Radioiodine Scan Index: A Simplified,Quantitative Treatment Response Parameter for Metastatic Thyroid Carcinoma

Purpose

We aimed to develop and validate a simplified, novel quantification method for radioiodine whole-body scans (WBSs) as a predictor for the treatment response in differentiated thyroid carcinoma (DTC) patients with distant metastasis.

Methods

We retrospectively reviewed serial WBSs after radioiodine treatment from 2008 to 2011 in patients with metastatic DTC. For standardization of TSH simulation, only a subset of patients whose TSH level was fully enhanced (TSH > 80 mU/l) was enrolled. The radioiodine scan index (RSI) was calculated by the ratio of tumor-to-brain uptake. We compared correlations between the RSI and TSH-stimulated serum thyroglobulin (TSH_s_Tg) level and between the RSI and Tg reduction rate of consecutive radioiodine treatments.

Results

A total of 30 rounds of radioiodine treatment for 15 patients were eligible. Tumor histology was 11 papillary and 4 follicular subtypes. The TSH_s_Tg level was mean 980 ng/ml (range, 0.5–11,244). The Tg reduction rate after treatment was a mean of −7 % (range, −90 %–210 %). Mean RSI was 3.02 (range, 0.40–10.97). RSI was positively correlated with the TSH_s_Tg level (R² = 0.3084, p = 0.001) and negatively correlated with the Tg reduction rate (R² = 0.2993, p = 0.037). The regression equation to predict treatment response was as follows: Tg reduction rate = −14.581 × RSI + 51.183.

Conclusions

Use of the radioiodine scan index derived from conventional WBS is feasible to reflect the serum Tg level in patients with metastatic DTC, and it may be useful for predicting the biologic treatment response after radioiodine treatment.     

Significance of SUV on Follow-up F-18 FDG PET at the Anastomotic Site of Gastroduodenostomy after Distal Subtotal Gastrectomy in Patients with Gastric Cancer

Purpose

The aim of this study was to characterize the patterns of fluorodeoxyglucose (FDG) uptake on F-18 FDG positron emission tomography/computed tomography (FDG PET/CT) at the anastomotic site of gastroduodenostomy after distal subtotal gastrectomy in patients with gastric cancer.

Methods

From May 2007 to May 2010, two or more follow-up measurements using FDG PET/CT scans were done for 19 patients (11 men, 8 women; mean age, 62.0 ± 10.3 years) who underwent distal subtotal gastrectomy with gastroduodenostomy between February 2006 and March 2008 for detecting gastric cancer recurrence at our medical center. The FDG PET/CT images were retrospectively reviewed. Patients with local recurrence, regional nodal metastasis or distant metastasis on follow-up studies were excluded. CT and endoscopy were done within 1 month before or after the FDG PET/CT scan. Eight patients had two follow-ups of FDG PET/CT, and 11 patients had three follow-ups. The mean interval between surgery and the first follow-up FDG PET/CT was 12.9 ± 0.8 months (n = 19); between the first and second it was 12.3 ± 1.0 months (n = 19); between the second and third it was 11.6 ± 0.7 months (n = 11). The F-18 FDG uptakes at the anastomotic site and fundus in the remnant stomach were measured by maximum standardized uptake value (SUVmax) using a region of interest technique.

Results

The SUVmax at the anastomotic site was significantly higher than that of the fundus on all series of first, second and third follow-up studies (3.3 ± 1.1 vs. 2.1 ± 0.7, p < 0.001: 3.1 ± 0.9 vs. 2.2 ± 0.7, p = 0.001: 3.0 ± 0.6 vs. 2.1 ± 0.7, p = 0.006, respectively). The SUVmax for the anastomotic site and fundus, and SUVmax ratio for the anastomotic site over the fundus were not significantly different throughout the series.

Conclusion

The SUVmax at the anastomotic site is significantly higher than that of the fundus and does not decrease significantly over time. Therefore, the local recurrence of gastric cancer after surgery could not be definitely differentiated from physiologic uptake or postoperative inflammatory change.     

Reproducibility of Gallbladder Ejection Fraction Measured by Fatty Meal Cholescintigraphy

Purpose

There are conflicting data in the literature regarding the reproducibility of the gallbladder ejection fraction (GBEF) measured by fatty meal cholescintigraphy (CS). We aimed to test the reproducibility of GBEF measured by fatty meal CS.

Methods

Thirty-five subjects (25 healthy volunteers and 10 patients with chronic abdominal pain) underwent fatty meal CS twice in order to measure GBEF1 and GBEF2. The healthy volunteers underwent a repeat scan within 1-13 months from the first scan. The patients underwent a repeat scan within 1-4 years from the first scan and were not found to have chronic acalculous cholecystitis (CAC). Our standard fatty meal was composed of a 60-g Snickers chocolate bar and 200 ml full-fat yogurt.

Results

The mean ± SD values for GBEF1 and GBEF2 were 52 ± 17% and 52 ± 16%, respectively. There was a direct linear correlation between the values of GBEF1 and GBEF2 for the subjects, with a correlation coefficient of 0.509 (p = 0.002). Subgroup data analysis of the volunteer group showed that there was significant linear correlation between volunteer values of GBEF1 and GBEF2, with a correlation coefficient of 0.473 (p = 0.017). Subgroup data analysis of the non-CAC patient group showed no significant correlation between patient values of GBEF1 and GBEF2, likely due to limited sample size.

Conclusions

This study showed that fatty meal CS is a reliable test in gallbladder motility evaluation and that GBEF measured by fatty meal CS is reproducible.     

Implications of Three-Phase Bone Scintigraphy for the Diagnosis of Bisphosphonate-Related Osteonecrosis of the Jaw

Purpose

Bisphosphonate (BP)-related osteonecrosis of the jaw (BRONJ) is a well-known serious complication of BP treatment. This study was undertaken to evaluate the diagnostic usefulness of three-phase bone scintigraphy in patients with BRONJ.

Methods

Forty-one patients (48 lesions) with clinically proven BRONJ (2 males, 39 females, age 74.3 ± 6.7 years) underwent Tc-99 m HDP bone scintigraphy. Visual interpretation and semiquantitative analysis of uptakes using lesion-to-contralateral uptake ratios during the blood pool phase (BUR) and during the osseous phase (OUR) were performed, and relations were sought between these and various clinical parameters.

Results

Three-phase bone scintigraphy showed increased perfusion and blood pooling in 21 (63.6 %) and 27 (81.8 %) of 33 lesions, respectively. The osseous phase was positive for 45 (93.8 %) of the 48 lesions. Of the four inflammatory clinical parameters of BRONJ [pus discharge, pain, swelling, and erythrocyte sedimentation rate (ESR)], patients with three or more parameters had more positive findings in vascular and blood pool phase images (p = 0.033, p = 0.027). By semiquantitative analysis, patients with a positive ESR had statistically higher BUR and OUR (both p < 0.001). Higher stage BRONJ lesions had higher OUR than lower stage lesions (p = 0.003). In addition, bone scintigraphy revealed three clinically covert BRONJ lesions without bone exposure, and four patients were up-staged based on bone scintigraphy.

Conclusions

Bone scintigraphy provides a relatively sensitive means of detecting BRONJ, so it was helpful for accurate BRONJ staging. Furthermore, increased uptakes in vascular and blood pool phases of three-phase bone scintigraphy were related to the inflammatory activity of BRONJ.     

Influence of cone beam CT scanning parameters on grey value measurements at an implant site

Objectives:

The aim of this study was to determine the grey value variation at the implant site with different scan settings, including field of view (FOV), spatial resolution, number of projections, exposure time and dose selections in two cone beam CT (CBCT) systems and to compare the results with those obtained from a multislice CT system.

Methods:

A partially edentulous human mandibular cadaver was scanned by three CT modalities: multislice CT (MSCT) (Philips, Best, the Netherlands), and two CBCT systems: (Accuitomo 170^®, Morita, Japan) and (NewTom 5G^®, QR, Verona, Italy). Using different scan settings 36 and 24 scans were obtained from the Accuitomo and the NewTom, respectively. The scans were converted to digital imaging and communications in medicine 3 format. The analysis of the data was performed using 3Diagnosys^® software (v. 3.1, 3diemme, Cantù, Italy) and Geomagic studio^® 2012 (Morrisville, NC). On the MSCT scan, one probe designating the site for pre-operative implant placement was inserted. The inserted probe on MSCT was transformed to the same region on each CBCT scan using a volume-based three-dimensional registration algorithm. The mean voxel grey value of the region around the probe was derived separately for each CBCT. The influence of scanning parameters on the measured mean voxel grey values was assessed.

Results:

Grey values in both CBCT systems significantly deviated from Hounsfield unit values measured with MSCT (p = 0.0001). In both CBCT systems, scan FOV and spatial resolution selections had a statistically significant influence on grey value measurements (p = 0.0001). The number of projections selection had a statistically significant influence in the Accuitomo system (p = 0.0001) while exposure time and dose selections had no statistically significant influence on grey value measurements in the NewTom (p = 0.43 and p = 0.37, respectively).

Conclusions:

Grey-level values from CBCT images are influenced by device and scanning settings.     

Detection of the genial spinal canal in atrophic mandibles with a CBCT: a cadaver study

Objectives:

The use of a single midline implant to retain a complete mandibular denture when more implants cannot be used is an incipient treatment modality. However, in the mandibular symphysis, the genial spinal canal (GSC) is an anatomical structure with neurovascular content that can be harmed during dental implant surgery. The purpose of the present study was to use CBCT of edentulous atrophic cadaver mandibles and evaluate how often the simulated placement of a single midline implant would contact the GSC if present.

Methods:

CBCT scans of 47 edentulous cadaver mandibles were performed. A digital simulation of the placement of a single midline implant (3.8 × 11.0 mm) was performed, and the implant–GSC contact was evaluated.

Results:

A GSC was detected in the CBCT scan of all atrophic mandibles. In 42 cases (89.4%), the single midline implant contacted the GSC. On average, the five cases without GSC contact had a higher alveolar ridge (4.1 mm) and a lower GSC (0.79 mm) than did the cases with GSC contact.

Conclusions:

CBCT scans can adequately detect the GSC during pre-surgical diagnostics. There is a high risk of implant–GSC contact during surgery of the anterior mandible. However, the clinical relevance of such a contact is not known yet, because none of the clinical studies evaluating a single midline implant has reported any implant–GSC contact-related complications.     

Bone ultrasound velocity in pediatric intensive care unit: a pilot study

Background

Bone loss has been documented in adults in intensive care wards. Children admitted to pediatric intensive care units (PICU) are also exposed to many potential risk factors for bone loss such as immobilization, catabolic state, and nutritional depletion. Quantitative ultrasound technique that measures speed of sound (SOS) correlates with bone mineral density (BMD) and strength. Herein is a clinical prospective longitudinal, observational pilot study to evaluate early bone changes that occur during the first few days of PICU admission.

Methods

Children are hospitalized in a pediatric intensive under general anesthesia and muscle paralysis. Bone SOS at the mid-shaft tibia was measured on the first day of hospitalization and on days 2 to 3 thereafter.

Results

Nineteen children were studied. Bone SOS decreased during the first 3 days of hospitalization from 3,297 ± 315 to 3,260 ± 311 m/min (p < 0.05). The decrease was approximately 1% of the original SOS over the first 2 to 3 days of admission.

Conclusion

There is a significant decrease in bone strength after 3 days in pediatric patients admitted to an intensive care department. Longitudinal studies of a larger group of children are necessary to determine the clinical meaning of the results and to possibly evaluate preventive approaches.     

Assessment of metal artefact reduction around dental titanium implants in cone beam CT

Objectives:

The aim of this study was to investigate if the metal artefact reduction (MAR) tool used in the software of the ORTHOPANTOMOGRAPH^® OP300 (Instrumentarium Dental, Tuusula, Finland) can improve the gray value levels in post-operative implant scans.

Methods:

20 potential implant sites were selected from 5 edentulous human dry mandibles. Each mandible was scanned by a CBCT scanner, and images were produced under three different conditions: implant sites drilled but no implants inserted, implants inserted without application of MAR and implants inserted with application of MAR. Using Geomagic^® Studio 2012 (Geomagic, Morrisville, NC) and 3Diagnosys^® v. 5.3.1 (3Diemme^® SRL, Cantù, Italy) software, three scans of each mandible were superimposed. The mean gray value of identical regions of bone around the implants was derived for each condition. The differences between gray value measurements at implant sites derived from different conditions were assessed.

Results:

A significant difference was found between mean gray values from the scans with no implants inserted and with implants inserted (with and without MAR) (p = 0.012). No significant difference was revealed for gray values measured from scans with and without MAR (p = 0.975).

Conclusions:

The MAR tool in the software of the ORTHOPANTOMOGRAPH OP300 CBCT scanner does not significantly correct the voxel gray values affected by the metal artefact in the vicinity of an implant in human dry mandibles.     

Clinical application of surface projection in the localization of metal foreign bodies using computed tomography scan

Objective:

To analyse the clinical efficacy of surface projection in the localization and removal of metal foreign bodies using CT scan.

Methods:

Total 795 cases with 1008 metal foreign bodies were treated at our hospital in 2012. Pre-operative surface projection was performed to localize foreign bodies in patients under the guidance of CT scan. The removal path from the skin surface to foreign body and puncture site were then determined. Finally, the foreign bodies were extracted using proper foreign body forceps which were chosen according to the size, depth and position of the foreign bodies in different parts of the human body. The incision length, operative time and intraoperative blood loss were recorded. Additionally, outpatient follow-up was scheduled post-operatively for 1 week.

Results:

The accurate localization rate under the guidance of CT scan was 100%, and 1008 pieces of metal foreign bodies were all successfully removed with a removal rate of 100%. The mean incision length was 0.4 ± 0.1 cm, the mean operative time was 4.1 ± 2.0 min and the intraoperative blood loss was 1.1 ± 0.5 ml. These results showed minimal invasiveness, shorter operative time and minimal blood loss, respectively. Additionally, the results of outpatient follow-up showed that the wound healed spontaneously. Moreover, there were no significant bleeding, incision infections or complications.

Conclusion:

Surface projection may be an accurate and effective method for the pre-operative localization and extraction of metal foreign bodies.

Advances in knowledge:

(1) Surface projection was applied for localization of metal foreign bodies in our study. (2) The accurate localization rate of surface projection under the guidance of CT scan was 100%. (3) All foreign bodies were successfully removed with a removal rate of 100%. (4) Surface projection technique has advantages in the removal of foreign bodies.     

The effective dose of different scanning protocols using the Sirona GALILEOS? comfort CBCT scanner

Objectives:

To determine the effective dose and CT dose index (CTDI) for a range of imaging protocols using the Sirona GALILEOS^® Comfort CBCT scanner (Sirona Dental Systems GmbH, Bensheim, Germany).

Methods:

Calibrated optically stimulated luminescence dosemeters were placed at 26 sites in the head and neck of a modified RANDO^® phantom (The Phantom Laboratory, Greenwich, NY). Effective dose was calculated for 12 different scanning protocols. CTDI measurements were also performed to determine the dose–length product (DLP) and the ratio of effective dose to DLP for each scanning protocol.

Results:

The effective dose for a full maxillomandibular scan at 42 mAs was 102 ± 1 μSv and remained unchanged with varying contrast and resolution settings. This compares with 71 μSv for a maxillary scan and 76 μSv for a mandibular scan with identical milliampere-seconds (mAs) at high contrast and resolution settings.

Conclusions:

Changes to mAs and beam collimation have a significant influence on effective dose. Effective dose and DLP vary linearly with mAs. A collimated maxillary or mandibular scan decreases effective dose by approximately 29% and 24%, respectively, as compared with a full maxillomandibular scan. Changes to contrast and resolution settings have little influence on effective dose. This study provides data for setting individualized patient exposure protocols to minimize patient dose from ionizing radiation used for diagnostic or treatment planning tasks in dentistry.     

Improved Detection of Lung or Bone Metastases with an I-131 Whole Body Scan on the 7th Day After High-Dose I-131 Therapy in Patients with Thyroid Cancer

Purpose

The purpose of this study is to compare post-therapy third day and seventh day I-131 whole body scans (3DWBS and 7DWBS) in detecting lung or bone metastasis from well-differentiated thyroid cancer.

Materials and Methods

We enrolled 52 patients with lung or bone metastasis out of 1,152 patients who were treated with high-dose I-131 therapy from January 2008 to June 2009. All patients underwent 3DWBS and 7DWBS. I-131 avidity was classified into three grades: no uptake, suspicious for uptake, and definite uptake. We compared the presence and grades of metastatic lesions on each scan. We categorized all cases into three groups based on I-131 uptake on each scan and compared several clinical parameters including FDG uptake and thyroglobulin (Tg) level among the groups.

Results

Sixty metastatic cases from 52 patients (45 lung and 15 bone metastases) were included. In 35 cases, I-131-avid metastatic lesions were detected by both 3DWBS and 7DWBS (group A). In 15 cases, metastatic lesions were missed on 3DWBS but detected on 7DWBS (group B). In 10 cases, I-131 uptake was not detected on either 3DWBS or 7DWBS (group C). Ten of 45 cases (22.2%) of lung metastasis that were negative on 3DWBS were detected on 7DWBS (p = 0.002). Five of 15 cases (33.3%) of bone metastasis that were negative on 3DWBS were detected on 7DWBS (p = 0.0625). The serum Tg level (TSH stimulated) was significantly different among groups A, B, and C (p = 0.0030). However, after exclusion of cases without a history of I-131 therapy, there was no significant difference in serum Tg level among the groups (p = 0.2330). The number of cases with a prior history of metastasis was higher in group A than in group B (p = 0.0069). However, there was no significant difference in prior history of metastasis between groups A and C (p = 0.8107).

Conclusion

7DWBS showed more lung or bone metastatic lesions than 3DWBS. After high-dose I-131 therapy, 7DWBS should be considered regardless of the results of the 3DWBS for the diagnosis of lung or bone metastasis from well-differentiated thyroid cancer.     

Prognostic Value of Metabolic Tumor Volume on 11C-Methionine PET in Predicting Progression-Free Survival in High-Grade Glioma

Purpose

C-11 methionine (MET) PET is commonly used for diagnosing high-grade glioma (HGG). Recently, volumetric analysis has been widely applied to oncologic PET imaging. In this study, we investigated the prognostic value of metabolic tumor volume (MTV) on MET PET in HGG.

Methods

A total of 30 patients with anaplastic astrocytoma (n = 12) and glioblastoma multiforme (n = 18) who underwent MET PET before treatment (surgery followed by chemo-radiotherapy) were retrospectively enrolled. Maximal tumor-to-normal brain ratio (TNR_max, maximum tumor activity divided by mean of normal tissue) and MTV (volume of tumor tissue that shows uptake >1.3-fold of mean uptake in normal tissue) were measured on MET PET. Adult patients were classified into two subgroups according to Radiation Therapy Oncology Group Recursive Partitioning Analysis (RTOG RPA) classification. Prognostic values of TNR_max, MTV and clinicopathologic factors were evaluated with regard to progression-free survival (PFS).

Results

Median PFS of all patients was 7.9 months (range 1.0–53.8 months). In univariate analysis, MTV (cutoff 35 cm³) was a significant prognostic factor for PFS (P = 0.01), whereas TNR_max (cutoff 3.3) and RTOG RPA class were not (P = 0.80 and 0.61, respectively). Treatment of surgical resection exhibited a borderline significance (P = 0.06). In multivariate analysis, MTV was the only independent prognostic factor for PFS (P = 0.03).

Conclusion

MTV on MET PET is a significant and independent prognostic factor for PFS in HGG patients, whereas TNR_max is not. Thus, performing volumetric analysis of MET PET is recommended in HGG for better prognostication.     

Comparison of mandibular bone microarchitecture between micro-CT and CBCT images

Objectives:

To compare microarchitecture parameters of bone samples scanned using micro-CT (µCT) to those obtained by using CBCT.

Methods:

A bone biopsy trephine bur (3 × 10 mm) was used to remove 20 cylindrical bone samples from 20 dry hemimandibles. Samples were scanned using µCT (µCT 35; SCANCO Medical, Brüttisellen, Switzerland) with a voxel size of 20 µm and CBCT (3D Accuitomo 170; J. Morita, Kyoto, Japan) with a voxel size of 80 µm. All corresponding sample scans were aligned and cropped. Image analysis was carried out using BoneJ, including the following parameters: skeleton analysis, bone surface per total volume (BS/TV), bone volume per total volume (BV/TV), connectivity density, anisotropy, trabecular thickness and spacing, structure model index, plateness and fractal dimension. Pearson and Spearman correlation coefficients (R) were calculated. CBCT values were then calibrated using the slope of the linear fit with the µCT values. The mean error after calibration was calculated and normalized to the standard deviation of the µCT values.

Results:

R-values ranged between 0.05 (plateness) and 0.83 (BS/TV). Correlation was significant for both Spearman and Pearson’s R for 8 out of 16 parameters. After calibration, the smallest normalized error was found for BV/TV (0.48). For other parameters, the error range was 0.58–2.10.

Conclusions:

Despite the overall correlation, this study demonstrates the uncertainty associated with using bone microarchitecture parameters on CBCT images. Although clinically relevant parameter ranges are not available, the errors found in this study may be too high for some parameters to be considered for clinical application.     

Gemstone spectral imaging reduced artefacts from metal coils or clips after treatment of cerebral aneurysms: a retrospective study of 35 patients

Objective:

This study aimed to evaluate the effect of gemstone spectral imaging (GSI) for metal artefact reduction in cerebral artery CT angiography (CTA) after metal coils or clips treatment.

Methods:

35 patients with cerebral aneurysms were treated with metal coils or clips and underwent CTA using gemstone spectral CT between February and December 2013. The data were reconstructed into three image groups including Group A (quality check images with 140 kVp), Group B (monochromatic image sets in the range of 40–140 keV) and Group C [monochromatic image sets with metal artefacts reduction software (MARS GE Medical Systems, Waukesha, WI)]. CT attenuation value of cerebral artery, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR) and the subjective score of all images were measured and compared statistically.

Results:

CT attenuation value of cerebral artery decreased in Groups B and C as the photon energy increased. The average energy levels of 60.05 ± 5.37 and 59.93 ± 5.57 keV presented the best CNR in Groups B and C, respectively. CNR values, SNR values and the subjective scores of the image quality of the two sets were higher than those of Group A.

Conclusion:

GSI reduced metal artefact and improved the image quality of CTA after metal coils or clips treatment in patients with cerebral aneurysm. The monochromatic images at the average energy level of 60.05 ± 5.37 keV with MARS and 59.93 ± 5.57 keV without MARS were suggested to be the optimal parameters.

Advances in knowledge:

GSI could reduce metal artefact after metal coils or clips treatment in patients with cerebral aneurysm.     

Relations Between Pathological Markers and Radioiodine Scan and 18F-FDG PET/CT Findings in Papillary Thyroid Cancer Patients With Recurrent Cervical Nodal Metastases

Purpose

The aim of this study was to investigate relationships between the immunohistochemical results and radioiodine scan and ¹⁸F-FDG PET findings in papillary thyroid cancer (PTC) patients with recurrent cervical nodal metastases.

Methods

A total of 46 PTC patients who had undergone a radioiodine scan and/or ¹⁸F-FDG PET/CT and a subsequent operation on recurrent cervical lymph nodes were enrolled. Twenty-seven patients underwent ¹⁸F-FDG PET/CT, 8 underwent radioiodine scans, and 11 underwent both scans. In all surgical specimens, the immunoexpressions of thyroglobulin (Tg), sodium-iodide symporter (NIS), glucose transporter 1 (Glut-1), and somatostatin receptor 1 and 2A (SSTR1 and SSTR2A) were assessed, and associations between these expressions and radioiodine scan and ¹⁸F-FDG PET findings were evaluated.

Results

Of the 38 patients who underwent ¹⁸F-FDG PET/CT, all patients with weak Tg expression had positive ¹⁸F-FDG uptake, while only 45 % of the patients with moderate or strong Tg expression showed positive uptake (p = 0.01). The proportion of patients with positive ¹⁸F-FDG uptake increased as the degree of Glut-1 expression with luminal accentuation increased. Of the 19 patients who underwent a radioiodine scan, the proportion with positive radioiodine uptake was greater among patients with strong NIS and SSTR2A expression than among patients expressing these markers at weak levels (p = 0.04 for all). All three patients with weak Tg expression were negative for radioiodine uptake.

Conclusion

The ¹⁸F-FDG uptakes of recurrent cervical nodes are related to strong Glut-1 expression with luminal accentuation and weak Tg expression, whereas radioiodine uptake is related to the strong expressions of NIS and SSTR2A.     

Factors Affecting Changes in the Glomerular Filtration Rate after Unilateral Nephrectomy in Living Kidney Donors and Patients with Renal Disease

Purpose

We evaluated the factors affecting changes in the postoperative glomerular filtration rate (GFR) after unilateral nephrectomy in living kidney donors and patients with renal disease.

Methods

We studied 141 subjects who underwent living donor nephrectomy for renal transplantation (n = 75) or unilateral nephrectomy for renal diseases (n = 66). The GFR of the individual kidney was determined by Tc-99m DTPA scintigraphy before and after nephrectomy. By performing multiple linear regression analysis, we evaluated the factors that are thought to affect changes in GFR, such as age, sex, body mass index (BMI), preoperative GFR, preoperative creatinine level, operated side, presence of diabetes mellitus (DM), presence of hypertension (HTN), and duration of follow-up.

Results

In both the donor nephrectomy and the disease nephrectomy groups, GFR increased significantly after nephrectomy (46.9 ± 8.4 to 58.1 ± 12.5 vs. 43.0 ± 9.6 to 48.6 ± 12.8 ml/min, p < 0.05). In the donor nephrectomy group, age was significantly associated with change in GFR (β = -0.3, p < 0.005). In the disease nephrectomy group, HTN, preoperative creatinine level, and age were significantly associated with change in GFR (β = -6.2, p < 0.005; β = -10.9, p < 0.01; β = -0.2, p < 0.01, respectively). This compensatory change in GFR was not significantly related to sex, duration of follow-up, or operated side in either group.

Conclusions

The compensatory change in the GFR of the remaining kidney declined with increasing age in both living kidney donors and patients with renal disease.     

Dynamic 1.5-T vs 3-T true fast imaging with steady-state precession (trueFISP)-MRI sequences for assessment of velopharyngeal function

Objectives:

To compare the image quality of MRI scans produced with 1.5- and 3.0-T devices during functional test condition.

Methods:

65 MRI scans obtained with 1.5- (n = 43) or 3.0-T (n = 22) true fast imaging with steady-state precession (trueFISP) sequences from patients with a history of a cleft palate were evaluated. Two experts assessed the MRI scans, independently of each other, and blinded to the MRI technique used. Subjective ratings were entered on a five-point Likert scale. The median planes of three anatomical structures (velum, tongue and pharyngeal wall) were assessed in three functional states (at rest, during phonation of sustained “e” and during articulation of “kkk”). In addition, MRI scans taken during velopharyngeal closure were evaluated.

Results:

Under blinded conditions, both observers (radiologist and orthodontist) independently rated the quality of 1.5-T scans higher than that of 3.0 T. Statistical analysis of pooled data showed that the differences were highly significant (p < 0.009) in 4 out of 10 test conditions. The greatest differences in favour of 1.5 T were observed for MRI scans of the velum.

Conclusions:

1.5 T used with trueFISP may be preferable over 3.0-T trueFISP for the evaluation of the velopharyngeal structures in the clinical routine.     

Correlation Analysis and Prognostic Impact of 18F-FDG PET and Excision Repair Cross-Complementation Group 1 (ERCC-1) Expression in Non-Small Cell Lung Cancer

Purpose

The aim of this study was to determine the relationship between [¹⁸]-2-fluoro-2-deoxy-D-glucose (FDG) uptake and excision repair cross-complementation group 1 (ERCC-1) expression and to evaluate the prognostic effect of these two factors in resectable non-small cell lung cancer (NSCLC) patients.

Methods

We retrospectively reviewed 212 patients with resectable NSCLC who underwent FDG positron emission tomography/computed tomography (PET/CT) scan for cancer staging and ERCC-1 expression analysis between January 2008 to December 2011. All patients were then followed-up for survival analysis. Semiquantitative evaluation of ERCC-1 was performed with the H-scoring system and was correlated with maximum standardized uptake value (SUVmax) of NSCLC. Univariate and multivariate analyses were performed to evaluate for FDG uptake and ERCC-1 expression predicting overall survival.

Results

In 212 patients (139 male, median age 68 ± 9.11), 112 patients had ERCC-positive tumors and 100 patients had ERCC-negative tumors. There was no significant difference in SUVmax between ERCC-1-positive tumors (8.02 ± 5.40) and ERCC-1-negative tumors (7.57 ± 6.56, p = 0.584). All patients were followed-up for a median of 40.5 months (95 % confidence interval [CI], 38.5–42.2 months). Univariate analysis and multivariate analysis for all patients showed that both ERCC-1 expression (hazard ratio [HR], 2.78; 95 % CI, 1.20–6.47) and FDG uptake (HR, 4.50; 95 % CI, 2.07–9.77) independently predicted overall survival.

Conclusions

We have found no statistical correlation between FDG uptake and ERCC-1 expression in NSCLC. However, both higher FDG uptake and positive ERCC-1 expression are independent predictive markers of prognosis, suggesting that both should be obtained during patient workup.     

Influence of exposure factors on the variability of CBCT voxel values: a phantom study

Objectives:

To assess the influence of milliamperage and kilovolt peak (kVp) on the variability of cone beam CT (CBCT) voxel values.

Methods:

CBCT scans were obtained from radiographic phantoms in varying concentrations of dipotassium hydrogen phosphate solutions (200–1200 mg ml⁻¹) under different protocols of milliamperage and kVp. In addition, scans were performed with and without a dental implant and exo-mass. The variability of CBCT voxel values was measured on each scan, and factorial analysis of variance and the post hoc Tukey test were performed (α = 0.05). Linear regression was performed to assess the relationship between voxel value variability and dipotassium hydrogen phosphate concentration.

Results:

milliamperage and the presence of a dental implant did not produce significant interference (p = 0.28 and 0.87, respectively) in voxel value variability. Scans at the highest kVp value presented a significant reduction (p ≤ 0.0001) in voxel value variability when only exo-mass was not present. Voxel value variability was not influenced by exo-mass in scans at the highest levels of milliamperage and kVp. The presence of exo-mass produced a significant reduction (p ≤ 0.0001) in voxel value variability in most of the scans. Higher concentrations yielded greater variations in voxel values in all scans, except for those operating at the highest levels of mAs and kVp.

Conclusions:

mAs did not influence the variability of CBCT voxel values; higher kVp reduced such variability when only the object was smaller than the field of view.