Recommended Resting-State fMRI Acquisition and Preprocessing Steps for Preoperative Mapping of Language and Motor and Visual Areas in Adult and Pediatric Patients with Brain Tumors and Epilepsy.

Resting-state (rs) fMRI has been shown to be useful for preoperative mapping of functional areas in patients with brain tumors and epilepsy. However, its lack of standardization limits its widespread use and hinders multicenter collaboration. The American Society of Functional Neuroradiology, American Society of Pediatric Neuroradiology, and the American Society of Neuroradiology Functional and Diffusion MR Imaging Study Group recommend specific rs-fMRI acquisition approaches and preprocessing steps that will further support rs-fMRI for future clinical use. A task force with expertise in fMRI from multiple institutions provided recommendations on the rs-fMRI steps needed for mapping of language, motor, and visual areas in adult and pediatric patients with brain tumor and epilepsy. These were based on an extensive literature review and expert consensus.Following rs-fMRI acquisition parameters are recommended: minimum 6-minute acquisition time; scan with eyes open with fixation; obtain rs-fMRI before both task-based fMRI and contrast administration; temporal resolution of ≤2 seconds; scanner field strength of 3T or higher. The following rs-fMRI preprocessing steps and parameters are recommended: motion correction (seed-based correlation analysis [SBC], independent component analysis [ICA]); despiking (SBC); volume censoring (SBC, ICA); nuisance regression of CSF and white matter signals (SBC); head motion regression (SBC, ICA); bandpass filtering (SBC, ICA); and spatial smoothing with a kernel size that is twice the effective voxel size (SBC, ICA).The consensus recommendations put forth for rs-fMRI acquisition and preprocessing steps will aid in standardization of practice and guide rs-fMRI program development across institutions. Standardized rs-fMRI protocols and processing pipelines are essential for multicenter trials and to implement rs-fMRI as part of standard clinical practice.

Cerebral Ketones Detected by 3T MR Spectroscopy in Patients with High-Grade Glioma on an Atkins-Based Diet.

BACKGROUND AND PURPOSE: Ketogenic diets are being explored as a possible treatment for several neurological diseases, but the physiologic impact on the brain is unknown. The objective of this study was to evaluate the feasibility of 3T MR spectroscopy to monitor brain ketone levels in patients with high-grade gliomas who were on a ketogenic diet (a modified Atkins diet) for 8 weeks. MATERIALS AND METHODS: Paired pre- and post-ketogenic diet MR spectroscopy data from both the lesion and contralateral hemisphere were analyzed using LCModel software in 10 patients. RESULTS: At baseline, the ketone bodies acetone and ß-hydroxybutyrate were nearly undetectable, but by week 8, they increased in the lesion for both acetone (0.06 ± 0.03 ≥ 0.27 ± 0.06 IU, P = .005) and ß-hydroxybutyrate (0.07 ± 0.07 ≥ 0.79 ± 0.32 IU, P = .046). In the contralateral brain, acetone was also significantly increased (0.041 ± 0.01 ≥ 0.16 ± 0.04 IU, P = .004), but not ß-hydroxybutyrate. Acetone was detected in 9/10 patients at week 8, and ß-hydroxybutyrate, in 5/10. Acetone concentrations in the contralateral brain correlated strongly with higher urine ketones (r = 0.87, P = .001) and lower fasting glucose (r = -0.67, P = .03). Acetoacetate was largely undetectable. Small-but-statistically significant decreases in NAA were also observed in the contralateral hemisphere at 8 weeks. CONCLUSIONS: This study suggests that 3T MR spectroscopy is feasible for detecting small cerebral metabolic changes associated with a ketogenic diet, provided that appropriate methodology is used.

Timing of colonoscopy after resection for colorectal cancer: are we looking too soon?

BACKGROUND: Based on current National Comprehensive Cancer Network guidelines, colonoscopic surveillance after colorectal cancer resection should begin at 1 year. OBJECTIVE: The aim of this study was to determine whether the incidence of cancer or advanced polyp detection rate was high enough to justify colonoscopy at 1 year. DESIGN: The Ochsner Clinic Tumor Registry Database was queried for patients who underwent a segmental colectomy or proctectomy between 2002 and 2010. Patients who had a preoperative colonoscopy and at least 1 documented postoperative colonoscopy were included. We considered new cancer or polyps of ≥1 cm as missed on the preoperative colonoscopy. Patients with an identified genetic trait causing a predisposition to colorectal cancer were excluded. RESULTS: Five hundred twelve patients underwent resection, and 155 met our inclusion criteria. The average age was 64 years, and 53% patients were male. There were 32.9% with stage I disease, 35% with stage II disease, 27.1% with stage III disease, and 5.2% with stage IV disease. Of these patients, 52.2% had a right colectomy, 7.1% had a left colectomy, 16.8% had a sigmoid colectomy, 22% had a low anterior resection, and 1.3% had a transanal resection. The average time to first postoperative colonoscopy was 478 days (SD ±283 days). Twenty-four patients had adenomatous polyps detected on their first surveillance colonoscopy, but only 5 (3.2%) polyps were ≥1 cm, and there was no correlation between stage of cancer and finding a polyp. No new cancers were detected, but 3 (1.9%) had an anastomotic recurrence. CONCLUSIONS: The performance of surveillance colonoscopy at 1 year resulted in the detection of only 5 missed polyps ≥1 cm and no metachronous cancers. Anastomotic recurrences were rare, and the majority were in patients who had rectal cancer that could be evaluated by in-office flexible sigmoidoscopy. Extending the time to first colonoscopy appears to be safe and would help conserve valuable resources, including physician and facility time, which is imperative in the current health care climate.

Percutaneous pediculoplasty for traumatic pedicle fracture. A technical case report.

The objective of this case is to illustrate a technique for performing fluoroscopically guided percutaneous pediculoplasty in the setting of traumatic or non-neoplastic pedicle fractures. Pediculoplasty has been described in the literature as a complimentary technique performed during vertebroplasty. In this case, isolated pediculoplasty is demonstrated using existing vertebroplasty equipment, which may be utilized as a primary intervention for pedicle fractures in patients who are poor surgical candidates.

Pulsed arterial spin-labeled MR imaging evaluation of tuberous sclerosis.

BACKGROUND AND PURPOSE: Tuberous sclerosis presents with characteristic cortical hamartomas and subependymal nodules associated with seizures. The purpose of this study was to use pulsed arterial spin-labeling (PASL) to quantify the perfusion of the cortical hamartomas and correlate the perfusion values with seizure frequency. MATERIALS AND METHODS: A retrospective search yielded 16 MR imaging examinations including conventional MR imaging and PASL perfusion performed in 13 patients (age range, 7 months to 23 years) with a history of tuberous sclerosis. The mean perfusion of each cortical hamartoma greater than 5 mm in size localized with conventional MR imaging sequences was obtained with use of manually drawn regions of interest. Cortical hamartomas were classified as normal, hyperperfused, or hypoperfused on the basis of the mean and SD of the unaffected cortex. Correlation was made between perfusion imaging, conventional imaging, and clinical history. RESULTS: Of the 245 cortical hamartomas, 227 (92.7%) were hypoperfused, 10 (4.1%) were hyperperfused, and 8 (3.3%) were unchanged relative to the mean gray matter. One patient had a subependymal giant cell astrocytoma with a mean perfusion of 93.5 mL/100 g tissue/min. There was a statistically significant positive correlation between seizure frequency and the number of hyperperfused cortical tubers (r = 0.51; n = 16; P = .04), with higher seizure frequency associated with a greater number of hyperperfused cortical tubers. There was no significant correlation, however, between seizure frequency and the overall number of cortical tubers (r = 0.20; n = 16; P = .47). CONCLUSIONS: The PASL technique can assess and quantify the perfusion characteristics of a cortical hamartoma. Most lesions are hypoperfused; however, both normally perfused and hyperperfused lesions occur. The presence of hyperperfused cortical tubers was associated with increased seizure frequency.

Endovascular histologic effects of ultrathin gold- or vitronectin-coated platinum aneurysm coils in a rodent arterial occlusion model: a preliminary investigation.

BACKGROUND AND PURPOSE: Novel stratagems to improve the efficacy of platinum coils in occluding cerebral aneurysms have primarily involved coating coils with materials thought likely to provoke more desirable histologic reactions. No investigations to date, however, have evaluated the utility of gold or vitronectin coatings, despite known endovascular histologic effects of these agents, which may be favorable for treating cerebral aneurysms. This study was conducted to evaluate the degree of endovascular histologic change associated with ultrathin gold- or vitronectin-coated platinum coils. It was hypothesized that such coatings would increase intra-aneurysmal intimal hyperplasia and the degree of luminal occlusion compared with standard platinum coils. MATERIALS AND METHODS: The ligated carotid artery rat model was used to study 4 different aneurysm coil conditions: no coil (sham-surgery controls), uncoated platinum coil, and gold- or vitronectin-coated platinum coil. Two weeks postimplantation, the aneurysms were harvested and stained with hematoxylin-eosin. Slides were evaluated for the degree of neointimal response by a pathologist blinded to treatment. Additional quantitative evaluation was performed blindly by using the ratio of intimal-to-luminal cross-sectional area. RESULTS: A gold- or vitronectin-coated platinum aneurysm coil produced a statistically significant increase in neointimal response compared with a sham (no coil). Arterial segments treated with gold-coated platinum coils also demonstrated a statistically significant 100% increase in neointimal response compared with those treated with bare platinum coils. CONCLUSIONS: In concordance with our hypothesis, ultrathin coatings of gold provoked a neointimal response and degree of luminal occlusion greater than that of plain platinum aneurysm coils in a rat arterial occlusion model.

Hypercapnia-induced cerebral hyperperfusion: an underrecognized clinical entity.

BACKGROUND AND PURPOSE: The incidence of cerebral hyperperfusion and hypoperfusion, respectively, resulting from hypercapnia and hypocapnia in hospitalized patients is unknown but is likely underrecognized by radiologists and clinicians without routine performance of quantitative perfusion imaging. Our purpose was to report the clinical and perfusion imaging findings in a series of patients confirmed to have hypercapnic cerebral hyperperfusion and hypocapnic hypoperfusion. MATERIALS AND METHODS: Conventional cerebral MR imaging examination was supplemented with arterial spin-labeled (ASL) MR perfusion imaging in 45 patients during a 16-month period at a single institution. Patients presented with an indication of altered mental status, metastasis, or suspected stroke. Images were reviewed and correlated with arterial blood gas (ABG) analysis and clinical history. RESULTS: Patients ranged in age from 1.5 to 85 years. No significant acute findings were identified on conventional MR imaging. Patients with hypercapnia showed global hyperperfusion on ASL cerebral blood flow (CBF) maps, respiratory acidosis on ABG, and diffuse air-space abnormalities on same-day chest radiographs. Regression analysis revealed a significant positive linear relationship between cerebral perfusion and the partial pressure of carbon dioxide (pCO(2); beta, 4.02; t, 11.03; P < .0005), such that rates of cerebral perfusion changed by 4.0 mL/100 g/min for each 1-mm Hg change in pCO(2). CONCLUSIONS: With the inception of ASL as a routine perfusion imaging technique, hypercapnic-associated cerebral hyperperfusion will be recognized more frequently and may provide an alternative cause of unexplained neuropsychiatric symptoms in hospitalized patients. In a similar fashion, hypocapnia may account for a subset of patients with normal MR imaging examinations with poor ASL perfusion signal.

Sacroplasty versus vertebroplasty: comparable clinical outcomes for the treatment of fracture-related pain.

BACKGROUND AND PURPOSE: Little is known about the long-term clinical outcomes of sacroplasty, a relatively new minimally invasive percutaneous procedure for the treatment of sacral insufficiency fractures. The first purpose of the present study, therefore, was to investigate the effects of sacroplasty on pain, mobility, and activities of daily living (ADLs). A second purpose was to compare clinical outcomes of sacroplasty with those of vertebroplasty, a similar but more established procedure. MATERIALS AND METHODS: A retrospective case series of 12 patients who had a sacroplasty and a control group of 21 patients who had undergone a vertebroplasty was conducted. A 12-item questionnaire and subsequent telephone interview requested each patient to rate the intensity of pain, as well as the ability to ambulate and perform ADLs, before sacroplasty or vertebroplasty, and at the time of the interview. RESULTS: There was a statistically significant decrease in overall self-reported pain, as well as an increase in self-reported ability to ambulate and perform ADLs after sacroplasty or vertebroplasty. These improvements were equivalent, regardless of which procedure the patient received. CONCLUSION: The present study suggests that the treatment of sacral insufficiency fractures with sacroplasty produces relatively long-lasting improvements in pain, mobility, and the ability to perform ADLs. These data also suggest that the clinical outcomes of sacroplasty are comparable with those of vertebroplasty, an accepted and more routinely performed procedure.

Long-term survival after treatment of malignant colonic polyps.

PURPOSE: This study was designed to evaluate the long-term outcome and survival of patients treated for malignant colonic polyps. METHODS: A retrospective review of 15,975 cases of colonoscopies with 8,685 endoscopic polypectomies performed between 1972 and 1990 was undertaken. In 65 patients, the polypectomy specimens contained invasive carcinoma. Six patients were excluded (follow-up, <6 months). Polyp data, operative findings, and follow-up on the remaining 59 patients were recorded. RESULTS: Malignant polyps were found in 35 males and 24 females who had an average age of 64 (range, 39-81) years. Follow-up ranged from 12 to 202 (mean, 90) months. Tumor differentiation was poor in one and well or moderately differentiated in 58 patients. Positive or indeterminate margins were found in 13 patients. Thirty-seven (63 percent) patients were managed with polypectomy and surveillance. Four of these (with rectal tumors) also had an additional local excision for questionable margins. One recurrence was noted in a patient who refused surgery, which was recommended because of indeterminate margins. Twenty-two patients (37 percent) underwent colectomy. Indications included Haggitt Level 3 or 4 invasion (19), inadequate margins (7), patient preference (1), and poor differentiation (1). Residual disease was found in colectomy specimens of three patients (14 percent). There were no cancer-related deaths in either treatment group. Life table analysis demonstrated a five-year survival of 82 percent for the colectomy group and 95 percent for the polypectomy group (P = 0.15). CONCLUSION: Treatment of patients with malignant polyps must be individualized based on evolving criteria. Patients in whom polypectomy margins are inadequate should undergo colectomy. With appropriate selection criteria, patients selected for colectomy had a five-year survival rate similar to the rate of those treated by polypectomy alone.

Treatment of colorectal and ileoanal anastomotic sinuses.

PURPOSE: This study is designed to describe a technique and report results for treating low anastomotic sinuses. METHODS: Restorative proctocolectomy and complicated low anterior resections were protected with diverting loop ileostomy. Contrast enemas identified anastomotic problems before ileostomy closure. Pouch-anal or colorectal anastomotic sinuses that failed to resolve with observation were treated before intestinal continuity was restored. With the patient receiving regional or general anesthesia, a rigid proctoscope or anoscope was used to identify the sinus opening. The common wall between the sinus and the bowel lumen was divided under direct vision with laparoscopic cautery scissors, and the sinus cavity was debrided with a suction cautery wand placed through the scope. RESULTS: Six patients with anastomotic sinuses have received outpatient treatment in the described manner during the past two years. Four patients had restorative proctocolectomies for ulcerative colitis, and two had low anastomosis for rectal cancer. Three patients presented with pelvic sepsis before the contrast study; the remainder were asymptomatic. Division of anastomotic sinus was performed one to eight months after diagnosis of the sinus. Following division, anastomotic cavities resolved in five patients by 1 month and in one patient by 12 months. In these six patients, there was one dilatable anastomotic stricture but no other anastomotic complications at follow-up 5 to 16 (mean, 9.2) months after sinus division. CONCLUSION: When used in conjunction with fecal diversion, sinus unroofing by division of the common wall between the sinus and bowel lumen treats low pelvic sinuses.

Thoracoscopic pleurodesis with minocycline vs talc in the porcine model.

BACKGROUND: Eighteen adult pigs (Sus scrofa) underwent thoracoscopy and were placed into one of three groups: no sclerosant, talc pleurodesis, or minocycline pleurodesis. METHODS: Animals were then sacrificed at matched time intervals. Gross inspection of the pleural cavity estimated percentage of pleural symphysis (>25% was considered substantial) and allowed assignment of a pleurodesis score based on a scale described by Bresticker. Microscopic examination evaluated degree of fibrosis as mild, moderate, or severe. RESULTS: The talc group had significantly better pleurodesis than the minocycline group as determined by (1) the proportion of animals with substantial surface pleural symphysis (5/6 vs 1/6, p < 0.01), (2) a higher pleurodesis score (3 vs 1.3, p < 0.05), and (3) the proportion of animals with moderate fibrosis (5/6 vs 0/6, p < 0. 01). CONCLUSIONS: The authors conclude that instillation of aerosolized talc produces significantly better fibrosis and pleural symphysis than atomized minocycline in this animal model.

Surgical excision of large rectal villous adenomas.

Large villous tumors occur most frequently in the rectosigmoid and have a significant incidence of harboring a malignancy. The presence or absence of malignancy may be determined only by complete excision. Presence of invasive carcinoma on pathologic examination requires surgical intervention appropriate for that diagnosis. Recurrence depends on the technique used for tumor removal. It is highest for fulguration and local excision and lowest for operations that excise all or part of the rectum. Because most recurrences can be managed with local measures and the risk of malignancy in recurrences is relatively low, the procedure with which the tumor can be completely excised with the least morbidity should be used. Local excision with or without mucosal closure should be used as first-line surgical therapy whenever possible. It should be possible to manage most tumors in the mid and low rectum with this technique. For larger tumors and those tumors more proximal, it may be necessary to use snare cautery in combination with local excision or fulguration. Alternately, for some proximal rectal lesions the two-scope technique mentioned earlier may allow local excision. For circumferential or near circumferential tumors in the low to mid rectum, circumferential mucosectomy should be used. It has been used successfully for tumors involving the entire rectum down to the dentate line. Although this technique has a low recurrence rate, the rate of incontinence associated with it precludes its use in smaller tumors that are amenable to local excision. Transanal endoscopic microsurgery described by Beuss et al can produce good results. The authors have no experience with this technique. However, because of its expense, the need for specialized training, and the infrequency with which other transanal techniques are insufficient, we fail to see a significant role for its use. If use of this technique becomes more widespread, additional data regarding its value will become available. Posterior approaches offer no advantage for removal of tumors that can be excised by transanal techniques. Most tumors that require partial or complete rectal excision should be amenable to anterior or low anterior resection. Low anterior resection is a less morbid procedure with which most surgeons have a fairly extensive experience. For extremely large tumors that extend to the dentate line, coloanal anastomosis is appropriate. The functional results are acceptable compared with the alternative of abdominoperineal resection. Abdominoperineal resection should be reserved for those patients with a diagnosis of invasive carcinoma in whom a lesser procedure would not constitute adequate treatment.

Functional importance of the synaptic plasma membrane calcium pump and sodium-calcium exchanger.

Two major Ca2+ transport mechanisms co-function in a preparation of synaptosomal plasma membrane vesicles: an (ATP + Mg2+)-dependent Ca2+ pump, and a reversible Na+-Ca2+ exchanger (Gill, D. L., Grollman, E.F., and Kohn, L. D. (1981) J. Biol. Chem. 256, 184-192). An accurate comparative analysis of the kinetics of the two Ca2+ transporters under free Ca2+ conditions precisely buffered with EGTA, reveals that both mechanisms have high affinity for Ca2+. The ATP-dependent Ca2+ pump displays simple saturation kinetics with a Km for Ca2+ of 0.11 microM and a Vmax of 2.2 nmol/min/mg of protein. In contrast, the Na+-Ca2+ exchanger has a complex dependence on free Ca2+, the activity continuing to saturate over a wide range of free Ca2+ concentrations from 0.03 microM to 3 mM. The curvilinear Eadie-Hofstee analysis reveals a distinct high affinity component for the exchanger with a Km for Ca2+ of approximately 0.5 microM, and a lower affinity component not accurately resolvable into a discrete Km value. 2 mM amiloride blocks Na+-Ca2+ exchange-mediated Ca2+ uptake by 90% over a wide range of free Ca2+ (0.3-3000 microM), suggesting a similar noncompetitive inhibition of both low and high affinity Ca2+ sites. Ca2+ accumulated in vesicles via either the Ca2+ pump or Na+-Ca2+ exchanger is rapidly (in less than 1 min) released by 0.1% saponin (w/v), although a minor component (8-10%) of Ca2+ pump activity is resistant to saponin addition. The IC50 for the effect of saponin is the same (0.01%, w/v) for both Ca2+ transport mechanisms. The ATP-dependent Ca2+ pump is shown to be highly sensitive to vanadate inhibition (Ki = 0.5 microM). The high saponin sensitivity of both Ca2+ transporters and the potent effect of vanadate on Ca2+ pumping, together with previous Na+ channel and Na+ pump flux studies in the same membrane vesicles (Gill, D. L. (1982) J. Biol. Chem. 257, 10986-10990), all strongly suggest that both of the high affinity Ca2+ transporters function in the plasma membrane where they are of major functional importance to the regulation of intrasynaptic free Ca2+ levels.