Ammar Mallouhi

Predictors of carpal tunnel syndrome : Accuracy of gray-scale and color doppler sonography

OBJECTIVEnThe purpose of this study was to retrospectively assess the accuracy of gray-scale and color Doppler sonography in the diagnosis of carpal tunnel syndrome.nnnMATERIALS AND METHODSnA total of 206 wrists in 151 patients with a clinical suspicion of carpal tunnel syndrome were examined with high-resolution sonography using a 7-15-MHz linear array transducer. The presence of median nerve swelling, edema, and flattening and increased bowing of the flexor retinaculum was evaluated with gray-scale sonography, and the presence of nerve hypervascularization was evaluated with color Doppler sonography. Sensitivity and specificity were calculated for each sonographic feature in comparison with nerve conduction studies as the standard of reference. Multivariate logistic regression analysis was used to determine variables predictive of carpal tunnel syndrome.nnnRESULTSnCarpal tunnel syndrome was confirmed in 172 wrists at nerve conduction studies. A median nerve cross-sectional area of at least 0.11 cm2 was calculated as a definition of median nerve swelling. In comparison with nerve conduction studies, nerve swelling showed the highest accuracy (91%) among gray-scale sonography criteria, and the presence of intraneural hypervascularization showed the highest accuracy (95%) among all sonography criteria. Logistic regression analysis showed that nerve hypervascularization was the only variable that independently predicted median nerve entrapment (odds ratio, 16.4; 95% confidence interval, 8.7-31.1; p <0.001).nnnCONCLUSIONnColor Doppler sonography is more accurate than gray-scale sonography for characterizing median nerve involvement in patients with suspected carpal tunnel syndrome.

Traumatic Arterial Injuries of the Extremities: Initial Evaluation with MDCT Angiography

OBJECTIVEnThe purpose of this study was to retrospectively assess the accuracy of MDCT angiography as the initial diagnostic technique to depict arterial injury in patients with extremity trauma.nnnMATERIALS AND METHODSnOver 36 months, 87 patients (16 females and 71 males; age range, 16-87 years) with clinically suspected arterial injury after extremity trauma underwent 4-MDCT angiography and 67 ultimately underwent surgery. Eighty patients had blunt injuries, and seven had penetrating injuries. The presence of arterial involvement was investigated prospectively by the radiologist in charge and retrospectively by two independent radiologists. Each detected arterial lesion was then characterized as a spasm, stenosis, occlusion, or rupture. The standard of reference was surgery in 67 patients, angiography in two patients, and clinical and radiologic follow-up findings in 18 patients. MDCT angiography was assessed by means of receiver operating characteristic (ROC) curve analysis for lesion detection and Spearmans rank correlation test for lesion characterization. Image quality, lesion depiction, and artifacts were subjectively assessed.nnnRESULTSnSixty-two traumatic arterial lesions were confirmed at surgery in 55 patients. MDCT angiography yielded high accuracy in detection (area under the ROC curve [Az] = 0.96; p < 0.001) and characterization (r = 0.94; p < 0.001) of traumatic arterial injuries and in recognizing an underlying dissection (Az= 0.82; p < 0.001). Prospective sensitivity and specificity were 95% and 87%, respectively, and retrospective sensitivity and specificity were 99% and 87%, respectively. MDCT angiography was considered to be sufficient for a reliable diagnosis in 83 patients (p < 0.001). Image quality and lesion depiction on MDCT angiograms were considered to be good and artifacts were considered mild with substantial interobserver agreement (kappa, 0.62-0.69).nnnCONCLUSIONnMDCT angiography provides significant and reproducible technique for the detection and characterization of arterial injuries to the extremities with high image quality and vascular delineation.

Diagnostic Performance of MDCT for Detecting Aortic Valve Regurgitation

OBJECTIVEnThis study evaluates whether ECG-gated 16-MDCT coronary angiography provides a reliable imaging technique for detecting aortic regurgitation (AR).nnnSUBJECTS AND METHODSnWe examined 71 patients prospectively with 16-MDCT angiography using retrospective ECG gating during the mid-to-end diastolic phase. A visible central valvular leakage area was considered as a diagnostic criterion for AR. The central valvular leakage area was quantified in patients with positive transthoracic echocardiography (TTE). We compared 16-MDCT to Doppler TTE, the accepted diagnostic standard based on semiquantitative regurgitation jet analysis (grade 0-3+ for mild, moderate, and severe).nnnRESULTSnThe overall sensitivity of 16-MDCT for the identification of patients with AR was 81%. The specificity was 91%, the negative predictive value was 70%, and the positive predictive value was 95%. Of the 71 patients, 48 had AR determined by TTE, and 16-MDCT correctly detected AR in 39 of those 48 patients. The sensitivity of 16-MDCT for the detection of patients with moderate and severe AR (grade > or = 1.5+) was 95%, and the specificity was 96% (20 of 21 patients). The sensitivity of 16-MDCT for identification of patients with mild AR (grade < or = 1+) was 70%, and the specificity was 92% (19 of 27 patients). Quantification of the central valvular leakage area was not possible in 50% of cases with AR by TTE because of valve calcifications.nnnCONCLUSIONnSixteen-MDCT coronary angiography provides an accurate, noninvasive imaging technique to detect moderate and severe aortic regurgitation (grade > or = 1.5+). However, severe valve calcifications and mild AR limit its results.

3T MR tomography of the brachial plexus: structural and microstructural evaluation.

Magnetic resonance (MR) neurography comprises an evolving group of techniques with the potential to allow optimal noninvasive evaluation of many abnormalities of the brachial plexus. MR neurography is clinically useful in the evaluation of suspected brachial plexus traumatic injuries, intrinsic and extrinsic tumors, and post-radiogenic inflammation, and can be particularly beneficial in pediatric patients with obstetric trauma to the brachial plexus. The most common MR neurographic techniques for displaying the brachial plexus can be divided into two categories: structural MR neurography; and microstructural MR neurography. Structural MR neurography uses mainly the STIR sequence to image the nerves of the brachial plexus, can be performed in 2D or 3D mode, and the 2D sequence can be repeated in different planes. Microstructural MR neurography depends on the diffusion tensor imaging that provides quantitative information about the degree and direction of water diffusion within the nerves of the brachial plexus, as well as on tractography to visualize the white matter tracts and to characterize their integrity. The successful evaluation of the brachial plexus requires the implementation of appropriate techniques and familiarity with the pathologies that might involve the brachial plexus.

Ultrasonography for depiction of brachial plexus injury.

Recent development of ultrasonographic equipment has allowed improved spatial resolution for visualizing normal and pathologic conditions of peripheral nerves. Regarding the brachial plexus, only ultrasonographic studies that have described the normal appearance have been reported. To the best of our knowledge, no case report regarding the ultrasonographic description of a brachial plexus lesion has been published. We report the ultrasonographic findings of a brachial plexus injury after extirpation of a suspected enlarged supraclavicular lymph node.

Is there a relation between non-calcifying coronary plaques and acute coronary syndromes? A retrospective study using multislice computed tomography.

Objectives: The purpose of this study was to assess whether different coronary plaque types as classified by multislice computed tomography (CT) are retrospectively correlated with acute coronary syndromes (ACS) in an unselected study population. Methods: Sixty-three consecutive patients were examined with 16-slice CT coronary angiography. Coronary plaque types were classified as calcifying type 1, mixed (calcifying > non-calcifying) type 2, mixed (non-calcifying > calcifying) type 3, and non-calcifying type 4. Patients who had an ACS within 17 days were included. All patients underwent invasive coronary angiography. Results: Fifty-eight patients (92%) had coronary plaques evaluated by CT: 18 type 1 (31%), 10 type 2 (17%), 16 type 3 (28%) and 14 type 4 (24%). The presence of a non-calcifying plaque component (types 2–4; 40 of 63 patients, 63%) was correlated with ACS (n = 15; 24%) (p < 0.001). Only type 3 was significantly correlated with ACS (p = 0.01), but plaque types 2 and 4 were not. The diagnostic accuracy of CT for detection of stenosis >50% in proximal segments was: sensitivity 98%, specificity 90%, negative predictive value 97%, positive predictive value 97% per patient. Conclusions: Mixed calcifying/non-calcifying plaques with a predominantly non-calcifying component (type 3) as classified by multislice CT are retrospectively correlated with ACS.

Local image variance of 7 Tesla SWI is a new technique for preoperative characterization of diffusely infiltrating gliomas: correlation with tumour grade and IDH1 mutational status

ObjectivesTo investigate the value of local image variance (LIV) as a new technique for quantification of hypointense microvascular susceptibility-weighted imaging (SWI) structures at 7 Tesla for preoperative glioma characterization.MethodsAdult patients with neuroradiologically suspected diffusely infiltrating gliomas were prospectively recruited and 7 Tesla SWI was performed in addition to standard imaging. After tumour segmentation, quantification of intratumoural SWI hypointensities was conducted by the SWI-LIV technique. Following surgery, the histopathological tumour grade and isocitrate dehydrogenase 1 (IDH1)-R132H mutational status was determined and SWI-LIV values were compared between low-grade gliomas (LGG) and high-grade gliomas (HGG), IDH1-R132H negative and positive tumours, as well as gliomas with significant and non-significant contrast-enhancement (CE) on MRI.ResultsIn 30 patients, 9 LGG and 21 HGG were diagnosed. The calculation of SWI-LIV values was feasible in all tumours. Significantly higher mean SWI-LIV values were found in HGG compared to LGG (92.7 versus 30.8; pu2009<u20090.0001), IDH1-R132H negative compared to IDH1-R132H positive gliomas (109.9 versus 38.3; pu2009<u20090.0001) and tumours with significant CE compared to non-significant CE (120.1 versus 39.0; pu2009<u20090.0001).ConclusionsOur data indicate that 7 Tesla SWI-LIV might improve preoperative characterization of diffusely infiltrating gliomas and thus optimize patient management by quantification of hypointense microvascular structures.Key Points• 7 Tesla local image variance helps to quantify hypointense susceptibility-weighted imaging structures.• SWI-LIV is significantly increased in high-grade and IDH1-R132H negative gliomas.• SWI-LIV is a promising technique for improved preoperative glioma characterization.• Preoperative management of diffusely infiltrating gliomas will be optimized.

Microsurgery and Radiosurgery for Brainstem Cavernomas: Effective and Complementary Treatment Options

OBJECTIVEnTo evaluate treatment options for brainstem cavernous malformations (BSCMs) using the results from a center with long-standing experience in microsurgical resection and Gamma Knife radiosurgery (GKRS) treatment of BSCMs.nnnMETHODSnStudy participants were 67 symptomatic patients with BSCMs who were treated either microsurgically (nxa0= 29) or radiosurgically (nxa0= 38). Patients were followed for a minimum of 2 years (median, 7.7 years). A recent follow-up was performed.nnnRESULTSnPatients receiving surgical treatment had mainly large, superficially seated lesions and experienced preoperative hemorrhages more often and presented with higher preoperative modified Rankin Scale scores. Patients receiving GKRS harbored smaller, deep-seated lesions, reflecting a selection bias. In both treatment groups, patients presented with significantly better modified Rankin Scale scores at follow-up than before intervention. Overall annual preoperative hemorrhage rates were 3.2% in microsurgery patients and 2.3% in radiosurgery patients. In the preoperative observation period, the rehemorrhage rate was 25.1% for microsurgery patients and 7.2% for radiosurgery patients. Hemorrhage rate after GKRS decreased significantly to 0.6% after 2 years. The postoperative hemorrhage rate was 8.8% but only for microsurgery patients with residual lesions. Advancements in microsurgical techniques improved surgical outcomes, resulting in a high total excision rate in the modern era.nnnCONCLUSIONSnIn the treatment of BSCM, patient selection and timing of surgery are crucial. If applied in a multidisciplinary neurosurgical center, microsurgery and radiosurgery are complementary treatment options that both result in reduced bleeding rates and improvement of clinical outcome.

Gamma Knife Radiosurgery in Recurrent Glioblastoma

Background: We evaluated Gamma Knife radiosurgery (GKRS) as a treatment option for patients with recurrent glioblastoma. Patients and Methods: 42 patients with histopathologically diagnosed recurrent grade IV tumor were treated with GKRS. All patients had undergone standard multimodal first-line treatment. The average time from diagnosis to GKRS was 17.0 months. The median target volume was 5.1 cm3. The median margin dose was 10 Gy and the median central dose 20 Gy. In a subset of patients, O6-methylguanine methyltransferase (MGMT) promoter methylation analysis by pyrosequencing was performed. Results: Most patients did not develop complications after GKRS. Time to radiological progression after initial GKRS was 4.4 months (95% CI: 3.1-5.7 months). Radiological progression mainly occurred beyond the GKRS-irradiated area. The median survival time after initial GKRS was 9.6 months (95% CI: 7.7-11.5 months). The median overall survival time from diagnosis was 25.6 months (95% CI: 21.8-29.3 months). Patients with MGMT promoter methylation survived significantly longer (33.4 months; 95% CI: 21.2-45.5 months) compared to patients without MGMT promoter methylation (16.0 months; 95% CI: 8.0-23.9 months). Conclusion: GKRS seems to be a relatively safe salvage treatment option for recurrent glioblastoma for highly selected patients but must be seen as part of a multimodal treatment algorithm.

Multimodal treatment of parasagittal meningiomas: a single-center experience

OBJECTIVE Treatment of parasagittal meningiomas is still considered a challenge in modern microsurgery. The use of microsurgical resection, radiosurgery, or a microsurgery-radiosurgery combination treatment strategy is often debated. The aim of this study was to evaluate the treatment of parasagittal meningioma and provide evidence that a multimodal approach reduces complication rates and achieves good tumor control rates. METHODS The authors retrospectively reviewed long-term follow-up data on 117 patients who had been treated for parasagittal meningiomas at their institution between 1993 and 2013. Treatment included microsurgery, Gamma Knife radiosurgery (GKRS), and radiotherapy. RESULTS The median tumor volume prior to the first microsurgical resection was largest in the microsurgery-radiosurgery combination treatment group. Invasion of the superior sagittal sinus was significantly associated with a Simpson Grade IV resection and subsequent radiosurgery treatment. The Simpson resection grade did not influence time to progression or recurrence in benign meningioma cases. Complete sinus occlusion was followed by microsurgical resection of the occluded sinus, by tumor resection without resection of the sinus, or by GKRS. Histopathology revealed WHO Grade I tumors in most patients. However, a high percentage (33%) of atypical or malignant meningiomas were diagnosed after the last microsurgical resection. The time to recurrence or progression after microsurgery was significantly longer in patients with WHO Grade I meningiomas than in those with Grade II or III meningiomas. At follow-up, tumor control rates after GKRS were 91% for presumed meningioma, 85% for benign meningioma, 71% for atypical meningioma, and 38% for malignant meningioma. CONCLUSIONS A multimodal treatment approach to parasagittal meningiomas reduces the rate of complications. Thus, microsurgery, radiotherapy, and radiosurgery are complementary treatment options. Gamma Knife radiosurgery is safe and effective in patients with meningiomas invading the superior sagittal sinus. The procedure can be part of a multimodal treatment plan or administered as a single treatment in well-selected patients.