MR Imaging Changes Research Articles

Hyperthermically induced changes in high spectral and spatial resolution MR images of tumor tissue—a pilot study

This pilot study investigated the feasibility of using MRI based on BOLD (blood–oxygen-level-dependent) contrast to detect physiological effects of locally induced hyperthermia in a rodent tumor model. Nude mice bearing AT6.1 rodent prostate tumors inoculated in the hind leg were imaged using a 9.4 T scanner using a multi-gradient echo pulse sequence to acquire high spectral and spatial resolution (HiSS) data. Temperature increases of approximately 6 °C were produced in tumor tissue using fiber-optic-guided light from a 250 W halogen lamp. HiSS data were acquired over three slices through the tumor and leg both prior to and during heating. Water spectra were produced from these datasets for each voxel at each time point. Time-dependent changes in water resonance peak width were measured during 15 min of localized tumor heating. The results demonstrated that hyperthermia produced both significant increases and decreases in water resonance peak width. Average decreases in peak width were significantly larger in the tumor rim than in normal muscle (p = 0.04). The effect of hyperthermia in tumor was spatially heterogeneous, i.e. the standard deviation of the change in peak width was significantly larger in the tumor rim than in normal muscle (p = 0.005). Therefore, mild hyperthermia produces spatially heterogeneous changes in water peak width in both tumor and muscle. This may reflect heterogeneous effects of hyperthermia on local oxygenation. The peak width changes in tumor and muscle were significantly different, perhaps due to abnormal tumor vasculature and metabolism. Response to hyperthermia measured by MRI may be useful for identifying and/or characterizing suspicious lesions as well as guiding the development of new hyperthermia protocols.

Abstract No. 238: Volumetric functional imaging biomarkers of early treatment response and survival to locoregional therapies in hepatocellular carcinoma: a single center survival study in a 141 patient cohort

To evaluate the ability of volumetric functional MR imaging changes in diffusion weighted (DWI) and contrast enhancement (CE-MR) to predict early (3-4 weeks) response to locoregional therapy (LRT) in hepatocellular carcinoma (HCC). Also, to compare volumetric imaging response to biochemical response (AFP) and to current excising anatomic response criteria (RECIST, EASL, mRECIST, Volumetrics).

MRI FLAIR Changes in Total Resection of Olfactory Groove Meningiomas through Expanded Endonasal Endoscopic Approaches

Background: olfactory groove meningiomas can grow insidiously and significantly compress the adjacent cerebral structures. One of the main challenges in their surgical management is achieving complete removal without further damage to the frontal lobes. Objective: The purpose of this study is to analyze and describe cerebral edema and FLAIR signal changes in MR imaging of olfactory groove meningiomas totally resected through EEA. Methods: Pre- and postoperative films of 20 consecutive olfactory groove meningiomas completely removed through EEA were reviewed. Tumor volume as well as pre- and postoperative FLAIR signal change volumes, was assessed using the DICOM image viewer OsiriX. Results: Mean tumor volume was 26.2 cm3 (±22.7), mean preoperative FLAIR change volume was 39.1 cm3 (±44.9), and mean postoperative FLAIR change volume was 4.2 cm3 (±5.9). In1 of the 20 cases analyzed (5%) there was increase of signal changes postoperatively, all other patients demonstrated image improvement. Conclusions: EEA appears to be a safe and effective method for total removal of olfactory groove meningiomas. FLAIR signal changes tend to resolve after tumor resection and do not seem to worsen with this operative technique. Further comparative studies are necessary to determine whether this feature differs from open approaches.

Serial MRI Features of Canine GM1 Gangliosidosis: A Possible Imaging Biomarker for Diagnosis and Progression of the Disease

GM1 gangliosidosis is a fatal neurodegenerative lysosomal storage disease caused by an autosomal recessively inherited deficiency of β-galactosidase activity. Effective therapies need to be developed to treat the disease. In Shiba Inu dogs, one of the canine GM1 gangliosidosis models, neurological signs of the disease, including ataxia, start at approximately 5 months of age and progress until the terminal stage at 12 to 15 months of age. In the present study, serial MR images were taken of an affected dog from a model colony of GM1 gangliosidosis and 4 sporadic clinical cases demonstrating the same mutation in order to characterize the MRI features of this canine GM1 gangliosidosis. By 2 months of age at the latest and persisting until the terminal stage of the disease, the MR findings consistently displayed diffuse hyperintensity in the white matter of the entire cerebrum on T2-weighted images. In addition, brain atrophy manifested at 9 months of age and progressed thereafter. Although a definitive diagnosis depends on biochemical and genetic analyses, these MR characteristics could serve as a diagnostic marker in suspect animals with or without neurological signs. Furthermore, serial changes in MR images could be used as a biomarker to noninvasively monitor the efficacy of newly developed therapeutic strategies.

Chronic granulomatous herpes encephalitis: a rare entity posing a diagnostic challenge

Herpesviruses can cause an acute, subacute, or chronic disease state in both immunocompetent and immunocompromised individuals. Herpes simplex virus (HSV) encephalitis is most often an acute monophasic disease process. Rarely, however, it may progress to a chronic state, and more rarely still to a granulomatous encephalitis. Prior studies have suggested that antiviral immunity with Toll-like receptors determines susceptibility to herpesviruses. The authors report the case of a 14-year-old girl with a remote history of treated HSV encephalitis, who had intractable seizures and worsening MR imaging changes that were concerning for either a neoplastic or an inflammatory process. She was found to have granulomatous herpes simplex encephalitis and had a low cytokine response to Toll-like receptor 3 stimulation.

Association of magnetic resonance imaging signal changes and outcome prediction after surgery for cervical spondylotic myelopathy

Few studies have evaluated the prognostic significance of different types of T2-weighted MR imaging changes in patients with cervical spondylotic myelopathy (CSM). The object of this study was to determine whether the type of increased signal intensity (ISI) was an independent predictor of outcome following central corpectomy in patients with CSM or ossification of the posterior longitudinal ligament (OPLL). Magnetic resonance images obtained in 197 patients who had undergone central corpectomy for CSM or OPLL were assessed for ISI within the cord on sagittal T2-weighted images and hypointensity on T1-weighted images. The T2-weighted changes were categorized as no change (Type 0), fuzzy (Type 1), or sharp (Type 2) based on the ISI characteristics. Outcomes were assessed as a change in Nurick grade of 1 grade or more from preoperatively to postoperatively, and cure as a follow-up Nurick grade of 0 or 1. Multilevel regression analysis was performed to identify predictors of change in Nurick grade ≥ 1 and cure. There were 30 patients (15.2%) with Type 0, 104 patients (52.8%) with Type 1, and 63 patients (32%) with Type 2 ISI on MR images. Age, duration of symptoms, and preoperative Nurick grade were similar among the groups. A preoperative Nurick grade of 4 or 5 (OR 0.23, p < 0.001) and presence of Type 2 ISI on T2-weighted images (OR 0.48, p = 0.04) negatively influenced the probability of cure after surgery. Hypointensity on T1-weighted images was only seen in patients who had Type 2 ISI changes. Among the 63 patients with Type 2 ISI, the presence of T1-weighted hypointensity (16 patients) was found to negatively impact cure (OR 0.1, p = 0.04). Increased signal intensity on preoperative T2-weighted MR images was seen in more than 80% of the cases. However, only Type 2 ISI on T2-weighted images had a prognostic significance of being associated with a decreased likelihood of cure in patients with CSM or OPLL. Hypointensity on T1-weighted images predicted a lower probability of cure among patients with Type 2 ISI on T2-weighted images.

A Comprehensive Review of MR Imaging Changes following Radiosurgery to 500 Brain Metastases

Stereotactic radiosurgery is known to control 85%-95% of intracranial metastatic lesions during a median survival of 6-8 months. However, with the advent of newer systemic cancer therapies, survival is improving; this change mandates a longitudinal quantitative analysis of the radiographic response of brain metastases to radiosurgery. MR imaging of 516 metastases in 120 patients treated with GK-SRS from June 2006 to December 2009 was retrospectively reviewed. Lesion volume at initial treatment and each follow-up was calculated by using the following formula: length × width × height / 2. Volume changes were correlated with patient demographics, histopathology, and radiation treatment variables. Thirty-two percent of lesions increased in volume following radiosurgery. Clinically, this translated into 54% of patients having ≥1 of their lesions increase in size. This increase begins at 6 weeks and can last beyond 15 months' post-SRS. Male sex (P = .002), mean voxel dose <37 Gy (P = .009), and initial treatment volume >500 mm(3) (P < .001) are associated with posttreatment increases in tumor size. Median survival following radiosurgery was 9.5 months for patients with all lesions exhibiting stable/decreased volumes, >18.4 months for patients with all lesions exhibiting increased volumes, and 16.4 months for patients with mixed lesional responses. Most metastatic lesions are stable or smaller in size during the first 36 months post-SRS. However, a transient increase in volume is seen in approximately one-third of lesions. Sex, treatment dose, initial lesion size, and histopathology all correlate with variations in lesion volume post-SRS. The longer the patient survives, the more likely an increase in lesion size will be seen on follow-up imaging.

Magnetic resonance imaging findings in treated spinal dural arteriovenous fistulas: lack of correlation with clinical outcomes

Little information is available on follow-up MR imaging after treatment of spinal dural arteriovenous fistulas (DAVFs). The authors studied MR imaging findings in treated spinal DAVFs in relation to clinical outcomes. A retrospective review of patients with spinal DAVFs who had undergone both pre- and postoperative spinal MR imaging was conducted. Postoperative MR images were obtained as routine follow-up studies or because of subjective or objective clinical deterioration. Several pre- and posttreatment MR imaging characteristics were evaluated by 2 neuroradiologists blinded to the clinical outcome. Clinical outcomes of motor, sensory, and urinary function (in relation to the patient's preoperative status) at the time of the postoperative MR imaging were obtained from the clinical record. The chi-square, Fisher exact, and rank-sum tests were performed to correlate imaging findings and changes with clinical outcomes. Thirty-four patients met inclusion criteria. Treatment was surgical in 33 patients and endovascular in 1 patient. Follow-up MR imaging was performed at a mean 168 ± 107 days after treatment. Twenty-seven patients (79.4%) were either clinically stable or improved, and 7 (20.6%) experienced worsening in one or more clinical outcomes. Most patients were found to have improvement of MR imaging changes. However, some degree of persistent spinal cord signal abnormality, enhancement, and swelling was observed in 31 (91.2%), 29 (85.3%), and 18 (52.3%) patients, respectively. Changes in these MR imaging characteristics compared with preoperative MR imaging did not correlate with clinical outcomes (p > 0.05), with the one exception of a significant correlation between change in urinary function and extent of spinal cord contrast enhancement (p = 0.026), a correlation of uncertain importance. Ten of the 34 patients underwent posttreatment digital subtraction angiography, and 3 of these patients had recurrent/residual DAVFs. Worsening of motor function significantly correlated with recurrent/residual DAVF (p = 0.053). Spinal cord abnormalities persist on postoperative MR imaging studies in patients with treated spinal DAVFs, and although they tend to mildly improve with time, these changes may not correlate with clinical outcomes. However, regardless of imaging findings, worsening motor function may correlate with a recurrent or residual DAVF.

Sequential follow-up MR studies of hepatocellular carcinoma after radio-frequency ablation

Objective To describe the characteristic MR appearances in hepatocellular carcinoma after radiofrequency ablation (RFA) during follow-up studies. Methods MR images of 110 patients with hepatocellular carcinoma after RFA ,which were categorized into 3 MR examination intervals ( ≤48 h, 1-6 m, ＞6 m), were analyzed retrospectively. The sequential changes of MR images were assessed and compared using Chi-square test. Results All RFA areas of 110 patients typically exhibited hyperintensity on GRE-T1 WI and hypointensity on TSE-T2 WI with fat suppression within 48 h after ablation. Subsequently,the signal intensities of the RFA areas decreased on GRE-T1 WI which showed significant differences after 6 months( P ＜0. 015 ). On GRE-T1 WI , RFA lesions were hyperintense in 72, iso-or hypo-intense in 4 at 1-6 months and hyperintense in 60, iso-or hypo-intense in 17 after 6 months. On TSE-T2 WI, 65 RFA lesions were hypointense, 11 isointense at 1-6 months and 47 were hypointense, 30 isointense after 6 months. The increased intensity on TSE-T2 WI showed significant differences after 6 months( P ＜ 0. 015 ).On contrast-enhanced MR images, RFA lesions showed peripheral rim of enhancement within 48 h and exhibited a tendency to show no enhancement ( n = 37 at 16 months and n = 63 after 6 months ) with significant differences between MR examination intervals( P ＜ 0. 015 ). In 6 patients with residual tumor or local tumor progression, nodular lesions were found at the periphery of the RFA. These nodular lesions showed moderate to marked enhancement as well as hypointense signal on GRE-T1WI, and moderate hyperintense signal on TSE-T2WI. Conclusion MR imaging could depict the characteristics of coagulative necrosis of tumor, residual tumor or local tumor progression in patients with hepatocellular carcinoma after RFA therapy. Key words: Liver neoplasms; Catheter ablation; Magnetic resonance imaging

Quality-of-life outcomes after Gamma Knife surgery for trigeminal neuralgia

Gamma Knife surgery (GKS) is an important part of the neurosurgical armamentarium for treatment of patients with trigeminal neuralgia (TN) and is regarded as the first-line treatment in patients with TN who have serious medical comorbidities. In this study, the authors investigated the efficacy of GKS on TN in patients with serious medical comorbidities. Between May 2004 and September 2007, 52 severely ill patients who also had TN with Barrow Neurological Institute (BNI) facial pain scores of IV or V were entered into this study. The patients' medical records and imaging findings were reviewed by an anesthesiologist and neurosurgeons to determine whether GKS was a reasonable approach to palliate the patient's pain. All patients underwent GKS, in which a maximum dose of 80 Gy was targeted to the trigeminal nerve with or without plugging to keep the dose received by the brainstem at less than 16 Gy. After treatment, every patient had clinical follow-up every 1-3 months and filled out questionnaires designed to assess BNI facial pain and numbness scores, visual analog scale scores, and 36-Item Short Form Health Survey (SF-36) scores every 3 months until the end of the study. Statistical analysis was performed to find favorable prognostic factors related to pain relief and changes in quality of life. The median age of the patients was 71 years, and the male/female ratio was 30:22. The median follow-up period was 54 months (at least 2 years). All patients had a positive initial response to GKS, with BNI facial pain scores at least 1 point less than respective pre-GKS scores. Three patients (5.7%) obtained BNI facial pain Score I. Twenty-three patients (44.2%) experienced pain recurrence at a median follow-up of 33 months. One patient suffered from angina and required time in an intensive care unit; another patient had bleeding from a pin wound that required suturing. Alterations in BNI scores were highly correlated to visual analog scale scores (R(2) = 0.978). In both univariate and multivariate analyses, a decreased BNI facial pain score at different time points was significantly (p < 0.05) related to younger patient age, no previous treatment, evidence of vessel compression on MR imaging, time of first GKS ≤ 24 months, physical function (SF-36), role limitation due to a physical problem (SF-36), role limitation due to an emotional problem (SF-36), mental health (SF-36), social functioning (SF-36), bodily pain (SF-36), and general health (SF-36), but was not related to vitality (SF-36). Five patients (9.6%) experienced facial numbness at a mean of 13.2 ± 3.1 months after GKS (4 patients with BNI facial numbness Score II and 1 with BNI facial numbness Score III). Post-GKS MR imaging changes, including focal contrast enhancement or T2-weighted signal alterations, were identified in 3 patients (5.7%). Gamma Knife surgery produced significant pain relief in severely ill patients who had TN without causing appreciable morbidity. The effect of reduced pain significantly paralleled an improvement in SF-36 quality-of-life indices.

Brain MR Imaging and1H-MR Spectroscopy Changes in Patients with Extrahepatic Portal Vein Obstruction from Early Childhood to Adulthood

MR imaging and (1)H-MR spectroscopy changes are well reported in cirrhotic patients, whereas they are inadequately reported in EHPVO. The aim of this study was to investigate age-related changes in brain MR imaging and metabolite profile in EHPVO with and without MHE and to explore any correlation of imaging and (1)H-MR spectroscopy parameters with blood ammonia. Sixty-three patients with EHPVO (children, 7-12 years [n = 22], adolescents, 13-18 years [n = 15] and adults, 19-41 years [n = 26]) and 47 healthy age/sex-matched volunteers were studied. Neuropsychological tests, MR imaging, (1)H-MR spectroscopy, and blood ammonia estimation were performed in all subjects. Of 63 EHPVO patients, 25 (40%) who had MHE showed significantly increased MD, Glx, and blood ammonia in all 3 age groups; however, myo-inositol was significantly lower only in adults when compared with controls. MD positively correlated with blood ammonia and Glx in all age groups. Brain choline levels were normal in all patients with different age groups. Increases in brain MD, Glx, and blood ammonia were associated with MHE in all age groups. Normal brain choline in EHPVO signifies healthy liver and may serve as a diagnostic marker for its differentiation from cirrhosis-induced encephalopathy. Significant decrease of myo-inositol in adults is probably due to cellular osmoregulation secondary to long-standing hyperammonemia.

Changes of renal blood flow after ESWL: Assessment by ASL MR imaging, contrast enhanced MR imaging, and renal resistive index

The annual incidence of stone formation is increased in the industrialised world. Extracorporeal shockwave lithotripsy is a non-invasive effective treatment of upper urinary tract stones. This study is aimed to evaluate changes of renal blood flow in patients undergoing extracorporeal shock wave lithotripsy (ESWL) by arterial spin labeling (ASL) MR imaging, contrast enhanced dynamic MR imaging, and renal resistive index (RI). Thirteen patients with nephrolithiasis were examined using MR imaging and Doppler ultrasound 12 h before and 12 h after ESWL. ASL sequence was done for both kidneys and followed by contrast enhanced MR imaging. In addition RI Doppler ultrasound measurements were performed. A significant increase in RI ( p < 0.001) was found in both treated and untreated kidneys. ASL MR imaging also showed significant changes in both kidneys ( p < 0.001). Contrast enhanced dynamic MR imaging did not show significant changes in the kidneys. ESWL causes changes in RI and ASL MR imaging, which seem to reflect changes in renal blood flow.

Spontaneous spinal subarachnoid hemorrhage associated with subdural hematoma at different spinal levels

We describe the clinical features and MR-imaging findings of spontaneous spinal subarachnoid hemorrhage located in the lumbar spine associated with subdural hematoma at a higher, thoracic level in a 66-year-old man without neurological deficit. The sequential MR-imaging changes of hemorrhage at various stages in its evolution are portrayed. The possible pathogenetic mechanism for these very unusual, combined hemorrhages in both spinal compartments is discussed.

A new score for assessing white matter changes in metachromatic leukodystrophy

Metachromatic leukodystrophy (MLD) is a neurodegenerative disorder interfering with sulfatide degradation. A late-infantile form can be distinguished from juvenile and adult forms. The aim of this project was the establishment of an objective score for describing changes in MR-imaging on the basis of previous attempts to describe such changes in adrenoleukodystrophy (Loes, 2003). It is not aimed at aiding in the initial diagnostic but should rather reliably describe the changes over time, as now, with bone marrow transplantation, a therapeutic option is available.

MR imaging changes in the trochanteric area of asymptomatic individuals: A potential for misdiagnosis of pain in the trochanteric region

Objective To investigate the MR imaging appearance of the trochanteric region in a group of patients referred for non-musculoskeletal conditions. Materials and methods Forty-five patients ( n = 90 hips) referred for non-musculoskeletal conditions were imaged with a coronal T1 weighted fat saturated sequence after intravenous administration of contrast medium. Findings were interpreted by consensus of two experienced radiologists. Results In 54 of 90 hips (60%) no signal changes were seen at the level of the greater trochanter. A linear area of contrast enhancement with a craniocaudal dimension of less than 3 cm, and thickness less than 0.3 cm was seen in 32 of 90 hips (35.6%). A fusiform area of contrast enhancement with a craniocaudal dimension of more than 3 cm, and thickness more than 0.3 cm was seen in 4 hips (4.4%). Conclusion An area of signal abnormality may be seen on contrast enhanced studies in asymptomatic persons, located in between the gluteus medius tendon and iliotibial band, and this should not be considered as a cause of pain in the trochanteric region.

Steroid-Responsive Encephalopathy Associated with Autoimmune Thyroiditis Presenting with Diffusion MR Imaging Changes: Fig 1.

Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT) presents with focal or diffuse nonenhancing MR imaging abnormalities in 50% of patients with SREAT during subacute exacerbation. Vasculitic changes in biopsy studies as well as the elevation of antithyroid antibodies and CSF protein suggests an inflammatory cause. We report the case of a patient with SREAT with changes on diffusion-weighted MR imaging, which improved with corticosteroid therapy and plasmapheresis, supporting the theory of inflammatory changes in exacerbation of presumptive SREAT.

Incidental Acute Infarcts Identified on Diffusion-Weighted Images: A University Hospital-Based Study: Fig 1.

Pathogenesis of leukoaraiosis is incompletely understood and accumulation of small infarctions may be one of the possible sources of such white matter lesions. Thus, the purpose of this study was to identify the rate of incident infarction as depicted on diffusion-weighted images (DWIs) obtained from a general patient population. During the 4-year study period, a total of 60 patients (36 men and 24 women) had an incidental DWI-defined infarction without overt clinical symptoms suggestive of a stroke or a transient ischemic attack. All of the MR images were obtained by using a similar protocol on 2 identical 1.5T whole-body scanners. The patient's vascular risk factors, as well as the presence of white matter lesions (WMLs) on MR imaging and atheromatous changes on MR angiography, were assessed retrospectively. The incidental DWI-defined infarcts were also characterized in terms of their lateralization, lobe, and specific location. A total of 16,206 consecutive brain MR images were done during the study period; the overall incidence of incidental infarcts was 0.37%. Most of these patients with an incidental infarct had vascular risk factors and WMLs on MR images. Most of these patients (80%) had a single lesion on DWI. A total of 88 lesions were identified; most were located in the white matter of the supratentorial brain, primarily in the frontoparietal lobes. There were also lesions involving the brain stem (n = 2). The lesions involving cerebrum were more commonly located in the right side (right to left = 52:34). Small, DWI-defined acute brain infarctions can be found incidentally in an asymptomatic population; this finding may account, at least in part, for the pathogenesis of WMLs identified on MR imaging.

Contribution of diffusion tensor MR imaging in detecting cerebral microstructural changes in adults with neurofibromatosis type 1.

After an early progression of signal intensity changes in T2-weighted MR images, also known as "neurofibromatosis bright objects," in patients with neurofibromatosis type 1 (NF-1), there is a tendency toward regression or even disappearance in early adulthood. The purpose of this study was to investigate whether adult patients with NF-1 exhibit generalized microstructural alterations even in normal-appearing brain regions. Conventional and diffusion tensor MR imaging of the brain was obtained in 10 adult patients with NF-1 and 10 age-matched healthy volunteers. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured in brain stem, basal ganglia, thalamus, corpus callosum, and frontal and parietooccipital white matter regions. Significantly increased ADC and decreased FA values were found in all regions of interest and in all patients with NF-1, irrespective of their scholastic achievement and subsequent professional performance, compared with control subjects (P < .001). There were no significant correlations with the age (P > .1) or with the lateralization between brain hemispheres (P > .05). Diffusion tensor imaging reveals globally elevated FA and decreased ADC values in the mature brains of patients with NF-1, which is most likely a consequence of diffuse and basic alterations in cerebral microstructure that result from the underlying gene mutation.

Substantia innominata: MR findings in Parkinson's disease.

To elucidate MR imaging changes of the substantia innominata in Parkinson's disease (PD), using a 1.5-T superconductive MR unit, the thickness of the substantia innominata was measured on coronal thin-section images in 44 PD patients and 20 age-matched control subjects. We also evaluated the correlation between the thickness of the substantia innominata and mental status in PD patients. Mean thickness of the substantia innominata was 2.3 mm in PD patients, and 2.5 mm in control subjects. Thinning of the substantia innominata was statistically significant in PD patients compared with control subjects, although there were large overlaps. Among the PD patients, thinning was remarkable in cases with dementia. A positive correlation between thickness of substantia innominata and score of Mini-Mental-Status-Examination was also observed in PD patients. Atrophy of the substantia innominata was demonstrated, especially in PD patients with cognitive impairment, on coronal MR images, and this is compatible with the previous pathological reports.

Characterizing changes in MR images with color-coded Jacobians.

Image registration is the process of establishing spatial correspondence between two images or between two image volumes. Registration can be achieved by rigid, elastic, or a combination of rigid and elastic transforms that attempt to bring the two images into coincidence. A rigid transform accounts for differences in positioning and an elastic transform describes deformations due to differences in tissue properties, temporal changes due to growth or atrophy, or differences between individuals. Deformation-based morphometry uses the resulting deformation fields from these transforms to evaluate differences between the images being registered. Three methods of registration were evaluated: rigid (affine) transformation, elastic optical flow transformation, and elastic spline transformation. All three methods produce vector deformation fields that map each point in one image to a point in the other image. A 12-color map of the transformation Jacobian was used to represent local volume changes. Using the three registration methods, color-mapped Jacobians were determined using a simulated three-dimensional block with known translation, rotation, expansion, contraction, and intensity modulations. Color-coded Jacobians were also generated for experimentally measured magnetic resonance image volumes of water-filled balloons and 7-year-old twin boys. Color-coded Jacobians overlaid on anatomical images provide a convenient method to identify regional tissue expansion and contraction.