A single-blinded pilot study assessing neurovascular contact by using high-resolution MR imaging in patients with trigeminal neuralgia

Objective

To assess the feasibility and utility of high-resolution three-dimensional magnetic resonance angiography (3D MRA) and contrast-enhanced 3D spoiled gradient-recalled imaging (3D SPGRI) for the purpose of visualization of neurovascular contact in trigeminal neuralgia (TN) patients.

Methods

Forty-five patients (25 males, 20 females; age range, 23–82 years; and mean age, 55.67 ± 18.23 years) with unilateral typical TN and 36 control subjects (21 males, 15 females; age range, 25–85 years; mean age, 57.53 ± 19.25 years) underwent high-resolution 3D MRA and contrast-enhanced 3D SPGRI assessment. The images were reviewed by two experienced neuroradiologists who were blinded to the clinical details. The imaging results were compared with the operative findings in all the patients; additionally, the degree of neurovascular contact was compared between the two groups based on MR imaging.

Results

In 45 patients with unilateral typical TN, the use of 3D MRA in conjunction with the contrast-enhanced 3D SPGRI identified neurovascular contact in 40 of the 42 symptomatic nerves; the contact was verified surgically. Based on the surgical findings, the sensitivity and specificity of MR imaging were 95.20% and 100%, respectively. Based on MRI, the compressing vessel (artery, vein) was correctly identified in 32 of the 39 cases verified by microvascular decompression. There was good agreement (K = 0.77; 95% confidence interval, 0.54–0.99) between the position (medial, lateral, superior, and inferior) of the compressing vessel relative to the trigeminal nerve as defined by MR imaging and the surgical findings. The rates of vascular contact with the trigeminal nerve as observed on MRI were 31.94%, 48.89%, and 88.9% in the control subjects, asymptomatic, and symptomatic side of patients, respectively.

Conclusion

The combined use of high-resolution 3D MRA and contrast-enhanced 3D SPGRI is an extremely sensitive and specific technique for demonstrating vascular contact with the trigeminal nerve in TN patients.     

Imaging of coronary artery anomalies using ECG-gated 64-row computed tomography angiography

Objective

To shed light on coronary artery anomalies among cardiac patients using ECG-gated 64-row MDCTA during assessment of coronary arteries.

Patients and methods

Study included 840 patients out of whom twenty-one patients have congenital coronary artery anomalies. Patients were examined using ECG gated 64-row MDCT; 80–100 ml contrast agent, followed by a 50 ml saline chaser injected at 5 ml/s, 350 ms gantry rotation time, 0.65 mm detector collimation, ECG tube current modulation and 100–120 kV. Post-processing was done on second workstation including 3D VR, MPR and CMPR images.

Results

Anomalies of the coronary arteries were diagnosed in twenty-one patients. The prevalence of congenital anomalies in this study was 2.5% and included: anomalous origin of right coronary artery in 4 cases (0.48%), anomalous origin of left circumflex artery in 3 cases (0.36%), myocardial bridging of LAD in 12 cases (1.4%) and coronary artery fistula in 2 cases (0.24%).

Conclusion

Coronary artery anomalies are not uncommon among cardiac patients. Myocardial bridging is the most common followed by anomalous origin and proximal course and lastly coronary artery fistula. 64-Row MDCTA is an excellent promising modality and should be the first non-invasive diagnostic tool to rule out such anomalies.     

Quantitative chemical-shift MR imaging cutoff value: Benign versus malignant vertebral compression – Initial experience

Purpose

To evaluate the diagnostic accuracy of in-phase/opposed-phase quantitative chemical shift magnetic resonance (MR) imaging of the spine and to determine the cutoff value that enables differentiation of malignant from benign compression fractures, in patients with known primary malignancy.

Patients and methods

Prospective assessment of thirty-two patients with known primary malignancy who presented with vertebral compression fractures, MR imaging of the spine at 1.5 Tesla with standard conventional MR sequences and additional chemical shift (in-phase/opposed-phase) imaging was done. Quantitative image analysis by drawing regions of interest (ROI) on the abnormal marrow of compressed (study group) and adjacent normal vertebra (control group) was also performed in each patient. The signal intensity ratio (SIR) of the marrow was determined by dividing the mean signal intensity on the opposed-phase to the mean signal intensity on the in-phase images and statistical analysis was performed.

Results

Mean SIR of benign vertebral compression [0.73 ± 0.07 (range 0.12–1.2)] was significantly lower than malignant SIR values [1.72 ± 0.14 (range 0.8–2.96)] (p < 0.0001; area under the ROC curve, 0.97). The optimal SIR cutoff value for separating benign and malignant vertebral compression was found to be 0.91 with a calculated sensitivity of 93%, specificity of 82% and accuracy of 88%.

Conclusion

Quantitative chemical shift MR imaging could be a valuable addition to standard MR imaging techniques and represent a rapid problem solving tool in differentiating benign from malignant vertebral compression, especially in patients with known primary malignancies.     

Diagnosis of spondylolysis on MRI: Importance of recognition of hypoplastic L5 on MRI

Objective

To perform a combined (retrospective and prospective) study to further characterize hypoplastic L5, its correlation with spondylolysis and other associated abnormalities on routine Computed tomography and magnetic resonance imaging.

Methods

We studied the Computed tomography and magnetic resonance imaging images of 29 patients with hypoplasia and posterior wedging of L5 with bilateral spondylolysis at L5. These cases were followed up retrospectively and prospectively. The anteroposterior diameter of L4, L5 and S1 was calculated and compared. The percentage of posterior wedging of L5 was calculated. Anterolisthesis, hypoplastic pedicle, facet joints, L4–5 and L5–S1 intervertebral discs, nerve roots and fragmentation of pars interarticularis were also studied.

Results

The mean difference of anteroposterior diameter between L4 and L5 was 2.75 mm and of L5 and S1 was 3.78 mm. The mean percentage of posterior wedging was 31%. Grade I anterolisthesis was present in 13 patients and grade II in 2 patients. Facet joint arthropathy was seen in 20 patients. In 24 patients, there was hypoplastic pedicle. Pars fragmentation was seen in 7 patients. L5–S1 disc disease was seen in 21 patients out of whom 8 had exiting nerve root compression. L4–L5 disc disease was seen in 10 patients of whom 5 had exiting nerve root compression.

Conclusions

Hypoplastic L5 is a strong predictor of bilateral spondylolysis even in the absence of true anterior slippage. True anterior slippage and disproportionate adjacent disc disease result in varying degrees of exiting nerve root compression.

Advances in knowledge

L5 hypoplasia can simulate anterolisthesis and can predict the bilateral spondylolysis. L5 hypoplasia can lead to early disc disease.     

The value of power and pulsed Doppler in the diagnosis of CTS: Is a solution in sight

Objective

To evaluate the value of power and pulsed Doppler in diagnosis of CTS and compare it with median nerve cross-sectional area (CSA) measured by gray-scale US and nerve conduction studies.

Patients and methods

Forty patients with definite clinical evidence of CTS and 20 healthy cases were enrolled in the study. All patients and controls underwent nerve conduction studies, gray-scale US (for measurement of CSA) and color Doppler (for assessment of vasomotor activity).

Results

Twenty eight patients (70%) had confirmed diagnosis by NCS while 12 patients (30%) were not detected by the NCS. The CSA ranged from 0.06 to 0.78 cm² with a mean of 0.19 + 0.12. Comparison between patients and controls as regards CSA showed highly statistically significant difference (P < 0.001). There was a significant difference between patients and controls as regards PS, ED & PI. Also there was a significant correlation between median nerve hypervascularization and the parameters of spectral Doppler and the severity of CTS by NCS and also with CSA.

Conclusion

Color Doppler imaging of the median nerve is a readily accessible and practical method for determining the degree of vasomotor impairment in CTS patients that may be valuable in evaluation and follow up of CTS patients in clinical practice.     

Glaucoma severity affects diffusion tensor imaging (DTI) parameters of the optic nerve and optic radiation

Objectives

To evaluate whether MR diffusion tensor imaging (DTI) of the optic nerve and optic radiation in glaucoma patients provides parameters to discriminate between mild and severe glaucoma and to determine whether DTI derived indices correlate with retinal nerve fibre layer (RNFL) thickness.

Methods

3-Tesla DTI was performed on 90 subjects (30 normal, 30 mild glaucoma and 30 severe glaucoma subjects) and the FA and MD of the optic nerve and optic radiation were measured. The categorisation into mild and severe glaucoma was done using the Hodapp–Parrish–Anderson (HPA) classification. RNFL thickness was also assessed on all subjects using OCT. Receiver operating characteristic (ROC) analysis and Spearman's correlation coefficient was carried out.

Results

FA and MD values in the optic nerve and optic radiation decreased and increased respectively as the disease progressed. FA at the optic nerve had the highest sensitivity (87%) and specificity (80%). FA values displayed the strongest correlation with RNFL thickness in the optic nerve (r = 0.684, p ≤ 0.001) while MD at the optic radiation showed the weakest correlation with RNFL thickness (r = −0.360, p ≤ 0.001).

Conclusions

The high sensitivity and specificity of DTI-derived FA values in the optic nerve and the strong correlation between DTI-FA and RNFL thickness suggest that these parameters could serve as indicators of disease severity.     

Ultrasound guided lateral femoral cutaneous nerve block in meralgia paresthesia; review of 25 cases

Aim

To evaluate the feasibility and efficacy of ultrasound guidance technique for the treatment of meralgia paresthetica (lateral femoral cutaneous neuropathy).

Methods

25 patients (10 males and 15 females); age 17–68 years; with meralgia paresthetica are diagnosed clinically by electromyography. A needle was inserted targeting the LFCN with ultrasound guidance, treatment with perineural injection of 2 mL of methylprednisolone acetate (40 mg/mL) and 8 mL of mepivacaine, 2%, under ultrasound guidance was performed.Main outcome measurements included the technical success of the procedure, regarding relief of symptoms (pain, burning sensation, and paresthesia) and change in the quality of life.

Results

Successful nerve block of the LFC nerve was achieved in 24 patients while 1 patient remained with mild VAS after third injection which disappeared two months later. Three patients underwent one injection, 6 two injections and 16 three injections with intervening period of 2 weeks between the first and second injections and one month between the second and third.

Conclusions

Ultrasound-guided perineural injection of the LFC nerve is quick, simple, economical, and effective in treatment of meralgia paresthetica.     

High field carotid vessel wall imaging: A study on reproducibility

Purpose

Currently, a multi-contrast protocol, including a combination of five MR-sequences is used as reference standard for morphologic imaging and quantitative measurements of the carotid artery vessel wall. The purpose of this study is to investigate the scan–rescan reproducibility together with intra- and inter-observer reproducibility of each of the five MR-sequences.

Methods

Twenty healthy volunteers (55% male, mean age = 26 years) underwent repeated MR-examinations (3T-Philips-MRI) of the left carotid artery vessel wall with five sequences; T1-TFE, T2-TSE, PD-TSE, T1-TSE and 3D TOF. A standard phased-array coil with two flexible elements of 14 cm × 17 cm was used to obtain nine transverse imaging sections of the left carotid artery with identical in-plane resolution (0.46 mm × 0.46 mm). Reproducibility analysis was performed in 3 slices of the common carotid artery for all sequences.

Results

For, scan–rescan reproducibility, intra class correlation coefficients (ICC) were excellent for all sequences and ranged from 0.79 to 0.95. The intra-observer ICC ranged from 0.89 to 0.98 and the inter-observer ICC ranged from 0.84 to 0.96, for both lumen and vessel wall assessment.

Conclusions

By high field MR imaging, vessel wall and lumen area of the carotid artery can be assessed with excellent scan–rescan, intra- and inter-observer reproducibility for all five sequences.     

Diffusion tensor imaging differentiates vascular parkinsonism from parkinsonian syndromes of degenerative origin in elderly subjects

Background and Purpose

The etiologic diagnosis of parkinsonian syndromes is of particular importance when considering syndromes of vascular or degenerative origin. The purpose of this study is to find differences in the white-matter architecture between those two groups in elderly patients.

Materials and Methods

Thirty-five patients were prospectively included (multiple-system atrophy, n = 5; Parkinson's disease, n = 15; progressive supranuclear palsy, n = 9; vascular parkinsonism, n = 6), with a mean age of 76 years. Patients with multiple-system atrophy, progressive supranuclear palsy and Parkinson's disease were grouped as having parkinsonian syndromes of degenerative origin. Brain MRIs included diffusion tensor imaging. Fractional anisotropy and mean-diffusivity maps were spatially normalized, and group analyses between parkinsonian syndromes of degenerative origin and vascular parkinsonism were performed using a voxel-based approach.

Results

Statistical parametric-mapping analysis of diffusion tensor imaging data showed decreased fractional anisotropy value in internal capsules bilaterally in patients with vascular parkinsonism compared to parkinsonian syndromes of degenerative origin (p = 0.001) and showed a lower mean diffusivity in the white matter of the left superior parietal lobule (p = 0.01).Fractional anisotropy values were found decreased in the middle cerebellar peduncles in multiple-system atrophy compared to Parkinson's disease and progressive supranuclear palsy. The mean diffusivity was increased in those regions for these subgroups.

Conclusion

Clinically defined vascular parkinsonism was associated with decreased fractional anisotropy in the deep white matter (internal capsules) compared to parkinsonian syndromes of degenerative origin. These findings are consistent with previously published neuropathological data.     

Efficacy of thyroid ultrasound elastography in differential diagnosis of small thyroid nodules

Objective

To explore the efficacy of thyroid ultrasound (US) elastography in differential diagnosis of small thyroid nodules.

Methods

This HIPAA-compliant study was approved by the Institutional Review Board and all patients provided written informed consent. Thirty-five patients with 38 small thyroid nodules as seen on transverse ultrasound image formed our study population. An US examination and a separate thyroid elastography examination with pulsation from the carotid artery used as the compression source were performed before fine-needle aspiration. Baseband US data were acquired for off-line elastography processing, where a semi-quantitative index for each nodule was calculated. The Kruskal–Wallis nonparametric rank sum test was used to assess equality of population means among the different types of thyroid nodules. Maximum likelihood estimation of the curve parameters for a binomial receiver operating characteristic (ROC) curve was performed.

Results

Elasticity contrast index calculated with elastography was effective in distinguishing between small papillary thyroid carcinomas (PTMC, n = 8) and other lesions (n = 30) in small thyroid nodules (p = 0.0036). The area under the ROC curve for diagnosing PTMCs was 0.812 with a 95% confidence interval of 0.653–0.920. The cut-off value of ECI of 3.6 led to a sensitivity of 100% and a specificity of 60% for detecting PTMCs.

Conclusion

Noninvasive evaluation of small thyroid nodules is possible using thyroid US elastography with in vivo compression to pick out the most suspicious thyroid nodules for fine-needle aspiration (FNA) and avoid FNA in benign nodules.     

Contribution of power Doppler and gray-scale ultrasound of the median nerve in evaluation of carpal tunnel syndrome

Aim of the work

To assess the role of gray-scale and power Doppler ultrasound (US) of the median nerve at the wrist in evaluating carpal tunnel syndrome (CTS).

Materials and methods

Seventy-one wrists in 51 patients with CTS in addition to 50 healthy volunteers that served as the control group were enrolled in this study. The following sonographic parameters were evaluated in both patients and controls: cross sectional area of the median nerve just proximal to the tunnel inlet (CSA1), at the pisiform bone level (CSA2), the CSA difference (ΔCSA), flattening ratio of the median nerve and bowing of the flexor retinaculum. The power Doppler US was used to assess the number of nerve vessels with estimation of the vascularity score.

Results

The ΔCSA revealed an excellent discriminative ability (AUC = 0.988) in differentiating patients with CTS at an optimal cut-off value of 3.9 mm². Intraneural hypervascularization was significantly correlated with the ΔCSA of the median nerve (P < 0.001), while not significantly correlated with the age of patients, median nerve flattening ratio and bowing of flexor retinaculum.

Conclusion

The ΔCSA and vascularity score of the median nerve are important and useful sonographic parameters in evaluation of CTS.     

Can preoperative MR imaging predict optic nerve invasion of retinoblastoma?

Purpose

To evaluate the accuracy of pre-operative MRI for the detection of optic nerve invasion in retinoblastoma.

Materials and methods

Institutional review board approval and informed consent were waived for this retrospective study. A total of 41 patients were included. Inclusion criteria were histologically proven retinoblastoma, availability of diagnostic-quality preoperative MR images acquired during the 4 weeks before surgery, unilateral retinoblastoma, and normal-sized optic nerve. Two radiologists retrospectively reviewed the MR images independently. Five imaging findings (diffuse mild optic nerve enhancement, focal strong optic nerve enhancement, optic sheath enhancement, tumor location, and tumor size) were evaluated against optic nerve invasion of retinoblastoma. The predictive performance of all MR imaging findings for optic nerve invasion was also evaluated by the receiver operating characteristic curve analysis.

Results

Optic nerve invasion was histopathologically confirmed in 24% of study population (10/41). The differences in diffuse mild enhancement, focal strong enhancement, optic sheath enhancement, and tumor location between patients with optic nerve invasion and patients without optic nerve invasion were not significant. Tumor sizes were 16.1 mm (SD: 2.2 mm) and 14.9 mm (SD: 3.6 mm) in patients with and without optic nerve involvement, respectively (P = 0.444). P-Values from binary logistic regression indicated that all five imaging findings were not significant predictors of tumor invasion of optic nerve. The AUC values of all MR imaging findings for the prediction of optic nerve invasion were 0.689 (95% confidence interval: 0.499–0.879) and 0.653 (95% confidence interval: 0.445–0.861) for observer 1 and observer 2, respectively.

Conclusion

Findings of MRI in patients with normal-sized optic nerves have limited usefulness in preoperatively predicting the presence of optic nerve invasion in retinoblastoma.     

Microstructural abnormalities in the trigeminal nerves of patients with trigeminal neuralgia revealed by multiple diffusion metrics

Objective

To investigate microstructural tissue changes of trigeminal nerve (TGN) in patients with unilateral trigeminal neuralgia (TN) by multiple diffusion metrics, and correlate the diffusion indexes with the clinical variables.

Methods

16 patients with TN and 6 healthy controls (HC) were recruited into our study. All participants were imaged with a 3.0 T system with three-dimension time-of-flight (TOF) magnetic resonance angiography and fluid attenuated inversion recovery (FLAIR) DTI-sequence. We placed regions of interest over the root entry zone of the TGN and measured fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD). The mean values of FA, MD, AD and RD were compared between the affected and unaffected sides in the same patient, and to HC values. The correlation between the side-to-side diffusion metric difference and clinical variables (disease duration and visual analogy scale, VAS) was further explored.

Results

Compared with the unaffected side and HC, the affected side showed significantly decreased FA and increased RD; however, no significant changes of AD were found. A trend toward significantly increased MD was identified on the affected side comparing with the unaffected side. We also found the significant correlation between the FA reduction and VAS of pain (r = −0.55, p = 0.03).

Conclusion

DTI can quantitatively assess the microstructural abnormalities of the affected TGN in patients with TN. Our results suggest demyelination without significant axonal injury is the essential pathological basis of the affected TGN by multiple diffusion metrics. The correlation between FA reduction and VAS suggests FA as a potential objective MRI biomarker to correlate with clinical severity.     

Hepatic artery stent-grafts for the emergency treatment of acute bleeding

Purpose

We evaluated the technical success and clinical efficacy of stent-graft implantation for the emergency management of acute hepatic artery bleeding.

Methods

Between January 2010 and July 2013, 24 patients with hemorrhage from the hepatic artery were scheduled for emergency implantation of balloon expandable stent-grafts. The primary study endpoints were technical and clinical success, which were defined as successful stent-graft implantation with sealing of the bleeding site at the end of the procedure, and cessation of clinical signs of hemorrhage. The secondary study endpoints were complications during the procedure or at follow-up and 30-day mortality rate.

Results

In 23 patients, hemorrhage occurred after surgery, and in one patient hemorrhage occurred after trauma. Eight patients had sentinel bleeding. In most patients (n = 16), one stent-graft was implanted. In six patients, two overlapping stent-grafts were implanted. The stent-grafts had a target diameter between 4 mm and 7 mm. Overall technical success was 88%. The bleeding ceased after stent-graft implantation in 21 patients (88%). The mean follow-up was 137 ± 383 days. In two patients, re-bleeding from the hepatic artery occurred during follow-up after 4 and 29 days, respectively, which could be successfully treated by endovascular therapy. The complication rate was 21% (minor complication rate 4%, major complication rate 17%). The 30-day mortality rate was 21%.

Conclusions

Implantation of stent-grafts in the hepatic artery is an effective emergency therapy and has a good technical success rate for patients with acute arterial hemorrhage.     

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.     

Multidetector CT and CT angiography in mesenteric ischemia

Purpose

To evaluate the role of 64-multidetector CT in assessment of mesenteric vascular ischemia in clinically suspected patients.

Patients and methods

This study included 38 patients during period from October 2009 to October 2011. The patients age ranged from 38 to 72 year old (mean age was 57 ± 11.2 years). All cases met the criteria of acute non traumatic (28 patients) or chronic abdominal pain (10 patients) and suspected mesenteric vascular ischemia. All 38 cases were evaluated in surgery department, then underwent CT of the abdomen and pelvis & CTA by using 64 multislice GE light speed VCT. MDCT& CT angiographic findings were correlated with surgical findings in acute mesenteric ischemia (AMI) cases & conventional angiography in chronic mesenteric ischemia (CMI) cases.

Results

MDCT findings alone were nonspecific for detection of MI. The sensitivity, specificity& accuracy of CTA in diagnosis of AMI after surgical confirmation were 96%, 66.6% & 92.8% respectively, while in CMI the sensitivity, specificity & accuracy were 88.8%, 100%, 90% respectively, after confirmation by conventional angiography.

Conclusion

CTA scan appears to be an excellent tool to find out and localize cases of AMI rather than in CMI cases.     

Long term results of endovascular treatment in renal arterial stenosis from Takayasu arteritis: Angioplasty versus stent placement

Purpose

To retrospectively evaluate and compare the long term patency and antihypertensive effect of angioplasty and stent insertion in renal artery stenosis caused by Takayasu arteritis, with CT angiography and clinical follow-up.

Materials and methods

We retrospectively analyzed and compared effects on hypertension and patency of renal artery in 16 patients (age ranging from 16 to 58 years, mean: 32.1 years) with renovascular hypertension caused by Takayasu arteritis who underwent endovascular treatment including angioplasty (n = 13) and stent placement (n = 9) for 22 stenotic renal arteries.

Results

Technical success was 95% (21/22) without major complications. In the last follow-up CT angiogram (mean 85 ± 41 months), restenosis was 8% (1/12) in angioplasty and 66% (6/9) in stent. Patency rates of angioplasty were 100%, 91.7%, 91.7% and primary unassisted and primary assisted patency rates of stent placement were 55.6%, 33.3%, 33.3% and 88.9%, 66.7%, 55.6% at 1-, 3- and 5-years, respectively. In clinical follow-up (mean 120 ± 37.8 months, range 48–183 months), beneficial effects on hypertension were obtained in 87% of patients (13/15) and there was no significant difference between the patients who were treated by only angioplasty and the patients who received stent placement in at least one renal artery, regardless of whether or not angioplasty had been performed in the other renal artery.

Conclusion

Compared with stent placement, angioplasty demonstrated better long term patency and similar clinical benefit on renovascular hypertension in renal artery stenosis of Takayasu arteritis. We suggest that stent placement should be reserved for obvious angioplasty failure.     

Can conventional magnetic resonance imaging predict survival in pediatric diffuse intrinsic pontine glioma? A single institution experience

Background

Pediatric diffuse intrinsic pontine glioma (DIPG) remains dismal regardless the new therapeutic and technical advances.

Objective

To investigate the value of magnetic resonance imaging (MRI) in predicting DIPG prognosis.

Patients and methods

Twenty-five DIPG patients with 95 (initial and post radiotherapy) MR examinations were studied. Hydrocephalus was detected in 6 cases (24%), basilar artery encasement in 20 (80%), ill defined border in 16 (64%), perilesional edema in 2 cases (8%) and none showed leptomeningeal spread. Conformal 3-dimensional radiotherapy (39 Gy/13 fractions or 54 Gy/30 fractions) was applied.

Results

The median overall survival (MOS) was 9.3 months (95% CI: 7.9–10.8) and the one year overall survival was 18 ± 8.9%. Post radiation MRI performed 3–6 months after treatment showed regression in 8 cases (32%), stationary course in 5 (20%) and progression in 12 cases (48%). The MOS was higher in children whose MRI showed regression (10.0, CI: 6.3–13.7) than those with radiological progression (8.0, CI: 5.9–10.1 months) or stationary course (7.0, CI: 4.9–9.1). However; these differences did not rank to the level of significance. There was no statistical association of tumor size (p = 0.907), presence of hemorrhage (p = 0.314), or surrounding edema (p = 0.263); entrapment of the basilar artery (p = 0.782); pattern of enhancement (p = 0.851); and hydrocephalus (p = 0.354) with the length of the overall survival.

Conclusions

Though MRI is the mainstay for the diagnosis of DIPG, yet its prognostic value is limited. New MR techniques as MR spectroscopy and diffusion tensor imaging should be evaluated as additional tools for prognostic evaluation of DIPG.     

Uncommon congenital extracardiac vascular anomalies detected on MSCT (Multi-Slice Computed Tomography) aortic angiography with 64-multislice technology

Objective

The purpose of this study was to evaluate the role of CT angiography in different encountered congenital vascular anomalies of pediatric age groups using 64 multislice CT scanner.

Subjective and methods

Through one year, a total of 15 patients having congenital extracardiac anomalies were encountered from those attending big trauma and emergency center and were studied in this work. Each patient’s parent was thoroughly asked about the detailed clinical history after reviewing the referring imaging request and laboratory findings. Exclusion criteria for CT were as follows: previous allergic reactions to iodine contrast media and severe renal insufficiency. CT examination was performed using 64 multislice CT machine.

Results

CTA examination was performed in a total of 15 patients. The age of the patients was ranging from 2 days to 14 yrs and 5 cases were females. Four cases came with cyanosis; one case came with follow up after operation for transposition of great arteries, while the remaining cases were suffering from medical problems such as respiratory distress or hypertension. Aortic arch hypoplasia, right sided aortic arch with mirror image or with aberrant left subclavian artery, hypoplastic left pulmonary artery with left sided aortic arch and aberrant right subclavian artery, hypoplastic left heart chambers, retrotracheal left pulmonary artery with patent ductus arteriosus (PDA), right superior partial anomalous pulmonary venous drainage (PAPVD) with ASD sinus venosum, postoperative assessment of transposition of great arteries (TGA), fibromuscular dysplasia involving the renal and common iliac arteries, and bilateral double renal arteries with ectopic right kidney were the different extracardiac vascular anomalies encountered in this work.

Conclusion

CTA provides an excellent means to detect a number of extracardiac vascular anomalies and allows accurate and fast noninvasive characterization of extracardiac vascular anatomy. It is a helpful tool in establishing the primary diagnosis, defining anatomic landmarks and relationships, identifying vascular anomalies and helping in postoperative follow-up.     

An evaluation of the accuracy of CT when determining resectability of pancreatic head adenocarcinoma after neoadjuvant treatment

Background

To evaluate the accuracy of MDCT for determination of resectability R0 after neoadjuvant therapy in patients with pancreatic head adenocarcinoma locally advanced.

Methods

From January 2005 to December 2010, 80 patients with pancreatic head adenocarcinoma underwent multidetector CT before surgery. Of these, 38 patients received neoadjuvant therapy because tumor was considered locally advanced on baseline CT scan. We retrospectively correlated imaging interpretations with operative and histological data and compared results in patients without (control group) or with (neoadjuvant group) preoperative treatment.

Results

41/42 patients in control group and 31/38 patients in neoadjuvant group finally had curative resection. While resection R0 is similar in both groups (83% and 81%), CT accuracy in determining resectability R0 was significantly decreased in neoadjuvant group (58% versus 83%; p = 0.039). CT scan specificity was significantly lower after neoadjuvant therapy (52% versus 88% in control group) due to an overestimation of vascular invasion: 12/31 patients with complete resection in neoadjuvant group were evaluated at high risk of incomplete resection on CT scan. Tumor size tends to be underestimated in control group (−2 mm) and overestimated in neoadjuvant group (+10 mm). T-staging accuracy was decreased in neoadjuvant group (39% versus 78% in control group; p = 0.002).

Conclusion

Neoadjuvant therapy significantly decreases the accuracy of CT scan in determining operability, T-staging, and resectability R0 of pancreatic head carcinoma. Overestimation of tumor size and vascular invasion significantly reduces CT scan specificity after preoperative treatment.