Alternate ventricular asymmetry could suggest a psychiatric diagnosis.

Routine magnetic resonance imaging (MRI) of the skull and brain for diagnostic purposes sometimes reveals a wider tip of the frontal ventricular horn on one side and a wider tip of the temporal horn on the other. A search for 'alternate ventricular asymmetry' in Google Scholar, Medline and PubMed Central yielded no results, so the digital archive of the hospital was searched for such cases. A total of 5908 examinations were reviewed and 508 cases were found, comprising 6% of the neurological inpatients and 20% of the psychiatric inpatients (P = 0.001 by χ2 ). The >3-fold difference in the incidence of this particular ventricular asymmetry implies that it could suggest a psychiatric diagnosis. Clin. Anat. 30:50-52, 2017. © 2016 Wiley Periodicals, Inc.

Ultrasonographic, CTI and MRI of Aberrant Internal Carotid Artery: Infrequent but Important to Know.

This article describes the aberrant course of the internal carotid artery (ICA) through the middle ear as an extremely rare vascular anomaly. On the basis of a case report, the findings of magnetic resonance imaging, computed tomography imaging, and especially color-coded duplex sonography are presented. The diagnosis of an aberrant ICA is important to avoid severe surgical complications of a retrotympanic mass as well as unnecessary diagnostic or therapeutic approaches in expectation of a stroke.

CT perfusion in acute ischemic stroke: a comparison of 2-second and 1-second temporal resolution.

BACKGROUND AND PURPOSE: CT perfusion data sets are commonly acquired using a temporal resolution of 1 image per second. To limit radiation dose and allow for increased spatial coverage, the reduction of temporal resolution is a possible strategy. The aim of this study was to evaluate the effect of reduced temporal resolution in CT perfusion scans with regard to color map quality, quantitative perfusion parameters, ischemic lesion extent, and clinical decision-making when using DC and MS algorithms. MATERIALS AND METHODS: CTP datasets from 50 patients with acute stroke were acquired with a TR of 1 second. Two-second TR datasets were created by removing every second image. Various perfusion parameters (CBF, CBV, MTT, TTP, TTD) and color maps were calculated by using identical data-processing settings for 2-second and 1-second TR. Color map quality, quantitative region-of-interest-based perfusion measurements, and TAR/NVT lesions (indicated by CBF/CBV mismatch) derived from the 2-second and 1-second processed data were statistically compared. RESULTS: Color map quality was similar for 2-second versus 1-second TR when using DC and was reduced when using MS. Regarding quantitative values, differences between 2-second and 1-second TR datasets were statistically significant by using both algorithms. Using DC, corresponding tissue-at-risk lesions were slightly smaller at 2-second versus 1-second TR (P < .05), whereas corresponding NVT lesions showed excellent agreement. With MS, corresponding tissue-at-risk lesions showed excellent agreement but more artifacts, whereas NVT lesions were larger (P < .001) compared with 1-second TR. Therapeutic decisions would have remained the same in all patients. CONCLUSIONS: CTP studies obtained with 2-second TR are typically still diagnostic, and the same therapy would have been provided. However, with regard to perfusion quantitation and image-quality-based confidence, our study indicates that 1-second TR is preferable to 2-second TR.

Hemorrhagic complications after systemic thrombolysis in acute stroke patients with abnormal baseline coagulation.

BACKGROUND AND PURPOSE: As patients with abnormal baseline coagulation were excluded from the large randomized trials, the safety of intravenous thrombolysis after ischaemic stroke in this patient population remains controversial. METHODS: We assessed the risk of symptomatic intracerebral hemorrhage (SICH) after systemic thrombolysis in patients with elevated baseline international normalized ratios (INRs) (≥1.3) or activated partial thromboplastin times (aPTT) (>37 s) using a prospectively recorded database from 2006 to 2010. An intracerebral hemorrhage leading to a deterioration of ≥4 points on the National Institutes of Health Stroke scale (NIHSS) was classified as symptomatic. RESULTS: Amongst 688 patients (mean age, 72 years; median NIHSS, 11, median onset-to-treatment time, 135 min), 36 patients (5%) had an abnormal baseline coagulation. Twenty-nine of these patients had taken oral anticoagulants leading to elevated baseline INRs (median INR: 1.5; IQR 1.4-1.9), whereas seven patients had elevated aPTTs because of heparin therapy (n = 2), a coagulation disorder (n = 2), or for unknown reasons (n = 3). The rate of SICH did not differ significantly between patients with abnormal and normal baseline coagulation (4.4% vs. 0%; P = 0.6). Moreover, the in-hospital mortality was not significantly different between both treatment groups (8.3% in patients with abnormal baseline coagulation vs. 8.7% in patients with normal baseline coagulation, P = 1.0). CONCLUSIONS: The risk of SICH following intravenous thrombolysis after ischaemic stroke does not appear to be increased in patients with abnormal baseline coagulation.

Perfusion CT in acute ischemic stroke: a qualitative and quantitative comparison of deconvolution and maximum slope approach.

BACKGROUND AND PURPOSE: PCT postprocessing commonly uses either the MS or a variant of the DC approach for modeling of voxel-based time-attenuation curves. There is an ongoing discussion about the respective merits and limitations of both methods, frequently on the basis of theoretic reasoning or simulated data. We performed a qualitative and quantitative comparison of DC and MS by using identical source datasets and preprocessing parameters. MATERIALS AND METHODS: From the PCT data of 50 patients with acute ischemic stroke, color maps of CBF, CBV, and various temporal parameters were calculated with software implementing both DC and MS algorithms. Color maps were qualitatively categorized. Quantitative region-of-interest-based measurements were made in nonischemic GM and WM, suspected penumbra, and suspected infarction core. Qualitative results, quantitative results, and PCT lesion sizes from DC and MS were statistically compared. RESULTS: CBF and CBV color maps based on DC and MS were of comparably high quality. Quantitative CBF and CBV values calculated by DC and MS were within the same range in nonischemic regions. In suspected penumbra regions, average CBF(DC) was lower than CBF(MS). In suspected infarction core regions, average CBV(DC) was similar to CBV(MS). Using adapted tissue-at-risk/nonviable-tissue thresholds, we found excellent correlation of DC and MS lesion sizes. CONCLUSIONS: DC and MS yielded comparable qualitative and quantitative results. Lesion sizes indicated by DC and MS showed excellent agreement when using adapted thresholds. In all cases, the same therapy decision would have been made.

Bone-subtraction CT angiography: evaluation of two different fully automated image-registration procedures for interscan motion compensation.

BACKGROUND AND PURPOSE: Bone-subtraction techniques have been shown to enhance CT angiography (CTA) interpretation, but motion can lead to incomplete bone removal. The aim of this study was to evaluate 2 novel registration techniques to compensate for patient motion. MATERIALS AND METHODS: Fifty-four patients underwent bone-subtraction CTA (BSCTA) for the evaluation of the neck vessels with 64-section CT. We tested 3 different registration procedures: pure rigid registration (BSCTA), slab-based registration (SB-BSCTA), and a partially rigid registration (PR-BSCTA) approach. Subtraction quality for the assessment of different vascular segments was evaluated by 2 examiners in a blinded fashion. The Cohen kappa test was applied for interobserver variability, and the Wilcoxon signed rank test, for differences between the procedures. Motion between the corresponding datasets was measured and plotted against image-quality scores. RESULTS: Algorithms with motion compensation revealed higher image-quality scores (SB-BSCTA, mean 4.31; PR-BSCTA, mean 4.43) than pure rigid registration (BSCTA, mean 3.88). PR-BSCTA was rated superior to SB-BSCTA for the evaluation of the cervical internal and external carotid arteries (P<.001), whereas there was no significant difference for the other vessels (P=.157-.655). Both algorithms were clearly superior to pure rigid registration for all vessels except the basilar and ophthalmic artery. Interobserver agreement was high (kappa=0.46-0.98). CONCLUSION: Bone-subtraction algorithms with motion compensation provided higher image-quality scores than pure rigid registration methods, especially in cases with complex motion. PR-BSCTA was rated superior to SB-BSCTA in the visualization of the internal and external carotid arteries.

Identifying the affected hemisphere by (1)H-MR spectroscopy in patients with temporal lobe epilepsy and no pathological findings in high resolution MRI.

Up to 30% of patients with temporal lobe epilepsy (TLE) remain without remarkable changes in MRI. In this study we investigated the role of (1)H-MR spectroscopy ((1)H-MRS) in lateralizing the affected hemisphere in the mentioned patient group. Twenty-two consecutive patients diagnosed with TLE were investigated by high resolution MRI and (1)H-MRS. We examined the incidence and diagnostic accuracy of temporal metabolite alterations determined by Linear Combination of Model Spectra (L C Model) via water reference. Metabolite values of each hemisphere of TLE patients were compared with healthy controls. Results of metabolite alterations were related to intensive video EEG focus localization. Reduction of N-acetylaspartate + N-acetylaspartyl-glutamate (tNAA) in the affected hemisphere revealed identification in six of nine patients (66%) with unilateral TLE. Group comparison revealed a significant reduction of tNAA (6.1+/-0.8*) in the involved temporal lobe compared with controls (6.67+/-0.4*, P=0.026). Choline levels were significantly increased in the affected hemisphere (1.42+/-0.17*) compared with healthy controls (1.22+/-0.17*, P=0.035). The results of our study show that (1)H-MRS is able to identify the affected hemisphere of MRI negative TLE patients and can be used as an additive tool in multimodal focus localization.

Bone-subtraction CT angiography for the evaluation of intracranial aneurysms.

PURPOSE: CT angiography (CTA) has been established for detection and therapy planning of intracranial aneurysms. The analysis of aneurysms at the level of the skull base, however, remains difficult because bone prevents a free view. We report initial clinical results of an approach for automatic bone elimination from CTA data. MATERIAL AND METHODS: Before the bone-removal process 2 datasets are acquired: nonenhanced spiral CT with reduced dose and contrast-enhanced CTA. The software automatically registers the nonenhanced data onto the CTA data and selectively removes bone. Vascular structures, as well as brain tissue, remain visible. In this study, we investigated 27 patients with 29 aneurysms, 13 of which were located at the skull base. 3D volume-rendered images with and without bone removal were reviewed and compared with digital subtraction angiography by 2 radiologists in consensus. RESULTS: All supraclinoidal aneurysms were detected on 3D volume-rendered images of both CTA and bone-subtraction CT angiography (BSCTA). Four intracavernous and 3 paraclinoid aneurysms of the internal carotid artery were not visible or were only partially visible on conventional 3D CTA, whereas they could be optimally visualized with BSCTA. Bone removal was successful in all patients; the average additional time for postprocessing was 6.2 minutes. In 7 patients (26%), perfect bone removal without any artifacts was achieved. In most patients, some bone remnants were still present, though it did not disturb the 3D visualization of vascular structures. CONCLUSION: BSCTA allows robust and fast selective elimination of bony structures, thus ascertaining a better analysis of arteries at the level of the skull base. This is useful for both detection and therapy planning of intracranial aneurysms.

Clinical evaluation of bone-subtraction CT angiography (BSCTA) in head and neck imaging.

Fifty-one patients were examined with bone subtraction CT angiography (BSCTA). Data were acquired on 4-and 64-slice spiral CT systems. The post-processing method is based on fully automatic registration of non-enhanced and contrast-enhanced CT data and subsequent selective bone removal. Vascular structures and brain tissue are retained with the original CTA noise level. Image quality and delineation of the pathologic process were assessed and artifacts introduced by the bone removal process recorded. The bone subtraction algorithm worked successfully in all examinations. The processing time was 6 min on average. Image quality was rated excellent in 20 (39%), good in 26 (51%) and acceptable in 5 (10%) patients. Ophthalmic arteries were visible in 12 (24%) patients bilaterally, in 13 (25%) patients unilaterally and in 26 (51%) patients at least at the origin. BSCTA improved visualization of the infraclinoid ICA and the vertebral arteries. The depiction of stenosis of the extracranial ICA and supraclinoid aneurysms was not significantly improved. In patients with suspicion of sinus thrombosis, BSCTA and conventional CTA yielded similar results. To conclude, BSCTA improves the visualization of vessels with close contact to bone and can improve the diagnostic accuracy and therapy planning of infraclinoid aneurysms.

Short TE single-voxel 1H-MR spectroscopy of hippocampal structures in healthy adults at 1.5 Tesla--how reproducible are the results?

The purpose of our study was to evaluate inter- and intra-subject variability and scan-rescan reproducibility of single-voxel 1H-MR spectroscopy (1H-MRS) in hippocampal structures at 1.5 T field strength. Thirty healthy adults were studied bilaterally by optimized, standardized short echo time single-voxel 1H-MRS (PRESS, TE=30 ms, TR=3000 ms, oblique voxel orientation, voxel size 2 cm3). Spectral analysis and absolute metabolite quantitation of N-acetylaspartate+N-acetylaspartyl-glutamate (tNAA), choline (Cho), creatine (Cr), total glutamate plus glutamine (Glu+Gln) and myo-inositol (Ins) were carried out by LCModel. Inter- and intra-individual reproducibility of these metabolite values were investigated by calculation of mean, standard deviation, coefficient of variation (CV), and by analysis of variance for repeated measurements. The smallest CV in intersubject variability was obtained for tNAA, followed by Cr, Cho, Ins and Glu+Gln. The results of the analysis of variance for repeated measures in inter-subject variability showed a marginal effect of scan repetition for Cr (p=0.063) and Glu+Gln (p=0.082); the rescan of both metabolites showed slightly higher concentrations. No statistical significant effect of scan repetition was seen for tNAA (p=0.913), Cho (p=0.857), and Ins (p=0.826). Rescan led to the same results and gave proof of good reproducibility. Scan-rescan testing in one subject showed comparable results: tNAA (CV=4.8%), followed by Cr, Ins, Glu+Gln and Cho (all CV above 10%).

[Cranial imaging and serology tests are not helpful in tonic pupil. A retrospective study]. / Kranielle Bildgebung und Serologie bei Pupillotonie nicht hilfreich. Eine retrospektive Studie.

BACKGROUND: Tonic pupil (TP) is a common disorder of parasympathetic innervation. In contrast to textbook recommendations, cranial imaging is still being performed in most of the patients with TP. The intention of the present study is to show that cranial imaging is of no benefit. PATIENTS AND METHODS: The medical records of 33 patients with TP were analyzed retrospectively. All patients had undergone a complete ophthalmological, orthoptic, and neurological investigation. Cranial imaging was performed by computed tomography or magnetic resonance imaging. Serology tests were carried out in some of the patients. RESULTS: Diagnostic imaging provided no additional data revealing the underlying cause of TP. CONCLUSIONS: Cranial imaging in isolated tonic pupil is not helpful. Because of therapeutic implications, diagnostic evaluation can be recommended only in patients older than 50 years to exclude giant cell arteritis and syphilis.

Bilateral orbital tumour as the presentation of mammographically occult breast cancer.

We report a rare case of bilateral orbital metastases as the presentation in a 63-year-old woman. Biopsy of a diffusely infiltrated medial rectus muscle suggested metastatic adenocarcinoma. Investigation revealed a palpable mass of the right breast not shown on mammography or sonography. Invasive lobular carcinoma was found at core-needle biopsy with histological features identical to those of the orbital lesion. Metastases to the extraocular muscles are uncommon, particularly as the initial abnormality in the absence of disseminated disease.

[Multimodal computed tomography in acute cerebral infarction. Experience with a standardized protocol in 100 patients]. / Multimodale Computertomographie beim akuten Hirninfarkt. Erfahrungen mit einem standardisierten Untersuchungsprotokoll bei 100 Patienten.

Computed tomography (CT) is the standard method of brain imaging in acute stroke. To an experienced examiner, nonenhanced CT will exclude hemorrhage and may indicate early ischemic signs. Reliable description of an ischemic area and the underlying vascular disease is not possible in the acute phase but is possible, particularly within the first hours, when therapeutic decisions on matters such as systemic thrombolysis are to be made. For such rapid decision-making, imaging must provide more information. Novel, contrast-enhanced CT techniques can provide this information. Perfusion CT (CTP) can show brain perfusion, allowing one to distinguish between reversible and irreversible damage in an ischemic area. Also, CT angiography (CTA) can detect occlusion or stenosis in the relevant vasculature. Using a modern, multislice CT scanner, it is now possible to combine these modalities of imaging. In a fast protocol for emergency evaluation, all three methods can be performed and evaluated to provide the crucial information within 15 min. In the first 102 patients examined within 6 h of symptom onset using this protocol, multimodal CT contributed substantially to therapeutic decisions, even though there are some limitations in these methods.

[Time consumption and quality of an automated fusion tool for SPECT and MRI images of the brain]. / Automatisierte Fusion von SPECT- und MRT-Bildern des Gehirns: Zeitbedarf und Ergebnisqualität.

AIM: Although the fusion of images from different modalities may improve diagnostic accuracy, it is rarely used in clinical routine work due to logistic problems. Therefore we evaluated performance and time needed for fusing MRI and SPECT images using a semiautomated dedicated software. PATIENTS, MATERIAL AND METHOD: In 32 patients regional cerebral blood flow was measured using (99m)Tc ethylcystein dimer (ECD) and the three-headed SPECT camera MultiSPECT 3. MRI scans of the brain were performed using either a 0,2 T Open or a 1,5 T Sonata. Twelve of the MRI data sets were acquired using a 3D-T1w MPRAGE sequence, 20 with a 2D acquisition technique and different echo sequences. Image fusion was performed on a Syngo workstation using an entropy minimizing algorithm by an experienced user of the software. The fusion results were classified. We measured the time needed for the automated fusion procedure and in case of need that for manual realignment after automated, but insufficient fusion. RESULTS: The mean time of the automated fusion procedure was 123 s. It was for the 2D significantly shorter than for the 3D MRI datasets. For four of the 2D data sets and two of the 3D data sets an optimal fit was reached using the automated approach. The remaining 26 data sets required manual correction. The sum of the time required for automated fusion and that needed for manual correction averaged 320 s (50-886 s). CONCLUSION: The fusion of 3D MRI data sets lasted significantly longer than that of the 2D MRI data. The automated fusion tool delivered in 20% an optimal fit, in 80% manual correction was necessary. Nevertheless, each of the 32 SPECT data sets could be merged in less than 15 min with the corresponding MRI data, which seems acceptable for clinical routine use.

1H-MR spectroscopy: a promising method in distinguishing subgroups in temporal lobe epilepsy?

Proton MR spectroscopy offers an additional noninvasive method of supporting focus lateralization in patients with intractable temporal lobe epilepsy. In this study involving 57 patients, the ability of multivoxel 1H-MRS to differentiate between mesial and lateral TLE was investigated in addition to its ability to lateralize the epileptogenic focus. Temporal lobe epilepsy (TLE) was classified into mesiobasal or lateral temporal lobe epilepsy according to the results of preoperative diagnostics including neurological and neuropsychological examinations, video-EEG monitoring and high resolution MRI. 1H-MR-spectroscopy (1H-MRS) showed that pathological changes in the mesial temporal lobes indicate a predominance in different parts of the ipsilateral temporal lobe (hippocampal and parahippocampal areas) correlating to the clinically defined groups. In addition, mesiobasal TLE tends to have higher concomitant contralateral abnormalities. Our results reveal that 1H-MRS is able to distinguish between mesiobasal and lateral pathologies in patients with TLE and represents a useful tool for noninvasive TLE classification.