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PubMedDate not supplied

Temperature dependence of canine brain tissue diffusion coefficient measured in vivo with magnetic resonance echo-planar imaging.

The intensity of conventional spin-echo diffusion-weighted magnetic resonance (MR) images is approximately linearly dependent on temperature over a restricted range using conventional diffusion-weighted spin-echo magnetic resonance imaging (MRI). However, conventional diffusion-weighted MRI is too motion sensitive for in vivo thermometry. The present work evaluated rapid diffusion-weighted echo-planar imaging (EPI), which is less sensitive to motion, for application to non-invasive thermometry in acrylamide gel materials and in vivo in canine brain tissue for applications in therapeutic hyperthermia. The rapidly switched, strong gradients needed for EPI were achieved using a 'local' z-axis gradient coil. Gel materials were heated with a small (10 cm diameter) spiral surface microwave (MW) applicator at 433 MHz, while in vivo heating was accomplished with whole body RF hyperthermia using an annular phased array (130 MHz). The MW or RF fields associated with heating and imaging (64 MHz) were decoupled using bandpass filters providing isolation in excess of 100 dB. This isolation was sufficient to allow simultaneous imaging and MW or RF heating without deterioration of the image signal-to-noise ratio. Using this system in a gel, temperature sensitivity of the diffusion coefficient was observed to be (3.04 +/- 0.03)%/degrees C which allowed temperature changes of 0.55 degrees C to be resolved for a 1.8 cm3 region in < 10 s of data acquisition. In vivo, cardiac gating of the pulse sequence was necessary to minimize motion artifacts in the brain. The temperature sensitivity of brain tissue was (1.9 +/- 0.1)%/degrees C allowing temperature changes of 0.9 degrees C to be resolved in a 0.9 cm3 volume in < 10 s of data acquisition. We conclude that with further optimization of the data acquisition conditions it will be possible to determine 0.5 degrees C temperature changes in 1 cm3 volumes in < 10 s using this technique.

Animals↗

PubMed1989

[Hanging survivor showing alpha coma--a case report].

A case of a survivor who showed alpha coma after an attempted suicide by hanging was reported. A 19 years old woman was admitted to the hospital because of respiratory arrest following a hanging attempt on October 10, 1987. She was found pendent completely. On admission she was comatose and the pupils were not reactive to light. The systolic blood pressure was 60 mmHg and immediately an endotracheal intubation was instituted. After six hours from the onset, the spontaneous respiration was restored and the pupils reacted briskly to light. At 48 hours later she was still comatose, presenting flaccid quadriplegia with no responses to stimulations. An EEG showed a moderate amount of regular, 8 approximately 10 Hz, 10 approximately 50 microV potentials distributed predominantly on the centro-parieto-occipital regions. This alpha rhythm had persisted until 72 hours from the onset, and subsequently diffuse 5 approximately 7Hz, 10 approximately 40 microV slow activity replaced the alpha frequency at 120 hours after the attempt. On the 5th hospital day the hyperbaric oxygen therapy was given and on the 7th day she had become conscious, but showed the apallic syndrome. The both auditory and somatosensory evoked potentials were normal. On the 45th day the brain MRI revealed diffuse cerebral cortical atrophy, although no lesions were visualized in the brain stem. She showed gradual progress towards neurologic recovery. This is the first presentation of a survivor from alpha coma caused by anoxic encephalopathy following a hanging attempt.

Adult↗

PubMed2003

[An autopsy case of encephalopathy associated with small cell carcinoma of the stomach with nonconvulsive status epilepticus resembling Creutzfeldt-Jakob disease].

A 64-year-old man developed progressive dementia and altered consciousness with myoclonus over 2 months. Neurological examination revealed mild dysphagia and negative myoclonus of both hands. Electroencephalography (EEG) showed continuous periodic synchronous discharge (PSD) of 1 Hz, although his EEG abnormality was not similar to that usually observed in Creutzfeldt-Jakob disease (CJD). Magnetic resonance imaging (MRI) of the brain revealed only few lacunes. Laboratory data were also normal. Since his consciousness level fluctuated and the PSD were spiky, we came to a diagnosis of nonconvulsive status epilepticus (NCSE). After administering the valproic acid, his symptoms and EEG finding improved. Nine months after the onset, despite his continued valproic acid, the patient had recurrent NCSE and PSD of 1 Hz. Diffusion-weighted MRI showed a T2-hyperintense lesion in the right parietal lobe, where SPECT scans showed hyperperfusion. After adding zonisamide, he improved slowly. The follow-up MRI and SPECT showed a disappearance of the previous lesion. Now CT scans of the abdomen showed enlarged periaortic lymph node and endoscopic ultrasonography disclosed a submucosal tumor of the stomach. Biopsy of the periaortic lymph node by laparotomy revealed undifferentiated adenocarcinoma with its origin being unclear. Chemotherapy didn't work well for the tumor and the patient underwent a downhill course, although his mental and neurological manifestation were mostly unremarkable. Two years and four months after the onset, he died in emaciation. Autopsy confirmed small cell carcinoma originating in the stomach and metastases in the liver and lungs. Neuropathological examination revealed only mild scattered gliosis. This case was unique in the prolonged CJD-like manifestations, which turned out to be due to NCSE. Despite anti-neuronal antibodies were not detected, we suspect yet another paraneoplastic brain syndrome in this patient.

Aged↗

PubMed2006

Relaxation and diffusion of perfluorocarbon gas mixtures with oxygen for lung MRI.

We report measurements of free diffusivity D(0) and relaxation times T(1) and T(2) for pure C(2)F(6) and C(3)F(8) and their mixtures with oxygen. A simplified relaxation theory is presented and used to fit the data. The results enable spatially localized relaxation time measurements to determine the local gas concentration in lung MR images, so the free diffusivity D(0) is then known. Comparison of the measured diffusion to D(0) will express the extent of diffusion restriction and allow the local surface-to-volume ratio to be found.

Data Interpretation, Statistical↗

PubMed1999

Progressive neurological deterioration and MRI changes in cblC methylmalonic acidaemia treated with hydroxocobalamin.

Cobalamin C (cblC) defects result in decreased activity of both methylmalonyl-CoA mutase and N5-methyltetrahydrofolate:homocysteine methyltransferase (methionine synthase), with subsequent methylmalonic acid-uria and homocystinuria. Patients typically show failure to thrive, developmental delay and megaloblastic anaemia. Vitamin B12 therapy has been beneficial in some cases. We report a now 4-year-old Hispanic girl with cblC disease documented by complementation analysis, with progressive neurological deterioration and worsening head MRI changes while on intramuscular hydroxocobalamin begun at age 3 weeks. Oral carnitine and folic acid were added at age 1 year. Blood levels of methylmalonic acid were reduced to treatment ranges. In the absence of acute metabolic crises, she developed microcephaly, progressive hypotonia and decreased interactiveness. Funduscopic examination was normal at age 13 months. At age 19 months, she developed nystagmus, and darkly pigmented fundi and sclerotic retinal vessels were observed on examination. Her neonatal head MRI was normal. By age 1 year, the MRI showed diffuse white-matter loss with secondary third and lateral ventricle enlargement, a thin corpus callosum, and normal basal ganglia. At age 15 months, progression of the white-matter loss, as well as hyperintense globi pallidi, were present. Interval progression of both grey- and white-matter loss was seen at age 27 months. We therefore caution that progressive neurological deterioration and head MRI abnormalities may still occur in cblC disease, despite early initiation of hydroxocobalamin therapy and improvement in toxic metabolite concentrations in physiological fluids.

Brain↗

PubMed1990

The use of magnetic resonance imaging in the diagnosis of pigmented villonodular synovitis.

Although the clinical and radiographic features of pigmented villonodular synovitis (PVS) have been well described, diagnosis is often delayed and high rates of recurrence after synovectomy are reported. Magnetic resonance imaging (MRI) has been shown to be useful in the diagnosis of soft tissue masses. Three patients with biopsy-proven PVS and radiographs showing only effusion underwent MRI in the axial, coronal, and sagittal planes. The margins of the diseased synovium were best demonstrated on long TR/TE (T2-weighted) images. The synovium contained areas of void signal intensity felt to be due to hemosiderin, interspersed with increased signal from both inflammation and fat. In all cases, the margins of the diseased synovium were clearly delineated, allowing classification as nodular or diffuse. No appreciable change in signal intensity was seen when comparing nodular and diffuse forms. MRI is useful but not specific for PVS, since rheumatoid synovitis may show a similar signal pattern. However, MRI in patients with suspected PVS may decrease the time until diagnosis, aid in preoperative planning and obtaining adequate margins of resection, and may be a non-invasive method of long-term follow up for possible recurrence.

Adolescent↗

PubMed2000

[Otogenic hypertrophic cranial pachymeningitis associated with edema of the temporal lobe and organic mental disorder-case report].

OBJECTIVE: Hypertrophic cranial pachymeningitis(HCP) is a rare disease which might be misdiagnosed. One typical case of otogenic hypertrophic cranial pachymeningitis (HCP) associated with edema of the temporal lobe and organic mental disorder was reported. Literatures associated with HCP were reviewed for reference. METHODS: In July, 1997, a 26-year-old man was admitted for right-sided severe headache, dizziness, nausea, vomiting, facial and abducens nerve palsy. MRI and CT revealed inflammation in the temporal bone and locally thickened dura mater with obvious enhancement as a band in the petrous apex and nearby tentorium cerebellum. The patient then underwent operation including decompression of the facial nerve, labyrinthectomy, and eradication of the inflammatory cells in the mastoid and petrous portion. Postoperatively, the clinical signs disappeared except hearing loss. Seven months later, the patient suffered from mental disorder with interrupted excitement to hit and abuse the family members. He was then treated in a psychosis hospital but no improvement could be seen. On May 13, 1998, MRI and the enhanced MRI demonstrated diffuse thickened tentorium cerebellum and dura mater in the middle cranial fossa. The inferior portion of the temporal lobe was obvious edema. The internal carotid artery was partially occluded due to the thickened wall of cavernous sinus. RESULTS: Hence, the diagnosis of HCP associated with edema of temporal lobe and organic mental disorder was established. The patient was cured by high dosage of penicillin. CONCLUSION: MRI is an essential method for diagnosis of HCP. Antibiotic was an effective treatment.

Adult↗

PubMed2007

Extracranial applications of diffusion-weighted magnetic resonance imaging.

Diffusion-weighted MRI has become more and more popular in the last couple of years. It is already an accepted diagnostic tool for patients with acute stroke, but is more difficult to use for extracranial applications due to technical challenges mostly related to motion sensitivity and susceptibility variations (e.g., respiration and air-tissue boundaries). However, thanks to the newer technical developments, applications of body DW-MRI are starting to emerge. In this review, we aim to provide an overview of the current status of the published data on DW-MRI in extracranial applications. A short introduction to the physical background of this promising technique is provided, followed by the current status, subdivided into three main topics, the functional evaluation, tissue characterization and therapy monitoring.

Animals↗

PubMed1994

[Hypomelanosis of Ito associated with hemimegalencephaly].

A girl aged 1 year and 2 months with hypomelanosis of Ito was reported. She suffered from intractable epileptic seizures since the second day after birth. Characteristic bizarre hypopigmented skin lesions were seen on her left shoulder and extended in a linear fashion to the flexion side of the left upper extremity. Brain MRI revealed diffuse enlargement of the left hemisphere, dilatation of the left lateral ventricle, and neuronal migration anomalies, indicating hemimegalencephaly. The types of her seizures were secondarily generalized or unilateral initially, followed by infantile spasms at 1.5 month. Around 4 months of age, frequent partial seizures appeared. Her seizures were intractable despite vigorous anticonvulsant therapy. As patients with hypomelanosis of Ito are frequently associated with neurological abnormalities, brain MRI studies were thought to be essential in detecting central nervous system anomalies, particularly in the presence of early onset intractable seizures.

Brain↗

PubMed2004

Identifying thresholds for penumbra and irreversible tissue damage.

Diffusion-weighted MRI (DWI) in combination with perfusion-weighted MRI (PWI) has become a widely accepted modality for the selection of patients amenable for acute therapy, if a mismatch between these procedures suggests viable penumbral tissue. However, DWI as well as PWI yields semiquantitative measures limiting the definitions of irreversible damage and of potentially viable penumbral tissue. These limitations of PWI/DWI may be better understood if findings in individual patients are compared with the results from measurements of blood flow, oxygen metabolism, and benzodiazepine receptor binding obtained with positron emission tomography (PET). Comparative studies with PET and MRI were performed in 3 groups of patients: (1) In 12 acute stroke patients, results from DWI (median, 6.5 hours after symptom onset) and 11C-flumazenil (FMZ) PET (median, 85 minutes between DWI and PET) were compared with infarct extension 24 to 48 hours later on T2-weighted MRI. (2) In 11 acute stroke patients, results from PWI (median, 8 hours after symptom onset) were compared with cerebral blood flow measurements obtained with [15O]H2O PET (interval, 60 minutes between PWI and PET). (3) In 10 patients with acute (n=5) or chronic stroke (n=5), results from PWI/DWI were compared with PET of cerebral blood flow and oxygen consumption to detect mismatch or increased oxygen extraction fraction as surrogate markers of penumbra. Results were: (1) from regions with increased DWI intensity, decreased apparent diffusion coefficient (ADC) and decreased FMZ binding probability curves were computed for eventual infarction, and 95% prediction limits were determined. These limits predicted 83.5% (FMZ), 84.7% (DWI), and 70.9% (ADC) of the final infarct volume. However, the false-positive predictions were much higher for the DWI variables (5.1 and 3.6 cm3 for DWI and ADC versus a median of 0 for FMZ). (2) The comparison of volumes generated by different time to peak (TTP) thresholds (PWI) and hypoperfusion <20 mL/100 g per minute (PET) indicates that a TTP delay of 4 to 6 seconds yields a fair estimate of hypoperfusion. (3) The PWI/DWI mismatch with TTP >4 seconds did not reliably correspond to the penumbra as assessed by PET (oxygen extraction fraction >150%). Only 6 of 10 patients with a mismatch had areas of penumbra. In these cases, the penumbra volume was overestimated by MRI. DWI correlates with FMZ results and, with a few exceptions, yields a good estimate of acute tissue damage and final infarct volume. PWI measures seem to be less reliable; the TTP prolongation of >4 seconds assessed only 83% of the volume of hypoperfusion <20 mL/100 g per minute. The mismatch volume imprecisely depicts increased oxygen extraction fraction, and, despite its clinical role for selection of patients for eventual therapy, it does not to seem to be a reliable correlate of penumbra.

Adult↗

PubMed1999

Decompressive craniectomy, reperfusion, or a combination for early treatment of acute "malignant" cerebral hemispheric stroke in rats? Potential mechanisms studied by MRI.

BACKGROUND AND PURPOSE: Both early reperfusion and decompressive craniectomy have proved beneficial in the treatment of large space-occupying "malignant" hemispheric stroke. The aim of this study was to directly compare the benefit of reperfusion with that of craniectomy and to study the effects of combined treatment in a rat model of focal cerebral ischemia. METHODS: Cerebral ischemia was introduced in 28 rats. Four groups were investigated: (1) no treatment, (2) decompressive craniectomy, (3) reperfusion, and (4) reperfusion and craniectomy as treatment at 1 hour after middle cerebral artery occlusion. Perfusion- and diffusion-weighted MRI were performed serially from 0.5 to 6 hours after middle cerebral artery occlusion. RESULTS: The 6-hour DWI-derived hemispheric lesion volumes in the reperfusion group (10.2+/-3.9%), the craniectomy group (23.0+/-6.4%), and the combination group (21.8+/-12.4) were significantly smaller than that in the control group (44.1+/-5.4%) (P<0.05). Reperfusion, craniectomy, and combined treatment led to higher perfusion in the cortex compared with the control group, whereas only reperfused animals achieved significantly higher perfusion in the basal ganglia. In 5 animals, combined reperfusion and decompressive craniectomy resulted in an early contrast media enhancement. CONCLUSIONS: Early reperfusion and craniectomy were shown to be effective in decreasing infarction volume by improving cerebral perfusion. Reperfusion remains the best therapy in malignant hemispheric stroke. Combined treatment yields no additional benefit compared with single treatment, probably because of early blood-brain barrier breakdown.

Acute Disease↗

PubMed2002

Comparative diagnostic utility of 1H MRS and DWI in evaluation of temporal lobe epilepsy.

OBJECTIVE: To compare the ability of diffusion-weighted MRI (DWI) and (1)H MRS to lateralize to the temporal lobe of seizure onset and to predict postoperative seizure control in patients with temporal lobe epilepsy (TLE). METHODS: Forty TLE patients who subsequently underwent epilepsy surgery and 20 normal subjects were studied with (1)H MRS and DWI. Medial parietal and temporal lobe N-acetylaspartate (NAA)/creatine (Cr) ratios and hippocampal and temporal stem apparent diffusion coefficients (ADC) were obtained. Lateralization to either temporal lobe with each MR measurement was based on the threshold values derived from +/-1-SD right/left ratios of normal subjects. RESULTS: Temporal lobe NAA/Cr lateralized to the operated temporal lobe in 18 of 40 (45%), hippocampal ADC in 32 of 40 (80%), and temporal stem ADC in 26 of 40 (65%) patients. Almost all of the cases that lateralized to the surgical side with NAA/Cr ratios (94%) had an excellent postoperative seizure control (p = 0.01). Lateralization to the side of surgery was not associated with surgical outcome with hippocampal and temporal stem ADC (p > 0.05). CONCLUSION: (1)H MRS and DWI complement each other in the clinical setting. DWI more frequently lateralized to the operated side, and (1)HMRS was a better predictor of postoperative seizure control.

Adolescent↗

PubMed1993

Early detection of regional cerebral ischemia using high-speed MRI.

BACKGROUND AND PURPOSE: Diffusion-weighted magnetic resonance imaging (MRI) has been shown to be effective in detailing regions of cerebral ischemia in which water proton translations or motions have been slowed. The corresponding perfusion patterns, however, have not been correlated. Further, the hemodynamics of normal and ischemic tissues and the changes due to mild insults are also not clear. This study describes high-speed MRI techniques and observations found in the early detection of regional cerebral ischemia in the cat. METHODS: Gradient-echo and spin-echo-planar MRI was used with middle cerebral artery balloon occluders to induce transient ischemia and reperfusion. RESULTS: Apparent diffusion fell within minutes after middle cerebral artery occlusion and correlated with near-total or total perfusion deficits. Reactive hyperemia, apnea, and vasodilatation appeared to be changed in ischemic and normal brain. CONCLUSIONS: Characterization of early ischemic events is dramatically improved when the motions of water (apparent diffusion), delivery of water (perfusion), and response to hemodynamic perturbations (regulatory response) are measured. All can be accomplished with high-speed MRI techniques described herein.

Animals↗

PubMed2004

MRI characteristics of sporadic CJD with valine homozygosity at codon 129 of the prion protein gene and PrPSc type 2 in Japan.

Two Japanese sporadic Creutzfeld-Jakob disease (sCJD) patients with valine homozygosity at codon 129 of the prion protein gene and protease-resistant prion protein (PrP(Sc)) type 2 (VV2) are described. In contrast with Western countries, this type of sCJD is very rare in Japan. In 123 sCJD cases, only two were recognised as VV2 by the Japanese CJD surveillance committee. The clinical symptoms and pathological findings of the patients were similar to those of European and US patients. The noteworthy finding of diffusion weighted MRI (DWI) was that an abnormal high intensity covered a wide range of the thalamus including the dorsomedial nucleus, the pulvinar, and the ventral anterior, lateral, and posterolateral nuclei. This thalamic pattern has not been recognised in sCJD with methionine homozygosity and PrP(Sc) type 1 (MM1) or methionine/valine heterozygosity and PrP(Sc) type 1 (MV1) which comprises the vast majority of sCJD. This finding may be characteristic to VV2 and may distinguish it from MM1, MV1, and variant CJD. DWI can provide a very important clue for the antemortem diagnosis of VV2 subjects.

Aged↗

PubMed2001

[A case of recurrent ischemic attacks: consecutive diffusion-weighted magnetic resonance imaging].

A 61-year-old man with recurrent ischemic attacks was examined by diffusion-weighted MRI (DWI). He had reversible right hemiparesis and dysarthria five times during admission. DWI was obtained on the first two attacks, the last attack and four days after the last attack. The first two attacks were clinically diagnosed as transient ischemic attack (TIA), and the last attack was cerebral infarction with symptoms persistent for one week with Babinski's sign. In the first and last images the apparent diffusion coefficient (ADC) declined to approximately 80% of the corresponding area. We conclude that different images showed TIA with ADC declining, TIA without ADC declining, the hyperacute phase of cerebral infarction before ADC declining, and cerebral infarction after ADC declining. Consecutive DWIs were helpful to understand the character of recurrent ischemic attacks.

Brain↗

PubMed2002

Appropriate neurological evaluation and multimodality magnetic resonance imaging in eclampsia.

HYPOTHESIS: Simultanagnosia is common in eclampsia and a visuospatial test may be the most appropriate method in assessing the degree and monitoring of neurological deficit. AIM: To determine a sensitive clinical test for the degree of neurological deficit in eclampsia and in monitoring neurological change. METHODS: Thirty women with eclampsia were evaluated by clinical neurological quantitative scales including the Canadian Neurological Scale, Glasgow Coma Scale, Mini-Mental State Examination, a validated Cookie Theft Picture Test (CTPT), magnetic resonance imaging (MRI) (T1/T2), diffusion weighted imaging (DWI) and magnetic resonance angiography (MRA). RESULTS: The CTPT, used to measure simultanagnosia, had a sensitivity of 100% (95% CI: 84.5-100), specificity of 33.3% (95% CI: 1.8-87.5) with positive predictive value of 93.1% (95% CI: 75.8-98.8) and negative predictive value of 100% (95% CI: 5.5-100). The degree of agreement between simultanagnosia as measured by CTPT and DWI was 93.3% (Kappa=0.474; P=0.001). Standard MRI compared with DWI had a sensitivity of 77.8% (95% CI: 57.3-90.6), specificity of 100% (95% CI: 31-100), positive predictive value of 100% (95% CI: 80.8-100) and negative predictive value of 33.3% (95% CI: 9-69.1). The degree of agreement between standard MRI and DWI was 90%, this was statistically significant (Kappa=0.412: P=0.001). CONCLUSIONS: The validated CTPT for simultanagnosia was abnormal in the majority (n=29; 96.7%) of eclamptic patients with other neurological scales normal. Standard MRI and DWI showed excellent correlation with this simple bedside clinimetric evaluation. The oedema in eclampsia is primarily of vasogenic origin.

Adolescent↗

PubMed1995

Nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester decreases ischemic damage in reversible focal cerebral ischemia in hyperglycemic rats.

We tested the hypothesis that the exacerbation of post-ischemic brain tissue injury associated with hyperglycemia in rats is due to toxic metabolism of nitric oxide. We used magnetic resonance imaging (MRI) techniques to measure neuronal and cerebrovascular injury in a 2-h transient focal cerebral ischemia model in normoglycemic and hyperglycemic rats at 3 and 24 h post-ischemia onset. We determined the effect of low dose (3 mg/kg i.p.) treatment with the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME). Compared to normoglycemia, preexisting hyperglycemia increased the volume of brain tissue exhibiting hyperintensity in diffusion weighted MRI (DWI) by factors of 5.6 and 6.2 at 3 h and 24 h post-ischemia, respectively. A similar increase in tissue volumes exhibiting hyperintense signal in T2-weighted MRI (T2WI) (3.3-fold and 5.6-fold) was observed. Cerebral blood volume MRI indicated a large focal no-reflow zone in hyperglycemic rats. Treatment with L-NAME eliminated the no-reflow zone in the hyperglycemic rats, and reduced tissue volumes of DWI hyperintensity by 86% and 93% at 3 h and 24 h, respectively. Similarly, tissue volumes of T2WI hyperintensity were reduced by 80% and 94% at 3 h and 24 h, respectively. Thus, nitric oxide is an important mediator in the exacerbation of post-ischemic brain injury in hyperglycemic rats. Inhibition of nitric oxide synthase limits edema formation, improves perfusion and reduces infarct volume.

Animals↗

PubMed2005

PASTA: pointwise assessment of streamline tractography attributes.

Diffusion tensor MRI tractography aims to reconstruct noninvasively the 3D trajectories of white matter fasciculi within the brain, providing neuroscientists and clinicians with a potentially useful tool for mapping brain architecture. While this technique is widely used to visualize white matter pathways, the associated uncertainty in fiber orientation and artifacts have, to date, not been visualized in conjunction with the trajectory data. In this work, the bootstrap method was used to determine the distributions of diffusion indices such as trace and anisotropy, together with the uncertainty in fiber orientation. A novel visualization scheme was developed to encode this information at each point along reconstructed trajectories. By integrating these schemes into a graphical user interface, a new tool which we call PASTA (Pointwise Assessment of Streamline Tractography Attributes) was created to facilitate identification of artifacts in tractography that would otherwise go undetected.

Brain Mapping↗