Does the kidney actually swell during an acute urinary tract obstruction?

BACKGROUND: The appearance of renal swelling during an acute obstruction of the urinary tract could be caused by hydronephrosis or an increase of the parenchymal volume. To the best of our knowledge no studies have been performed regarding renal parenchymal volume change during an acute urinary tract obstruction. PURPOSE: To investigate the change in renal parenchymal volume during an acute urinary tract obstruction and to correlate any such volume change to the degree of secondary signs of obstruction. MATERIAL AND METHODS: In total, 20 patients with obstructive ureterolithiasis were retrospectively and randomly included. Two observers measured the parenchymal volume of the obstructed and the contralateral kidney in CT examinations before, during, and after obstruction. Hydronephrosis, hydroureter, perirenal stranding, and thickening of the renal fascia were graded and correlated to volume change. RESULTS: A decreased volume was noted after obstruction in the obstructed kidneys (-24%) (P < 0.0001) and in the contralateral kidneys (-5%) (P = 0.0110) with a positive correlation of change in volume (P = 0.011). The volume of the obstructed kidneys was larger than the contralateral kidneys during obstruction (P < 0.0001) but not after obstruction (P = 0.559). No significant difference in volume was found before compared to after obstruction. Secondary signs of obstruction did not correlate to volume change. CONCLUSION: The parenchymal volume increases in the obstructed kidneys as well as in the contralateral kidneys during obstruction. The increase in volume was larger in the obstructed kidneys compared to the contralateral kidneys. After obstruction the kidneys regained their original volume. Secondary signs did not correlate to volume change.

Patient compliance with Twin Block appliance during treatment of Class II malocclusion: a randomized controlled trial on two check-up prescriptions.

BACKGROUND: Compliance is crucial for the treatment outcome with removable appliances. Previous studies on treatment with the Twin Block appliance have focused on effectiveness in relation to other treatment methods or wear-time. Studies on different check-up intervals to improve compliance seem to be lacking. OBJECTIVES: To compare the impact of two different check-up prescriptions on patient compliance and treatment outcome during treatment with Twin Block. TRIAL DESIGN: Two-arm parallel group, single-centre, randomized controlled trial. MATERIALS AND METHODS: Seventy-three patients, 38 boys, and 35 girls, mean age 11.2 years, were included and block-randomized into two groups treated with a Twin Block appliance. Group 1 was called for check-up visit every sixth week and group 2 every fourth week. Compliance was evaluated with a TheraMon® microsensor, moulded into the appliance, measuring wear-time. Overjet, overbite, and molar relationships were assessed on study casts before and after treatment. The treatment outcomes were analysed on an intention-to-treat basis. RESULTS: In group 1, the reduction of overjet was 5.2 mm and the mean wear-time was 6.9 hours. In group 2, the reduction was 4.7 mm and the wear-time was 6.1 hours. Seventy-four per cent of the patients presented an overjet of 4 mm or less. Wear-time did not correlate to age, gender, or severity of malocclusion. HARMS: No harm was observed in any patient. Lateral open bites were registered during treatment but were normalized at the end of the treatment. LIMITATIONS: The trial was a single-centre study and long-term effects were not evaluated. CONCLUSIONS: During treatment with the Twin Block appliance, a 4-week check-up interval did not improve treatment outcome or increase wear-time, compared to a 6-week check-up interval. The mean wear-time was 6.5 hours per day, even if the recommendation was 12 hours. CLINICAL TRIAL REGISTRATION: NCT05155774.

In vitro CT visualization of the biopsy location by filling the core biopsy needle with contrast media.

BACKGROUND: When performing computed tomography (CT)-guided biopsy procedures with non-disposable, automatic biopsy instruments, the actual course of the biopsy needle is not registered. PURPOSE: To evaluate the ability to visualize the sampling location after CT-guided biopsy in vitro using a novel method, where the space between the inner needle and the outer cannula in a core biopsy needle is filled with contrast media; and to compare the grade of visibility for two different concentrations of contrast media. MATERIAL AND METHODS: Core needle biopsies were performed in a tissue phantom using biopsy needles primed with two different iodine contrast media concentrations (140 mg I/mL and 400 mg I/mL). Commercially available needle-filling contraptions with sealing membranes were used to fill the needles. Each biopsy was imaged with CT, and the visibility was evaluated twice by three senior radiologists in a randomized order. RESULTS: The presence of traces was confirmed after biopsy, almost without exception for both concentrations. The visibility was sufficient to determine the biopsy location in all observations with the 400 mg I/mL filling, and in 7/10 observations with the 140 mg I/mL filling. The grade of visibility of the trace and the proportion of the biopsy needle course outlined were higher with the 400 mg I/mL filling. CONCLUSION: With CT-guided biopsy in vitro, the sampling location can be visualized using a novel method of priming the biopsy needle with iodine contrast media, specifically highly concentrated contrast media.

Accuracy of iodine quantification using dual-energy computed tomography with focus on low concentrations.

BACKGROUND: Iodine quantification using dual-energy computed tomography (DECT) is helpful in characterizing, and follow-up after treatment of tumors. Some malignant masses, for instance papillary renal cell carcinomas (p-RCC), are hard to differentiate from benign lesions because of very low contrast enhancement. In these cases, iodine concentrations might be very low, and it is therefore important that iodine quantification is reliable even at low concentrations if this technique is used. PURPOSE: To examine the accuracy of iodine quantification and to determine whether it is also accurate for low iodine concentrations. MATERIAL AND METHODS: Twenty-six syringes with different iodine concentrations (0-30 mg I/mL) were scanned in a phantom model using a DECT scanner with two different kilovoltage and image reconstruction settings. Iodine concentrations were measured and compared to known concentration. Absolute and relative errors were calculated. RESULTS: For concentrations of 1 mg I/mL or higher, there was an excellent correlation between true and measured iodine concentrations for all settings (R = 0.999-1.000; P < 0.001). For concentrations <1.0 mg I/mL, the relative error was greater. Absolute and relative errors were smaller using tube voltages of 80/Sn140 kV than 100/Sn140 kV (P < 0.01). Reconstructions using a 3.0-mm slice thickness had less variance between repeated acquisitions versus 0.6 mm (P < 0.001). CONCLUSION: Iodine quantification using DECT was in general very accurate, but for concentrations < 1.0 mg I/mL the technique was less reliable. Using a tube voltage with larger spectral separation was more accurate and the result was more reproducible using thicker image reconstructions.

Split renal function after treatment of small renal masses: comparison between radiofrequency ablation and laparoscopic partial nephrectomy.

BACKGROUND: Radiofrequency ablation (RFA) and laparoscopic partial nephrectomy (LPN) are used to treat small renal masses (SRM; ≤4 cm), although there are conflicting results in the changes in creatinine and estimated glomerular filtration rate (eGFR) after treatment. On contrast-enhanced computed tomography (CE-CT) images, the quantity and quality of renal function can be evaluated by calculating the split renal function (SRF). PURPOSE: To compare renal function after RFA or LPN treatment of SRMs through evaluation of the SRF in the affected kidney. MATERIAL AND METHODS: Single T1a renal tumors successfully treated with RFA (n = 60) or LPN (n = 31) were retrospectively compared. The SRF was calculated on pre-treatment CE-CT images and the first follow-up exam after completed treatment. Serum creatinine and eGFR values were collected simultaneously. To compare renal function outcomes, Student's t-test and multivariable linear regression models (adjusted to RFA/LPN treatment, pre-treatment SRF/eGFR, BMI, age, tumor characteristics, and Charlson Comorbidity Index) were used. RESULTS: SRF was reduced in both groups, although reduction was greater in the LPN group (LPN -5.7%) than in the RFA group (RFA -3.5%; P = 0.013). After adjusted analysis, the LPN group still had greater SRF reduction (difference 3.2%, 95% confidence interval 1.3-1.5; P = 0.001). There was no difference between groups in the change of creatinine/eGFR after treatment. CONCLUSION: Both RFA and LPN are nephron-sparing when treating SRMs. However, in this series, reduction of SRF in the affected kidney was smaller after RFA, having a more favorable preservation of renal function than LPN.

Translation and validation of the English-language instrument Orthognathic Quality of Life Questionair into Swedish.

INTRODUCTION: In orthognathic surgery, understanding the patient's motives for treatment is a key factor for postoperative patient satisfaction and treatment success. In countries/systems where orthognathic surgery is funded by public means, patients are referred mainly due to functional problems, although studies of quality of life related changes after treatment indicate that psychosocial and aesthetic reasons might be equal or more important for the patient. There is no available validated condition specific instruments in the Swedish language for quality of life evaluation of patients with dentofacial deformities. Aims/objectives: Cross cultural translation and adaptation of the English-language instrument 'Orthognathic Quality of Life Questionnaire' (OQLQ) into Swedish. Methods: OQLQ was translated into Swedish. A total of 121 patients in four groups were recruited and the Swedish version of the OQLQ (OQLQ-S) was tested by psychometric methods. Reliability was assessed by internal consistency and test-retest reliability. Validity was evaluated by face, convergent and discriminant validity. Results/findings and conclusions: OQLQ-S is reliable and showed good construct validity and internal consistency and can be used in a Swedish speaking population as a complement to clinical variables to evaluate patients with dentofacial deformity.

Open vs closed surgical exposure of palatally displaced canines: a comparison of clinical and patient-reported outcomes-a multicentre, randomized controlled trial.

OBJECTIVES: To compare treatment time, patients' perceptions during orthodontic treatment, dental fear and side effects, between open and closed surgical exposures in patients with palatally displaced canines (PDCs). TRIAL DESIGN: Multicentre, randomized controlled trial, with random 1:1 allocation of two parallel groups. MATERIALS AND METHODS: One hundred and twenty patients from three different orthodontic centres were randomized into one of the two intervention arms, open or closed surgical exposure. Both techniques had mucoperiosteal flaps raised and bone removed above the PDCs. In open exposure, tissue was removed above the canine, and glass ionomer - reaching above soft tissue - was built on the crown. The canine was then left to erupt spontaneously, prior to orthodontic alignment. At closed exposure, a chain was bonded to the canine and orthodontic traction was applied under the mucosa until eruption. Orthodontic alignment of the canines was undertaken after eruption into the oral cavity, with fixed appliances in both groups. All participants were treated according to intention to treat (ITT). BLINDING: Due to the nature of this trial, only outcome assessors could be blinded to the intervention group. RESULTS: One hundred and seventeen patients completed the trial. All PDCs were successfully aligned. Total treatment time was equal in the two techniques, mean difference -0.1 months (95% CI -3.2 to 2.9, P = 0.93). The closed group experienced more pain and discomfort during the active orthodontic traction. Dental fear, root resorption and periodontal status did not show any clinically significant differences between the groups. GENERALIZABILITY: Results of this randomized controlled trial (RCT) can be generalized only to a similar population aged 9-16 years, if exclusion criteria are met. CONCLUSION: The closed exposure group experienced more pain and discomfort mostly during active orthodontic traction. All other studied outcomes were similar between the two exposure groups. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT02186548 and Researchweb.org, ID: 127201.

Microwave ablation of 105 T1 renal tumors: technique efficacy with a mean follow-up of two years.

BACKGROUND: Thermal ablation (TA) with radiofrequency (RFA) or cryoablation (CA) are established treatments for small renal masses (≤4 cm). Microwave ablation (MWA) has several potential benefits (decreased ablation time, less susceptibility to heat-sink, higher lesion temperatures than RFA) but is still considered experimental considering the available small-sample studies with short follow-up. PURPOSE: To evaluate technique efficacy and complications of our initial experience of renal tumors treated using percutaneous MWA with a curative intent. MATERIAL AND METHODS: A total of 105 renal tumors (in 93 patients) were treated between April 2014 and August 2017. MWA was performed percutaneously with computed tomography (CT) guidance under conscious sedation (n=82) or full anesthesia. Patients were followed with contrast-enhanced CT scans at six months and yearly thereafter for a minimum of five years. The mean follow-up time was 2.1 years. The percentage of tumors completely ablated in a single session (primary efficacy rate) and those successfully treated after repeat ablation (secondary efficacy rate) were recorded. Patient and tumor characteristics as well as complications were collected retrospectively. RESULTS: The median patient age was 70 years and median tumor size was 25 mm. Primary efficacy rate was 96.2% (101/105 tumors). After including two residual tumors for a second ablation session, secondary efficacy was 97.1% (102/105). Periprocedural complications were found in 5.2% (5/95) sessions: four Clavien-Dindo I and one Clavien-Dindo IIIa. One postprocedural Clavien-Dindo II complication was found. CONCLUSION: MWA has high efficacy rates and few complications compared to other TA methods at a mean follow-up of two years.

Consultation on UTUC, Stockholm 2018 aspects of diagnosis of upper tract urothelial carcinoma.

PURPOSE: To summarize knowledge on upper urinary tract carcinoma (UTUC) regarding diagnostic procedures, risk factors and prognostic markers. METHODS: A scoping review approach was applied to search literature in Pubmed, Web of Science, and Embase. Consensus was reached through discussions at Consultation on UTUC in Stockholm, September 2018. RESULTS: Tumor stage and grade are the most important prognostic factors. CT urography (CTU) including corticomedullary phase is the preferred imaging modality. A clear tumor on CTU in combination with high-grade UTUC in urine cytology identifies high-risk UTUC, and in some cases indirect staging can be obtained. Bladder urine cytology has limited sensitivity, and in most cases ureterorenoscopy (URS) with in situ samples for cytology and histopathology are mandatory for exact diagnosis. Image-enhancing techniques, Image S1 and narrow-band imaging, may improve tumor detection at URS. Direct confocal laser endomicroscopy may help to define grade during URS. There is strong correlation between stage and grade, accordingly correct grading is crucial. The correlation is more pronounced using the 1999 WHO than the 2004 classification: however, the 1999 system risks greater interobserver variability. Using both systems is advisable. A number of tissue-based molecular markers have been studied. None has proven ready for use in clinical practice. CONCLUSIONS: Correct grading and staging of UTUC are mandatory for adequate treatment decisions. Optimal diagnostic workup should include CTU with corticomedullary phase, URS with in situ cytology and biopsies. Both WHO classification systems (1999 and 2004) should be used to decrease risk of undergrading or overtreatment.

Periprocedural outcome after laparoscopic partial nephrectomy versus radiofrequency ablation for T1 renal tumors: a modified R.E.N.A.L nephrometry score adjusted comparison.

BACKGROUND: Comparable oncological outcomes have been seen after surgical nephrectomy and thermal ablation of renal tumors recently. However, periprocedural outcome needs to be assessed for aiding treatment decision. PURPOSE: To compare efficacy rates and periprocedural outcome (technical success, session time, hospitalization time, and complications) after renal tumor treatment with laparoscopic partial nephrectomy (LPN) or radiofrequency ablation (RFA). MATERIAL AND METHODS: The initial experience with 49 (treated with LPN) and 84 (treated with RFA) consecutive patients for a single renal tumor (diameter ≤ 5 cm, limited to the kidney) during 2007-2014 was evaluated. Patient and tumor characteristics, efficacy rates, and periprocedural outcome were collected retrospectively. The stratified Mantel Haenzel and Van Elteren tests, adjusted for tumor complexity (with the modified R.E.N.A.L nephrometry score [m-RNS]), were used to assess differences in treatment outcomes. RESULTS: Primary efficacy rate was 98% for LPN and 85.7% for RFA; secondary efficacy rate was 93.9% for LPN and 95.2% for RFA; and technical success rate was 87.8% for LPN and 100% for RFA. Median session (m-RNS adjusted P < 0.001; LPN 215 min, RFA 137 min) and median hospitalization time were longer after LPN (m-RNS adjusted P < 0.001; LPN 5 days, RFA 2 days). Side effects were uncommon (LPN 2%, RFA 4.8%). Complications were more frequent after LPN (m-RNS adjusted P < 0.001; LPN 42.9%, RFA 10.7%). CONCLUSION: Both methods achieved equivalent secondary efficacy rates. RFA included several treatment sessions, but session and hospitalization times were shorter, and complications were less frequent than for LPN. The differences remained after adjustment for renal tumor complexity.

Closed vs open surgical exposure of palatally displaced canines: surgery time, postoperative complications, and patients' perceptions: a multicentre, randomized, controlled trial.

Background: Closed and open surgical techniques are two different main approaches to surgical exposure of palatally displaced canines (PDCs). Because there is insufficient evidence to support one technique over the other, there is a need for randomized controlled trials. Objectives: To compare surgery time, complications and patients' perceptions between closed and open surgical techniques in PDCs. Trial design: The trial was a multicentre, randomized, controlled trial with two parallel groups randomly allocated in a 1:1 ratio. Material and methods: Study participants were 119 consecutive patients from 3 orthodontic centres, with PDCs planned for surgical exposure, randomly allocated according to a computer-generated randomization list, using concealed allocation. Full-thickness mucoperiosteal flap was raised, and bone covering the canine was removed in both interventions. In closed exposure, an attachment with a chain was bonded to the canine and the flap was sutured back with the chain penetrating the mucosa. In open exposure, a window of tissue around the tooth was removed and glass ionomer cement placed on the canine crown, to prevent gingival overgrowth during spontaneous eruption. Patient perceptions were assessed with two questionnaires, for the evening on the day of operation and 7 days post-surgery. Blinding: It was not possible to blind either patients or care providers to the interventions. The outcome assessors were blinded and were unaware of patients' intervention group. Results: Seventy-five girls and 44 boys, mean age 13.4 years (SD 1.46) participated in the study and got either of the interventions (closed exposure, n = 60; open exposure, n = 59). Surgery time did not differ significantly between the interventions. Complications though were more severe in bilateral cases and the patients experienced more pain and impairment in the open group. Conclusion: There were no statistically significant differences regarding surgery time between the groups. Postoperative complications were similar between the groups in unilateral PDCs, but more common in the open group in bilateral cases. More patients in the open group experienced pain and impairment compared to the closed group. Trial registration: Trial registration: ClinicalTrials.gov, ID: NCT02186548 and Researchweb.org, ID: 127201.

Comparison of post contrast CT urography phases in bladder cancer detection.

OBJECTIVES: The aim of this study was to investigate which post-contrast phase(s) in a four-phase CT urography protocol is (are) most suitable for bladder cancer detection. METHODS: The medical records of 106 patients with visible haematuria who underwent a CT urography examination, including unenhanced, enhancement-triggered corticomedullary (CMP), nephrographic (NP) and excretory (EP) phases, were reviewed. The post-contrast phases (n = 318 different phases) were randomized into an evaluation order and blindly reviewed by two uroradiologists. RESULTS: Twenty-one patients were diagnosed with bladder cancer. Sensitivity for bladder cancer detection was 0.95 in CMP, 0.83 in NP and 0.81 in EP. Negative predictive value (NPV) was 0.99 in CMP, 0.96 in NP and 0.95 in EP. The sensitivity was higher in CMP than in both NP (p-value 0.016) and EP (p-value 0.0003). NPV was higher in CMP than in NP (p-value 0.024) and EP (p-value 0.002). CONCLUSIONS: In the CT urography protocol with enhancement-triggered scan, sensitivity and NPV were highest in the corticomedullary phase, and this phase should be used for bladder assessment. KEY POINTS: • More bladder tumours are detected during the corticomedullary phase than during other phases. • Sensitivity and NPV for bladder cancer detection were highest in corticomedullary phase. • The corticomedullary phase in CT urography should be used for bladder assessment.

Predictive factors for complete renal tumor ablation using RFA.

BACKGROUND: Radiofrequency ablation (RFA) can be used to treat renal masses in patients where surgery is preferably avoided. As tumor size and location can affect ablation results, procedural planning needs to identify these factors to limit treatment to a single session and increase ablation success. PURPOSE: To identify factors that may affect the primary efficacy of complete renal tumor ablation with radiofrequency after a single session. MATERIAL AND METHODS: Percutaneous RFA (using an impedance based system) was performed using computed tomography (CT) guidance. Fifty-two renal tumors (in 44 patients) were retrospectively studied (median follow-up, 7 months). Data collection included patient demographics, tumor data (modified Renal Nephrometry Score, histopathological diagnosis), RFA treatment data (electrode placement), and follow-up results (tumor relapse). Data were analyzed through generalized estimating equations. RESULTS: Primary efficacy rate was 83%. Predictors for complete ablation were optimal electrode placement (P = 0.002, OR = 16.67) and increasing distance to the collecting system (P = 0.02, OR = 1.18). Tumor size was not a predictor for complete ablation (median size, 24 mm; P = 0.069, OR = 0.47), but all tumors ≤2 cm were completely ablated. All papillary tumors and oncocytomas were completely ablated in a single session; the most common incompletely ablated tumor type was clear cell carcinoma (6 of 9). CONCLUSION: Optimal electrode placement and a long distance from the collecting system are associated with an increased primary efficacy of renal tumor RFA. These variables need to be considered to increase primary ablation success. Further studies are needed to evaluate the effect of RFA on histopathologically different renal tumors.

Contrast enhancement in bladder tumors examined with CT urography using traditional scan phases.

BACKGROUND: Bladder assessment in an early contrast-enhancing computed tomography urography (CTU) phase requires that bladder tumors be enhanced using contrast material. PURPOSE: To investigate the enhancement pattern in bladder tumors using a CTU protocol where the scan is enhancement triggered. MATERIAL AND METHODS: Fifty patients diagnosed with bladder cancer were examined during the unenhanced (UP), corticomedullary (CMP), and excretory phases (EP). Twenty-one patients, all aged 50 years or older, were also examined during the nephrographic phase (NP). A ROI placed in the aorta was used to start the scan during the CMP when the attenuation reached 200 Hounsfield units (HU). The NP and EP were started with a 40 s and 300 s delay, respectively, after the CMP was finished. Attenuation and size measurements were made in the axial plane. RESULTS: Mean contrast enhancement of bladder tumors was 37, 25, and 17 HU in the CMP, NP, and EP, respectively. The differences in contrast enhancement were significant across all three phases. Eighty-eight percent of patients showed the highest contrast enhancement in the CMP. In 96% of the cases, contrast enhancement >20 HU was seen. The mean value of the shortest dimension of the bladder tumors was 22 ± 12 mm. CONCLUSION: The contrast enhancement is significantly higher in the CMP than in the NP and EP, suggesting that the CMP is preferable when assessing the bladder in the early contrast enhancing phase.

Three-dimensional computed tomographic analysis of changes to the external features of the nose after surgically assisted rapid maxillary expansion and orthodontic treatment: a prospective longitudinal study.

INTRODUCTION: The aim of this prospective, longitudinal study was to evaluate changes to the external shape and form of the nose after surgically assisted rapid maxillary expansion and orthodontic treatment. The changes were registered using a 3-dimensional computer tomography technique, based on superimposition on the anterior base of the skull. METHODS: The subjects comprised 35 patients (mean age, 19.7 years; range, 16.1-43.9 years). Low-dose, helical computerized tomography images were taken at treatment start and after orthodontic treatment, about 18 months postsurgery. The 3-dimensional models were registered and superimposed on the anterior cranial base. RESULTS: There were in general significant widening and overall anterior and inferior displacement of the nasal soft tissues. The changes varied in size and direction. No correlation was found between the initial and final widths of the nose, or between the initial and final widths of the nostrils. CONCLUSIONS: After surgically assisted rapid maxillary expansion, the most obvious changes to the external features of the nose were at the most lateral alar bases. The difference in lateral displacement profoundly influenced the perception of a more rounded nose. Patients with narrow and constrained nostrils can benefit from these changes. The 3-dimensional superimposition applied in this study is a reliable method, circumventing projection and measurement errors.

Evaluation of surgically assisted rapid maxillary expansion and orthodontic treatment. Effects on dental, skeletal and nasal structures and rhinological findings.

Surgically Assisted Rapid Maxillary Expansion (SARME) is frequently used to treat skeletal maxillary transverse deficiency (MTD) in skeletally mature and non-growing individuals. Despite previous research in the field, questions remain with respect to the long-term stability of SARME and its effects on hard and soft tissue. The overall aim of the present doctoral work was to achieve a greater understanding of SARME, using modern image technology and a multidisciplinary approach, with special reference to effects on the hard and soft tissues and respiration. A more specific aim was to evaluate the long-term stability in a retrospective sample of patients treated with SARME and orthodontic treatment and to compare the results with a matched, untreated control group. The studies in this doctoral project are thus based on two different samples and study designs. The first sample, Study I (Paper I), is a retrospective, consecutive, long-term follow-up material of study models from 31 patients (17 males and 14 females) treated with SARME and orthodontic treatment between 1991 and 2000. The mean pre-treatment age was 25.9 years (SD 9.6) with a mean follow-up time of 6.4 years (SD 3.3). Direct measurements on study models were made with a digital sliding caliper at reference points on molars and canines. To evaluate treatment outcome and long-term stability, the results were compared with study models from an untreated control group, matched for age, gender and follow-up time. The second sample, Study II (Papers II-IV), is a prospective consecutive, longitudinal material of 40 patients scheduled to undergo SARME and orthodontic treatment between 2006 and 2009. In Paper II, one patient was excluded because of a planned adenoidectomy. The final sample comprised 39 patients (16 males and 23 females). The mean age at treatment start was 19.9 years (range 15.9 - 43.9). Acoustic rhinometry, rhinomanometry and a questionnaire were used to assess the degree of nasal obstruction at three time-points; pre-treatment, three months after expansion and after completed treatment (mean 18 months). In Papers III-IV, three patients declined to participate and two had to be excluded because their CT-records were incomplete. The final sample comprised 35 patients (14 males and 21 females). The mean age at treatment start was 19.7 years (range 16.1 - 43.9). Helical CT-images were taken pre treatment and eighteen months' post-expansion. 3D models were registered and superimposed at the anterior cranial base. The automated voxel-based image registration method allows precise, accurate measurements in all areas of the maxilla. In Papers II-IV, the treatment groups constituted their own control groups. The main findings in the retrospective, long-term follow-up study were that SARME and orthodontic treatment normalized the transverse discrepancy and was stable for a mean of 6 years post-treatment. Pterygoid detachment did not entirely eliminate the side effect of buccal tipping of the posterior molars. Relapse is time-related and is most pronounced during the first 3 years after treatment. Thus the retention period should be extended and should be considered for this period. The main rhinological findings in the prospective longitudinal study were that SARME had a short-term, favourable effect on nasal respiration, but the effect did not persist in the long-term. However, subjects with pretreatment nasal obstruction reported a lasting sensation of improved nasal function. SARME and orthodontic treatment had a significant but non-uniform skeletal treatment effect, with significantly greater expansion posteriorly than anteriorly. The expansion was parallel anteriorly but not posteriorly. The lateral tipping of the posterior segment was significant, despite careful surgical separation. No correlation was found between tipping and the patient's age. Furthermore, SARME and orthodontic treatment significantly affected all dimensions of the external features of the nose. The most obvious changes were at the most lateral alar-bases. The difference in lateral displacement profoundly influenced the perception of a more rounded nose. There were no predictive correlations between the changes. Patients with narrow and constrained nostrils can benefit from these changes with respect to the subjective experience of nasal obstruction. It is questionable whether an alar-cinch suture will prevent widening at the alar-base. The 3D superimposition applied in Study II is a reliable method, circumventing projection and measurement errors. In conclusion, SARME and orthodontic treatment normalize the transverse deficiency, with long-term stability. SARME has a favourable effect on the subjective perception of nasal respiration. SARME significantly affects dental, skeletal and nasal structures.

How much dose can be saved in three-phase CT urography? A combination of normal-dose corticomedullary phase with low-dose unenhanced and excretory phases.

OBJECTIVE: The purpose of this study was to investigate the degree to which the total radiation dose for CT urography can be lowered by selective reduction of the dose in the unenhanced and excretory phases when images in these phases are systematically evaluated alongside normal-dose corticomedullary phase images. SUBJECTS AND METHODS: Twenty-seven patients (mean age, 74±9 years) underwent single-bolus CT urography with acquisition in the unenhanced, corticomedullary, and 5-minute excretory phases. The scanning parameters for normal-dose CT urography were as follows: 16×0.75 mm, 120 kV, and automatic exposure control technique reference tube loads of 100, 120, and 100 effective mAs (mAseff). The patients also underwent low-dose unenhanced and excretory phase scanning, in which the dose was escalated stepwise from a volume CT dose index (CTDIvol) of 1.7 to 6.6 mGy (reference 20-40-60-80 mAseff). Images were analyzed for quality and diagnostic confidence. If low-dose scans of three patients were inadequate, the study continued to the next dose level. When 20 patients were successfully included in the unenhanced and excretory phase groups, the study ended. Doses were calculated with a CT patient dosimetry calculator. RESULTS: Combined with the normal dose for corticomedullary phase scanning, doses of CTDIvol 1.5 mGy for the unenhanced phase and CTDIvol 2.7 mGy for the excretory phase were sufficient. The effective dose for three-phase CT urography was lowered from 16.2 to 9.4 mSv, a decrease of 42%. Diagnostic confidence in low-dose images was equal to that in normal-dose images when low-dose unenhanced and excretory phase images were read along-side normal-dose corticomedullary phase images. CONCLUSION: With a three-phase CT urographic protocol, significant dose reductions in the unenhanced and excretory phases can be achieved when these phases are combined with a normal-dose corticomedullary phase.

Immobilized redox mediators for electrochemical NAD(P)+ regeneration.

The applicability of dissolved redox mediators for NAD(P)(+) regeneration has been demonstrated several times. Nevertheless, the use of mediators in solutions for sensor applications is not a very convenient strategy since the analysis is not reagentless and long stabilization times occur. The most important drawbacks of dissolved mediators in biocatalytic applications are interferences during product purification, limited reusability of the mediators, and their cost-intensive elimination from wastewater. Therefore, the use of immobilized mediators has both economic and ecological advantages. This work critically reviews the current state-of-art of immobilized redox mediators for electrochemical NAD(P)(+) regeneration. Various surface modification techniques, such as adsorption polymerization and covalent linkage, as well as the corresponding NAD(P)(+) regeneration rates and the operational stability of the immobilized mediator films, will be discussed. By comparison with other existing regeneration systems, the technical potential and future perspectives of biocatalytic redox reactions based on electrochemically fed immobilized mediators will be assessed.

Measurement of transplanted pancreatic volume using computed tomography: reliability by intra- and inter-observer variability.

BACKGROUND: Unlike other solid organ transplants, pancreas allografts can undergo a substantial decrease in baseline volume after transplantation. This phenomenon has not been well characterized, as there are insufficient data on reliable and reproducible volume assessments. We hypothesized that characterization of pancreatic volume by means of computed tomography (CT) could be a useful method for clinical follow-up in pancreas transplant patients. PURPOSE: To evaluate the feasibility and reliability of pancreatic volume assessment using CT scan in transplanted patients. MATERIAL AND METHODS: CT examinations were performed on 21 consecutive patients undergoing pancreas transplantation. Volume measurements were carried out by two observers tracing the pancreatic contours in all slices. The observers performed the measurements twice for each patient. Differences in volume measurement were used to evaluate intra- and inter-observer variability. RESULTS: The intra-observer variability for the pancreatic volume measurements of Observers 1 and 2 was found to be in almost perfect agreement, with an intraclass correlation coefficient (ICC) of 0.90 (0.77-0.96) and 0.99 (0.98-1.0), respectively. Regarding inter-observer validity, the ICCs for the first and second measurements were 0.90 (range, 0.77-0.96) and 0.95 (range, 0.85-0.98), respectively. CONCLUSION: CT volumetry is a reliable and reproducible method for measurement of transplanted pancreatic volume.

Three-dimensional assessment of transverse skeletal changes after surgically assisted rapid maxillary expansion and orthodontic treatment: a prospective computerized tomography study.

INTRODUCTION: The aim of this prospective longitudinal study was to evaluate transverse skeletal changes after surgically assisted rapid maxillary expansion. The changes were registered by using a 3-dimensional computerized tomography technique based on superimposition on the anterior base of the skull. METHODS: The subjects comprised 35 patients (mean age, 19.7 years; range, 16.1-43.9 years). Low-dose, helical computerized tomography images were taken at treatment start and after orthodontic treatment. The 3-dimensional models were registered and superimposed at the anterior cranial base. RESULTS: Surgically assisted rapid maxillary expansion had a significant transverse skeletal treatment effect, significantly greater posteriorly than anteriorly. The expansion was parallel anteriorly, but posteriorly there was significant transverse tipping. Although there was no statistically significant difference between the changes at the corresponding landmarks, the range of standard deviations was marked. CONCLUSIONS: The results showed that, for registering transverse skeletal changes after surgically assisted rapid maxillary expansion, 3-dimensional superimposition is a reliable method, circumventing projection and measurement errors. Surgically assisted rapid maxillary expansion had a significant but nonuniform skeletal treatment effect. Despite careful surgical separation, pronounced posterior tipping occurred. No correlation was found between the severity of tipping and the patient's age.