was evaluated on the Euroqol (EQ-5D) scale, and cost of a quality-adjusted life year (QALY) calculated. RESULTS: The overall 3-year mortality rate was 62% for subarachnoid haemorrhage (SAH, 29 patients) and 31% for other neurological emergencies (13 patients). Patients with SAH were on average 13 years older than the other indications mean. Of the non-survivors, 45% died within a month and 95% within 1 year. Median EQ-5D index values were poor (0.15 for SAH and 0.62 for the other emergencies, versus 0.85 for the normal population), but of the survivors, 73% and 89% were able to live at home. The cost of neurosurgical treatment for one QALY was 11,000 € for SAH and 2000 € for other emergencies. CONCLUSION: Mortality after non-traumatic neurological emergencies leading to decompressive craniectomy was high, and the HRQoL index of the survivors was poor. Most survivors were, however, able to live at home, and the cost of neurosurgical treatment for a QALY gained was acceptable.

Reorganization of the composition of brain oscillations and their temporal characteristics during opioid withdrawal.

Majority of the opioid-dependence and withdrawal studies are dominated with many inconsistencies and contradictions. One of the reasons for such inconsistencies may be methodological while performing EEG analysis. To overcome methodological limitations, in the present study we examined the composition of electroencephalographic (EEG) brain oscillations in broad frequency band (0.5-30 Hz) in 13 withdrawal opioid-dependent patients and 14 healthy subjects during resting condition (closed eyes). The exact compositions of brain oscillations and their temporal behaviour were assessed by the probability-classification analysis of short-term EEG spectral patterns (SPs). It was reported that early withdrawal had a generalized effect: the activity in all EEG channels was affected nearly equally. EEG of withdrawal patients was characterized by (a) different dominant SP types (had unique SP types which describe beta-frequency band), (b) increased number of SP types observed in each EEG channel, (c) a larger percentage of alpha(2)-, beta- and poly-rhythmic activity, and by a smaller percentage of delta-, - and alpha(1)-rhythmic activity, (d) predominantly right-sided asymmetry and (e) longer periods of temporal stabilization for alpha- and beta-brain oscillations and by shorter periods of temporal stabilization for -activity when compared with control subjects. When taken together, these findings suggest a considerable reorganization of composition of brain oscillations, which reflects a disorganization process and an allostatic state with neuronal activation in EEG of opioid withdrawal patients.

MR imaging after aneurysmal subarachnoid hemorrhage and surgery: a long-term follow-up study.

BACKGROUND AND PURPOSE: We assumed that patients with surgically treated aneurysmal subarachnoid hemorrhage (SAH) might have more lesions than those revealed by CT that could be visible on MR images. METHODS: We conducted a retrospective study of a series of 147 patients with aneurysmal SAH who were treated surgically within 3 days of the onset of SAH. One hundred four patients (mean age, 48.8 years) underwent MR imaging studies 2.1 to 5.6 years (mean, 3.3 years) postoperatively. RESULTS: Eighty-four (81%) patients presented a total of 152 areas of increased signal intensity on T2-weighted images, consistent with infarction; 48% of the patients had lesions in the frontal lobes. CT performed 3 months postoperatively revealed hypodense areas on the scans of only 57% of the patients and showed lesions in the frontal lobes of only 16% of the patients. CONCLUSION: Patients who undergo early surgery for aneurysmal SAH have more lesions than are revealed by CT. The difference is remarkable, especially in the frontal lobes.

Pancreatic carcinoma and fast MR imaging: technical considerations for signal intensity difference measurements.

The aim of the study was to find the fast magnetic resonance imaging (MRI) sequence with the best conspicuity of pancreatic lesions at 1.0 T and 1.5 T. A total of 51 patients were studied. At 1.0 T, 22 patients with verified malignant pancreatic lesions were studied using the T1-weighted breath-hold spoiled Gradient Echo 2D FLASH(75) or FLASH(80) sequences, both non-enhanced and enhanced with gadolinium. The relative signal intensity difference (SIDR) between lesion and pancreas was measured. At 1.5 T, 20 patients with primary malignant lesions of the pancreas, and nine patients with 13 benign cystic lesions were examined with the breath-hold T2-weighted TrueFISP, HASTE, T1-weighted 2D FLASH(80) and FLASH(50) fat saturation sequences, the latter also enhanced. The signal intensity (SI) values of the pancreas and lesions as well as the pancreatic standard deviation (S.D.) were assessed, and the contrast-to-noise ratio (C/N) was determined. Statistical significances were calculated using an analysis of variance. No statistically significant difference between the sequences used in the conspicuity of cancer was found, either at 1.0 T or at 1.5 T. At 1.5 T, the T2-weighted TrueFISP and HASTE sequences could differentiate benign, cystic lesions from malignant lesions.

Estimation or quantification of tumour volume? CT study on irregular phantoms.

PURPOSE: To compare radiologists' subjective size estimation to computerised volume quantification of tumour-like phantoms in spiral CT. MATERIAL AND METHODS: Eight tubular phantoms with the inside irregularly covered with silicone (8.7-31.6 ml) were imaged. The phantoms were pairwise compared to analyse the differences in silicone volumes. The observers, 2 radiologists and 2 residents, used both subjective image analysis (2 sessions) and computerised volume quantification (1 session). Accuracy and observer agreement of both methods were calculated. RESULTS: Subjective size estimation was correct in 51% (mean weighted kappa, Kqw=0.73). Using four observers' mean value (Kqw=0.81) or median value (Kqw=0.77) slightly improved the results. Average intra-observer agreement was better than average interobserver agreement. In computerised volume quantification 70% of all classifications were correct (mean Kqw=0.85). The results were moderate even when every second or fourth slice were measured. CONCLUSION: Subjective size estimation of irregular tumours should be repeatedly performed by the same observer, or by using the mean or median estimate of several observers. Computer-based methods are even more reliable and their use is especially recommended for film readers with limited radiological experience. Only every fourth slice may be measured without a major loss of measurement accuracy.

Basal brain injury in aneurysm surgery.

OBJECTIVE: The goal of this study was to determine the frequency of lesions in the basal frontotemporal area that were related to surgical damage to the brain tissue. METHODS: A prospective series of 101 patients with ruptured intracranial aneurysms were examined with high-field magnetic resonance imaging, 2 to 6 years (mean, 3.3 yr) after early surgery. RESULTS: Lesions in the basal frontotemporal region, on the side of the pterional approach, were observed for 36 patients. These lesions were not visible in computed tomographic scans obtained pre- or postoperatively or 3 months after subarachnoid hemorrhage. Patients with ruptured aneurysms in the anterior communicating artery exhibited fewer of these lesions than did patients with aneurysms in the internal carotid artery or middle cerebral artery; this difference was not statistically significant. The age of the patient, the duration and depth of hypotension, the amount of blood or ventricular enlargement in pre- and postoperative computed tomographic scans, and the incidence and severity of angiographic vasospasm in pre- and postoperative angiograms did not predict the existence of these lesions. The clinical conditions of the patients, as assessed using the Glasgow Outcome Scale, at 3 months after surgery and at the time of magnetic resonance imaging did not predict the existence of these lesions. Nine of the 10 patients who underwent surgical treatment of unruptured aneurysms on the contralateral side exhibited no signs of tissue damage. CONCLUSION: Surgical treatment of ruptured intracranial aneurysms seems to cause damage in the basal frontotemporal region in one-third of patients. The significance of these lesions remains unclear.

Detection of severe acute pancreatitis by contrast-enhanced magnetic resonance imaging.

The aim of the study was to assess the ability of MRI to differentiate between the two forms of severity of acute pancreatitis (AP), which is important for the detection of patients who require intensive monitoring and therapy. The second objective was to evaluate whether the distinction would be possible regardless of the MRI equipment. Magnetic resonance imaging was performed before and after intravenous administration of a gadolinium (Gd) chelate at 1.0 T using the breath-hold multislice rapid gradient-echo turbo fast low-angle shot (FLASH) sequence in 14 patients, and at 1.5 T with the 2D FLASH(50) sequence with fat saturation in 18 patients with acute pancreatitis early in the course of the disease. The patients were classified according to the Atlanta classification system as having the mild (MAP) or severe (SAP) form of the disease. At 1.0 T with use of a body coil, contrast-enhanced MRI failed to distinguish mild from severe pancreatitis. At 1.5 T with a phased-array body coil, the signal intensities of the patients with SAP were statistically significantly lower than those of the MAP group. Our initial clinical experience suggests that MRI with a sufficient magnetic field gradient strength may be useful for separating the two forms of acute pancreatitis in their early phases.

Multiphase segmented k-space velocity mapping in pulsatile flow waveforms.

The aim of the present study was to obtain the precision of flow measurement in breath-hold segmented k-space flow sequences. The results are based on studies of pulsatile flow in a phantom tube. The ultimate purpose is to use these sequences to measure coronary flow. In abdominal and cardiothoracic magnetic resonance imaging the image quality is degraded due to respiratory motion. In the segmented k-space acquisition method, one obtains many phase-encoding steps or views per cardiac phase. This shortens imaging time in the order of phase-encoding lines and makes it possible to image in a single breath-hold, thereby eliminating respiratory artefacts and improving edge detection. With breath-hold multiframe cine flow images it is possible to evaluate flow in all abdominal and cardiothoracic areas, including the coronary arteries. Our study shows that velocity curves shift in time when the number of k-space ky-lines per segment (LPS) are varied; this shift is linear as a function of LPS. The mean velocity Vmean in the center of mass of the pulsatile peak is constant (Vmean = 40.1 +/- 2.9 cm/s) and time t = -10.1 x LPS + 268 (r = 0.993, p < 0.0001). Correlation between theoretical and experimental flow curves is also linear as a function of LPS: C = -0.977 * LPS (r = 0.987, p < 0.0001). It is concluded that velocity curves move with LPS and are smoothed when the breath-hold velocity mapping is used. The more LPS is gathered the more inaccurate results are. LPS 7 or more cannot be considered clinically relevant.

Optimising imaging parameters in experimental spiral CT.

PURPOSE: This in vitro study was conducted to analyse lesion detection and relative radiation exposure in different CT techniques. MATERIAL AND METHODS: We used a plastic phantom (12 x 8 x 2 cm) containing holes filled with air or fluid of varying densities to simulate lesions. This was imaged with Siemens Somatom Plus S and GE High Speed Advantage units. We varied table feeds (3 and 6 mm/s in Siemens and 3 and 4.5 mm/s in GE) and increments (2 mm and 4 mm) while keeping collimation at 3 mm. The SmartScan program of GE and the reformatting algorithm of Siemens were also analysed. To evaluate the different methods, the phantom lesions were counted by 3 observers. Radiation exposures associated with each technique were also measured. RESULTS: The images reformatted to a coronal direction were significantly inferior (p < 0.01) to those in other techniques. The use of SmartScan did not influence lesion detection, nor did changes in pitch or increment. Spiral and non-spiral techniques proved to be equal. Radiation exposure was lowest when a greater pitch or the SmartScan program was used. CONCLUSION: Radiation exposure in CT can be limited without significantly impairing the image quality by using low-dose techniques. Reformatting to a coronal direction should be used with care as it debases the image quality.

Structural changes in the renal proximal tubular cells induced by iodinated 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.

Contrast-enhanced magnetic resonance imaging for the detection of acute haemorrhagic necrotizing pancreatitis.

Eleven piglets with haemorrhagic necrotizing pancreatitis and nine piglets with oedematous pancreatitis were imaged using a multi-breath-hold TurboFLASH (TR 6.5 ms, TE 3 ms, TI 300 ms, flip angle 8 degrees , three slices) pre-excited T1-weighted sequence with an IV bolus injection of gadopentetate dimeglumine (Gd-DTPA, 0. 3 mmol/kg) as a contrast agent to show dynamic contrast enhancement of the pancreas by MRI. All piglets were imaged according to the same protocol before inducing the disease. Following the IV Gd-DTPA bolus, time-enhancement curve of the pancreas during haemorrhagic necrotizing pancreatitis was significantly lower than during oedematous pancreatitis. The enhancement curves for the healthy piglets and piglets with oedematous pancreatitis did not differ significantly. Each piglet served as its own control. Because the results of this initial study are similar to those obtained with contrast-enhanced CT, we conclude that our results may encourage further clinical trials, and contrast-enhanced dynamic MRI may be an alternative to the established method of CT for diagnosing acute haemorrhagic necrotizing pancreatitis.