Radiology reporting in rectal cancer using MRI: adherence to national template for structured reporting.

BACKGROUND: In 2014, a national workshop program was initiated and a reporting template and manual for rectal cancer primary staging using magnetic resonance imaging (MRI) was introduced and made available by the national Swedish Colorectal Cancer Registry. PURPOSE: To evaluate the effect of the national template program by identify if there was a gap between the content in Swedish MRI reports from 2016 and the national reporting template from 2014. The aim was to explore and compare differences in content in reporting practice in different hospitals in relation to the national reporting template, with focus on: (i) identifying any implementational differences in reporting styles; and (ii) evaluating if reporting completeness vary based on such implementational differences. MATERIAL AND METHODS: A total of 250 MRI reports from 10 hospitals in four healthcare regions in Sweden were collected. Reports were analyzed using qualitative content analysis with a deductive thematic coding scheme based on the national reporting template. RESULTS: Three different implemented reporting styles were identified with variations of content coverage in relation to the template: (i) standardized and structured protocol (reporting style A); (ii) standardized semi-structured free-text (reporting style B); and (iii) regular free-text (reporting style C). The relative completeness of reporting practice of rectal cancer staging in relation to the national reporting template were 92.9% for reporting style A, 77.5% for reporting style B, and 63.9% for reporting style C. CONCLUSION: The implementation of template-based reporting according to reporting style A is a key factor to conform to evidence-based practice for rectal cancer reporting using MRI.

Rectal cancer staging using MRI: adherence in reporting to evidence-based practice.

BACKGROUND: Magnetic resonance imaging (MRI) is the first-line imaging modality for local staging of rectal cancer. The radiology report should deliver all relevant available imaging information to guide treatment. PURPOSE: To explore and describe if there was a gap between the contents in MRI reports for primary staging of rectal cancer in Sweden in 2010 compared to evidence-based practice. MATERIAL AND METHODS: A total of 243 primary MRI staging reports from 2010, collected from 10 hospitals in four healthcare regions in Sweden, were analyzed using content analysis with a deductive thematic coding scheme based on evidence-based practice. Focus was on: (i) most frequently reported findings; (ii) correlation to key prognostic findings; and (iii) identifying if any findings being reported were beyond the information defined in evidence-based practice. RESULTS: Most frequently reported findings were spread through the bowel wall or not, local lymph node description, tumor length, and distance of tumor from anal verge. These items accounted for 35% of the reporting content. Of all reported content, 86% correlated with the evidence-based practice. However, these included more information than was generally found in the reports. When adjusting for omitted information, 48% of the reported content were accounted for. Of the reported content, 20% correlated to key pathological prognostic findings. Six types of findings were reported beyond the evidence-based practice, representing 14% of the total reporting content. CONCLUSION: There was a gap between everyday practice and evidence-based practice in 2010. This indicates a need for national harmonization and implementation of standardized structured reporting templates.

Preventing contrast medium-induced acute kidney injury : Side-by-side comparison of Swedish-ESUR guidelines.

A side-by-side comparison of updated guidelines regarding contrast medium-induced acute kidney injury (CI-AKI) from the Swedish Society of Uroradiology (SSUR) and the European Society of Urogenital Radiology (ESUR) is presented. The major discrepancies include a higher glomerular filtration rate (GFR) threshold as a risk factor for CI-AKI and for discontinuation of metformin by SSUR, i.e., < 45 ml/min versus < 30 ml/min/1.73 m2 by ESUR, when intravenous or intra-arterial contrast media (CM) with second-pass renal exposure is administered. SSUR also continues to recommend consideration of traditional non-renal risk factors such as diabetes and congestive heart failure, while ESUR considers these factors as non-specific for CI-AKI and does not recommend any consideration. Contrary to ESUR, SSUR also recommends discontinuation of NSAID and nephrotoxic medication if possible. Insufficient evidence at the present time motivates the more cautionary attitude taken by SSUR. Furthermore, SSUR expresses GFR thresholds in absolute values in ml/min as recommended by the National Kidney Foundation for drugs excreted by glomerular filtration, while ESUR uses the relative GFR normalised to body surface area in ml/min/1.73 m2. CM dose/GFR ratio thresholds established for coronary angiography/interventions are also applied as recommendations for CM-enhanced CT by SSUR, since SSUR regards coronary procedures as a second-pass renal exposure of CM with no obvious difference in the incidence of AKI compared with IV CM administration. Finally, SSUR recommends reducing the gram-iodine dose/GFR ratio from < 1.0 in patients not at risk to < 0.5 in patients at risk of CI-AKI, while ESUR has no such recommendation. KEY POINTS: • The more cautionary attitude taken by SSUR compared with that of ESUR is motivated by insufficient evidence regarding risk for contrast medium-induced acute kidney injuries (CI-AKI). • SSUR recommends that absolute and not relative GFR should be used when dosing drugs eliminated by the kidneys such as contrast media. • According to SSUR the gram-iodine dose/GFR ratio should be < 0.5 in patients at risk of CI-AKI, while ESUR has no such recommendation.

Infant abuse diagnosis associated with abusive head trauma criteria: incidence increase due to overdiagnosis?

Background: The hypothesis of this study is that the diagnosis of infant abuse is associated with criteria for shaken baby syndrome (SBS)/abusive head trauma (AHT), and that that changes in incidence of abuse diagnosis in infants may be due to increased awareness of SBS/AHT criteria. Methods: This was a population-based register study. Setting: Register study using the Swedish Patient Register, Medical Birth Register, and Cause of Death Register. The diagnosis of infant abuse was based on the International Classification of Diseases, 9th and 10th revision. Participants: All children born in Sweden during 1987-2014 with a follow-up until 1 year of age (N = 2 868 933). SBS/AHT criteria: subdural haemorrhage, cerebral contusion, skull fracture, convulsions, retinal haemorrhage, fractures rib and long bones. Outcomes: Incidence, rate ratios, aetiologic fractions and Probit regression analysis. Results: Diagnosis of infant abuse was strongly associated with SBS/AHT criteria, but not risk exposure as region, foreign-born mother, being born preterm, multiple birth and small for gestational age. The incidence of infant abuse has increased tenfold in Sweden since the 1990s and has doubled since 2008, from 12.0 per 100 000 infants during 1997-2007 to 26.5/100 000 during 2008-2014, with pronounced regional disparities. Conclusions: Diagnosis of infant abuse is related to SBS/AHT criteria. The increase in incidence coincides with increased medical preparedness to make a diagnosis of SBS/AHT. Hidden statistics and a real increase in abuse are less plausible. Whether the increase is due to overdiagnosis cannot be answered with certainty, but the possibility raises ethical and medico-legal concerns.

Cognitive function following head CT in childhood: a randomized controlled follow-up trial.

Background The question has been raised whether low dose radiation toward the brain in childhood can affect cognitive functions. Purpose To examine if a head computed tomography (CT) examination in childhood affect later cognitive functions. Material and Methods A total of 147 participants (67 girls/women, 80 boys/men) from a previous randomized controlled trial on management strategies after mild head injury (head CT examination or in-hospital observation) were followed up. Participants were aged 6-16 years (mean age = 11.2 ± 2.8) at first inclusion and 11-24 years (mean age = 17.8 ± 2.9) at follow-up. Computerized neuropsychological measures used for the assessment were motor speed and coordination, reaction time, selective attention, visuospatial ability, verbal and non-verbal short-term and long-term memory, and executive function tests from the neurocognitive test battery EuroCog and the Wechsler Memory Scale III. Results were analyzed with Student's t-tests and multivariate analyses adjusting for sex, age at time of injury/exposure, and age at assessment were performed with Factorial ANOVAs. Results The exposed and unexposed groups did not differ in any of the neuropsychological measures and results did not change when sex, age at time of injury/exposure, and age at assessment were included in the analyses. Conclusion A head CT examination at the age of 6-16 years does not seem to affect later cognitive functions.

Risk of Meningioma after CT of the Head.

Purpose To investigate the association between exposure to head computed tomography (CT) and subsequent risk of meningioma. Materials and Methods The study was approved by the local ethics committee. A cohort of 26 370 subjects was retrospectively collected from a radiology archive of CT examinations of the head performed from 1973 through 1992. For comparison, an age- and sex-matched cohort of 96 940 subjects who were not exposed to CT (unexposed cohort) was gathered. The risk of meningioma was assessed by using data from the Swedish Cancer Registry; however, one-third of patients with meningioma had to be excluded because they either had a prevalent meningioma or other brain tumor at the first CT examination or had undergone radiation treatment to the head. Hazard ratios (HRs) were calculated from time of exposure to the occurrence of meningioma or death or until December 31, 2010, with logistic regression. Results Comparison of exposed and unexposed cohorts showed that there was no statistically significant increase in the risk of meningioma after exposure to CT of the head (HR: 1.49; 95% confidence interval: 0.97, 2.30; P = .07). If incident cases at the time of the first CT examination were not excluded, the risk of meningioma would have been falsely increased (HR: 2.28; 95% confidence interval: 1.56, 3.33; P = .0001). Conclusion When prevalent cases of meningioma at first exposure to CT of the head are excluded, no statistically significant increase in risk of meningioma was found among exposed subjects compared with unexposed control subjects. © RSNA, 2017.

Arterio-portal shunts in the cirrhotic liver: perfusion computed tomography for distinction of arterialized pseudolesions from hepatocellular carcinoma.

OBJECTIVES: To determine perfusion computed tomography (P-CT) findings for distinction of arterial pseudolesions (APL) from hepatocellular carcinoma (HCC) in the cirrhotic liver. METHODS: 32 APL and 21 HCC in 20 cirrhotic patients (15 men; 65 ± 10 years), who underwent P-CT for evaluation of HCC pre- (N = 9) or post- (N = 11) transarterial chemoembolization, were retrospectively included using CT follow-up as the standard of reference. All 53 lesions were qualitatively (visual) and quantitatively (perfusion parameters) analysed according to their shape (wedge, irregular, nodular), location (not-/adjunct to a fistula), arterial liver perfusion (ALP), portal venous liver perfusion (PLP), hepatic perfusion index (HPI). Accuracy for diagnosis of HCC was determined using receiver operating characteristics. RESULTS: 18/32 (56 %) APL were wedge shaped, 10/32 (31 %) irregular and 4/32 (12 %) nodular, while 11/21 (52 %) HCC were nodular or 10/21 (48 %) irregular, but never wedge shaped. Significant difference between APL and HCC was seen for lesion shape in pretreated lesions (P < 0.001), and for PLP and HPI in both pre- and post-treated lesions (all, P < 0.001). Diagnostic accuracy for HCC was best for combined assessment of lesion configuration and PLP showing an area under the curve of 0.901. CONCLUSION: Combined assessment of lesion configuration and portal venous perfusion derived from P-CT allows best to discriminate APL from HCC with high diagnostic accuracy. KEY POINTS: • Arterio-portal shunting is common in the cirrhotic liver, especially after local treatment. • Arterial pseudolesions (APL) due to shunting might mimic hepatocellular carcinoma (HCC). • Perfusion-CT allows for qualitative and quantitative assessment of liver lesions. • Lesion configuration fails to discriminate APL from HCC in locally treated patients. • Integration of quantitative perfusion analysis improves accuracy for diagnosis of HCC.

Renal versus splenic maximum slope based perfusion CT modelling in patients with portal-hypertension.

PURPOSE: To assess liver perfusion-CT (P-CT) parameters derived from peak-splenic (PSE) versus peak-renal enhancement (PRE) maximum slope-based modelling in different levels of portal-venous hypertension (PVH). MATERIAL AND METHODS: Twenty-four patients (16 men; mean age 68 ± 10 years) who underwent dynamic P-CT for detection of hepatocellular carcinoma (HCC) were retrospectively divided into three groups: (1) without PVH (n = 8), (2) with PVH (n = 8), (3) with PVH and thrombosis (n = 8). Time to PSE and PRE and arterial liver perfusion (ALP), portal-venous liver perfusion (PLP) and hepatic perfusion-index (HPI) of the liver and HCC derived from PSE- versus PRE-based modelling were compared between the groups. RESULTS: Time to PSE was significantly longer in PVH groups 2 and 3 (P = 0.02), whereas PRE was similar in groups 1, 2 and 3 (P > 0.05). In group 1, liver and HCC perfusion parameters were similar for PSE- and PRE-based modelling (all P > 0.05), whereas significant differences were seen for PLP and HPI (liver only) in group 2 and ALP in group 3 (all P < 0.05). CONCLUSION: PSE is delayed in patients with PVH, resulting in a miscalculation of PSE-based P-CT parameters. Maximum slope-based P-CT might be improved by replacing PSE with PRE-modelling, whereas the difference between PSE and PRE might serve as a non-invasive biomarker of PVH. KEY POINTS: • Peak-splenic enhancement is decreased and delayed in patients with portal-venous hypertension • The maximum-slope method uses PSE to calculate arterial and portal-venous liver perfusion • Peak-renal enhancement (PRE) is insensitive to PVH and might improve perfusion modelling • The difference between PSE and PRE might serve as a non-invasive PVH biomarker.

Torsten Almén (1931-2016): the father of non-ionic iodine contrast media.

The Swedish radiologist Torsten Almén is the first clinical radiologist ever to have made a fundamental contribution to intravascular contrast medium design, the development of non-ionic contrast media. He became emotionally triggered by the patients' severe pain each time he injected the ionic "high-osmolar" contrast media when performing peripheral arteriographies in the early 1960s. One day he got a flash of genius that combined the observation of pain, a pathophysiological theory and how to eliminate it with suitable contrast media chemistry. After self-studies in chemistry he developed the concept of iodine contrast media not dissociating into ions in solution to reduce their osmolality and even reach plasma isotonicity. He offered several pharmaceutical companies his concept of mono- and polymeric non-ionic agents but without response, since it was considered against the chemical laws of that time. Contrast media constructed as salts and dissociating into ions in solution was regarded an absolute necessity to achieve high enough water solubility and concentration for diagnostic purposes. Finally a small Norwegian company, Nyegaard & Co., took up his idea 1968 and together they developed the essentially painless "low-osmolar" monomeric non-ionic metrizamide (Amipaque) released in 1974 and iohexol (Omipaque) in 1982 followed by the "iso-osmolar" dimeric non-ionic iodixanol (Visipaque) released in 1993. This has implied a profound paradigm shift with regard to reduction of both hypertonic and chemotoxic side effects, which have been a prerequisite for the today's widespread use of contrast medium-enhanced CT and advanced endovascular interventional techniques even in fragile patients.

The effect of arm positioning on timing and enhancement of intravenous contrast media at coronary computed tomography angiography.

BACKGROUND: Adequate intravenous contrast media (CM) enhancement is crucial for evaluation of the coronary arteries. PURPOSE: To compare the timing and enhancement of intravenous CM at coronary computed tomography angiography (CCTA) when positioning the arms in the traditional superior direction with that of positioning them in the ventral direction during the CM injection. MATERIAL AND METHODS: One hundred patients were randomized into two groups. Group A (n = 50) had their arms positioned in the superior direction, resting on a head and arm support. Group B (n = 50) held their arms resting on the front panel of the computer tomography (CT) scanner. Scanning delay time was defined by test bolus technique. A total of 60 mL iodixanol, 320 mg/mL, was followed by a 50 mL saline flush at 6 mL/s. Cardiac output (CO) and heart rate (HR) were obtained before scanning. The attenuation was calculated by placing regions of interest (ROI) in ascending aorta, left atrium, and inferior vena cava. RESULTS: More patients in group A compared with group B (26 versus 14) showed a higher attenuation of the left atrium in comparison to the ascending aorta (P < 0.05). Body weight (BW) and CO were significantly related to the attenuation of ascending aorta (P < 0.01). CONCLUSION: By placing the arms in a ventral, instead of superior position the frequency of too early imaging at CCTA can be reduced.

Fluorescence labeled microbubbles for multimodal imaging.

Air-filled polyvinyl alcohol microbubbles (PVA-MBs) were recently introduced as a contrast agent for ultrasound imaging. In the present study, we explore the possibility of extending their application in multimodal imaging by labeling them with a near infrared (NIR) fluorophore, VivoTag-680. PVA-MBs were injected intravenously into FVB/N female mice and their dynamic biodistribution over 24 h was determined by 3D-fluorescence imaging co-registered with 3D-µCT imaging, to verify the anatomic location. To further confirm the biodistribution results from in vivo imaging, organs were removed and examined histologically using bright field and fluorescence microscopy. Fluorescence imaging detected PVA-MB accumulation in the lungs within the first 30 min post-injection. Redistribution to a low extent was observed in liver and kidneys at 4 h, and to a high extent mainly in the liver and spleen at 24 h. Histology confirmed PVA-MB localization in lung capillaries and macrophages. In the liver, they were associated with Kupffer cells; in the spleen, they were located mostly within the marginal-zone. Occasional MBs were observed in the kidney glomeruli and interstitium. The potential application of PVA-MBs as a contrast agent was also studied using ultrasound (US) imaging in subcutaneous and orthotopic pancreatic cancer mouse models, to visualize blood flow within the tumor mass. In conclusion, this study showed that PVA-MBs are useful as a contrast agent for multimodal imaging.

Corpus callosum atrophy is strongly associated with cognitive impairment in multiple sclerosis: Results of a 17-year longitudinal study.

BACKGROUND: Cognitive impairment is common in multiple sclerosis (MS) and may be subtle. The corpus callosum is essential for connectivity-demanding cognitive tasks and is significantly affected in MS, therefore it may serve as a marker for cognitive function. OBJECTIVE: The objective of this paper is to longitudinally study the normalized corpus callosum area (nCCA) as a marker of cognitive function and disability in MS. METHODS: Thirty-seven MS patients were followed from 1996 with follow-ups in 2004 and 2013. A healthy matched control group was recruited. The Expanded Disability Status Scale (EDSS) and Symbol Digit Modalities Test (SDMT) were assessed. The nCCA was measured on T2-weighted images. Volumetry was performed with FreeSurfer. RESULTS: Disease duration spanned five decades (1.6-46 years). Annual corpus callosal atrophy rate decreased with disease duration. nCCA was strongly correlated with SDMT (r = 0.793, p < 0.001) and moderately correlated with EDSS (r = -0.545, p < 0.001) after adjusting for disease duration, age and sex. The correlations of brain parenchymal fraction, white matter fraction, gray matter fraction and normalized lesion volume were less strong. CONCLUSIONS: The nCCA correlates well with physical and cognitive disability in time perspectives close to two decades, outperforming volumetric measurements. The nCCA is fast and could be feasible for clinical implementation where it may help identify patients in need of neuropsychological evaluation.

Perfusion computed tomography for detection of hepatocellular carcinoma in patients with liver cirrhosis.

PURPOSE: To evaluate the diagnostic performance of dynamic perfusion CT (P-CT) for detection of hepatocellular carcinoma (HCC) in the cirrhotic liver. MATERIALS AND METHODS: Twenty-six cirrhotic patients (19 men, aged 69 ± 10 years) with suspicion of HCC prospectively underwent P-CT of the liver using the 4D spiral-mode (100/80 kV; 150/175mAs/rot) of a dual-source system. Two readers assessed: (1) arterial liver-perfusion (ALP), portal-venous liver-perfusion (PLP) and hepatic perfusion-index (HPI) maps alone; and (2) side-by-side with maximum-intensity-projections of arterial time-points (art-MIP) for detection of HCC using histopathology and imaging follow-up as standard of reference. Another reader quantitatively assessed perfusion maps of detected lesions. RESULTS: A total of 48 HCCs in 21/26 (81%) patients with a mean size of 20 ± 10 mm were detected by histopathology (9/48, 19%) or imaging follow-up (39/48, 81%). Detection rates (Reader1/Reader2) of HPI maps and side-by-side analysis of HPI combined with arterial MIP were 92/88% and 98/96%, respectively. Positive-predictive values were 63/63% and 68/71%, respectively. A cut-off value of ≥85% HPI and ≥99% HPI yielded a sensitivity and specificity of 100%, respectively, for detection of HCC. CONCLUSION: P-CT shows a high sensitivity for detection of HCC in the cirrhotic liver. Quantitative assessment has the potential to reduce false-positive findings improving the specificity of HCC diagnosis. KEY POINTS: • Visual analysis of perfusion maps shows good sensitivity for detection of HCC. • Additional assessment of anatomical arterial MIPs further improves detection rates of HCC. • Quantitative perfusion analysis has the potential to reduce false-positive findings. • In cirrhotic livers, a hepatic-perfusion-index ≥ 9 9% might be specific for HCC.

Visualization of dialysis fistula by computed tomography using time-resolved 3D volume rendering.

BACKGROUND: To evaluate the function of arteriovenous (AV) dialysis fistula using dynamic computed tomography (CT) and time-resolved 3-dimensional (3D) volume rendering (VR). METHODS: Seven patients referred for angiographic CT examination of the AV dialysis fistula were enrolled. Twenty-four grams of iodine were administered intravenously (iomeprol 400 mg I/mL at 6 mL/sec) followed by a 50-mL saline flush. Dynamic scanning was performed for 15-24 sec. CT images were then postprocessed on a dedicated workstation creating time-resolved 3D VR images and movies. RESULTS: All studies showed good image quality showing pathology in 6 of 7 patients. Unexpected findings were observed in 1 patient, aneurysm (n = 1). Radiation dose was 5 mSv. CONCLUSIONS: The function of AV dialysis fistula can be visualized using dynamic CT and time-resolved 3D VR.

Contrast-enhanced ultrasound using real-time contrast harmonic imaging in invasive breast cancer: comparison of enhancement dynamics with three different doses of contrast agent.

BACKGROUND: In the last few years new potential applications have been developed for contrast-enhanced ultrasound (CEUS) and the management of breast diseases, but there is still some debate concerning the optimal dose to evaluate breast lesions, especially as a diagnostic tool. PURPOSE: To compare different CEUS doses of injected contrast agent in order to establish an optimal dose for the diagnosis of invasive breast cancer. MATERIAL AND METHODS: In Group A we compared the bolus dose of 1.2 mL vs. 2.4 mL and in Group B we compared the bolus dose of 2.4 mL vs. 4.8 mL (26 and 25 invasive carcinomas, respectively). CEUS was performed in real-time contrast harmonic imaging (CHI) using a L9-3 MHz probe. All examinations were recorded in a contrast side/side imaging mode loop for 120 s. Wash-in and wash-out patterns of the contrast agent were analyzed with advanced US quantification software and kinetic curves were used for statistical analysis. RESULTS: In Group B (2.4 mL vs. 4.8 mL), more and stronger correlation was found among kinetic parameters (area under the curve, P < 0.00001; lognormal model parameters, µ, P = 0.0007 and σ, P < 0.0001; mean transit time, P < 0.0001; model-based wash-out ratios, W21m, P = 0.0002; W50m, P = 0.0001; time-to-peak, P = 0.005) as compared to Group A (1.2 mL vs. 2.4 mL). CONCLUSION: The optimal way to evaluate kinetic features of invasive breast tumors using real-time CEUS is with an injection of contrast agent of either 2.4 mL or 4.8 mL.

Time-resolved computed tomography of the liver: retrospective, multi-phase image reconstruction derived from volumetric perfusion imaging.

OBJECTIVE: To assess feasibility and image quality (IQ) of a new post-processing algorithm for retrospective extraction of an optimised multi-phase CT (time-resolved CT) of the liver from volumetric perfusion imaging. METHODS: Sixteen patients underwent clinically indicated perfusion CT using 4D spiral mode of dual-source 128-slice CT. Three image sets were reconstructed: motion-corrected and noise-reduced (MCNR) images derived from 4D raw data; maximum and average intensity projections (time MIP/AVG) of the arterial/portal/portal-venous phases and all phases (total MIP/ AVG) derived from retrospective fusion of dedicated MCNR split series. Two readers assessed the IQ, detection rate and evaluation time; one reader assessed image noise and lesion-to-liver contrast. RESULTS: Time-resolved CT was feasible in all patients. Each post-processing step yielded a significant reduction of image noise and evaluation time, maintaining lesion-to-liver contrast. Time MIPs/AVGs showed the highest overall IQ without relevant motion artefacts and best depiction of arterial and portal/portal-venous phases respectively. Time MIPs demonstrated a significantly higher detection rate for arterialised liver lesions than total MIPs/AVGs and the raw data series. CONCLUSION: Time-resolved CT allows data from volumetric perfusion imaging to be condensed into an optimised multi-phase liver CT, yielding a superior IQ and higher detection rate for arterialised liver lesions than the raw data series. KEY POINTS: • Four-dimensional computed tomography is limited by motion artefacts and poor image quality. • Time-resolved-CT facilitates 4D-CT data visualisation, segmentation and analysis by condensing raw data. • Time-resolved CT demonstrates better image quality than raw data images. • Time-resolved CT improves detection of arterialised liver lesions in cirrhotic patients.

Automatic individualized contrast medium dosage during hepatic computed tomography by using computed tomography dose index volume (CTDI(vol)).

PURPOSE: To compare hepatic parenchymal contrast media (CM) enhancement during multi-detector row computed tomography (MDCT) and its correlation with volume pitch-corrected computed tomography dose index CTDI(vol)) and body weight (BW). MATERIAL AND METHODS: One hundred patients referred for standard three-phase thoraco-abdominal MDCT examination were enrolled. BW was measured in the CT suite. Forty grams of iodine was administered intravenously (iodixanol 320 mg I/ml at 5 ml/s or iomeprol 400 mg I/ml at 4 ml/s) followed by a 50-ml saline flush. CTDI(vol) presented by the CT equipment during the parenchymal examination was recorded. The CM enhancement of the liver was defined as the attenuation HU of the liver parenchyma during the hepatic parenchymal phase minus the attenuation in the native phase. RESULTS: Liver parenchymal enhancement was negatively correlated to both CTDI(vol) (r = -0.60) and BW (r = -0.64), but the difference in correlation between those two was not significant. CONCLUSION: CTDI(vol) may replace BW when adjusting CM doses to body size. This makes it potentially feasible to automatically individualize CM dosage by CT. KEY POINTS: • CTDI vol is related to liver CM enhancement in the parenchymal phase. • CTDI vol provides comparable information to body weight (BW). • CTDI vol may be used when automatically adjusting CM dose for patient size.

Radiologically isolated syndrome--incidental magnetic resonance imaging findings suggestive of multiple sclerosis, a systematic review.

With increasing availability of magnetic resonance imaging (MRI), there is also an increase in incidental abnormal findings. MRI findings suggestive of multiple sclerosis in persons without typical multiple sclerosis symptoms and with normal neurological findings are defined as radiologically isolated syndrome (RIS). Half of the persons with RIS have their initial MRI because of headache, and some have a subclinical cognitive impairment similar to that seen in multiple sclerosis. Radiological measurements also show a similarity between RIS and multiple sclerosis. Approximately two-thirds of persons with RIS show radiological progression and one-third develop neurological symptoms during mean follow-up times of up to five years. Cervical cord lesions are important predictors of clinical conversion. Management has to be individualised, but initiation of disease modifying therapy is controversial and not recommended outside of clinical trials since its effects have not been studied in RIS. Future studies should try to establish the prevalence and long-term prognosis of RIS, its impact on quality of life, and define the role of disease modifying therapy in RIS.

Correlation of contrast-enhanced ultrasound kinetics with prognostic factors in invasive breast cancer.

OBJECTIVES: To correlate contrast-enhanced ultrasound (CEUS) kinetic parameters with traditional and molecular prognostic factors in invasive breast cancer. METHODS: Seventy-five invasive breast cancers were evaluated with contrast harmonic imaging after the injection of a bolus dose of 2.4 ml sulphur hexafluoride microbubble contrast agent. The lognormal function was used for quantitative analysis of kinetic data. These parameters correlated with traditional prognostic factors (tumour size, histological type, tumour grade, axillary lymph node status) and immunohistochemical biomarkers (ER, PR and HER2 status). RESULTS: Statistically significant correlation was found between time-to-peak and tumour grade (P value = 0.023), PR status (P value = 0.042) and axillary node status (P value = 0.025). Wash-out ratio, measured at 21 s was significantly associated with ER status (P value = 0.042) and PR status (P value = 0.026). CONCLUSIONS: Invasive breast carcinomas exhibiting earlier peak enhancement and faster elimination of microbubble contrast agent at CEUS are found to be associated with established predictors of poor prognosis.