MR spectroscopy,S100B protein and NSE analysis as early predictors of hypoxic ishaemic encephalopathy

Aim of work

The aim of this work is to assess S100B protein, neuron specific enolase and magnetic resonance spectroscopy as biochemical and imaging findings in neonatal hypoxic ischemic encephalopathy.

Methods

This prospective study on 30 full-term neonates suffering from HIE who were attendants of the Neonatology Unit of Pediatric Department and Radiodiagnosis Department of Tanta University Hospital. Duration of the study extended from June 2010 to June 2012.

Results

Thirty patients (16 males and 14 females), HIE group classification according to Lac/Cr ratio in MRS to three groups: Groups – group I: where Lac/Cr < 0.5, group II: where Lac/Cr 0.5–1.5 and group III: where Lac/Cr > 1.5.¹HMRS group I contained 17 patients (15 patients were present in Sarnat stage I and two patients were present in Sarnat stage II). Group II contained nine patients (all patients were present in Sarnat stage II). Group III contained four patients (all patients were present in Sarnat stage III).Serum level of S100B protein and NSE were significantly higher in the HIE group than control group also serum level of S100B protein and NSE in HIE stage III was significantly higher than control, HIE stage I and stage II.

Conclusion

¹HMRS is a useful tool for evaluating the severity and prognosis of HIE noninvasively. Higher lactate/Cr ratio in basal ganglia and thalamus predict the poor prognosis of neonates.Serum level of S100B protein and NSE has an important meaning in adjuvant diagnosing and ruling out diagnosis of early HIE and prognosis of birth asphyxia.     

A prospective observational study of early fetal growth velocity and its association with birth weight,gestational age at delivery,preeclampsia, and perinatal mortality

Objectives

We aimed to measure early fetal growth velocity and to correlate this with the birth weight, gestational age at delivery, and with the incidence of adverse pregnancy outcomes specifically preeclampsia and perinatal mortality.

Methods

A data based prospective observational study, wherein sonographic biometry data and specific pregnancy outcome related data were collected from pregnant women's records, starting soon after their first antenatal visit. Early fetal growth velocity was measured using BPD growth between 11 and 14 weeks scan and anomaly scan and standardizing this by Z scoring.

Results

Out of 607 fetuses, 41 (6.7%) were slow growing, 531 (87.4%) normally growing, and 35 (5.7%) fast growing (Z scoring <10th^, 10–90th, and >90th percentiles respectively). As fetal growth velocity increased, the mean birth weight decreased from 2958.7 ± 388.9 (<10th centile), 2742.1 ± 576.6 (10–90th centile), to 2339.3 ± 729.4 (>90th centile); and gestational age at delivery decreased from 38.5 ± 1.3 (<10th centile), 37.5 ± 2.1 (10–90th centile), to 36.4 ± 2.2 (>90th centile), and both these trends were statistically significant (p < 0.001).Faster growing fetuses had a higher risk of preterm delivery(spontaneous + indicated) compared to other 2 groups [OR 4.42 (2.18,8.98)], and slower growing fetuses had a higher risk of postdated deliveries compared to other 2 groups [OR 3.042 (1.44, 6.45)].We found no significant association between early fetal growth velocity and incidence of small for gestational age at birth/low birth weight at term, preeclampsia, and perinatal mortality.

Conclusions

Early fetal growth velocity between first and second trimesters, may be one of the important factors influencing ultimate birthweight and gestational age at delivery.     

Transcranial ultrasound Doppler parameters in cerebral vessels may predict intracerebral hemorrhage in preterm newborns

Purpose

The purpose of this study was to assess the screening of intracerebral vessels in preterm newborns in early postnatal period by transcranial ultrasound (US) Doppler parameters; as a predictive method of identifying preterm infants at risk of intracerebral hemorrhage.

Patients and Methods

The study was conducted as a screening study for 39 preterm neonates, their gestational age (GA) ranged between 26 and 35 weeks, and their birth weights (BW) ranged from 900 to 2500 g. They were considered clinically at risk of intracerebral hemorrhage (ICH) due to their prematurity and low birth weight. The study was focused on transcranial US Doppler examinations of cerebral vessels on the first two days of life while still no clinical evidence of ICH was detected. The routine US examination included searching for ICH, then Doppler examination was done and included measurement of peak-systolic velocity (PSV), end diastolic velocity (EDV), mean velocity (MV) and Doppler indices; resistance index (RI) and pulsatility index (PI) in anterior cerebral artery (ACA) and middle cerebral artery (MCA). US and Doppler examinations were then repeated within 4-7 days for only 34 newborns as five newborns died before the time of follow up study, we searched for newborns who developed ICH and measured all these Doppler parameters again for all the remained 34 newborns and these results were correlated with clinical assessment.

Results

All the 34 preterm newborns showed no ICH by transcranial US at the initial examination. On the follow up US-Doppler study, 16 of them (47%) developed ICH and they are classified as hemorrhage group and 18 of them (53%) did not develop ICH and they are classified as non-hemorrhage or control group. There was no statistically significant difference (P-value of >0.05) between the two groups as regards the GA, weight, mean value of PSV and MV in both Doppler examinations, and mean value of RI and PI in the initial Doppler examination, while there was statistically significant difference (P-value of <0.05) between the two groups as regards the mean value of EDV in the initial Doppler examination. Also there was statistically highly significant difference (P-value of <0.001) between the two groups as regards mean value of EDV, RI and PI in the follow up examination. The final interpretation that both newborn weight of less than 1800 g and EDV value in intracerebral vessels in the initial Doppler examination of more than 9.2 cm/s were the most sensitive predictors of intracerebral hemorrhage and both GA of less than 31.8 week and EDV value in the initial Doppler examination of more than 9.2 cm/s were the most sensitive predictors for high grades of intracerebral hemorrhage.

Conclusion

Our study showed that the most sensitive Doppler parameter which can be used as a predictor marker for intracerebral hemorrhage in preterm newborns in early postnatal period was end diastolic velocity > 9.2 cm/s and so offers a measurable screening predictor parameter, when clinical symptoms of hemorrhage may be still silent and so preventive and therapeutic actions could be useful.     

Can diffusion tensor imaging predict motor power affection after moderate traumatic brain injury?

Objective

To determine whether commissural and projection fibers fractional anisotropy (FA) abnormalities can help in the prediction of long-term outcome of motor power affection after moderately severe traumatic brain injury (TBI).

Methods

MRI protocol included diffusion tensor imaging (DTI) and was performed for 32 patients with moderate TBI and 32 matched control subjects. Regions of interests were applied in the FA maps in the corpus callosum, internal capsules posterior limb, and cerebral peduncles. Results were compared in patients with motor power affection and patients without motor power affection to the control group.

Results

All patients had FA values lower than the control group with significance differences in the corpus callosum. Patient group with weakness had FA values lower than the control groups with significance differences in the posterior limb of the left internal capsules (p = 0.001) and left cerebral peduncles (p < 0.001). Significant differences were found when comparing the posterior limb of the left internal capsule (p = 0.002) and left cerebral peduncle (p = 0.022) to the right side in the weakness group.

Conclusion

FA values measured in the acute stage provided information about associated and projectional fibers disruptions, which have a prognostic value about motor power affection.     

Assessment of acromial morphology in association with rotator cuff tear using magnetic resonance imaging

Purpose

To identify the morphological characteristics of the acromion associated with RCT using MRI. Also, to recognize which type of the acromion could be risk factor for full thickness RCT.

Materials and methods

Fifty-six patients with RCT (either partial or full thickness tear) and 30 control volunteers were enrolled in this study. Their shoulders were imaged by MRI. The acromial shapes were classified into type I (flat), type II (curved), type III (hooked) and type IV (convex). Additional measurements including acromial thickness, acromio-humeral distance (AHD), acromial index (AI) and lateral acromial angle (LAA) were performed for further assessment.

Results

Type-II was the most commonly encountered acromial shape in both patients with RCT (44.6%) and control group (43.3%) with no significant difference in the incidence of each acromial shape between the two groups (P > 0.05). The acromial thickness, AHD, AI and LAA were significantly different in patients with RCT compared to control group (P < 0.001). Full thickness tear was significantly associated with type-III (P < 0.05).

Conclusion

Type-III acromion (hooked shaped) could be a risk factor for full thickness RCT.     

Potential of diffusion tensor MR imaging in the assessment of cognitive impairments in children with periventricular leukomalacia born preterm

Purpose

To investigate MR diffusion tensor imaging (DTI) and fiber tractography (FT) in the assessment of altered major white matter fibers correlated with cognitive functions in preterm infants with periventricular leukomalacia (PVL), to explore the neural foundation for PVL children's cognitive impairments.

Materials and methods

Forty six preterm infants (16 ± 4.7 months) suffered from PVL and 16 age-matched normal controls were recruited. Developmental quotient (DQ) was recorded to evaluate PVL children's cognitive functions. According to the DQ scores, patients were divided into three groups: mild, moderate and severe cognitive impairment groups. DTI scan was performed. Fractional anisotropy (FA) values of major white matter fibers were measured and their correlation with cognitive levels was evaluated.

Results

Compared with the control group, the PVL group showed a significant mean FA reduction in bilateral corticospinal tract (CST), anterior/posterior limb of internal capsule (ICAL/ICPL), arcuate fasciculus (AF), corona radiate (CR), superior longitudinal fasciculus (SLF), splenium of corpus callosum (SCC) (p < 0.05) and bilateral posterior thalamic radiation (PTR) (p < 0.01). The FA values of left CST, bilateral AF, anterior cingulum (ACG), SLF, ICAL, ICPL, PTR, CR, genu of corpus callosum (GCC), SCC and middle cerebellar peduncle showed significant negative correlations with the cognitive levels.

Conclusions

DTI can provide more information for understanding the pathophysiology of cognitive impairment in preterm infants with PVL.     

Use of session RPE to training load quantification and training intensity distribution in taekwondo athletes

Objective

The purposes of this study were to: verify whether rating of perceived exertion (RPE) can be used to determine the training load, using heart rate (HR) and blood lactate concentration ([BLa⁻]) as the criteria measurements, and determine the association and agreement of training intensity distribution based on RPE and [BLa⁻] responses in taekwondo training.

Methods

Eleven elite taekwondo athletes performed a progressive test, in order to estimate maximal HR, and two training sessions. Twenty-two training loads were quantified based on RPE (session-RPE), HR and [BLa⁻] responses. The training intensity distribution was performed using RPE and [BLa⁻] responses. The level of statistical significance was set at P < 0.05.

Results

All correlations between session-RPE with HR and [BLa⁻] methods were statistically significant (r = 0.52–0.71, P < 0.05). The association between proportions of training intensity distribution based on RPE and [BLa⁻] responses were significant (P > 0.05) with a high agreement (k = 0.71).

Conclusion

Taekwondo coaches can use RPE to quantify training loads and training intensity distribution in order to better plan and assist training program.     

Diagnosis of early sacroiliitis in seronegative spondyloarthropathies by DWI and correlation of clinical and laboratory findings with ADC values

Purpose

Sacroiliitis is one of the diagnostic criteria of seronegative SpA. The purpose of our study is to show the signal characteristics of the sacral and iliac surfaces by DWI which may contribute in early diagnosis of sacroiliitis and investigate the correlation between ADC values and clinical and laboratory parameters.

Materials and methods

62 patients with inflammatory low back pain, with a history or suspect of seronegative SpA are enrolled into the study. 40 age and sex-matched subjects without SpA constituted the control group. After obtaining routine T1 and T2 weighted sequences, echo planar imaging at b values of 0, 400 and 800 was performed. ADC values on both surfaces of the both sacroiliac joints were measured in all subjects. The CRP and sedimentation results and the presence of arthritis and enthesitis were also correlated with the ADC values.

Results

ADC values on both surfaces of the both sacroiliac joints were found 0.23 × 10⁻³ mm²/sn in the control group. In the patient group, mean ADC value of 0.48 × 10⁻³ mm²/sn was obtained (p < 0.001), which was statistically significant, compatible with the increased diffusion due to medullary edema in early sacroiliitis. There was a slight correlation between CRP and ADC values; presumed to be showing the relation between the activity of the disease and the active inflammation on DWI. There was no correlation between arthritis and enthesitis and the ADC values (p > 0.001).

Conclusion

DWI, by measuring ADC values, adds significant information in the early diagnosis of sacroiliitis and may help to evaluate the efficiency of the treatment.     

Ultrasonographic and clinical study of post-stroke painful hemiplegic shoulder

Aim of the work

To describe the structural abnormalities of the painful hemiplegic shoulder (PHS) by ultrasound (U/S) and their relationship with some clinical variables.

Materials and methods

Eighty consecutive patients with post-stroke PHS were subjected to both clinical assessment and ultrasonographic examination of both shoulders. Ultrasonographic imaging data were classified into five grades.

Results

The biceps tendon sheath effusion (51.25%) and the SA–SD bursitis (43.75%) were the most frequent abnormalities in the affected painful shoulder. No significant relationship (P = 0.114) was found between the U/S grades of the painful hemiplegic shoulder and the Brunnstrom motor recovery stages. Ultrasonographic grades of the unaffected shoulder were significantly correlated with the stroke duration (P < 0.001), the Brief Pain Inventory score (P < 0.05), shoulder pain duration (P < 0.001), and degree of spasticity (P < 0.001).

Conclusion

Ultrasonography is an essential method in evaluation of post-stroke PHS. However, the U/S grades were not correlated with the stages of motor recovery. Avoiding overuse of the unaffected shoulder will be helpful for prevention of shoulder injuries following hemiplegic stroke.     

Role of postoperative multislice computed tomography in assessment of pedicle screw placement in spinal surgical fixation

Objective

To evaluate the role of three-dimensional (3D) volume rendering computed tomography (CT), in the postoperative assessment of pedicle screw placement.

Methods

Ninety-eight patients with previous spinal fixation surgery were included. All inserted screws were evaluated post operatively within the first month using CT. Degree of misplacement and difference between CT images were recorded.

Results

Seventy six, 68 and 39 misplaced screws were detected in 3D reformatted image, coronal reconstruction and axial CT images, respectively. Dorsal spine had the higher rate of violation of 46 (9.95%) with the highest rate at T4 (12.8%) compared with lumbar of 32 (6.9%). Statistically significant differences were found between lateral and medial violation (P value −0.03), between findings of 3D CT reformatted and axial images (P = 0.04), and also in detecting end plate perforation and anterior vertebral encroachment in different CT images (P value −0.013). Sensitivity for 3D reformatted image and axial image compared with surgical finding in six revised screws was 100% and 95.8% and specificity was 100% and 88.7%, respectively. Highly momentous agreement is reported with Kappa coefficient = 0.95 ± <0.001.

Conclusion

We conclude that postoperative evaluation of pedicle screw using 3D CT reconstruction was a reliable method.     

Value of renal resistive index in hepatitis C virus related liver cirrhosis and its response to midodrine

Background

Hyperdynamic circulatory state in liver cirrhosis is characterized by increased splanchnic blood flow and renal vasoconstriction.

Aim

To evaluate the relationship between renal resistive indices (RI) and HCV liver cirrhosis severity and RI value in predicting 6 month survival of those patients. Also we aimed to assess the effect of midodrine on RI.

Patients and methods

120 patients with HCV liver cirrhosis and 40 healthy controls were enrolled in the study. INR, total bilirubin, albumin, creatinine and sodium were measured in all patients. Both patients and controls underwent abdominal ultrasound with duplex Doppler examination of the kidneys with RI calculated. Patients were followed for 6 months. Surviving patients with highest risk underwent renal duplex with RI calculation (RI2). They then received oral midodrine at a dose of 7.5 mg three times daily for 3 months with revaluation of RI (RI3).

Results

57 (47.5%) patients had high RI (RI > 0.7) while 63 (52.5%) patients had normal RI. Patients had significantly higher RI than healthy controls (P < 0.001). There was a significant positive correlation between RI and MELD, MELD-Na, and Child class (r = 0.859, r = 0.769, rho = 0.56 respectively and P < 0.001). Patients with RI > 0.73 are at higher risk of death within 6 months (P < 0.001). Administration of midodrine resulted in no significant difference in RI in the 37 surviving patients with baseline RI > 0.73 (P = 0.1605).

Conclusion

RI is strongly correlated with liver cirrhosis severity and had comparable prognostic value with MELD score. Midodrine had no significant effect on RI in high risk patients.     

Atherosclerotic imaging using 4 types of superparamagnetic iron oxides: New possibilities for mannan-coated particles

Purpose

We used magnetic resonance imaging (MRI) and histologic techniques to compare the uptake by the rabbit atherosclerotic wall of 4 types of superparamagnetic iron oxide (SPIO) particles, i.e. SPIO, mannan-coated SPIO (M-SPIO), ultrasmall SPIO (USPIO), and mannan-coated USPIO (M-USPIO).

Materials and methods

All experimental protocols were approved by our institutional animal experimentation committee. We intravenously injected 12 Watanabe heritable hyperlipidemic rabbits with one of the 4 types of SPIO (0.8 mmol Fe/kg). Two other rabbits served as the control. The rabbits underwent in vivo contrast-enhanced magnetic resonance angiography (MRA) before- and 5 days after these injections; excised aortae were subjected to in vitro MRI. In the in vivo and in vitro studies we assessed the signal intensity of the vessels at identical regions of interest (ROI) and calculated the signal-to-noise ratio (SNR). For histologic assessment we evaluated the iron-positive regions in Prussian blue-stained specimens.

Results

There were significant differences in iron-positive regions where M-USPIO > USPIO, M-SPIO > SPIO, USPIO > SPIO (p < 0.05) but not between M-USPIO and M-SPIO. The difference between the pre- and post-injection SNR was significantly greater in rabbits treated with M-USPIO than USPIO and in rabbits injected with M-SPIO than SPIO (p < 0.05). On in vitro MRI scans SNR tended to be lower in M-USPIO- and M-SPIO- than USPIO- and SPIO-treated rabbits (p < 0.1).

Conclusion

Histologic and imaging analysis showed that mannan-coated SPIO and USPIO particles were taken up more readily by the atherosclerotic rabbit wall than uncoated SPIO and USPIO.     

MR determination of neonatal spinal canal depth

Objectives

Lumbar punctures (LPs) are frequently performed in neonates and often result in traumatic haemorrhagic taps. Knowledge of the distance from the skin to the middle of the spinal canal (mid-spinal canal depth – MSCD) may reduce the incidence of traumatic taps, but there is little data in extremely premature or low birth weight neonates. Here, we determined the spinal canal depth at post-mortem in perinatal deaths using magnetic resonance imaging (MRI).

Patients and methods

Spinal canal depth was measured in 78 post-mortem foetuses and perinatal cases (mean gestation 26 weeks; mean weight 1.04 kg) at the L3/L4 inter-vertebral space at post-mortem MRI. Both anterior (ASCD) and posterior (PSCD) spinal canal depth were measured; MSCD was calculated and modelled against weight and gestational age.

Results

ASCD and PSCD (mm) correlated significantly with weight and gestational age (all r > 0.8). A simple linear model MSCD (mm) = 3 × Weight (kg) + 5 was the best fit, identifying an SCD value within the correct range for 87.2% (68/78) (95% CI (78.0, 92.9%)) cases. Gestational age did not add significantly to the predictive value of the model.

Conclusion

There is a significant correlation between MSCD and body weight at post-mortem MRI in foetuses and perinatal deaths. If this association holds in preterm neonates, use of the formula MSCD (mm) = 3 × Weight (kg) + 5 could result in fewer traumatic LPs in this population.     

CT quantification of emphysema: Is semi-quantitative scoring a reliable enough method?

Objective

To evaluate whether a simple semi-quantitative method aided by software enhanced visualization can be reliable enough for the quantification of emphysema during the daily workload.

Patients and methods

Thirty patients with COPD were included. Patients had a standard non enhanced MDCT study of the chest using a 16 slice machine. The images were evaluated visually and scored. This scoring was repeated after applying a density mask. Three radiologists evaluated the images on separate occasions. Repeatability was also tested. The CT emphysema index and the mean lung attenuation were calculated. The extent of airway disease was not assessed.

Results

Kappa test between the 3 readers revealed slight agreement (k = 0.122, p = 0.001) before the density mask and substantial agreement (k = 0.75, p < 0.0005) after its application. A high degree of repeatability was found. The median visual score after density mask application, showed a stronger correlation to the emphysema index (r = 0.81, p < 0.0005) than before.

Conclusion

We present a simple visual score for quantitation of emphysema, that when combined with a simple density mask, the inter-rater agreement and repeatability of scoring are markedly improved. This method appears to be fast and easy to perform.     

Altered microstructural connectivity of the superior and middle cerebellar peduncles are related to motor dysfunction in children with diffuse periventricular leucomalacia born preterm: A DTI tractography study

Purpose

To investigate the microstructural integrity of superior cerebellar peduncles (SCP) and middle cerebellar peduncles (MCP) by using DTI tractography method, and further to detect whether the microstructural integrity of these major cerebellar pathways is related to motor function in children with diffuse periventricular leucomalacia (PVL) born preterm.

Materials and methods

46 children with diffuse PVL (30 males and 16 females; age range 3–48 months; mean age 22.4 ± 6.7 months; mean gestational age 30.5 ± 2.2 weeks) and 40 healthy controls (27 males and 13 females; age range 3.5–48 months; mean age 22.1 ± 5.8 months) were enrolled in this study. DTI outcome measurements, fractional anisotropy (FA), for the SCP, MCP and cortical spinal tract (CST) were calculated. The gross motor function classification system (GMFCS) was used for assessing motor functions.

Results

Compared to the controls, patients with diffuse PVL had a significantly lower FA in bilateral SCP, MCP and CST. There was a significant negative correlation between GMFCS levels and FA in bilateral SCP, MCP and CST in the patients group. In addition, significant inverse correlation of FA value was found between not only the contralateral but also the ipsilateral CST and SCP/MCP.

Conclusions

These findings suggest that the injury of SCP and MCP may contribute to the motor dysfunction of diffuse PVL. Moreover, the correlations we found between supratentorial and subtentorial injured white matter extend our knowledge about the cerebro-cerebellar white matter interaction in children with diffuse PVL.     

Brain magnetic resonance imaging findings in cryptogenic stroke patients under 60 years with patent foramen ovale

Purpose

To compare magnetic resonance imaging (MRI) brain feature in cryptogenic stroke patients with patent foramen ovale (PFO), cryptogenic stroke patients without PFO and patients with cardioembolic stroke.

Materials and methods

The ethics committee required neither institutional review board approval nor informed patient consent for retrospective analyses of the patients’ medical records and imaging data. The patients’ medical files were retrospectively reviewed in accordance with human subject research protocols. Ninety-two patients under 60 years of age were included: 15 with cardioembolic stroke, 32 with cryptogenic stroke with PFO and 45 with cryptogenic stroke without PFO. Diffusion-weighted imaging of brain MRI was performed by a radiologist blinded to clinical data. Univariate, Fischer's exact test for qualitative data and non-parametric Wilcoxon test for quantitative data were used.

Results

There was no statistically significant difference found between MRI features of patients with PFO and those with cardioembolic stroke (p < .05). Patients without PFO present more corticosubcortical single lesions (p < .05) than patients with PFO. Patients with PFO have more often subcortical single lesions larger than 15 mm, involvement of posterior cerebral arterial territory and intracranial occlusion (p < .05) than patients with cryptogenic stroke without PFO.

Conclusion

Our study suggests a cardioembolic mechanism in ischemic stroke with PFO.     

Influence of different frequencies and insertion depths on the diagnostic accuracy of liver elastography by acoustic radiation force impulse imaging (ARFI)

Background

Acoustic Radiation Force Impulse Imaging (ARFI) is an innovative elastography for staging of liver fibrosis. We evaluated the diagnostic accuracy of different probes to perform ARFI at different insertion depths.

Methods

In a prospective study, 89 chronic HCV infected patients underwent ARFI elastography using both available probes (c-ARFI: C4-1-MHz; l-ARFI: L9-4 MHz) in comparison to Fibroscan^®. Variability of ARFI elastography at different insertion depths was systematically evaluated in 39 patients (44%). According to Fibroscan^® elastography, 32 patients (36%) presented with liver cirrhosis, 23 patients (26%) had significant fibrosis and 34 patients (38%) had no significant fibrosis.

Results

Mean propagation velocity with c-ARFI was 1.70 ± 0.67 m/s and 1.91 ± 0.87 m/s with l-ARFI. Results of both probes were correlated to each other (p < 0.001; r = 0.70) and to Fibroscan^® (p < 0.001, r = 0.82 and 0.84, respectively). In patients with significant fibrosis or with cirrhosis, mean values by l-ARFI were significantly higher than by c-ARFI (p < 0.001). For detection of liver cirrhosis, AUROC was 0.97 for c-ARFI (cut-off level 1.72 m/s) and 0.90 for l-ARFI (cut-off 2.04 m/s). Correlation coefficients of c-ARFI with Fibroscan^® were highest at an insertion depth of 5–6 cm (r = 0.882 and 0.864, respectively, p < 0.001) and at 3–4 cm for l-ARFI (r = 0.850 and 0.838, respectively, p < 0.001).

Conclusions

ARFI elastography with the linear and with the convex probes showed comparable validity and accuracy in the estimation of liver stiffness. The linear probe gave higher ARFI values. The most accurate insertion depth was 5–6 cm for c-ARFI and 3–4 cm for l-ARFI indicating that measurements should not be performed close to the liver capsule.     

T1 mapping for detection of left ventricular myocardial fibrosis in hypertrophic cardiomyopathy: A preliminary study

Purpose

To investigate the diagnostic value of T1 mapping imaging of evaluating fibrosis in patients with hypertrophic cardiomyopathy (HCM).

Materials and methods

21 subjects with HCM and 18 healthy volunteers underwent conventional late gadolinium enhancement (LGE) imaging and T1 mapping imaging. The region of myocardium in HCM is divided into remote area of LGE, peri-LGE, LGE (halo-like LGE and typical patchy LGE). These regions combined with normal volunteers’ myocardium were calculated by the reduced percent of T1 value (RPTV).

Results

The RPTV in healthy volunteers was no significant comparing with that in the remote area of LGE in HCM subjects (3.98 ± 3.19 vs. 3.34 ± 2.75, P > 0.05). There were significant statistical differences in pairwise among the remote area of LGE, peri-LGE, halo-like LGE and typical patchy LGE in the RPTV (P < 0.0001). ROC curves indicated that the T1 mapping imaging has a greater area under the curve comparing with that of traditional LGE imaging (0.975 ± 0.07 vs. 0.753 ± 0.26, P < 0.0001).

Conclusions

HCM has a high prevalence of fibrosis and with varying severity. T1 mapping imaging can be a useful method to evaluate the severity of the fibrosis in HCM.     

Diffusion tensor imaging of periventricular leukomalacia – Initial experience

Aim of the study

To investigate the role of MR diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) in the assessment of altered major white matter fibers in preterm infants and children with PVL.

Patients and methods

We used diffusion tensor imaging to evaluate the major white matter tract fibers in 15 children with periventricular leukomalacia in correlation with cognitive and motor disability. Mean age of the patients was 28.5 months (range: 9–84 months). 5 normal control children were recruited (mean age: 21.4, range: 11–60 months). MR imaging was obtained by using a 1.5-T, whole-body scanner. DTI was acquired after the routine sequences. Then, data post-processing and fiber-tracking method was applied.

Results

This study demonstrated the existence of the WM tract injury in PVL patients using the DTI tractography approach in correlation with neurodevelopmental delay in patients with various degrees of cognitive and motor impairment. Compared with the normal control group, the following abnormalities were detected on qualitative analysis of the white matter tracts.

Corticospinal tracts

Decreased volume and cross-sectional area on the affected side.

Ascending sensorimotor tracts

Thinning of sensory fiber tracts and posterior thalamic radiations.

Commissural and association tracts

Significant damage of the callosal fibers was reported in cases with partial agenesis of the corpus callosum.

Conclusion

DTI proved to be a promising noninvasive method for assessing the severity of white matter tract injury in patients with PVL. This is owing to the capability of fiber-tracking techniques to provide more information for understanding the pathophysiologic features of sensorimotor and cognitive disability associated with PVL. This will allow for the early intervention and initiation of rehabilitation programs aiming for minimizing the associated neurological deficit.     

Quantitative analysis of left ventricular strain using cardiac computed tomography

Objectives

To investigate whether cardiac computed tomography (CCT) can determine left ventricular (LV) radial, circumferential and longitudinal myocardial deformation in comparison to two-dimensional echocardiography in patients with congestive heart failure.

Background

Echocardiography allows for accurate assessment of strain with high temporal resolution. A reduced strain is associated with a poor prognosis in cardiomyopathies. However, strain imaging is limited in patients with poor echogenic windows, so that, in selected cases, tomographic imaging techniques may be preferable for the evaluation of myocardial deformation.

Methods

Consecutive patients (n = 27) with congestive heart failure who underwent a clinically indicated ECG-gated contrast-enhanced 64-slice dual-source CCT for the evaluation of the cardiac veins prior to cardiac resynchronization therapy (CRT) were included. All patients underwent additional echocardiography. LV radial, circumferential and longitudinal strain and strain rates were analyzed in identical midventricular short axis, 4-, 2- and 3-chamber views for both modalities using the same prototype software algorithm (feature tracking). Time for analysis was assessed for both modalities.

Results

Close correlations were observed for both techniques regarding global strain (r = 0.93, r = 0.87 and r = 0.84 for radial, circumferential and longitudinal strain, respectively, p < 0.001 for all). Similar trends were observed for regional radial, longitudinal and circumferential strain (r = 0.88, r = 0.84 and r = 0.94, respectively, p < 0.001 for all). The number of non-diagnostic myocardial segments was significantly higher with echocardiography than with CCT (9.6% versus 1.9%, p < 0.001). In addition, the required time for complete quantitative strain analysis was significantly shorter for CCT compared to echocardiography (877 ± 119 s per patient versus 1105 ± 258 s per patient, p < 0.001).

Conclusion

Quantitative assessment of LV strain is feasible using CCT. This technique may represent a valuable alternative for the assessment of myocardial deformation in selected patients with poor echogenic windows and general contraindications for magnetic resonance imaging.