The purposes of this study were: (1) to determine the prevalence of abnormal 99mTc-HMPAO SPECT scans in patients suffering from persistent post-concussive syndrome (PPCS) after mild closed head injury (CHI); (2) to compare SPECT with structural neuroimaging (MRI and CT) in patients with mild CHI; and (3) to investigate correlations between SPECT and clinical data obtained from the patient sample (neuropsychological testing, demographics, psychiatric diagnoses). Forty-three patients were included. SPECT was read as abnormal in 53% of patients and showed a total of 37 lesions while MRI was read as abnormal in 9% and CT scan in only 4.6% of patients after mild CHI. SPECT appears to be more sensitive in detecting cerebral abnormalities after mild CHI, especially in patients with PPCS symptoms, than either CT or MRI. No statistically significant relationship was found between SPECT scan abnormalities and age, past psychiatric history, history of substance abuse, or history of multiple CHI. Education level did not differ between patients with normal and abnormal SPECT. Current neuropsychiatric symptoms did not seem to have any impact on the results of SPECT scan.

BackgroundThis study proposes and validates a method of measuring 3D strain in myocardium using a 3D Cardiovascular Magnetic Resonance (CMR) tissue-tagging sequence and a 3D optical flow method (OFM).MethodsInitially, a 3D tag MR sequence was developed and the parameters of the sequence and 3D OFM were optimized using phantom images with simulated deformation. This method then was validated in-vivo and utilized to quantify normal sheep left ventricular functions.ResultsOptimizing imaging and OFM parameters in the phantom study produced sub-pixel root-mean square error (RMS) between the estimated and known displacements in the x (RMSx = 0.62 pixels (0.43 mm)), y (RMSy = 0.64 pixels (0.45 mm)) and z (RMSz = 0.68 pixels (1 mm)) direction, respectively. In-vivo validation demonstrated excellent correlation between the displacement measured by manually tracking tag intersections and that generated by 3D OFM (R ≥ 0.98). Technique performance was maintained even with 20% Gaussian noise added to the phantom images. Furthermore, 3D tracking of 3D cardiac motions resulted in a 51% decrease in in-plane tracking error as compared to 2D tracking. The in-vivo function studies showed that maximum wall thickening was greatest in the lateral wall, and increased from both apex and base towards the mid-ventricular region. Regional deformation patterns are in agreement with previous studies on LV function.ConclusionA novel method was developed to measure 3D LV wall deformation rapidly with high in-plane and through-plane resolution from one 3D cine acquisition.

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A simultaneous bilateral back-projection method for 3D dynamic contrast-enhanced (DCE)-MRI of the breasts was developed and evaluated. Using a double-side band modulation of the RF slab excitation pulse, discontinuous volumes that included both breasts were simultaneously selected. The number of slice phase-encoding steps was undersampled by a factor of 2, and the resulting signal aliasing from one volume to the other was removed using SENSE processing. In-plane encoding was performed with an interleaved radial acquisition reconstructed using dynamic k-space-weighted image contrast (KWIC) temporal filtering. Image resolution was 0.5 ؋ 0.5 ؋ 3.0 mm 3 with an effective temporal resolution of 15 s for both breast volumes. Combined with the 2؋ acceleration from SENSE encoding, this is a 16؋ acceleration factor over a conventional MR bilateral breast scan. An initial evaluation of these methods was performed on a cohort of women who presented with palpable or mammographically visible breast abnormalities. A total of 73 abnormalities were found in 45 of the 54 bilateral examinations that were performed. In 11 of these cases there was a significant finding in the contralateral breast. Dynamic contrast-enhanced (DCE)-MRI of the breast has shown promising results for detecting breast abnormalities (1-4). The architectural features that are visible after enhancement have a high correlation to cancer (5,6), and the enhancement dynamics have also been shown to be highly correlated to benign or malignant lesions (7). Combined interpretations have been shown to improve diagnostic performance compared to that achieved by separate approaches (8 -10). However, even for a unilateral breast study, it is difficult to simultaneously acquire both highspatial-resolution data for architectural analysis and hightemporal-resolution data for contrast kinetic classification because of the different demands involved. The high-resolution images that are necessary to distinguish features for architectural interpretation require a relatively long acquisition time. For example, to image the entire breast, a 3D acquisition of 32 slices with a sampling matrix of 512 ϫ 384 takes ϳ2 min. Acquiring fewer slices or reducing the matrix size will speed acquisition, but at the cost of reduced coverage or spatial resolution. The importance of using a high frame rate for enhancement dynamics analyses was shown by Lucht et al. (11), who observed a significant increase in diagnostic performance when they used 28 points as compared to three time points.As the value of DCE-MRI of the breast becomes appreciated by clinicians and its usage increases, there will be a demand for bilateral acquisitions. However, the problem of imaging at a high frame rate while preserving spatial resolution is compounded in the case of bilateral imaging. In a conventional bilateral examination the acquisitions are interleaved, which doubles the scan repetition time (TR) and reduces the temporal resolution. A coarse representation of the contrast kinetics is the best that can be ac...

Background:Spinal anesthesia is used commonly intraoperatively. However, local anesthetics are associated with relatively short duration of action. A number of adjuvants have been used to prolong the postoperative analgesia.Objectives:To compare efficacy of dexmedetomidine and fentanyl when given intrathecally as an adjuvant to 2.5 ml of 0.75% isobaric ropivacaine.Materials and Methods:Sixty selected patients were randomized to receive 2.5 ml of 0.75% isobaric ropivacaine with dexmedetomidine 5 mcg (Group RD) or 20 mcg of fentanyl (Group RF) intrathecally for lower limb surgeries, block characteristics, hemodynamic changes, and adverse effects were compared.Results:Efficacy of both the drugs when given intrathecally was studied. Mean time needed for sensory blockade at T10 was 156.4667 ± 33.78 s in Group RD and 185.2000 ± 35.17 s in Group RF. The results are clinically and statistically significant (P - 0.002). The mean of total duration of sensory block in Group RD was 194.400 min while it was 139.9000 min in Group RF which was clinically and statistically significant (P - 0.0001). Time taken for onset of motor block was almost same in both groups. The mean of total duration of motor block in Group RD was 136.7333 min while it was 94.8667 min in Group RF which was clinically and statistically significant (P - 0.000).Conclusion:Dexmedetomidine at a dose of 5 μg added to 2.5 ml of ropivacaine provided earlier sensory blockade, prolonged duration of sensory and motor blockade for patients under intrathecal anesthesia for lower limb surgeries with no sedation.