Morphological Magnetic Resonance Research Articles

Free breathing 1H MRI of the human lung with an improved radial turbo spin-echo.

To optimize a radial turbo spin-echo sequence for motion-robust morphological lung magnetic resonance imaging (MRI) in free respiration. A versatile multi-shot radial turbo spin-echo (rTSE) sequence is presented, using a modified golden ratio-based reordering designed to prevent coherent streaking due to data inconsistencies from physiological motion and the decaying signal. The point spread function for a moving object was simulated using a model for joint respiratory and cardiac motion with a concomitant T2 signal decay and with rTSE acquisition using four different reordering techniques. The reordering strategies were compared in vivo using healthy volunteers and the sequence was tested for feasibility in two patients with lung cancer and pneumonia. Simulations and in vivo measurements showed very weak artifacts, aside from motion blur, using the proposed reordering. Due to the opportunity for longer scan times in free respiration, a high signal-to-noise ratio (SNR) was achieved, facilitating identification of the disease as compared to standard half-Fourier-acquisition single-shot turbo spin-echo (HASTE) scans. Additionally, post-processing allowed modifying the T2 contrast retrospectively, further improving the diagnostic fidelity. The proposed radial TSE sequence allowed for high-resolution imaging with limited obscuring artifacts. The radial k-space traversal allowed for versatile post-processing that may help to improve the diagnosis of subtle diseases.

Abstract 2682: ELTD1 as a target for anti-cancer therapy in rodent gliomas

Abstract Despite current therapies, glioblastoma multiforme (GBM) is a devastating cancer with a very poor prognosis. Specific protein biomarkers for GBM enable not only new prognostic avenues to tailor treatment, but valuable therapeutic targets to interfere with GBM growth. We recently discovered a new biomarker for high-grade gliomas, ELTD1 (epidermal growth factor, latrophilin, and 7 transmembrane domain-containing protein 1 on chromosome 1), via a novel bioinformatics approach, GAMMA (Global microarray meta-analysis). ELTD1 was found to be significantly higher (p<0.05) in high-grade gliomas (50 patients) compared with low-grade gliomas (21 patients). ELTD1 gene expression was found to be associated with tumor grade, survival across grade, and an increase in the mesenchymal subtype. From our previous results we hypothesized that ELTD1 may be a potential therapeutic target in high-grade gliomas. We tested the hypothesis in an orthotopic GL261 mouse glioma model in animals treated with an anrti-ELTD1 antibody, compared to those that were treated with an anti-VEGF antibody or an anti-c-Met antibody, and untreated tumors. Tumor volumes were measured by morphological magnetic resonance imaging (MRI). Our data in orthotopic GL261 glioma-bearing mice shows that injection of anti-ELTD1 antibodies lead to a significant decrease in tumor volumes (p<0.0001) and a significant increase in animal survival (p<0.05), superior to that achieved by a mouse anti-VEGF antibody or an antibody against c-Met, when compared to untreated mice. Tumor volumes were obtained at various time-points, and compared at 21 days following intracerebral implantation of GL261 cells in male C57BL6 mice. These tumor volumes at 21 days were 86.03+/-41.54 mm3 for untreated mice (n=5); 13.04+/-5.35 mm3 for anti-ELTD1 treated mice (n=5); 33.16+/-12.48 mm3 for anti-VEGF treated mice (n=4); and 28.49+/-11.11 mm3 for anti-c-Met treated mice (n=5). The mean days of survival for untreated, ELTD1, VEGF or c-Met treatment groups were 23.8+/-1.79, 28.2+/-2.39, 27+/-1.15 or 27+/-1.87 days, respectively. These pre-clinical results indicate that an additional therapy in the form of an anti-ELTD1 antibody either as a sole agent or in combination with current or new therapies could potentially provide high-grade glioma patients with a better prognostic outcome. Citation Format: Rheal A. Towner, Richard Pody, Nataliya Smith, Debra Saunders, Charity Njoku, Jonathan D. Wren. ELTD1 as a target for anti-cancer therapy in rodent gliomas. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2682. doi:10.1158/1538-7445.AM2014-2682

Automatic lung segmentation method for MRI-based lung perfusion studies of patients with chronic obstructive pulmonary disease.

A novel fully automatic lung segmentation method for magnetic resonance (MR) images of patients with chronic obstructive pulmonary disease (COPD) is presented. The main goal of this work was to ease the tedious and time-consuming task of manual lung segmentation, which is required for region-based volumetric analysis of four-dimensional MR perfusion studies which goes beyond the analysis of small regions of interest. The first step in the automatic algorithm is the segmentation of the lungs in morphological MR images with higher spatial resolution than corresponding perfusion MR images. Subsequently, the segmentation mask of the lungs is transferred to the perfusion images via nonlinear registration. Finally, the masks for left and right lungs are subdivided into a user-defined number of partitions. Fourteen patients with two time points resulting in 28 perfusion data sets were available for the preliminary evaluation of the developed methods. Resulting lung segmentation masks are compared with reference segmentations from experienced chest radiologists, as well as with total lung capacity (TLC) acquired by full-body plethysmography. TLC results were available for thirteen patients. The relevance of the presented method is indicated by an evaluation, which shows high correlation between automatically generated lung masks with corresponding ground-truth estimates. The evaluation of the developed methods indicates good accuracy and shows that automatically generated lung masks differ from expert segmentations about as much as segmentations from different experts.

Cerebral reorganization of language and motor control secondary to chronic hemispheric vasculopathy in a patient with homozygous sickle‐cell disease

A 43-year-old man with homozygous sickle-cell disease (SCD) had a first ischemic stroke in the left middle cerebral artery territory at the age of 15 years, with a minor persistent neurological deficit of right limbs due to occlusion of the left middle cerebral artery with a Moya-Moya-like lenticular-striatal collateral network. At 32 years, he had a second left hemisphere stroke, involving the whole territory of the middle and posterior cerebral arteries, sparing only prefrontal areas. This second major infarct produced only limited clinical symptoms: incomplete right hemiparesis and hypoesthesia, right lateral hemianopia, and reduced verbal fluency without overt aphasia. Morphological magnetic resonance imaging (MRI) showed atrophy of the left cerebral hemisphere and peduncle associated with Wallerian degeneration. Single-photon-emission computed tomography (SPECT) showed hypoperfusion of the entire left cerebral hemisphere. In contrast, no vasculopathy was revealed by magnetic resonance angiography (MRA), SPECT, or transcranial doppler ultrasonography of the right cerebral hemisphere. Functional mapping of the motor cortex was obtained with trans-cranial magnetic stimulation (TMS) with MRI-guided navigation 1. Navigated TMS showed that all motor-evoked potentials recorded on the right side of the body had their origin in the right precentral cortex. In addition, functional MRI showed that language functions had been lateralized in the right hemisphere (Image 1). This unusual lateralization of motor and language functions in the right hemisphere suggests successful adaptive neuroplasticity from the damaged left hemisphere to the right hemisphere. As no sign of cerebral vasculopathy was found in this hemisphere, chronic blood-exchange transfusions (BET) could be stopped and replaced by oral hydroxyurea. BET is the treatment of choice for reducing the risk of stroke in children with SCD and abnormal cerebral blood flow on trans-cranial doppler or MRA 2. Despite its recognized benefits, BET is associated with various complications, for example, infections, alloimmunization, hemolytic transfusion reactions, and iron overload. Functional MRI and TMS provide simultaneous analyses of brain-function localization and could thus represent a complementary tool for therapy management: if specific functional areas are identified in brain regions at risk of hypoperfusion, treatment should be reinforced, including BET, whereas affected nonfunctional areas are not therapeutic targets. This case illustrates the importance of functional and neurocognitive rehabilitation of SCD patients who have had a stroke, particularly during childhood when the vasculopathy appears. Even though very few studies have evaluated the impact of rehabilitation of SCD patients 3, our observations support that functional reorganization can occur in this particular population.

Detection of cartilage damage in femoroacetabular impingement with standardized dGEMRIC at 3 T

This study aimed at identifying the optimal threshold value to detect cartilage lesions with Standardized delayed Gadolinium-Enhanced MRI of Cartilage (dGEMRIC) at 3 T and evaluate intra- and inter-observer repeatability. We retrospectively reviewed 20 hips in 20 patients. dGEMRIC maps were acquired at 3 T along radial imaging planes of the hip and standardized to remove the effects of patient's age, sex and diffusion of gadolinium contrast. Two observers separately evaluated 84 Standardized dGEMRIC maps, both by visual inspection and using an average index for a region of interest (ROI) in the acetabular cartilage. A radiologist evaluated the acetabular cartilage on morphologic MR images at exactly the same locations. Using intra-operative findings as reference, the optimal threshold to detect cartilage lesions with Standardized dGEMRIC was assessed and results were compared with the diagnostic performance of morphologic magnetic resonance imaging (MRI). Using z < -2 as threshold and visual inspection of the color-adjusted maps, sensitivity, specificity and accuracy for Observer 1 and Observer 2, were 83%, 60% and 75%, and 69%, 70% and 69%, respectively. Overall performance was 52%, 67% and 58%, when using an average z for the acetabular cartilage, compared to 37%, 90% and 56% for morphologic assessment. The kappa coefficient was 0.76 and 0.68 for intra- and inter-observer repeatability, respectively, indicating substantial agreement. Standardized dGEMRIC at 3 T is accurate in detecting cartilage damage and could improve preoperative assessment in femoroacetabular impingement (FAI). As cartilage lesions in FAI are localized, visual inspection of the Standardized dGEMRIC maps is more accurate than an average z for the acetabular cartilage.

Effect of MRI Acoustic Noise on Cerebral Fludeoxyglucose Uptake in Simultaneous MR-PET Imaging

Integrated scanners capable of simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) data acquisition are now available for human use. Although the scanners' manufacturers have made substantial efforts to understand and minimize the mutual electromagnetic interference between the 2 modalities, the potential physiological inference has not been evaluated. In this study, we have studied the influence of the acoustic noise produced by the magnetic resonance (MR) gradients on brain fludeoxyglucose (FDG) uptake in the Siemens MR-BrainPET prototype. Although particular attention was paid to the primary auditory cortex (PAC), a brain-wide analysis was also performed. The effects of the MR on the PET count rate and image quantification were first investigated in phantoms. Next, 10 healthy volunteers underwent 2 simultaneous FDG-PET/MR scans in the supine position with the FDG injection occurring inside the MR-BrainPET, alternating between a "quiet" (control) environment in which no MR sequences were run during the FDG uptake phase (the first 40 minutes after radiotracer administration) and a "noisy" (test) environment in which MR sequences were run for the entire time. Cortical and subcortical regions of interest were derived from the high-resolution morphological MR data using FreeSurfer. The changes in the FDG uptake in the FreeSurfer-derived regions of interest between the 2 conditions were analyzed from parametric and static PET images, and on a voxel-by-voxel basis using SPM8 and FreeSurfer. Only minimal to no electromagnetic interference was observed for most of the MR sequences tested, with a maximum drop in count rate of 1.5% and a maximum change in the measured activity of 1.1% in the corresponding images. The region of interest-based analysis showed statistically significant increases in the right PAC in both the parametric (9.13% [4.73%]) and static (4.18% [2.87%]) images. The SPM8 analysis showed no statistically significant clusters in any images when a P < 0.05 (corrected) was used; however, a P < 0.001 (uncorrected) resolved bilateral statistically significant clusters of increased FDG uptake in the area of the PAC for the parametric image (left, 8.37% [1.55%]; right, 8.20% [1.17%]) but only unilateral increase in the static image (left, 8.68% [3.89%]). Although the operation of the BrainPET prototype is virtually unaffected by the MR scanner, the acoustic noise produced by the MR gradients causes a focal increase in the FDG uptake in the PAC, which could affect the interpretation of pathological (or brain-activation-related) changes in the FDG uptake in this region if the expected effects are of comparable amplitude.

Autologous Collagen-induced Chondrogenesis: Single-stage Arthroscopic Cartilage Repair Technique

Autologous collagen-induced chondrogenesis is a novel, single-staged arthroscopic cartilage repair technique using microdrilling and atelocollagen or fibrin gel application under carbon dioxide insufflation. Atelocollagen is a highly purified type I collagen obtained following the treatment of skin dermis with pepsin and telopeptide removal, making it nonimmunogenic. In this procedure, atelocollagen mixed with fibrinogen and thrombin in a 2-way syringe can maintain the shape of the articular surface approximately 5 minutes after application due to the reaction between the thrombin and fibrinogen. Carbon dioxide insufflation facilitates the application of the gel under dry conditions. Ten patients (mean age, 38 years) with symptomatic chondral defects in the knee who were treated arthroscopically with microdrilling and atelocollagen application were retrospectively analyzed. All defects were International Cartilage Repair Society grade III or IV and were 2 to 8 cm(2) in size intraoperatively. For the clinical assessment, Lysholm score was assessed preoperatively and at 2-year follow-up. All patients underwent morphological magnetic resonance imaging at 1.5-Tesla at 1-year follow-up. Mean Magnetic Resonance Imaging Observation of Cartilage Repair Tissue score at 1-year follow-up was 70.4 ± 20.2 (range, 15-95). The Magnetic Resonance Imaging Observation of Cartilage Repair Tissue score for patellar lesions was similar to that of lesions in other locations: 73.3 ± 11.7 vs 68.1 ± 25.5, respectively. This technique had encouraging clinical results at 2-year follow-up. Morphological magnetic resonance imaging shows good cartilage defect filling, and the biochemical magnetic resonance imaging suggests hyaline-like repair tissue.

Imaging biopsy composition at ACL reconstruction.

Early-stage osteoarthritis (OA) includes glycosaminoglycan (GAG) loss and collagen disruption that cannot be seen on morphological magnetic resonance imaging (MRI). T1ρ MRI is a measurement that probes the low-frequency rate of exchange between protons of free water and those from water associated with macromolecules in the cartilage's extracellular matrix. While it has been hypothesized that increased water mobility resulting from early osteoarthritic changes cause elevated T1ρ MRI values, there remain several unknown mechanisms influencing T1ρ measurements in cartilage. The purpose of this work was to relate histological and biochemical metrics directly measured from osteochondral biopsies and fluid specimens with quantitative MRI-detected changes of in vivo cartilage composition. Six young patients were enrolled an average of 41 days after acute anterior cruciate ligament (ACL) rupture. Femoral trochlear groove osteochondral biopsies, serum, and synovial fluid were harvested during ACL reconstruction to complement a presurgery quantitative MRI study (T1ρ, T2, delayed gadolinium-enhanced MRI of cartilage [dGEMRIC] relaxation times). A high-resolution MRI scan of the excised osteochondral biopsy was also collected. Analyses of in vivo T1ρ images were compared with ex vivo T1ρ imaging, GAG assays and histological GAG distribution in the osteochondral biopsies, and direct measures of bone and cartilage turnover markers and "OA marker" 3B3 in serum and synovial fluid samples. T1ρ relaxation times in patients with a torn ACL were elevated from normal, indicating changes consistent with general fluid effusion after blunt joint trauma. Increased chondrogenic progenitor cell (CPC) production of chondroprotective lubricin may relate to cartilage surface disruption by blunt trauma and CPC amplification of joint inflammation. Disparity between ex vivo and matched in vivo MRI of trochlear cartilage suggests MRI signal differences that may be related to the synovial fluid environment. T1ρ is emerging as a promising MRI biomarker to relate noninvasive measures of whole-joint condition and cartilage composition to direct measures of cartilage changes in the acute phase of joint injuries.

Morphology of Large Rotator Cuff Tears and of the Rotator Cable and Long-term Shoulder Disability in Conservatively Treated Elderly Patients

The objective of this study was to describe the morphology of the rotator cuff tendon tears and long-term shoulder disability in conservatively treated elderly patients and determine if an association exists between these factors. Assessment of the rotator cuff tendon tear dimensions and depth, rotator interval involvement, rotator cable morphology and location, and rotator cuff muscle status was carried out on magnetic resonance studies of 24 elderly patients treated nonoperatively for rotator cuff tendon tears. Long-term shoulder function was measured using the Western Ontario Rotator Cuff (WORC) index; Disabilities of the Shoulder, Arm, and Hand questionnaire; and the American Shoulder Elbow Self-assessment form, and a correlation between the outcome scores and morphologic magnetic resonance findings was carried out. The majority of large rotator cuff tendon tears are limited to the rotator cuff crescent. Medial rotator interval involvement (isolated or in association with lateral rotator interval involvement) was significantly associated with WORC physical symptoms total (P = 0.01), WORC lifestyle total (P = 0.04), percentage of all WORC domains (P = 0.03), and American Shoulder Elbow Self-assessment total (P = 0.01), with medial rotator interval involvement associated with an inferior outcome. Medial rotator interval tears are associated with long-term inferior outcome scores in conservatively treated elderly patients with large rotator cuff tendon tears.

Glioblastoma Multiforme versus Solitary Supratentorial Brain Metastasis: Differentiation Based on Morphology and Magnetic Resonance Signal Characteristics

To evaluate the diagnostic potential of a multi-factor analysis of morphometric parameters and magnetic resonance (MR) signal characteristics of a mass and peritumoral area to distinguish solitary supratentorial metastasis from glioblastoma multiforme (GBM). MR examinations of 51 patients with histologically proven GBM and 44 with a single supratentorial metastasis were evaluated. A large variety of morphologic criteria and MR signal characteristics in different sequences were analyzed. The data were subjected to logistic regression to investigate their ability to discriminate between GBM and cerebral metastasis. Receiver-operating characteristic (ROC) analysis was used to select an optimal cut-off point for prediction and to assess the predictive value in terms of sensitivity, specificity, and accuracy of the final model. The logistic regression analysis revealed that the ratio of the maximum diameter of the peritumoral area measured on T2-weighted images (d T2) to the maximum diameter of the enhancing mass area (d T1, post-contrast) is the only useful criterion to distinguish single supratentorial brain metastasis from GBM with a lower ratio favoring GBM (accuracy 68 %, sensitivity 84 % and specificity 45 %). The cut-off point for the ratio d T2/d T1 post-contrast was calculated as 2.35. Measurement of maximum diameters of the peritumoral area in relation to the enhancing mass can be evaluated easily in the clinical routine to discriminate GBM from solitary supratentorial metastasis with an accuracy comparable to that of advanced MRI techniques.

Differentiation of an Intrapancreatic Accessory Spleen from a Small (&lt;3-cm) Solid Pancreatic Tumor: Value of Diffusion-weighted MR Imaging

To evaluate the value of diffusion-weighted (DW) imaging in differentiation of an intrapancreatic accessory spleen (IPAS) from a small (<3 cm) solid pancreatic tumor. This retrospective study was approved by the institutional review board, and informed consent was waived. Twenty patients with IPAS and 22 patients with small solid pancreatic tumors were included. All patients underwent abdominal magnetic resonance (MR) imaging with DW and gadoxetic acid-enhanced imaging. Qualitative (signal intensity) and quantitative (signal intensity and apparent diffusion coefficient [ADC]) evaluations were performed by two observers. Fisher exact test and Mann-Whitney U test were used for comparing groups. Compared with the spleen, the IPAS showed isointensity more frequently than did small pancreatic tumors on T2-weighted images (95% [19 of 20] vs 41% [nine of 22]), arterial phase images (100% [20 of 20] vs 18% [four of 22]), portal phase images (100% [20 of 20] vs 23% [five of 22]), late phase images (100% [20 of 20] vs 41% [nine of 22]), and DW images with b value of 0 sec/mm(2) (100% [20 of 20] vs 9% [two of 22]), b value of 100 sec/mm(2) (95% [19 of 20] vs 27% [six of 22]), and b value of 800 sec/mm(2) (100% [20 of 20] vs 27% [six of 22]), with significant differences (P < .01). The means of the absolute value of relative signal intensity and ADC ratio on DW images of IPAS were significantly lower and closer to zero than those of pancreatic tumors (P < .05). Visual assessment of the similarity between pancreatic lesion and spleen on DW images for diagnosis of IPAS yielded diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 95% (40 of 42), 100% (20 of 20), 91% (20 of 22), 91% (20 of 22), and 100% (20 of 20), respectively, for observer 1 and 90% (38 of 42), 95% (19 of 20), 86% (19 of 22), 86% (19 of 22), and 95% (19of 20), respectively, for observer 2. In addition to conventional morphologic MR imaging, DW imaging can be used as a tool for differentiating IPAS from solid pancreatic tumors. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12112765/-/DC1.

Is MRI a useful tool to distinguish between serous and mucinous borderline ovarian tumours?

To analyse the morphological magnetic resonance imaging (MRI) features of borderline ovarian tumours (BOT) and to evaluate whether MRI can be used to distinguish serous from mucinous subtypes. A retrospective study of 72 patients who underwent BOT resection was undertaken. MRI images were reviewed blindly by two radiologists to assess MRI features: size, tumour type, grouped and irregular thickened septa, number of septa, loculi of different signal intensity, vegetations, solid portion, signal intensity of vegetations, normal ovarian parenchyma, and pelvic ascites. Statistical analysis was performed using Mann-Whitney and Fisher's exact tests. Logistic regression analysis was used to assess the predictive value of the MRI findings for histological subtypes. At histology, there were 33 serous BOT (SBOT) and 39 mucinous BOT (MBOT). Predictive MRI criteria for SBOT were bilaterality, predominantly solid tumour, and the presence of vegetations, especially exophytic or with a high T2 signal (p<0.01), whereas predictive MRI criteria for MBOT were multilocularity, number of septa, loculi of different signal intensity, and grouped and irregular thickened septa (p<0.01). Using multivariate analysis, vegetations were independently associated with SBOT [odds ratio (OR)=29.5] and multilocularity with MBOT (OR=3.9). Vegetations and multilocularity are two independent MRI features that can help to distinguish between SBOT and MBOT.

Quantitative Morphological Magnetic Resonance Imaging Follow-up of Low-Grade Glioma

Supratentorial hemispheric diffuse low-grade gliomas (LGGs), i.e., World Health Organization grade II gliomas, are a heterogeneous group of tumors. During their natural course, LGGs tend to progress to a higher grade of malignancy, leading to neurological disability and ultimately to death. In this review, we will show, that during their low-grade period, these tumors exhibit systematically a spontaneous and continuous radiological growth, whatever their histological subtypes. The radiological tumor growth is easily quantified by measuring the evolution of the equivalent tumor diameter (calculated from the tumor volume), obtaining the velocity of diametric expansion (VDE). The spontaneous VDE of LGGs varies markedly with an average VDE of about 4 mm/year. It depends on intrinsic factors (1p19q codeletion status, P53 overexpression status) and can be modified by extrinsic factors (pregnancy). The spontaneous VDE carries a strong prognostic significance regarding progression-free and overall survivals. As a consequence, VDE should be integrated along with the other "static" parameters (multimodal imaging, histological and molecular analyses) in the initial investigations. In addition, the assessment of VDE obtained before, during, and after a particular oncological treatment helps in analyzing their effects on LGGs on an individual basis, helping to guide the decision making.

Genitourinary Applications of Diffusion-weighted MR Imaging in the Pelvis

Diffusion-weighted (DW) magnetic resonance (MR) imaging has a large number of potential clinical applications in the female and male pelvis and can easily be added to any routine MR protocol. In the female pelvis, DW imaging allows improvement of staging in endometrial and cervical cancer, especially in locally advanced disease and in patients in whom contrast medium administration should be avoided. It can also be helpful in characterizing complex adnexal masses and in depicting recurrent tumor after treatment of various gynecologic malignancies. DW imaging shows promising results in monitoring treatment response in patients undergoing radiation therapy of cervical cancer. An increase in apparent diffusion coefficient (ADC) values of responders precedes changes in size and may therefore allow early assessment of treatment success. In the male pelvis, the detection of prostate cancer in the peripheral zone is relatively easier than in the central gland based on the underlying ADC values, whereas overlapping values reported in the central gland still need further research. DW imaging might also be applied in the noninvasive evaluation of bladder cancer to differentiate between superficial and muscle-invasive tumors. Initial promising results have been reported in differentiating benign from malignant pelvic lymph nodes based on the ADC values; however, larger-scale studies will be needed to allow the detection of lymph node metastases in an individual patient. Prerequisites for successfully performing DW imaging of the female and male pelvis are standardization of the DW imaging technique, including the choice of b values, administration of an antiperistaltic drug, and comparison of DW findings with those of morphologic MR imaging.

MR imaging of rectal cancer before and after chemoradiation therapy

This study was done to determine the diagnostic accuracy of magnetic resonance (MR) imaging in patients with rectal carcinoma by comparing post-chemoradiation MR imaging with pathological specimens. We enrolled 39 patients with locally advanced rectal cancer. All patients received chemoradiation therapy before surgery and neoadjuvant chemoradiation therapy followed by MR imaging. MR images were analysed by a team of two expert radiologists unaware of the clinical and histopathological findings. Following neoadjuvant chemoradiation therapy, the analysis of MR images showed 23 (59%) patients with a rectal disease staged ≤T2 and 16 (41%) with a disease staged >T2. Post-treatment histological staging (TNM) revealed 13 patients with a disease >T2 and 26 patients with a disease ≤T2. Cohen's kappa to measure concordance between post-chemoradiation MR staging and histological response showed 83.6% concordance for disease confined to the serosa (≤T3): concordance was 97.22% for disease ≤N1 and 33.33% for disease >N1. MR imaging is critical for discovering T3 disease; moreover, morphological MR imaging does not always provide the opportunity to discern small residual cancer cells hidden in fibrotic tissue that could cause involvement of circumferential resection margin (CRM) on histology.

Lhermitte-Duclos disease presenting with positron emission tomography-magnetic resonance fusion imaging: a case report

IntroductionLhermitte-Duclos disease or dysplastic gangliocytoma of the cerebellum is an extremely rare tumor. It is a slowly enlarging mass within the cerebellar cortex. The majority of cases are diagnosed in the third or fourth decade of life.Case presentationWe report the case of a 37-year-old Caucasian woman who underwent positron emission tomography-computed tomography with fluorine-18-fluorodeoxyglucose for evaluation of a solitary lung node. No pathological uptake was detected in the solitary lung node but the positron emission tomography-computed tomography of her brain showed intense tracer uptake, suggestive of a malignant neoplasm, in a mass in her left cerebellar lobe. Our patient had experienced two years of occipital headache and movement disorder. Subsequently, magnetic resonance imaging was performed with contrast agent administration, showing a large subtentorial mass in her left cerebellar hemisphere, with compression and dislocation of the fourth ventricle. Metabolic data provided by positron emission tomography and morphological magnetic resonance imaging views were fused in post-processing, allowing a diagnosis of dysplastic gangliocytoma with increased glucose metabolism. Total resection of the tumor was performed and histological examination confirmed the diagnosis of Lhermitte-Duclos disease.ConclusionsOur case indicates that increased uptake of fluorine-18-fluorodeoxyglucose may be misinterpreted as a neoplastic process in the evaluation of patients with Lhermitte-Duclos disease, but supports the usefulness of integrated positron emission tomography-magnetic resonance imaging in the exact pathophysiologic explanation of this disease and in making the correct diagnosis. However, an accurate physical examination and exact knowledge of clinical data is of the utmost importance.

Structural Abnormalities of the Central Auditory Pathway in Infants with Nonsyndromic Cleft Lip and/or Palate

To investigate possible structural abnormalities of the central auditory pathway in infants with nonsyndromic cleft lip and/or palate (NSCL/P). Twenty-seven Chinese infants with NSCL/P, aged from 6 to 24 months. Morphological magnetic resonance imaging (MRI) measurements of the central auditory nervous system (CANS) in infants with NSCL/P were analyzed and compared with those of age- and sex-matched normal controls. No significant group differences were found in general brain measurements, including volumes of the brain stem and right hemisphere. However, infants with NSCL/P had statistically significantly smaller volumes of the left thalamus and left auditory cortex and notably decreased thickness of the left auditory cortex. Cortical abnormalities were more marked compared with other MRI measurements. Structural CANS abnormalities in infants with NSCL/P may be located mainly in the left cerebral hemisphere. The development and maturation of the auditory cortex in infants with NSCL/P may be abnormal when compared with those of normal children.

Diffusion magnetic resonance imaging of chest tumors

This review provides an overview of the current status of the published data on diffusion magnetic resonance (MR) imaging of chest tumors. Diffusion MR imaging is a non-invasive imaging technique that measures the differences in water mobility in different tissue microstructures and quantifies them based on the apparent diffusion coefficient. Diffusion MR imaging has been used for the characterization, grading and staging of lung cancer as well as for differentiating central tumors from post-obstructive consolidation. In addition, this technique helps in differentiating malignant from benign pulmonary and mediastinal tumors as well as in the characterization of pleural mesothelioma and effusion. Diffusion MR imaging can be incorporated into routine morphological MR imaging to improve radiologist confidence in image interpretation and to provide functional assessments of chest tumors during the same examination. Diffusion MR imaging could be used in the future as a functional imaging technique for tumors of the chest.

Asymmetric deformation of contracting human gastrocnemius muscle

Muscle fiber deformation is related to its cellular structure, as well as its architectural arrangement within the musculoskeletal system. While playing an important role in aponeurosis displacement, and efficiency of force transmission to the tendon, such deformation also provides important clues about the underlying mechanical structure of the muscle. We hypothesized that muscle fiber cross section would deform asymmetrically to satisfy the observed constant volume of muscle during a contraction. Velocity-encoded, phase-contrast, and morphological magnetic resonance imaging techniques were used to measure changes in fascicle length, pinnation angle, and aponeurosis separation of the human gastrocnemius muscle during passive and active eccentric ankle joint movements. These parameters were then used to subsequently calculate the in-plane muscle area subtended by the two aponeuroses and fascicles and to calculate the in-plane (dividing area by fascicle length), and through-plane (dividing muscle volume by area) thicknesses. Constant-volume considerations of the whole-muscle geometry require that, as fascicle length increases, the muscle fiber cross-sectional area must decrease in proportion to the length change. Our empirical findings confirm the definition of a constant-volume rule that dictates that changes in the dimension perpendicular to the plane, i.e., through-plane thickness, (-6.0% for passive, -3.3% for eccentric) equate to the reciprocal of the changes in area (6.8% for passive, 3.7% for eccentric) for both exercise paradigms. The asymmetry in fascicle cross-section deformation for both passive and active muscle fibers is established in this study with a ∼22% in-plane and ∼6% through-plane fascicle thickness change. These fiber deformations have functional relevance, not only because they affect the force production of the muscle itself, but also because they affect the characteristics of adjacent muscles by deflecting their line of pull.

Chiropractic management of a US Army veteran with low back pain and piriformis syndrome complicated by an anatomical anomaly of the piriformis muscle: a case study

ObjectiveThe purpose of this article is to present the case of a patient with an anatomical anomaly of the piriformis muscle who had a piriformis syndrome and was managed with chiropractic care. Case ReportA 32-year-old male patient presented to a chiropractic clinic with a chief complaint of low back pain that radiated into his right buttock, right posterior thigh, and right posterior calf. The complaint began 5 years prior as a result of injuries during Airborne School in the US Army resulting in a 60% disability rating from the Veterans Administration. Magnetic resonance imaging demonstrated a mildly decreased intradiscal T2 signal with shallow central subligamentous disk displacement and low-grade facet arthropathy at L5/S1, a hypolordotic lumbar curvature, and accessory superior bundles of the right piriformis muscle without morphologic magnetic resonance imaging evidence of piriformis syndrome. Intervention and OutcomeChiropractic treatment included lumbar and sacral spinal manipulation with soft tissue massage to associated musculature and home exercise recommendations. Variations from routine care included proprioceptive neuromuscular facilitation stretches, electric muscle stimulation, acupressure point stimulation, Sacro Occipital Technique pelvic blocking, CranioSacral therapy, and an ergonomic evaluation. ConclusionA patient with a piriformis anomaly with symptoms of low back pain and piriformis syndrome responded positively to conservative chiropractic care, although the underlying cause of the piriformis syndrome remained.