Glutamate quantification in patients with supratentorial gliomas using chemical shift imaging.

This study aimed to evaluate and validate chemical shift imaging (CSI) for in vivo glutamate (Glu) quantification in patients with supratentorial gliomas. If validated, CSI could become an extremely useful tool to investigate metabolic dysfunction of Glu in excitotoxic neuropathologies. Quantitative CSI estimates of Glu concentrations were compared with known concentrations of Glu in aqueous phantom solutions. Forty-one patients with known or likely supratentorial gliomas underwent preoperative CSI. The spectra obtained were analyzed for Glu concentrations and Glu to creatine (Cr) ratios. These in vivo measurements were correlated against ex vivo Glu content quantified by high performance liquid chromatography (HPLC) measured in 65 resected brain tumor and peritumoral brain specimens. For the phantom solutions the CSI estimates of Glu concentration and the Glu/Cr ratios were highly correlated with known Glu concentration (r² = 0.95, p = 0.002, and r² = 0.97, p < 0.0001, respectively). There was a modest, but statistically significant, correlation between the ex vivo measured Glu and in vivo spectroscopic Glu concentration (r² = 0.22, p = 0.04) and ratios of Glu to Cr (r² = 0.30, p = 0.002). Quantitative measurement of Glu content is feasible in patients with supratentorial gliomas using CSI. The in vitro and in vivo results suggest that this has the potential to be a reliable quantitative imaging assay for brain tumor patients. This may have wide clinical research applications in a number of neurological disorders where Glu excitotoxicity and metabolic dysfunction are known to play a role in pathogenesis, including tumor associated epilepsy, epilepsy, stroke and neurotrauma.

Diffusion tensor imaging in glioblastoma multiforme and brain metastases: the role of p, q, L, and fractional anisotropy.

BACKGROUND AND PURPOSE: Microinvasive tumor cells, which are not detected on conventional imaging, contribute to poor prognoses for patients diagnosed with glioblastoma multiforme (GBM, WHO grade IV). Diffusion tensor imaging (DTI) shows promise in being able to detect this infiltration. This study aims to detect a difference in diffusion properties between GBM (infiltrative) and brain metastases (noninfiltrative). MATERIALS AND METHODS: For 49 tumors (30 GBM, 19 metastases), DTI measures (p, q, L, and fractional anisotropy [FA]) were calculated for regions of gross tumor (excluding hemorrhagic and necrotic core), peritumoral edema, peritumoral margin (edema most adjacent to tumor), adjacent normal-appearing white matter (NAWM), and contralateral white matter. Parametric and nonparametric statistical tests were used to determine significance, and receiver operating characteristic (ROC) curve analyses were performed. RESULTS: Mean values of p, L, and FA from regions of signal-intensity abnormality differed from those of normal brain in both tumors. The mean q value did not differ significantly compared with that in normal brain in any region in metastases or in adjacent NAWM of GBM. For GBM compared with metastases, q and FA were significantly lower in gross tumor (P < .001) and q was significantly lower in peritumoral margin (P < .001), which may be due to tumor infiltration. Significant overlap was present, which was reflected in the ROC curve analyses (area under the curve values from 0.732 to 0.804). CONCLUSIONS: DTI may be used to help differentiate between GBM and brain metastases. The results also suggest that DTI has the potential to assist in detecting infiltrative tumor cells in surrounding brain.

Elevated hematocrit is associated with reduced reperfusion and tissue survival in acute stroke.

BACKGROUND: Elevated hematocrit (Hct) contributes to blood viscosity and has an adverse effect in acute stroke. The authors investigated the influence of Hct on tissue fate using serial MRI in acute stroke patients. METHODS: The effects of Hct on reperfusion, penumbral salvage, and infarct expansion in 64 patients presenting within 24 hours of stroke onset were measured. MRI was performed at baseline (< 24 hours), days 3 to 5, and 90 days from stroke onset. RESULTS: Median Hct was 42% with a bimodal distribution. There was a strong inverse relationship between Hct and reperfusion (Spearman rho = -0.74, p < 0.0001). The odds of major reperfusion (> 50% resolution of the baseline perfusion-weighted imaging deficit) were significantly lower with increasing Hct (odds ratio [OR] = 0.53; 95% CI = 0.97 to 1.00), independent of age, perfusion, and diffusion lesion volumes and recombinant tissue plasminogen activator (rtPA) administration. There was a trend toward reduced penumbral salvage at days 3 to 5 with increasing Hct (p = 0.06, 95% CI = -4.76 to 0.14). An increasing Hct was a significant predictor of infarct growth (OR = 1.26, 95% CI = 1.00 to 1.59), independent of baseline perfusion and diffusion volumes and glucose. The effect of Hct on reperfusion and infarct expansion was similar irrespective of rtPA administration (p = 0.31) and independent of smoking status. CONCLUSIONS: Higher hematocrit (Hct) values have a significant independent association with reduced reperfusion and greater infarct size after ischemic stroke. An elevated Hct may also be a potential physiologic determinant of reduced penumbral salvage.

Correlation of ultrasound and magnetic resonance imaging with clinical outcome after patellar tenotomy: prospective and retrospective studies. Victorian Institute of Sport Tendon Study Group.

OBJECTIVE: To report the appearances of ultrasound (US) and magnetic resonance imaging (MRI) before and after surgery for chronic patellar tendinopathy and to correlate postoperative appearances with clinical outcome. DESIGN: A 12-month prospective longitudinal study and a retrospective study, each part using different patients. Prospective study included clinical assessment, ultrasound, and MRI all performed before and 12 months after surgery. Retrospective study included ultrasound and clinical assessment only (i.e., no MRI) 24 to 67 months after surgery. SETTING: Institutional athlete study group in Australia (Victorian Institute of Sport Tendon Study Group). PATIENTS: In the prospective study, 13 patients (all male; 15 tendons) who underwent patellar tenotomy; in the retrospective study, 17 different patients (18 tendons) who had undergone identical surgery. MAIN OUTCOME MEASURES: Ultrasound and MRI appearances and clinical assessment at baseline and 12 months after surgery (prospective study). Ultrasound appearance and clinical assessment 24 to 67 months after surgery (retrospective study). Dimensions of abnormal regions on imaging were measured. Clinical assessment included categorical rating and numerical Victorian Institute of Sport Assessment (VISA) score. RESULTS: In the prospective study, preoperative ultrasound and MRI appearances confirmed the clinical diagnosis of patellar tendinopathy. Postoperative ultrasound and MRI also revealed abnormalities consistent with patellar tendinopathy. Despite this, 11 of 15 (73%) tendons were rated clinically as either good or excellent. Imaging modalities were unable to distinguish tendons rated as good or excellent from those rated poor at 12 months. In the retrospective study, ultrasound images revealed abnormalities despite full clinical recovery. There was no correlation between dimension of ultrasound abnormality and either VISA score or time since surgery. CONCLUSION: After open patellar tenotomy, MRI and ultrasound findings remain abnormal despite clinical recovery. Thus, clinicians ought to base postoperative management of patients undergoing patellar tenotomy on clinical grounds rather than imaging findings. At present, there appears to be no role for routine postoperative imaging of patients recovering slowly after patellar tenotomy. However, this is not to suggest that imaging cannot play a role in special circumstances.

Reduction of length of stay and cost of transurethral resection of the prostate by early catheter removal.

OBJECTIVE: To determine whether early removal of the indwelling Foley catheter after transurethral resection of the prostate (TURP) significantly shortens the hospital stay without causing additional morbidity and thus saves costs. PATIENTS AND METHODS: For the year commencing 1 July 1991, 119 patients who had undergone TURP had their indwelling catheter removed on the first day after surgery. The results and morbidity of this group of patients were compared with those in 152 patients undergoing TURP during the previous year. The economic consequences of this protocol were calculated using both Medicare and CHAMPUS data. RESULTS: The demographics of the patients in both groups were similar. Post-operative complications occurred in 5% of the study patients and in 6.6% of controls; a transfusion was required in 2.5% and 1.3%, clot retention developed in 1.7% and 3.3% and the hospital stay was reduced from 3.1 to 1.28 days in the study and control patients, respectively. Using Medicare data, the mean cost saving of early catheter removal would be $829 and $1406 for patients aged < 70 and > 70 years, respectively. For CHAMPUS patients, the cost saving would be $1983. CONCLUSION: Early removal of the catheter after TURP did not increase morbidity and maintained the efficacy of the procedure. If this practice was adopted nationally, the savings resulting from the reduction in hospital stay would be considerable.

Balloon dilation of the prostate: correlation with magnetic resonance imaging and transrectal ultrasound findings.

Alternative treatments for benign prostatic hyperplasia are under intense scrutiny. Initial reports on balloon dilation therapy showed success rates of 60% to 90%, although follow-up was brief. We present a prospective non-blinded study assessing the efficacy of an investigational balloon dilatation catheter (105 Fr at 3 atm) as well as the MRI findings preoperatively and postoperatively. Twenty-seven men underwent balloon dilation and have been followed for at least 1 year. Twelve patients (44%) ultimately required definitive transurethral prostatectomy during follow-up. A mild improvement was noted in the symptom score and flow rate in the responder group. Fracture of the anterior commissure was accomplished in only 5 patients (18%) despite diligent efforts. The MRI scans showed no change in the prostate in any patients. Intraoperative transrectal ultrasound scanning suggested that proximal balloon migration can occur. Our experience with this balloon system leads us to recommend that it remain an investigational procedure.

Febrile seizures and hippocampal sclerosis: frequent and related findings in intractable temporal lobe epilepsy of childhood.

The relationship between hippocampal sclerosis, febrile seizures, and complex partial seizures in temporal lobe epilepsy continues to be the subject of great debate in the literature. Hippocampal sclerosis is reported infrequently in young children with temporal lobe epilepsy, a factor that has supported the theory that hippocampal sclerosis develops in later life during the course of recurrent complex partial seizures. In a blinded review of magnetic resonance imaging in 53 children, aged 2-17 years (mean: 10 years) with temporal lobe epilepsy, hippocampal sclerosis was diagnosed in 30 children (57%), concordant with ictal electroencephalographic lateralization in 93% and pathologic diagnosis in all children who had undergone surgery and had hippocampal tissue available for histologic examination. Fourteen of the children (47%) with hippocampal sclerosis were younger than 10 years of age, the youngest being 2 years. Thirty-four children (64%) had histories of neurologic insults prior to the onset of complex partial seizures, including idiopathic febrile seizures in 22. Hippocampal sclerosis was associated with a history of a neurologic insult prior to the onset of complex partial seizures (P < .001) and was not associated with age at onset of temporal lobe epilepsy, age at magnetic resonance imaging, duration of epilepsy, or presence of secondarily generalized seizures. These findings suggest that hippocampal sclerosis is underdiagnosed in children and is the cause and not the consequence of temporal lobe epilepsy.

Relative performance characteristics of prostate specific antigen and prostatic specific antigen density for the diagnosis of carcinoma of the prostate.

Prostate specific antigen (PSA) has become an important method for early detection of prostate cancer. It has been suggested that prostate specific antigen density (PSAD) may be a more efficient test for early detection than PSA alone. A series of 327 men undergoing prostate biopsy were evaluated by PSA and PSAD. When the receiver operating characteristic curves of both tests were compared, they demonstrated little improvement in the efficiency of detection with the use of PSAD. The five-fold increase in the cost of PSAD over PSA alone does not justify its inclusion in a plan for early detection for carcinoma of the prostate.

Hippocampal sclerosis in children with intractable temporal lobe epilepsy: detection with MR imaging.

OBJECTIVE: Hippocampal sclerosis is the most common lesion associated with temporal lobe epilepsy. Temporal lobectomy is effective for the control of medically refractory seizures in these patients. Before the advent of MR imaging, hippocampal sclerosis was rarely diagnosed preoperatively. The purpose of this study was to determine the frequency of hippocampal sclerosis in children with intractable temporal lobe epilepsy and the accuracy and reliability with which hippocampal sclerosis can be diagnosed on the basis of MR findings in children. MATERIALS AND METHODS: We reviewed the MR images of 53 children (mean age, 10 years) with medically refractory temporal lobe epilepsy. The MR images were reviewed blindly and independently by two radiologists on two occasions, and were classified as showing hippocampal sclerosis, other lesions, or no abnormality. Hippocampal sclerosis was diagnosed when evidence of hippocampal atrophy was present or hippocampal signal intensity was abnormal without evidence of a mass lesion. RESULTS: MR images showed hippocampal sclerosis in 30 children (57%), other lesions in 10 (19%) (tumors in eight, cavernous angioma in one, and ectopic gray matter in one), and no abnormality in 13 (24%) (intraobserver agreement: kappa = 0.77 and 0.84, interobserver agreement: kappa = 0.76). MR lateralization was concordant with ictal EEG in 36 (92%) of 39 children. Hippocampal sclerosis was bilateral in one child and associated with extrahippocampal lesions in nine. Hippocampal sclerosis was detected on MR images of 11 (85%) of 13 children with pathologic confirmation of hippocampal sclerosis. Beneficial results were seen in 26 (90%) of 29 children who had temporal lobectomy. CONCLUSION: Hippocampal sclerosis is the most common lesion in children with intractable temporal lobe epilepsy, and it can be detected reliably and accurately on MR images. We suspect that hippocampal sclerosis is underdiagnosed in children, possibly leading to postponement of surgery in children with refractory seizures.

Morbidity with contemporary prostate biopsy.

To determine the incidence of complications associated with contemporary prostate biopsy, a review of 670 men undergoing transrectal prostate biopsy using 18 gauge biopsy needles was conducted. Of the men 580 received 1 to 3 days of ciprofloxacin antibiotic prophylaxis. A total of 16 patients (2.1%) suffered complications of whom 4 (0.6%) required hospitalization. These data demonstrate the low morbidity associated with contemporary transrectal prostate biopsy.

Extragonadal yolk sac tumor in a superior scrotal mass.

We report a case of an extragonadal yolk sac tumor in a superior scrotal mass. Testicular ultrasonography was normal preoperatively and after chemotherapy. Serum alpha-fetoprotein was initially increased to 344.55 ng./ml. (normal 0 to 15) but it returned to normal after surgery and chemotherapy.

Cocaine and lidocaine as topical urethral anesthetics.

To evaluate the efficacy of topical cocaine combined with lidocaine as a urethral anesthetic, a double-blind, randomized, prospective study was performed comparing lidocaine combined with cocaine or placebo in male outpatient cystoscopy. Evaluations were based on a scale of 1 to 10, with 1 representing no discomfort and 10 extreme discomfort as judged by the patient, and 1 representing the best tolerance and 10 extreme intolerance as judged by the physician. Patients who received lidocaine plus cocaine reported a mean score of 3.33 for over-all discomfort of cystoscopy. This was not significantly different than for lidocaine alone. This finding indicates a lack of a summation effect in combining topical anesthetics. Patients undergoing repeat examinations were no more comfortable than those undergoing initial cystoscopy but older patients tolerated the procedure significantly better than younger patients.