Pelvic Computed Tomography Examinations Research Articles

Value of deep-learning image reconstruction at submillisievert CT for evaluation of the female pelvis

To assess the value of deep-learning reconstruction (DLR) at submillisievert computed tomography (CT) for the evaluation of the female pelvis, with standard dose (SD) hybrid iterative reconstruction (IR) images as reference. The present study enrolled 50 female patients consecutively who underwent contrast-enhanced abdominopelvic CT for clinically indicated reasons. Submillisievert pelvic images were acquired using a noise index of 15 for low-dose (LD) scans, which were reconstructed with DLR (body and body sharp), hybrid-IR, and model-based IR (MBIR). Additionally, SD scans were reconstructed with a noise index of 7.5 using hybrid-IR. Radiation dose, quantitative image quality, overall image quality, image appearance using a five-point Likert scale (1-5: worst to best), and lesion evaluation in both SD and LD images were analysed and compared. The submillisievert pelvic CT examinations showed a 61.09±4.13% reduction in the CT dose index volume compared to SD examinations. Among the LD images, DLR (body sharp) had the highest quantitative quality, followed by DLR (body), MBIR, and hybrid-IR. LD DLR (body) had overall image quality comparable to the reference (p=0.084) and favourable image appearance (p=0.209). In total, 40 pelvic lesions were detected in both SD and LD images. LD DLR (body and body sharp) exhibited similar diagnostic confidence (p=0.317 and 0.096) compared with SD hybrid-IR. DLR algorithms, providing comparable image quality and diagnostic confidence, are feasible in submillisievert abdominopelvic CT. The DLR (body) algorithm with favourable image appearance is recommended in clinical settings.

Obstetric pelvimetry by three-dimensional computed tomography in non-pregnant Japanese women: a retrospective single-center study

Objective While a basic understanding of pelvic size and typology is still important for obstetricians, pelvic measurement data for Japanese women are very scarce. To our best knowledge, no large-scale pelvimetry studies of Japanese women have been made for the past 50 years. This study aimed to investigate the accurate size, particularly the obstetric conjugate (OC) and transverse diameter of the pelvic inlet (TD), of modern Japanese women, using three-dimensional (3D) computed tomography (CT), and to obtain their reference values. Methods This retrospective, single-center observational study enrolled Japanese non-pregnant women aged between 20 and 40 years, who underwent pelvic CT examination from 2016 to 2021. CT was performed for various reasons, including acute abdomen, search for cancer metastases, and follow-up of existing disease. However, no cases were taken for pelvic measurements. Pelvimetry was performed retrospectively using a 3D workstation. The OC was measured on a strict lateral view and the TD was measured on an axial-oblique view. Other clinical data, such as age, height, and weight, were also extracted from the medical charts and analyzed. Results A total of 1,263 patients were enrolled, with the mean age of 32.7 years (standard deviation [SD] 6.2). The mean height, weight, and body mass index were 158.8 cm (SD 5.8), 54.8 kg (SD 11.7), and 21.7 kg/m2 (SD 4.4), respectively. The mean OC length was 127.0 mm (SD 9.5, 95% confidence interval [CI] 126.5–127.5), while the mean TD length was 126.8 mm (SD 7.5, 95% CI 126.4–127.2). Both values were normally distributed. Height was significantly associated with OC (regression coefficient = 0.75 [95% CI 0.66–0.84], p < .001) and TD (regression coefficient = 0.63 [95% CI 0.56–0.70], p < .001). Age showed a weak but statistically significant positive association with TD (regression coefficient = 0.14 [95% CI 0.07–0.20], p < .001) and OC (regression coefficient = −0.10 [95% CI −0.18 to −0.01], p = .026). Conclusion The 3D CT pelvimetry in 1,263 non-pregnant Japanese women of childbearing age revealed the mean OC and TD of 127.0 mm, and 126.8 mm, which were 11.8 mm and 4.3 mm larger, respectively, than those in the survey in 1972. Our data will be referred to in clinical practice as the standard pelvic measurement values for the Japanese population.

Patient-specific fetal radiation dosimetry for pregnant patients undergoing abdominal and pelvic CT imaging.

Accurate estimation of fetal radiation dose is crucial for risk-benefit analysis of radiological imaging, while the radiation dosimetry studies based on individual pregnant patient are highly desired. To use Monte Carlo calculations for estimation of fetal radiation dose from abdominal and pelvic computed tomography (CT) examinations for a population of patients with a range of variations in patients' anatomy, abdominal circumference, gestational age (GA), fetal depth (FD), and fetal development. Forty-four patient-specific pregnant female models were constructed based on CT imaging data of pregnant patients, with gestational ages ranging from 8 to 35weeks. The simulation of abdominal and pelvic helical CT examinations was performed on three validated commercial scanner systems to calculate organ-level fetal radiation dose. The absorbed radiation dose to the fetus ranged between 0.97 and 2.24 mGy, with an average of 1.63±0.33 mGy. The CTDIvol -normalized fetal dose ranged between 0.56 and 1.30, with an average of 0.94±0.25. The normalized fetal organ dose showed significant correlations with gestational age, maternal abdominal circumference (MAC), and fetal depth. The use of ATCM technique increased the fetal radiation dose in some patients. A technique enabling the calculation of organ-level radiation dose to the fetus was developed from models of actual anatomy representing a range of gestational age, maternal size, and fetal position. The developed maternal and fetal models provide a basis for reliable and accurate radiation dose estimation to fetal organs.

REDUCTION OF THE COMPUTED TOMOGRAPHY DOSE TO THE GONADS OF ADOLESCENT AND YOUNG ADULT MALES THROUGH USE OF A TUNGSTEN-CONTAINING RUBBER SHEET.

This study aims to measure the shielding effect of a novel tungsten rubber sheet (TRS) on the exposure of male gonads to ionizing radiation during upper abdominal and abdominal plus pelvic computed tomography (CT) examinations. The air kerma at the gonad with and without shielding was measured using an anthropomorphic body phantom. Gonads were shielded using: (1) 360° wrap with TRS (0.5-mm thick) and (2) 180° wrap with TRS. The air kerma at a position of male gonads in a pelvic scan was 21.8mGy, even when the gonads were in the off-axis range. The TRS reduced the dose to the male gonads in abdominal plus pelvic CT examinations by 61% and 38% for the 360° and 180° TRS wrap, respectively.

Radiation Dose Optimization Based on Saudi National Diagnostic Reference Levels and Effective Dose Calculation for Computed Tomography Imaging: A Unicentral Cohort Study

Few studies have reviewed the reduction of doses in Computed tomography (CT), while various diagnostic procedures use ionizing radiation to explore the optimal dose estimate using multiple exposure quantities, including milliampere-seconds, kilovoltage peak, and pitch factors while controlling the CT dose index volume (CTDIvol) and dose length product (DLP). Therefore, we considered optimizing CT protocols to reduce radiation and organ doses during head, chest, abdominal, and pelvic CT examinations. For establishing institutional diagnostic reference levels as a benchmark to correlate with national diagnostic reference levels (NDRLs) in KSA conforming to international guidelines for radiation exposure, 3000 adult-patients underwent imaging of organs. Dose parameters were obtained using Monte Carlo software and adjusted using the Siemens Teamplay™ software. CTDIvol, DLP, and effective dose were 40.67 ± 3.8, 757 ± 63.2, and 1.74 ± 0.19, for head; 14.9 ± 1.38, 547 ± 42.9, and 7.27 ± 0.95 for chest; and 16.84 ± 1.45, 658 ± 53.4, and 10.2 ± 0.66 for abdomen/pelvis, respectively. The NDRL post-optimization comparison showed adequate CT exposure. Head CT parameters required additional optimization to match the NDRL. Therefore, calculations were repeated to assess radiation doses. In conclusion, doses could be substantially minimized by selecting parameters per clinical indication of the study, patient size, and examined body region. Additional dose reduction to superficial organs requires a shielding material.

MRI-Based Radiotherapy Planning to Reduce Rectal Dose in Excess of Tolerance.

Materials and Methods This prospective single-arm study enrolled 15 men treated with IG-IMRT for localized prostate cancer. All participants received a dedicated 3 Tesla MRI examination of the prostate in addition to a pelvic CT examination for treatment planning. Two volumetric modulated arc therapy (VMAT) plans with a prescription dose of 79.2 Gy were designed using identical constraints based on CT- and MRI-defined consensus volumes. The volume of rectum exposed to 70 Gy or more was compared using the Wilcoxon paired signed rank test. Results For CT-based treatment plans, the median volume of rectum receiving 70 Gy or more was 9.3 cubic centimeters (cc) (IQR 7.0 to 10.2) compared with 4.9 cc (IQR 4.1 to 7.8) for MRI-based plans. This resulted in a median volume reduction of 2.1 cc (IQR 0.5 to 5.3, P < .001). Conclusions Using MRI to plan prostate IG-IMRT to a dose of 79.2 Gy reduces the volume of rectum receiving radiation dose in excess of tolerance (70 Gy or more) and should be considered in men who are at high risk for late rectal toxicity and are not good candidates for other rectal sparing techniques such as hydrogel spacer. This trial is registered with NCT02470910.

Lumbar Disc Herniation is a Nonnegligible Factor for the Degeneration of Sacroiliac Joints

Sacroiliac joint (SIJ) abnormality is a potential source of low back pain (LBP), therefore numerous patients receive various treatments because of the degenerative changes of SIJ. However, the outcome is unfavorable for patients because these morphologic alterations are common but not the origins of LBP. Previous studies revealed lumbar fusion and transitional vertebra increased the prevalence of degeneration of SIJ. Lumbar disc herniation (LDH) is one of the most common lumbar diseases, but there is no study regarding the relationship between LDH and SIJ degradation. The aim of this study was to investigate the severity of SIJ degeneration in patients with LBP with LDH. The relationship between degenerative changes of SIJ and LDH was also assessed. Retrospective observational study. This study was conducted in 2 medical centers located in southeast and midwest China, respectively. Lumbar and pelvic computed tomography (CT) scans of patients with LDH (LDH group) from January 2016 to May 2020 were reviewed using a picture archiving and communication system. The control group was age, gender, and body mass index-matched patients with LBP without LDH. Patients underwent whole abdomen and pelvic CT examinations due to non-musculoskeletal disorders. Scores of SIJ degeneration were compared between patients with LDH and the control group. Differences in SIJ degeneration among patients with LDH with diverse characteristics, symptoms, and complications were also evaluated. Univariate and multivariate linear mixed model (LMM) was chosen to identify the factors associated with SIJ degeneration. CT examinations of 782 patients with LDH were assessed, whereas 223 patients were in the control group. The SIJ degeneration score of the LDH group and control group were 6.00 (5.00) and 3.00 (4.00) (P < 0.05). Age and whether patients suffered from LDH were included in the LMM, which involved all reviewed patients (P < 0.05). Regarding the characteristics of LDH, the patients with more herniated discs had more severe SIJ degeneration. The score of SIJ degradation in patients with upper LDH was significantly higher than the other patients with LDH (12.00 [4.00] vs. 6.00 [4.00]; P < 0.05). Similarly, more significant SIJ degeneration was observed in patients with LDH who had secondary lumbar spinal stenosis (10.00 [4.00] vs. 5.00 [4.00]; P < 0.05). The scores of SIJ degradation were significantly greater in patients with LDH with sciatica, numbness, weakness, and/or cauda equina syndrome. Age and LDH were identified as associated factors for more serious degeneration of SIJ among patients with LDH. The main limitation of this study was the retrospective observational nature. Hence our study described that SIJ degeneration was relevant to LDH, but the causal relationship was uncertain. Magnetic resonance imaging was not chosen in this study. The SIJ degeneration in patients with LDH was more serious than in individuals without LDH. SIJ degeneration was more significant in patients with LDH with more pathological alterations, symptoms, and complications. Age and LDH relate to SIJ degeneration. Therefore the diagnosis and selection of treatment for SIJ changes should comprehensively consider the coexistence of LDH.

Acetabular shape and orientation of the spastic hip in children with cerebral palsy.

To see if three-dimensional (3D) methods could bring new understanding to acetabular changes in shape and orientation in the spastic hip and in which direction(s) acetabular orientation might change, which is crucial for planning appropriate hip correction surgery. We performed a retrospective study of pelvic computed tomography (CT) examinations in 20 consecutive patients (10 females, 10 males). The mean age of patients was 12 years 9 months (SD 2y; range: 9-16y) at the time of the CT examination. The control group consisted of 18 consecutive pelvic CT examinations (36 acetabula) of deceased individuals (six females, 12 males) aged 4 to 17 years (mean age: 10y 6mo; SD 5y 2mo) whose whole-body CT scans were taken shortly after their death. We compared 3D CT reconstructions of 28 unstable and dislocated hips in children with bilateral cerebral palsy (Gross Motor Function Classification System levels IV and V) with the unaffected side and typically developing controls to assess spatial orientation (inclination, anteversion, and tilt), acetabular volume, and surface area. Additionally, we analysed the multiple factors that may lead to structural and spatial changes of the acetabulum. Patients with dislocated and spastic hips had significantly lower anteversion (-3.2° and -1.4° respectively, p<0.001), increased inclination (85.2° and 85.3° respectively, p<0.001), and decreased tilt (24.6° [p=0.014] and 20.7° [p=0.013] respectively) compared with typically developing individuals. Regarding acetabular volume and surface area, dislocated and unstable hips had significantly lower volume (17.6ml vs 31.5ml respectively, p<0.001) and surface area (28.9cm2 vs 36.2cm2 respectively, p<0.001) than unaffected hips. Among several factors, only Reimer's migration index had an influence on acetabular orientation (i.e. anteversion, p=0.01), volume (p<0.001), and surface (p=0.004). Acetabula in patients with spastic hip disease were severely retroverted with increased steepness; acetabular orientation was distorted superoposteriorly. In rare cases, acetabular orientation was distorted only superiorly or superoanteriorly. Acetabular orientation was distorted superoposteriorly in most patients with severe bilateral cerebral palsy. More pronounced acetabular changes were found in hips with a higher Reimer's migration index.

Sex Identification Using Adult Pelvic 3D CT Scan: An Anthropometric Study

In anthropological assessments, pelvic indices are used as additional measurements. Computed tomography (CT) is used to examine modern human variation and extending osteological assessment resources to researchers, which provides more quantitative data. This study aims to obtain data on age distribution of adults who were performed 3D CT pelvis and radiometric variables in pelvic anthropometry studies. Methods: This study used observational analytical design with cross-sectional approach. Population of study was all patients in Radiology Installation of Dr. Soetomo General Hospital, Surabaya, Indonesia who underwent pelvic 3D CT examination from September to December 2019. Radiologic component and demographic data were collected and statistically analyzed. Results: There were 204 samples included, where it was found that the patients’ mean age was 50.23 ± 14.36 years. All radiologic components were also significantly different between sexes (p<0.05), except for transverse diameter of sacral segment (p=0.180). Conclusion: There were differences in age distribution of adults undergoing pelvic 3D CT as well as radiometric variables in pelvic anthropometric studies. Multicentric studies are needed to obtain a greater variety of data and produce more accurate data and formulas.

Value of Follow-Up Chest Computed Tomography in the Surveillance of Patients with Hepatocellular Carcinoma.

PurposeTo evaluate the value of follow-up chest CT in the surveillance of HCC patients.BackgroundImaging guidelines for the surveillance of hepatocellular carcinoma (HCC) patients recommend multiple follow-up computed tomography (CT) examinations of the chest, abdomen, and pelvis. Imaging studies are a major driver of rising healthcare costs. The appropriate use of imaging studies must be evaluated to provide valued health care.MethodsWe reviewed the radiology reports of baseline and follow-up chest, abdominal, and pelvic CT examinations of HCC patients. We categorized the incidence of malignancy in the chest and abdomen for the baseline and follow-up examinations. We also categorized the follow-up examinations as showing improved disease, stable disease, or disease progression. We correlated any progression of disease in the chest with progression of disease in the abdomen. We determined the extent to which disease progression in the chest occurred alongside that in the abdomen. Descriptive statistical analysis was carried out using R (version 3.5.2, R Development Core Team).ResultsOf the 226 patients included in our study, only 7 (3%) had disease progression in the chest without corresponding disease progression in the abdomen and pelvis on follow-up CT. Only 1.8% of patients with disease progression in the chest had a negative CT chest at baseline.ConclusionFollow-up chest CT has limited benefit in the surveillance of HCC patients, especially those with negative baseline chest CT findings.

Computed Tomography Characteristics of the Acetabulum in Developmental Dysplasia of the Hip

Background: Low-dose computed tomography (CT) is the preferred method for post-reduction evaluation of hips of infants in spica casts, but the assessment of acetabular morphological features in developmental dysplasia of the hip (DDH) using CT has not be done before. Objectives: To determine CT imaging characteristics of the acetabulum in DDH and to be able to determine DDH in pelvic CT examinations performed for different purposes. Patients and Methods: CT images of 102 consecutive patients with DDH (90 females, 12 males) and 51 age-matched controls (26 females, 25 males) were included in this study. Acetabular shape abnormalities, surface irregularity, subcortical sclerosis, shallowing, and measurement of acetabular cortical bone thickness were evaluated in coronal reformatted images. Differences in the cortical thickness of dysplastic and normal hips were assessed. Results: Forty-four patients (43.1%) had unilateral and 58 had bilateral DDH (56.9%). Acetabular margin irregularity was present in all patients with unilateral DDH and 55 of the 58 patients with bilateral DDH (94%). Thickening on the inferior part of the ilium compared to the normal side was seen in 41 of the 44 unilateral DDH patients (93%). In the 44 patients with unilateral DDH, the mean cortical thickness measured from the central part of the acetabulum was 0.86 ± 0.03 mm and 0.65 ± 0.03 mm on the normal and dysplastic sides, respectively (P = 0.0001). This difference was more distinct at the acetabular rim, measuring 1.11 ± 0.06 mm and 0.70 ± 0.04 mm on normal and dysplastic sides, respectively (P = 0.0001). Conclusion: Acetabular marginal irregularity and flattening is a reliable finding in the diagnosis of DDH when combined with thickening on the inferior part of ilium and will help in the diagnosis of DDH in patients older than 6 months old with a pelvic CT scan due to diseases other than DDH.

Radiation dose reduction for musculoskeletal computed tomography of the pelvis with preserved image quality.

To analyze the impact of pelvic computed tomography (CT) technique optimization on estimated dose and subjective and objective image quality. An institutional review board (IRB)-approved retrospective records review was performed with waived informed consent. Five CT scanners (various manufacturers/models) were standardized to match the lowest dose profile on campus via subjective assessment of clinical images by experienced musculoskeletal radiologists. The lowest dose profile had previously been established through image assessment by experienced musculoskeletal radiologists after a department-wide radiation dose reduction initiative. A consecutive series of 60 pre- and 59 post-optimization bony pelvis CTs were analyzed by two residents, who obtained signal-to-noise ratio for femoral cortex and marrow, gluteus medius muscle, and subcutaneous and visceral fat in a standardized fashion. Two blinded attending radiologists ranked image quality from poor to excellent. Pre- and post-optimization subjects exhibited no difference in gender, age, or BMI (p > 0.2). Mean CT dose index (CTDIvol) and dose-length product (DLP) decreased by approximately 45%, from 39± 14 to 18± 12mGy (p < 0.0001) and 1,227± 469 to 546± 384mGy-cm (p < 0.0001). Lower body mass index (BMI) was associated with a larger dose reduction and higher BMI with higher DLP regardless of pre- or post-optimization examination. Inter-observer agreement was 0.64-0.92 for SNR measurements. Cortex SNR increased significantly for both observers (p < 0.02). Although qualitative image quality significantly decreased for one observer (p < 0.01), adequate mean quality (3.3 out of 5) was maintained for both observers. Subjective and objective image quality for pelvic CT examination remains adequate, despite a substantially reduced radiation dose.

Ovarian Cancer: Prevalence in Incidental Simple Adnexal Cysts Initially Identified in CT Examinations of the Abdomen and Pelvis.

Purpose To evaluate the rate of malignancy in incidentally detected simple adnexal cysts at computed tomography (CT) to determine if simple-appearing cysts require follow-up. Materials and Methods In this HIPAA-compliant, institutional review board-approved retrospective cohort study, an institutional database was searched for abdominal and pelvic CT studies performed between June 2003 and December 2010 in women reported to have adnexal cysts. Adnexal cyst characterization was determined by prospective report description as well as image review by a research fellow and by a fellowship-trained abdominal radiologist for examinations with disagreement between the original report and the research fellow's assessment. Patients with known ovarian cysts or ovarian cancer at time of the index CT examination were excluded. Clinical outcome was assessed by using follow-up imaging studies, medical records, and the state cancer registry. Benign outcome was determined by benign findings at surgery, a decrease in size or resolution of a simple-appearing cyst at follow-up imaging, or stability of the cyst for at least 1 year. Descriptive statistics and 95% confidence intervals (CIs) were calculated. Results Among 42 111 women who underwent abdominal and pelvic CT examinations in the study period, 2763 (6.6%; 95% CI: 6.3%, 6.8%) (mean age, 48.1 years ± 18.1; range, 15-102 years) had a newly detected finding of ovarian cyst described in the body or impression section of the report. Median cyst size was 3.1 cm (range, 0.8-20.0 cm). Eighteen (0.7%; 95% CI: 0.4%, 1.0%) of 2763 patients were found to have ovarian cancer after an average follow-up of 5.1 years ± 3.8 (range, 0-12.8 years). None (95% CI: 0%, 0.4%) of 1031 women with simple-appearing cysts were given a diagnosis of ovarian cancer. This included none (95% CI: 0%, 0.4%) of 904 women with simple-appearing cysts with an adequate reference standard for benign outcome. Conclusion The prevalence of previously unknown adnexal cysts at CT was 6.6%, with an ovarian cancer rate of 0.7% (95% CI: 0.4%, 1.0%). All simple-appearing cysts were benign (95% CI: 99.6%, 100%). © RSNA, 2017 Online supplemental material is available for this article.

"Incidentalomas" on abdominal and pelvic CT in emergency radiology: literature review and current management recommendations.

The purpose of this article is to familiarize radiologists and clinicians with a subset of common and uncommon incidental findings on abdominal and pelvic computed tomography examinations, including hepatic, splenic, renal, adrenal, pancreatic, aortic/iliac arterial, gynecological, and a few other miscellaneous findings, with an emphasis on "incidentalomas" discovered in the emergency setting. In addition, we will review the complex problem of diagnosing such entities, and provide current management recommendations. Representative case examples, which we have encountered in our clinical practices, will be demonstrated.

PATIENT DOSES IN COMPUTED TOMOGRAPHY EXAMINATIONS IN TWO REGIONS OF THE RUSSIAN FEDERATION.

Computed tomography (CT) is often a justified diagnostic tool, but is also associated with high exposure of the patients. Due to the rapid increase in the number of CT units and thus the availability of CT examinations in Russia, there is a growing need for optimisation within this field. In order to develop proper optimisation procedures for CT, the two regions St. Petersburg and Belgorod of Russia were chosen, representing an urban and a rural region, respectively. In 2014, a survey was conducted of the parameters applied in CT examinations in these regions, and the results show that the highest effective doses were observed for investigations of abdomen, reaching up to 137 mSv, and pelvic CT examinations, reaching up to 58 mSv, both with contrast agents. The dose distributions were approximately log-normal, and for the majority of the examinations, the 75th percentiles of the CT dose distributions in the Belgorod region were higher than observed in St. Petersburg. The aim of the current project is primarily to define and implement diagnostic reference levels as a part of the process of optimisation of CT examinations in Russia.

Pelvic enthesopathy on CT is significantly more prevalent in patients with diffuse idiopathic skeletal hyperostosis (DISH) compared with matched control patients.

The purpose of this study is to evaluate the prevalence of pelvic enthesopathy on computed tomography (CT) in patients with DISH compared to matched control group. Pelvic CT examinations of patients with DISH (Resnick criteria) were retrospectively evaluated for the presence of enthesophytes at four entheseal sites bilaterally: ischial tuberosity, pubis, greater trochanter, and anterior superior iliac spine (ASIS). This was compared with age- and gender-matched control group of consecutive patients with <2 flowing osteophytes on CT along the entire spine. Multivariate analysis of variance (ANOVA) was applied to examine the degree of difference between pelvic enthesopathy in DISH patients and controls and to estimate the potential predictive ability of the different findings. Logistic regression analysis was used to estimate the odds ratio of the studied findings. Pelvic CTs of 210 patients (149:61, M:F; average age, 72.3years) were evaluated: DISH group, 104 patients (74:30, M:F); matched control group, 106 patients (75:31, M:F). Mean total and local enthesopathy scores were significantly higher in the DISH group compared with the control group (total 5.03:1.9; ASIS 1.58:0.55; pubis 0.94:0.36; ischial tuberosity 1.47:0.76; greater trochanter 1.04:0.24; p < 0.001). ASIS and greater trochanter enthesophytes were the most robust contributors that significantly distinguished between patients with DISH and those without DISH. Prominent enthesophytes were more common among DISH patients (DISH:controls, 52:13, p = 0.02). Prominent pelvic enthesophytes detected on CT have a strong discriminating power between DISH and non-DISH patients. Results imply that pelvic enthesopathy may be included in the radiographic criteria for DISH.

Low-Dose Pelvic Computed Tomography Using Adaptive Iterative Dose Reduction 3-Dimensional Algorithm

To evaluate the image quality and radiation dose reduction in pelvic computed tomography (CT) achieved with an adaptive iterative dose reduction 3-dimensional (AIDR 3D) algorithm using a phantom model. Two phantoms were scanned using a 320-detector row CT scanner with 8 tube current levels, and the images were reconstructed with a standard filtered back projection (FBP) algorithm and with an AIDR 3D algorithm. Compared with FBP, AIDR 3D reduced image noise and improved contrast-to-noise ratios. The diagnostic performance for detection of low-contrast targets of AIDR 3D images obtained with 100 mA at 120 kVp was almost as good as that of the FBP images obtained with 200 mA. The AIDR 3D algorithm substantially reduced image noise and improved the image quality of pelvic CT images compared with those obtained with the FBP algorithm and can thus be considered a promising technique for low-dose pelvic CT examinations.

Precision of a Novel Computed Tomographic Method for Quantification of Femoral Varus in Dogs and an Assessment of the Effect of Femoral Malpositioning

To assess the precision of a novel protocol for determination of femoral varus angle (FVA) using computed tomography (CT) in dogs, and to quantify the effect of femoral rotational and sagittal plane malpositioning on measured FVA. Cross-sectional study. Femora (n = 66) from dogs that had pelvic limb CT examination for patellar instability (26) or other reasons (10). Three observers measured FVA of each of 66 femora on three separate occasions. Standardized orientation of a volume rendered image was achieved by superimposition of the caudal and distal aspects of the femoral condyles on a lateral projection, definition of a sagittal plane axis, and finally rotation through 90° to yield a cranial projection. Intra- and inter-observer variability were estimated using the intra-class correlation coefficient. The effect of variation in rotational and sagittal plane orientation on measured FVA was subsequently quantified using 6 femora with FVAs between -0.4° and 19°. Intra-class correlation coefficients for the 3 observers, indicating intra-observer variation, were 0.982, 0.937, and 0.974. The intra-class correlation coefficient of the means of the results from each observer, indicating inter-observer variation, was 0.976. Consistent linear variations in measured FVA occurred as a result of rotational malpositioning in all 6 tested femora, and as a result of sagittal plane malpositioning in femora with FVAs ≥ 7.9°. The reported protocol for the measurement of FVA in dogs is repeatable and reproducible. Small variations in femoral orientation, as might be expected with conventional radiography, lead to clinically significant alterations in measured FVA.

Use of Pelvic Computed Tomography and Sonography in Women of Reproductive Age in the Emergency Department

The purpose of this study was to review use of pelvic computed tomography (CT) and sonography in the emergency department for women of reproductive age and to identify cases in which sonography might have been adequate. Computed tomographic and sonographic examinations of the pelvis performed on women up to 55 years of age in our emergency department during a 6-month period were reviewed. Repeated CT and CT with indications for which sonography would not be the first-line imaging modality (eg, diverticulitis and trauma) were excluded. For the sonographic-only assessment, repeated sonography and sonography with indications for which CT would not be the first-line imaging modality (eg, vaginal bleeding) were excluded. Patient referral indications, imaging diagnoses, and discharge diagnoses were compared for the groups with CT only, CT first, sonography first, and sonography only. Of 509 women who underwent CT, 407 (80%) underwent CT only; 54 (11%) underwent CT first; and 48 (9%) underwent pelvic sonography first. The percentages with negative CT findings were 42%,17%, and 50%, respectively. Overall, 63 (CT only), 38 (CT first), and 12 (sonography first) patients had CT diagnoses of pelvic conditions only (113 of 509 women [22%]). Of the patients with CT and discharge diagnoses of pelvic conditions, 36 of 44 (82%) had CT only or CT first; 58 of 110 (53%) of cases with sonography only showed acute pelvic conditions. Twenty-two percent of pelvic CT examinations performed in women of reproductive age in our emergency department showed only pelvic conditions, suggesting that sonography would have been a reasonable primary imaging test for these patients.

Greek Dose Reference Levels in Pediatric Pelvis Computed Tomography Examinations

The fact that children do undergo computed tomography (CT) examinations similar to those for adults adults has been a research issue, especially since the former are exposed to greater risk levels (developing stochastic late effects, such as cancer) due to their increased radiosensitivity compared to the latter. In a previous research paper (), the values of dose levels were recorded, analyzed, and compared with the reference values for groups of 0, 1, 5 and 10 y-old children for the regions of head, chest, and abdomen. In this paper, the same age group has been considered for measuring dose levels of the pelvic region. Scanning the pelvic region has been one of the most important CT examination procedures, in which unfortunately part of the lower abdomen region is included without adapting any pediatric protocols. Furthermore, the study determines whether the adjustment of the scanning parameters results in any possible reduction in the radiation dose levels to which the patient is being exposed during the examination. The present work also includes the Greek reference levels for the pelvic CT examination for the 5- and 10-y-old children that have been used for comparison against the European ones.