Technical cost of radiologic examinations: analysis across imaging modalities

PURPOSE: To determine the individual technical costs of general diagnostic radiographic, ultrasonographic (US), computed tomographic (CT), magnetic resonance (MR) imaging, and scintigraphic examinations and interventional radiology. MATERIALS AND METHODS: The Radiology Cost and Productivity Benchmarking Study method of the University HealthSystem Consortium, a cooperative group of academic medical centers, was modified and extended to the six imaging modalities in a tertiary care academic setting. Hospital billing and cost records were analyzed for fiscal year 1996. Costs were divided into labor and nonlabor categories and were allocated to individual imaging modalities on the basis of resources consumed. Physician cost and hospital overhead were not included. Unit costs were analyzed per technical relative value unit (RVU) and per examination. RESULTS: The costs per technical RVU for diagnostic radiography, US, CT, MR imaging, scintigraphy, and interventional radiology were $65. 06, $28.74, $20.95, $17.69, $42.19, and $89.03, respectively. The technical costs per examination for diagnostic radiography, US, CT, MR imaging, scintigraphy, and interventional radiology were $41.92, $50.28, $112.32, $266.96, $196.88, and $692.60, respectively. CONCLUSION: The method of unit cost analysis for individual imaging modalities was successfully tested in a tertiary care setting. The method should be adopted to allow cost comparison across many institutions, which will permit the promotion of best practices.     

Technical cost of CT examinations

PURPOSE: To measure the technical cost of different categories of computed tomographic (CT) examinations. MATERIALS AND METHODS: For fiscal year 1997, the technical costs of performing CT examinations in a tertiary care academic medical center were measured. Costs were divided into labor and nonlabor categories. Indirect departmental costs were fully allocated according to activity-based methods. Hospital overhead costs were set at 85% of the departmental budget. Physician costs, including those related to image interpretation were not included. The technical cost of CT was determined on a per technical relative value unit (RVU) basis and on a per examination basis. For the latter, the technical cost of nonenhanced CT, contrast material-enhanced diagnostic CT, and interventional CT procedures were determined. RESULTS: In fiscal year 1997, 45,599 examinations (22,158 [48.6%] abdominal and/or pelvic, 12,115 [26.6%] head and neck, 6,572 [14.4%] thoracic, 1,593 [3.5%] interventional, and 3,161 [6.9%] other) were performed with five CT scanners for a technical RVU output of 254,461. Of 45,599 examinations, 31,007 (68%) were performed with intravenously administered contrast medium. Overall labor costs were $1,744,653, and nonlabor costs were $2,912,282. The cost of a hypothetical CT examination with a mean technical RVU of 5.58 was $189. The overall cost per examination was $150 for nonenhanced CT, $237 for contrast-enhanced CT, and $462 for interventional CT. CONCLUSION: Although CT is based on sophisticated technology, the mean technical cost of a diagnostic CT examination is less than $200.     

Expanding X-chromosomal forensic haplotype frequencies database: Italian population data of four linkage groups

Requests for solving complex kinship casework involving at least one female are increasing and in these circumstances the analysis of X-chromosomal STR markers plays a relevant role. Actually, it is well known the superior statistical power of X-STRs compared to autosomal markers in solving relationship when two sisters or half-sisters are involved and none of parents is available, in maternity testing or in cases involving close relatives as alternative putative fathers. In addition, the possibility to amplify more loci simultaneously and the strategy based on the analysis of four linkage groups to obtain the X-haplotype provide a powerful and validated tool. Nevertheless, haplotypes frequency distribution in different populations is still needed for calculation of probabilities in relationship testing. Published haplotype frequencies from German population data are available, but in different caseworks we found unreported X-haplotypes. To enlarge the forensic X-chromosome database, we present haplotype frequencies and other parameter of forensic interest obtained from 200 anonymous DNA samples of unrelated Italian males for the four linkage groups included in the Investigator Argus X-12 kit. From the comparison of the Italian sample haplotype frequencies with other populations, significant genetic distances were found with Asian and African populations, but not with Europeans. Finally, casework examples of complex kinship analysis are presented.     

Heart rate and GPS data analysis of kiteboard course racing during the Italian Championship

Background

Despite the growing popularity of kiteboard course racing, there is a paucity of scientific literature about the performance in this sport.

Purpose

The aim of the present study was to analyze displacement (speed and direction) and heart rate (HR) data in high-level kiteboarders during competition.

Methods

Five kiteboarders, ages 33.8 ± 5.3 years, weight: 80.6 ± 4.8 kg, height: 181.2 ± 7.8 cm, were monitored with a GPS receiver and an HR monitor during four races of the Italian Kiteboarding Championship for a total of 46 regattas.

Results

Each regatta lasted 926 ± 175 s and was composed by 11 ± 1 beats. The average sailing speed recorded in competition was 8.9 ± 0.9 m/s. The speed was higher (p < 0.01) in the downwind leg (9.9 ± 1.4 m/s) than in the upwind leg (7.9 ± 0.3 m/s). The orientation of the kiteboard with respect to the wind direction during the upwind sailing phase was 66.4° ± 6.3°, resulting in being wider than in traditional sailing sports. The mean HR was 82.7 ± 0.9% of HR_reserve and 86% ± 1.2 HR_max, showing a relatively high exercise intensity compared to most of other sailing sports.

Conclusion

The duration and intensity of a kiteboard racing suggest the need of specific physical training programs for competitive kiteboarders.

     

Italian population data on the loci MR,GYPA, HBGG,D7S8 and GC

Allele and genotype frequencies for the five loci LDLR, GYPA, HBGG, D7S8 and GC were determined for 374 unrelated Italians using a multiplex PCR-amplification and typing commercial kit. The distribution of the genotype frequencies showed no deviations from Hardy-Weinberg expectations. The combined power of discrimination and chance of exclusion for all five loci were 0.999 and 0.702, respectively. A test for homogeneity was performed and no significant differences were observed among the Caucasian population samples.     

Estimation of dose to the unborn child at diagnostic X-ray examinations based on data registered in RIS/PACS

The aim of this work was to determine mean absorbed doses to the unborn child in common conventional X-ray and computed tomography (CT) examinations and to find an approach for estimating foetal dose based on data registered in the Radiological Information System/Picture Archive and Communication System (RIS/PACS). The kerma-area product (KAP) and CT dose index (CTDI_vol) in common examinations were registered using a human-shaped female dosimetry phantom. Foetal doses, D_f, were measured using thermoluminescent dosimeters placed inside the phantom and compared with calculated values. Measured foetal doses were given in relation to the KAP and the CTDI_vol values, respectively. Conversion factor D_f/KAP varies between 0.01 and 3.8 mGy/Gycm², depending on primary beam position, foetus age and beam quality (tube voltage and filtration). Conversion factors D_f/CTDI_vol are in the range 0.02 – 1.2 mGy/mGy, in which the foetus is outside or within the primary beam. We conclude that dose conversion factors based on KAP or CTDI_vol values automatically generated by the RIS/PACS system can be used for rapid estimations of foetal dose for common examination techniques. Ethical Committee: No patients were involved in this study.     

Rheumatoid arthritis and its variants: analysis of scintiphotographic, radiographic, and clinical examinations.

99mTc pyrophosphate radionuclide scans of the axial and appendicular skeletons in 23 patients with rheumatoid arthritis and 15 patients with systemic arthritic conditions were compared to clinical and radiographic examinations. The nuclear scan was the most sensitive indicator of active disease and correlated extremely well with the other methods. A pattern of abnormal radionuclide activity in rheumatoid arthritis consisting of a symmetric peripheral joint process can be distinguished from that of the rheumatoid variants which tend to have more central skeletal involvement and asymmetric peripheral articular involvement. The nuclear scan is less specific than the radiograph in its ability to distinguish among the clinical entities. However, documentation of scintigraphic activity often antedated radiographic or clinical abnormalities.     

North Italian population genetic data on the STR system HumFGA

Frequency data for the STR system HumFGA were obtained from a North Italian population sample (Milano area) of 201 unrelated individuals. PCR products were detected by horizontal polyacrylamide gel electrophoresis and a total of 15 alleles were identified by side-by-side comparison with a commercially available sequenced allelic ladder. The observed genotype distribution showed no significant deviation from Hardy-Weinberg equilibrium. The high information content (discrimination power > 0.96, polymorphism information content > 0.84) render this system a useful tool in forensic routine casework both in criminal and paternity cases. Received: 7 January 1997     

Dose-area product readings for fluoroscopic and plain film examinations, including an analysis of the source of variation for barium enema examinations

This paper contains the results of an investigation undertaken between 1994 and 1996 using dose-area product (DAP) meters for monitoring radiation doses from six types of simple examinations and seven types of complex examinations. Mean hospital DAP levels have been compared with National Reference Levels (NRL), with most departments producing levels lower than NRLs. DAP readings have allowed the proposal of provisional Reference Levels (RL) to be set for simple and complex examinations. The results were also compared with recently published data from the National Radiological Protection Board (NRPB), highlighting those hospitals which need to make changes in radiographic technique. The study of DAP reference doses also confirms that dose levels for complex investigations are clearly related to technique, in terms of screening time and number of films. Although the use of increased screening tube kilovoltage may be relevant, the overall effect is small. The results suggest that there is still a need to optimize the protocols for these examinations. The use of digital equipment has been shown to have a complex effect on dose, particularly in the case of investigations involving both films and fluoroscopy.     

Comparison of image quality and patient dose for chest x-ray examinations on conventional and low cost computed radiography systems

PurposeThe aims of this study were to assess if clinical chest radiographs taken at two computed radiography (CR) facilities fulfill standard quality criteria on conventional display monitor and the status of patient doses.MethodsTwenty-five adult patients were x-rayed at 102–109 kVp using Fuji type C image plates and low cost Philips PCR digitizer. Another group of 25 patients were x-rayed at 120 kVp using CRMD 4.0 image plates and conventional Agfa 75 CR digitizer. All 50 radiographs were independently assessed by four radiologists on conventional display monitor (model HP M70) with image software using six standard quality criteria. Entrance surface air kerma (ESAK) was determined using the measured incident air kerma values and exposure parameters.ResultsThe results show that the differences in visualization of anatomical structure in terms of image quality criteria were comparable (p > 0.05), with the exception of the visualisation of intervertebral disc spaces. However, the ESAK values for Philips PCR were higher than those for Agfa CR 75 (p < 0.001).ConclusionImages from a low cost CR system can display anatomic details comparably to conventional CR system but at the cost of higher radiation dose. Optimisation of variables that effect patient dose is desirable when using low cost CR systems.     

胸腹水TP、ADA、LDH、CA125四项指标联合检测的临床意义

目的探讨胸腹水总蛋白（TP）、腺苷脱氢酶（ADA）、乳酸脱氢酶（LDH）、糖基抗原125（CA125）四项指标联合检测在良、恶性胸腹水中的临床鉴别诊断意义。方法回顾性分析我院2007～2008年住院诊断有胸腹水的患者,分成良性肿瘤组和恶性肿瘤组两组,分析两组患者胸腹水中TP、ADA、LDH、CA125的检测结果,数据采用方差分析法进行统计分析。结果恶性组患者胸腹水标本中TP、LDH、CA125值较良性组明显升高（P〈0．05）,ADA结果良性组高于恶性组（P〈0．05）。结论联合检测TP、ADA、LDH、CA125对胸腹水性质的鉴别诊断有重要临床参考价值。     

基于自组织特征映射神经网络的肝脏^31P磁共振波谱分析

目的：探讨基于神经网络的^31PMR波谱在辨别肝细胞癌,正常肝和肝硬化中的价值。方法：运用自组织特征映射神经网络（SOM）分析66个^31P MRS数据,其中包括肝细胞癌（13个样本）,正常肝脏（16个样本）和肝硬化（37个样本）。结果：^31P MRS可以用于肝细胞癌与肝硬化结节的诊断和鉴别诊断,经四个实验证明,基于神经网络模型的。^31P MR波谱数据分析可以将肝细胞癌的诊断正确率从85．4％提高到92．31％。结论：基于神经网络模型的。^31PMRS波谱数据分析为活体肝细胞癌的诊断提供了一种有价值的诊断手段。     

The effect of different statistical approaches on image quality data obtained from radiological examinations

IntroductionSelection of optimal image acquisition protocols in medical imaging remains a grey area, the superimposed use of the Likert scale in radiological image quality evaluations creates an additional challenge for the statistical analysis of image quality data.Using a simulation study, we have trialled a novel approach to analysing radiological image quality Likert scale data.MethodsA simulation study was undertaken where simulated datasets were generated based on the distribution of Likert scale values according to varying image acquisition protocols from a real dataset. Simulated Likert scale values were pooled in four different ways; the mean, median, mode and the summation of patient Likert scale values of which the total was assigned a categorical Likert scale value. Estimates of bias, MAPE and RMSPE were then calculated for all four pooling approaches to determine which method most accurately represented an expert's opinion.ResultsWhen compared to an expert's opinion, the method of summation and categorisation of Likert scale values was most accurate 49 times out of the 114 (43.0%) tests. The mean 28 times out of 114 (24.6%), the median 23 times out of 114 (20.2%) and the mode 17 times out of 114 (14.9%).ConclusionWe conclude that our method of summation and categorisation of Likert scale values is most often the best representation of the simulated data compared to the expert's opinion.Implications for practiceThere is scope to reproduce this simulation study with multiple observers to reflect clinical reality more accurately with the dynamic nature of multiple observers. This also prompts future investigation into other anatomical areas, to see if the same methods produce similar results.     

Prevalence of idiopathic cuneate gyrus herniation based on emergency room CT examinations

Idiopathic brain herniation caused by a focal dural defect can be confused for a mass or post-traumatic herniation. The prevalence of idiopathic brain herniation has never been described. We sought to ascertain the prevalence of idiopathic cuneate gyrus herniation in a general emergency room (ER) population on computed tomography (CT) imaging. The purpose of this study is to elucidate cuneate gyrus herniation and differentiate it from other pathologic conditions such as mass or traumatic herniation and to provide its anatomical prevalence in an ER population. Consecutive emergency room CT scans of the brain were evaluated prospectively for cuneate gyrus herniation over a 1 year period by a neuroradiologist. Of 1,500 brain CT scans evaluated, 11 patients demonstrated idiopathic cuneus gyrus herniation. The prevalence was 0.73 %. CT manifestations are normal brain tissue herniating into the superior cerebellar cistern. Idiopathic brain herniation can be mistaken for a pathologic process. We found the prevalence of one such idiopathic brain herniation, involving the cuneus gyrus, to be exceedingly rare. CT imaging demonstrates normal brain tissue herniating beyond the dural boundary.     

Assessment of fetal distress based on magnetic resonance examinations: preliminary report

RATIONALE AND OBJECTIVES: Hypoxia is the main cause of injuries and intrauterine death of the fetus. Therefore, the main aim of monitoring and assessment of the fetus should be diagnosis of fetal distress before irreversible changes occur. Besides the fetal condition assessment methods used so far, in recent years in obstetrics new non-invasive imaging methods were introduced such as magnetic resonance (MR). This method enables morphologic evaluation of brain and brain tissue metabolism using magnetic resonance spectroscopy (MRS). MATERIALS AND METHODS: Twenty pregnant women with pregnancy-induced hypertension (11 cases, including 3 with coexisting diabetes mellitus and 2 with intrauterine growth retardation), chronic hypertension (2 cases), gestational diabetes mellitus (6 cases), and suspected intrauterine fetal growth retardation (IUGR) participated in the study. Cardiotocography (CTG) and Doppler ultrasound examination of the blood flow in the umbilical artery and in the middle cerebral artery were performed. RESULTS: In case of abnormal CTG and Doppler study records that indicated fetal hypoxia, MR studies showed the existence of ischemic focus in 5 patients and abnormal spectral images in 6 patients. CONCLUSION: The results of the preliminary study suggests that the use of MR in prenatal diagnosis may revolutionize the early detection of fetal injury in fetal distress. It is a valuable component of the diagnostic process, supplementing other examinations. The use of MR to assess fetal condition gives additional information and helps to make decisions about therapeutic actions.