Dose-volume response in acute dysphagia toxicity: Validating QUANTEC recommendations into clinical practice for head and neck radiotherapy.

PURPOSE: To determine the validity of QUANTEC recommendations in predicting acute dysphagia using intensity-modulated head and neck radiotherapy. MATERIAL AND METHODS: Seventy-six consecutive patients with locally advanced squamous cell carcinoma (SCC) of the head and neck +/- systemic therapy were analyzed. Multiple dose parameters for the larynx (V50Gy, Dmean and Dmax) were recorded. Acute dysphagia toxicity was prospectively scored in all treatment weeks (week 1-6 or 1-7) using CTCAEv3 by three blinded investigators. QUANTEC larynx recommendations (V50Gy < 27%, Dmean < 44 Gy, Dmean < 40 Gy, Dmax < 66 Gy) were used to group the cohort (i.e. V50Gy < 27% vs. V50Gy > 27%). The proportion of patients with Grade 3 dysphagia was compared within each group. RESULTS: There was a significant reduction in the incidence of grade 3 toxicity in the V50Gy < or > 27% group at week 5 (14.3% vs. 45.2%, p = 0.01) and 6 (25.9% vs. 65.9%, p < 0.01). A significant reduction at week 5 (14.7% vs. 50.0, p = 0.02) and 6 (32.4% vs. 67.6%, p = 0.01) was seen in Dmean < 44 Gy when compared to Dmean > 44 Gy. Dmean < 40 Gy also delivered a significant reduction at week 5 (5.6% vs. 42.3%, p < 0.01) and week 6 (23.5% vs. 59.3%, p = 0.01). A significant toxicity reduction at treatment week 6 (28.0% vs. 63.0%, p = 0 < 01) was seen from Dmax < 66 Gy to Dmax > 66 Gy. V50Gy > 27% (p < 0.01), Dmean > 40 Gy (p = 0.01) and Dmax > 66 Gy (p < 0.01) were also predictors of Grade 3 dysphagia when analyzed with multiple clinical risk factors. CONCLUSIONS: QUANTEC late toxicity recommendations for dose to larynx during IMRT are a useful predictor for acute dysphagia toxicity in this patient cohort. Furthermore, this included chemoradiotherapy regimes and post-operative radiotherapy patients, allowing for prophylactic implementation of supportive care measures.

Changes in aldehyde dehydrogenase-1 expression during neoadjuvant chemotherapy predict outcome in locally advanced breast cancer.

INTRODUCTION: Although neoadjuvant chemotherapy (NAC) for locally advanced breast cancer can improve operability and local disease control, there is a lack of reliable biomarkers that predict response to chemotherapy or long-term survival. Since expression of aldehyde dehydrogenase-1 (ALDH1) is associated with the stem-like properties of self-renewal and innate chemoresistance in breast cancer, we asked whether expression in serial tumor samples treated with NAC could identify women more likely to benefit from this therapy. METHODS: Women with locally advanced breast cancer were randomly assigned to receive four cycles of anthracycline-based chemotherapy, followed by four cycles of taxane therapy (Arm A), or the same regimen in reverse order (Arm B). Tumor specimens were collected at baseline, after four cycles, and then at surgical resection. ALDH1 expression was determined by immunohistochemistry and correlated with tumor response using Fisher's exact test while Kaplan-Meier method was used to calculate survival. RESULTS: A hundred and nineteen women were enrolled into the study. Fifty seven (48%) were randomized to Arm A and 62 (52%) to Arm B. Most of the women (90%) had ductal carcinoma and 10% had lobular carcinoma. Of these, 26 (22%) achieved a pathological complete response (pCR) after NAC. There was no correlation between baseline ALDH1 expression and tumor grade, stage, hormone receptor, human epidermal growth factor receptor 2 (HER2) status and Ki67 index. ALDH1 negativity at baseline was significantly associated with pCR (P = 0.004). The presence of ALDH1(+) cells in the residual tumor cells in non-responding women was strongly predictive of worse overall survival (P = 0.024). Moreover, serial analysis of specimens from non-responders showed a marked increase in tumor-specific ALDH1 expression (P = 0.028). Overall, there was no survival difference according to the chemotherapy sequence. However, poorly responding tumours from women receiving docetaxel chemotherapy showed an unexpected significant increase in ALDH1 expression. CONCLUSIONS: ALDH1 expression is a useful predictor of chemoresistance. The up-regulation of ALDH1 after NAC predicts poor survival in locally advanced breast cancer. Although the chemotherapy sequence had no effect on overall prognosis, our results suggest that anthracycline-based chemotherapy may be more effective at targeting ALDH1(+) breast cancer cells. TRIAL REGISTRATION: ACTRN12605000588695.

Routine sonographic measurement of the near-field lateral ventricle during second-trimester morphologic scans.

OBJECTIVES: The purpose of this study was to determine whether measurement of the near-field lateral ventricular diameter can be reliably obtained within a practical time frame during second-trimester obstetric scans by angling the fetal head approximately 30° away from the horizontal image axis such that the posterior aspect of the fetal head lies closer to the transducer. METHODS: Fifty consecutive singleton pregnancies presenting for a routine-second trimester scan were recruited for this study. The far-field lateral ventricular diameter was measured, followed by the near-field lateral ventricular diameter using the proposed technique. The measurements were repeated by a second operator who was blinded to the first measurement. Both operators recorded the measurements taken and scored the level of visibility of the near-field lateral ventricle. The difference between the two operators' measurements was compared by a κ analysis. RESULTS: The near-field lateral ventricle was visualized in 49 of 50 cases (98%). There was no statistically significant difference in the measurement of the near-field lateral ventricular diameter by the two operators (P = .34). There was, however, a statistically significant difference in the time it took each operator to obtain the near-field measurement after the far-field measurement (P = .01). CONCLUSIONS: Manipulating the transducer to position the falx of the fetal head approximately 30° away from the horizontal image axis allows the near-field lateral ventricle to be routinely visualized and measured with a high degree of interoperator agreement and within a practical time frame once the operator is experienced in performing the technique.

The prognostic significance of aldehyde dehydrogenase 1A1 (ALDH1A1) and CD133 expression in early stage non-small cell lung cancer.

BACKGROUND: Expression of aldehyde dehydrogenase 1A1 (ALDH1A1) and CD133 has been functionally associated with a stem cell phenotype in normal and malignant cells. The prevalence of such cells in solid tumours should therefore correlate with recurrence and/or metastasis following definitive surgical resection. The aim of this study was to evaluate the prognostic significance of ALDH1A1 and CD133 in surgically resected, early stage non-small cell lung cancer (NSCLC). METHODS: A retrospective analysis of ALDH1A1 and CD133 expression in 205 patients with pathologic stage I NSCLC was performed using immunohistochemistry. The association between the expression of both markers and survival was determined. RESULTS: We identified 62 relapses and 58 cancer-related deaths in 144 stage 1A and 61 stage 1B patients, analysed at a median of 5-years follow-up. Overexpression of ALDH1A1 and CD133, detected in 68.7% and 50.7% of primary tumours, respectively, was an independent prognostic indicator for overall survival by multivariable Cox proportional hazard model (p=0.017 and 0.039, respectively). Overexpression of ALDH1A1, but not of CD133, predicted poor recurrence-free survival (p=0.025). When categorised into three groups according to expression of ALDH1A1/CD133, patients with overexpression of both ALDH1A1 and CD133 belonged to the group with the shortest recurrence-free and overall survival (p=0.015 and 0.017, respectively). CONCLUSIONS: Expression of ALDH1A1 and CD133, and coexpression of ALDH1A1 and CD133, is strongly associated with poor survival in early-stage NSCLC following surgical resection. These data are consistent with the hypothesis that expression of stem cell markers correlates with recurrence as an indirect measure of self-renewal capacity.

Quantitative guidelines for the prediction of ultrasound contrast agent destruction during injection.

Experiments and theory were undertaken on the destruction of ultrasound contrast agent microbubbles on needle injection, with the aim of predicting agent loss during in vivo studies. Agents were expelled through a variety of syringe and needle combinations, subjecting the microbubbles to a range of pressure drops. Imaging of the bubbles identified cases where bubbles were destroyed and the extent of destruction. Fluid-dynamic calculations determined the pressure drop for each syringe and needle combination. It was found that agent destruction occurred at a critical pressure drop that depended only on the type of microbubble. Protein-shelled microbubbles (sonicated bovine serum albumin) were virtually all destroyed above their critical pressure drop of 109 ± 7 kPa Two types of lipid-shelled microbubbles were found to have a pressure drop threshold above which more than 50% of the microbubbles were destroyed. The commercial lipid-shelled agent Definity was found to have a critical pressure drop for destruction of 230 ± 10 kPa; for a previously published lipid-shelled agent, this value was 150 ± 40 kPa. It is recommended that attention to the predictions of a simple formula could preclude unnecessary destruction of microbubble contrast agent during in vivo injections. This approach may also preclude undesirable release of drug or gene payloads in targeted microbubble therapies. Example values of appropriate injection rates for various agents and conditions are given.

Effectiveness of mastoid process percussion for identification of the vertebral artery ostium on Doppler studies.

OBJECTIVES: The pretransverse or first segment of the vertebral artery may be confused with adjacent branches of the proximal subclavian artery during Doppler assessment. This study investigated the effectiveness of mastoid process percussion, the "mastoid tap" maneuver, for identification of the vertebral artery ostium. METHODS: Fifty patients presenting consecutively for carotid sonography were recruited. Doppler waveforms were collected at the vertebral artery ostia, thyrocervical trunks, and proximal subclavian arteries while the mastoid tap maneuver was performed. The outcome indicator was serrate distortion of the Doppler waveform. Two raters graded the waveforms according to a 3-grade system: grade 0, no distortion; grade 1, mild distortion; and grade 3, marked distortion. The difference between the proportions of the vertebral artery ostia and thyrocervical trunks showing waveform distortion was evaluated with the χ(2) test. The differences in the extents of waveform distortion in the ipsilateral vertebral artery ostia, thyrocervical trunks, and subclavian arteries were evaluated with Friedman and Wilcoxon signed rank tests. RESULTS: Ninety-five vertebral artery ostia in 50 patients were successfully assessed. There was a significant difference between the proportions of vertebral artery ostia (95 of 95 [100%]) and thyrocervical trunks (9 of 95 [9.5%]) that showed waveform distortion (P < .001). There were significant differences in the extents of distortion between the ipsilateral vertebral artery ostia and thyrocervical trunks and between the ipsilateral vertebral artery ostia and subclavian arteries, with the vertebral artery ostia showing a higher degree of distortion in both cases (P < .001). CONCLUSIONS: The mastoid tap maneuver is useful for distinguishing between the vertebral arteries and thyrocervical trunks on Doppler studies.

Validation of a 4D-PET maximum intensity projection for delineation of an internal target volume.

PURPOSE: The delineation of internal target volumes (ITVs) in radiation therapy of lung tumors is currently performed by use of either free-breathing (FB) (18)F-fluorodeoxyglucose-positron emission tomography-computed tomography (FDG-PET/CT) or 4-dimensional (4D)-CT maximum intensity projection (MIP). In this report we validate the use of 4D-PET-MIP for the delineation of target volumes in both a phantom and in patients. METHODS AND MATERIALS: A phantom with 3 hollow spheres was prepared surrounded by air then water. The spheres and water background were filled with a mixture of (18)F and radiographic contrast medium. A 4D-PET/CT scan was performed of the phantom while moving in 4 different breathing patterns using a programmable motion device. Nine patients with an FDG-avid lung tumor who underwent FB and 4D-PET/CT and >5 mm of tumor motion were included for analysis. The 3 spheres and patient lesions were contoured by 2 contouring methods (40% of maximum and PET edge) on the FB-PET, FB-CT, 4D-PET, 4D-PET-MIP, and 4D-CT-MIP. The concordance between the different contoured volumes was calculated using a Dice coefficient (DC). The difference in lung tumor volumes between FB-PET and 4D-PET volumes was also measured. RESULTS: The average DC in the phantom using 40% and PET edge, respectively, was lowest for FB-PET/CT (DCAir = 0.72/0.67, DCBackground 0.63/0.62) and highest for 4D-PET/CT-MIP (DCAir = 0.84/0.83, DCBackground = 0.78/0.73). The average DC in the 9 patients using 40% and PET edge, respectively, was also lowest for FB-PET/CT (DC = 0.45/0.44) and highest for 4D-PET/CT-MIP (DC = 0.72/0.73). In the 9 lesions, the target volumes of the FB-PET using 40% and PET edge, respectively, were on average 40% and 45% smaller than the 4D-PET-MIP. CONCLUSION: A 4D-PET-MIP produces volumes with the highest concordance with 4D-CT-MIP across multiple breathing patterns and lesion sizes in both a phantom and among patients. Freebreathing PET/CT consistently underestimates ITV when compared with 4D PET/CT for a lesion affected by respiration.

White matter fiber tractography: why we need to move beyond DTI.

OBJECT: Diffusion-based MRI tractography is an imaging tool increasingly used in neurosurgical procedures to generate 3D maps of white matter pathways as an aid to identifying safe margins of resection. The majority of white matter fiber tractography software packages currently available to clinicians rely on a fundamentally flawed framework to generate fiber orientations from diffusion-weighted data, namely diffusion tensor imaging (DTI). This work provides the first extensive and systematic exploration of the practical limitations of DTI-based tractography and investigates whether the higher-order tractography model constrained spherical deconvolution provides a reasonable solution to these problems within a clinically feasible timeframe. METHODS: Comparison of tractography methodologies in visualizing the corticospinal tracts was made using the diffusion-weighted data sets from 45 healthy controls and 10 patients undergoing presurgical imaging assessment. Tensor-based and constrained spherical deconvolution-based tractography methodologies were applied to both patients and controls. RESULTS: Diffusion tensor imaging-based tractography methods (using both deterministic and probabilistic tractography algorithms) substantially underestimated the extent of tracks connecting to the sensorimotor cortex in all participants in the control group. In contrast, the constrained spherical deconvolution tractography method consistently produced the biologically expected fan-shaped configuration of tracks. In the clinical cases, in which tractography was performed to visualize the corticospinal pathways in patients with concomitant risk of neurological deficit following neurosurgical resection, the constrained spherical deconvolution-based and tensor-based tractography methodologies indicated very different apparent safe margins of resection; the constrained spherical deconvolution-based method identified corticospinal tracts extending to the entire sensorimotor cortex, while the tensor-based method only identified a narrow subset of tracts extending medially to the vertex. CONCLUSIONS: This comprehensive study shows that the most widely used clinical tractography method (diffusion tensor imaging-based tractography) results in systematically unreliable and clinically misleading information. The higher-order tractography model, using the same diffusion-weighted data, clearly demonstrates fiber tracts more accurately, providing improved estimates of safety margins that may be useful in neurosurgical procedures. We therefore need to move beyond the diffusion tensor framework if we are to begin to provide neurosurgeons with biologically reliable tractography information.

The impact of time between staging PET/CT and definitive chemo-radiation on target volumes and survival in patients with non-small cell lung cancer.

BACKGROUND AND PURPOSE: To investigate the impact of treatment delays on radiation therapy (RT) target volumes and overall survival (OS) in patients with non-small cell lung cancer (NSCLC) who underwent two baseline FDG PET/CT scans. MATERIAL AND METHODS: Patients underwent a staging (PET1) and RT planning (PET2) FDG PET/CT scan. At PET1 all patients were eligible for radical chemo-RT. OS and progression-free survival (PFS) were compared for patients remaining eligible for radical RT and those treated palliatively because PET2 showed progression. RT target volumes were contoured using PET1 and PET2. Normal tissue doses were compared for patients remaining eligible for radical RT. RESULTS: Eighty-two patients underwent PET2 scans between October 2004 and February 2007. Of these, 21 had a prior PET1 scan, median 23 days apart (range 8-176 days). Six patients (29%) were unsuitable for radical RT after PET2; five received palliative treatment and one received no treatment. Patients treated palliatively had significantly worse OS and PFS than patients treated radically p<0.001. Mean RT tumour volume increased from 105cc to 198cc (p<0.005) between scans. CONCLUSIONS: Disease progression while awaiting initiation of curative RT in NSCLC is associated with larger treatment volumes and worse survival.

Ultrasound study of liver disease caused by Schistosoma mansoni in rural Zambian schoolchildren.

OBJECTIVE: To evaluate the prevalence of Schistosoma mansoni-related liver disease in school-age children who live beside the Zambezi River in the Chitokoloki district, North Western Province, Zambia. METHODS: Liver ultrasounds of school students from the Chitokoloki day school, grades 1-12, were performed. Liver patterns, periportal branch wall thickening and portal hypertension were assessed to evaluate the presence of liver fibrosis due to S. mansoni infection. To obtain incidence rates of acute disease, stool specimens were examined from a subgroup for the presence of S. mansoni eggs using the formol detergent sedimentation technique. RESULTS: Of 976 enrolled students, 764 (78.2%) were examined by ultrasound. Of those, 284 (37.2%) had findings indicative of periportal fibrosis on ultrasound. Stool specimen were collected from 414 (54%) students of which six (1.5%) were positive for S. mansoni eggs. CONCLUSION: School students living along the Zambezi River, Zambia have a relatively high prevalence of S. mansoni-related liver disease. These findings suggest that all schoolchildren in this area should receive treatment against S. mansoni.

Hippocampal calcification prevalence at CT: a retrospective review.

PURPOSE: To determine the prevalence of intrahippocampal calcification at brain computed tomography (CT), evaluate any association with calcification involving the intracranial arteries or lentiform nuclei, and assess the clinical importance of intrahippocampal calcification. MATERIALS AND METHODS: Study approval was obtained by the Southern Health Human Research Ethics Committee, which waived the requirement for informed consent because of the retrospective nature of the study. The presence of intrahippocampal calcification was assessed by four readers through retrospective review of 300 randomly selected nonenhanced brain CT scans. In addition, the presence of calcification involving the intracranial arteries and lentiform nuclei was assessed, and the clinical histories were reviewed in those patients with intrahippocampal calcifications and a matched control cohort without intrahippocampal calcification. Differences in proportion of patients with intrahippocampal calcifications across different age groups were assessed by using χ2 analysis. Interrater agreement and intrarater agreement were assessed by using κ analysis. RESULTS: Intrahippocampal calcification was demonstrated in 47 (15.7%) of 300 patients, and 47 (21.7%) of 217 patients older than 50 years of age. Its prevalence increased with age (P=.008). All patients with intrahippocampal calcification and the control cohort demonstrated calcification involving the intracranial arteries. Eleven (23.4%) of 47 patients with intrahippocampal calcification had calcification within the lentiform nuclei compared with 14 (29.8%) of 47 in the control cohort (P=.67). The anatomic distribution of intrahippocampal calcification was similar to that described in vascular fibrosis and calcification. CONCLUSION: The prevalence of intrahippocampal calcification appears to increase with age and is a relatively common finding in patients older than 50 years. It has a similar anatomic distribution to microscopic vascular fibrosis and calcification and likely reflects its latter stages.

Increased cardiovascular and renal risk is associated with low nephron endowment in aged females: an ovine model of fetal unilateral nephrectomy.

Previously we have shown that ovariectomised (OVX) female sheep have reduced renal function and elevated blood pressure from 6 months of age following fetal uninephrectomy (uni-x) at 100 days of gestation (term = 150 days). In the current study we examined if in intact female sheep the onset of decline in renal function and elevation in blood pressure was prevented. Studies were performed at 1 year, 2 and 5 years of age. Following fetal uni-x at 100 days, intact female sheep had ~30% reduction in glomerular filtration rate (GFR) at 1 year, which did not exacerbate with age (P(treatment) = 0.0001, P(age) = 0.7). In contrast renal blood flow was similar between the treatment groups at 1 year of age but had declined in the uni-x animals at 5 years of age (P(treatment × age) = 0.046). Interestingly, intact uni-x sheep did not develop elevations in arterial pressure until 2 years of age. Furthermore, uni-x animals had a similar capacity to respond to a cardiac challenge at 1 year and 2 years of age, however, cardiac functional reserve was significantly reduced compared to sham group at 5 years of age. Uni-x animals exhibited an increase in left ventricular dimensions at 5 years of age compared to the sham animals and compared to 2 years of age (P(treatment)<0.001, P(treatment × age)<0.001). In conclusion, the onset of renal dysfunction preceded the onset of hypertension in intact female uni-x sheep. Furthermore, this study showed that the intact females are protected from the impact of a reduced nephron endowment on cardiovascular health early in life as opposed to our findings in young male sheep and OVX uni-x female sheep. However, with ageing this protection is lost as evidenced by presence of left ventricular hypertrophy and impaired cardiac function in 5 year old uni-x female sheep.

Intrauterine growth restriction coupled with hyperglycemia: effects on cardiac structure in adult rats.

BACKGROUND: Intrauterine growth restriction (IUGR) has been linked to heart disease in adulthood. Hence the IUGR heart is likely to be vulnerable to diabetic heart disease. The aim of this study was to examine the effect of induction of type 1 diabetes on myocardial collagen deposition and cardiac function in adult rats with a history of IUGR, after controlling blood glucose levels. METHODS: IUGR was induced by protein restriction in the pregnant female rat. When the offspring were 24 wk of age, diabetes was induced in male IUGR and non-IUGR rats by means of streptozotocin; insulin injections were used to maintain blood glucose levels at a mild (7-10 mmol/l; n = 8 per group) or moderate level (10-15 mmol/l; n = 8 per group). Echocardiography and cardiac morphology analyses were carried out when the rats were 32 wk of age. RESULTS: IUGR offspring exhibited cardiac hypertrophy at 32 wk, including a thicker posterior wall and increased interstitial fibrosis in the left ventricle. Hyperglycemia led to an increase in heart size and myocardial fibrosis. The response to hyperglycemia was not different between IUGR and non-IUGR rats; however, cardiac fibrosis was greatest when diabetes was present along with a history of IUGR. In general, maintaining blood glucose levels at a mildly hyperglycemic level attenuated the adverse effects of hyperglycemia but did not reverse the fibrosis. CONCLUSION: Exacerbated fibrosis in hyperglycemic hearts of IUGR offspring may lead to long-term cardiac dysfunction.

The clinical significance and management of lesion motion due to respiration during PET/CT scanning.

Lesion movement during positron emission tomography (PET) scan acquisition due to normal respiration is a common source of artefact. A PET scan is acquired in multiple couch positions of between 2 and 5 min duration with the patient breathing freely. A PET-avid lesion will become blurred if affected by respiratory motion, an effect similar to that created when a person moves in a photograph. This motion also frequently causes misregistration between the PET and computed tomography (CT) scan acquired for attenuation correction and anatomical correlation on hybrid scanners. The compounding effects of blurring and misregistration in whole-body PET/CT imaging make accurate characterization of PET-avid disease in areas of high respiratory motion challenging. There is also increasing interest in using PET quantitatively to assess disease response in both clinical reporting and trials. However, at this stage, no response criteria take the effect of respiratory motion into account when calculating the standardized uptake value on a PET scan. A number of different approaches have been described in the literature to address the issue of respiratory motion in PET/CT scanning. This review details the clinical significance of lesion movement due to respiration and discusses various imaging techniques that have been investigated to manage the effects of respiratory motion in PET/CT scanning.

Occlusion and stenosis of the posterior circumflex humeral artery: detection with ultrasound in a normal population.

INTRODUCTION: The posterior circumflex humeral artery (PCHA) travels together with the axillary nerve through the quadrilateral space of the shoulder. Angiographic occlusion of this artery upon abduction and external rotation (ABER) of the arm has been accepted as evidence of mechanical compression of the axillary nerve and thus considered pathognomonic of quadrilateral space syndrome (QSS). The specificity of this sign for QSS has however been called into question as there are, to date, limited data on the incidence of axillary neurovascular compression during ABER in a normal population. We set out to determine the rate of stenosis or occlusion of the PCHA on ABER in healthy volunteers using ultrasound. METHODS: Healthy volunteers asymptomatic for shoulder complaints were recruited from patients attending the clinic for ultrasound imaging not related to the shoulder, as well as volunteers among staff. Doppler sampling of the PCHA of both shoulders of participants was conducted in neutral and abduction and externally rotated positions. Each shoulder was treated as a separate entity. RESULTS: Results showed that 15/93 (16%) of shoulders demonstrated Doppler ultrasound evidence of occlusion or significant stenosis in the absence of shoulder complaints. CONCLUSION: Occlusion or stenosis of the PCHA on ABER is an uncommon finding in an asymptomatic population. Axillary neurovascular compression is unlikely if colour Doppler ultrasound does not show PCHA compromise during ABER.

Coronary image quality of 320-MDCT in patients with heart rates above 65 beats per minute: preliminary experience.

OBJECTIVE: High heart rate may negatively influence the image quality of cardiac CT. The technical advances of 320-MDCT may overcome issues with poor image quality associated with high heart rate. This study aimed to evaluate the coronary image quality of 320-MDCT in patients with heart rates above 65 beats/min. MATERIALS AND METHODS: Patients who presented for cardiac CT were divided into two groups according to heart rate, either greater than 65 beats/min or less than or equal to 65 beats/min. Two radiologists were blinded to the patient groups and evaluated images of 15 coronary artery segments per patient using 320-MDCT with consensus agreement. The image quality was scored subjectively as 1 or 2 (diagnostic quality) or 3 (poor quality and nondiagnostic). RESULTS: There were no statistically significant differences between the two groups in terms of age, sex, and body mass index (p > 0.05). The median heart rate was 70 beats/min (range, 67-110 beats/min) for the group with heart rate greater than 65 beats/min and 60 beats/min (range, 48-65 beats/min) for the group with heart rate less than or equal to 65 beats/min (p < 0.001). In patients with heart rates greater than 65 beats/min, diagnostic quality images (scores of 1 or 2) were obtained in 95.6% of the analyzed segments, compared with 96.9% in the group with heart rate less than or equal to 65 beats/min (p = 0.7). CONCLUSION: Our initial evaluation suggests that coronary artery images of diagnostic quality can be obtained using 320-MDCT in most patients with heart rates greater than 65 beats/min, in percentages similar to those for patients with heart rates less than or equal to 65 beats/min. This finding may be the result of the inherent image acquisition and reconstruction technique of 320-MDCT.

Induction of hyperglycemia in adult intrauterine growth-restricted rats: effects on renal function.

Intrauterine growth restriction (IUGR) leads to a reduction in nephron endowment at birth and is linked to renal dysfunction in adulthood. The aim of the present study was to determine whether kidneys of IUGR rat offspring are more vulnerable to a secondary insult of hyperglycemia. IUGR was induced in Wistar-Kyoto rats by maternal protein restriction. At 24 wk of age, diabetes was induced in male IUGR and non-IUGR offspring by streptozotocin injection; insulin was injected daily to maintain blood glucose levels at either a mild (7-10 mmol/l; n=8/group) or a moderate (10-15 mmol/l; n=8/group) level. At 32 wk of age, renal function was assessed using ultrasound and [(3)H]inulin and [(14)C]para-aminohippurate clearance techniques. Conscious mean arterial blood pressure and heart rate were unchanged in IUGR offspring. Relative kidney length was increased significantly in IUGR offspring, and renal function was altered significantly; of importance, there was a significant increase in filtration fraction, indicative of glomerular hyperfiltration. Induction of hyperglycemia led to marked impairment of renal function. However, the response to hyperglycemia was not different between IUGR and non-IUGR offspring. Maintaining blood glucose levels at a mild hyperglycemic level led to marked improvement in all measures of renal function in IUGR and non-IUGR offspring. In conclusion, while the IUGR offspring showed evidence of hyperfiltration, the response to hyperglycemia was similar in IUGR and non-IUGR kidneys in adulthood. Importantly, maintaining blood glucose levels at a mild hyperglycemic level markedly attenuated the renal dysfunction associated with diabetes, even in IUGR offspring.

Voice recognition versus transcriptionist: error rates and productivity in MRI reporting.

PURPOSE: Despite the frequent introduction of voice recognition (VR) into radiology departments, little evidence still exists about its impact on workflow, error rates and costs. We designed a study to compare typographical errors, turnaround times (TAT) from reported to verified and productivity for VR-generated reports versus transcriptionist-generated reports in MRI. METHODS: Fifty MRI reports generated by VR and 50 finalized MRI reports generated by the transcriptionist, of two radiologists, were sampled retrospectively. Two hundred reports were scrutinised for typographical errors and the average TAT from dictated to final approval. To assess productivity, the average MRI reports per hour for one of the radiologists was calculated using data from extra weekend reporting sessions. RESULTS: Forty-two % and 30% of the finalized VR reports for each of the radiologists investigated contained errors. Only 6% and 8% of the transcriptionist-generated reports contained errors. The average TAT for VR was 0 h, and for the transcriptionist reports TAT was 89 and 38.9 h. Productivity was calculated at 8.6 MRI reports per hour using VR and 13.3 MRI reports using the transcriptionist, representing a 55% increase in productivity. CONCLUSION: Our results demonstrate that VR is not an effective method of generating reports for MRI. Ideally, we would have the report error rate and productivity of a transcriptionist and the TAT of VR.

Diagnostic accuracy of contrast-enhanced ultrasound in differentiating benign and malignant focal liver lesions: a retrospective study.

PURPOSE: The purpose of this study was to assess the diagnostic accuracy of our early experience with contrast-enhanced ultrasound (CEUS) in the characterisation of focal liver lesions (FLLs) using histopathology, contrast-enhanced computed tomography (CT), magnetic resonance imaging (MRI) or other imaging follow-up as the standard of reference. MATERIALS AND METHODS: Seventy-three patients with 82 FLLs who underwent liver CEUS from January 2006 to December 2008 were retrospectively reviewed. CEUS was performed with up to 4.8 mL of SonoVue® (Bracco, Milan, Italy) using a low mechanical index mode. The CEUS findings were compared with histopathology, or where histopathology was not available, clinical and imaging follow-up over at least 12 months was used as the standard of reference. RESULTS: Of the 82 FLLs, 50 were malignant and 32 were benign at final diagnosis. CEUS correctly identified 43 malignant FLLs, with final diagnosis confirmed by histopathology in 13 lesions and clinico-radiological follow-up in 30 lesions. Twenty-nine lesions were correctly identified as benign on CEUS, with all these lesions confirmed on clinico-radiological follow-up. CEUS demonstrated a sensitivity of 86.0% and a specificity of 90.6% in the characterisation of liver lesions as malignant, with an overall accuracy of 87.8% (P < 0.05). CONCLUSION: Our early experience has shown that CEUS can be accurate in differentiating malignant from benign FLLs and may become a useful first-line imaging tool where CT or MRI are not available or contra-indicated.

High rates of tumor growth and disease progression detected on serial pretreatment fluorodeoxyglucose-positron emission tomography/computed tomography scans in radical radiotherapy candidates with nonsmall cell lung cancer.

BACKGROUND: The authors studied growth and progression of untreated nonsmall cell lung cancer (NSCLC) by comparing diagnostic and radiotherapy (RT) planning fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) scans before proposed radical chemo-RT. METHODS: Patients enrolled on a prospective clinical trial were eligible for this analysis if they underwent 2 pretreatment whole body FDG-PET/CT scans, >7 days apart. Scan 1 was performed for diagnosis/disease staging and scan 2 for RT planning. Interscan comparisons included disease stage, metabolic characteristics, tumor doubling times, and change in treatment intent. RESULTS: Eighty-two patients underwent planning PET/CT scans between October 2004 and February 2007. Of these, 28 patients (61% stage III, 18% stage II) had undergone prior staging PET/CT scans. The median interscan period was 24 days (range, 8-176 days). Interscan disease progression (TNM stage) was detected in 11 (39%) patients. The probability of upstaging within 24 days was calculated to be 32% (95% confidence interval [CI], 18%-49%). Treatment intent changed from curative to palliative in 8 (29%) cases, in 7 because of PET. For 17 patients who underwent serial PET/CT scans under standardized conditions, there was a mean relative interscan increase of 19% in tumor maximum standardized uptake value (SUV) (P=.022), 16% in average SUV (P=.004), and 116% in percentage injected dose (P=.002). Estimated doubling time of FDG avid tumor was 66 days (95% CI, 51-95 days). CONCLUSIONS: Rapid tumor progression was detected in patients with untreated, predominantly stage III, NSCLC on serial FDG-PET/CT imaging, highlighting the need for prompt diagnosis, staging, and initiation of therapy in patients who are candidates for potentially curative therapy.