Quantifying metal-induced susceptibility artifacts of the instrumented spine at 1.5T using fast-spin echo and 3D-multispectral MRI.

PURPOSE: To evaluate magnetic resonance imaging (MRI) artifacts near metallic spinal instrumentation using both conventional metal artifact reduction sequences (MARS) and 3D multispectral imaging sequences (3D-MSI). MATERIALS AND METHODS: Both MARS and 3D-MSI images were acquired in 10 subjects with titanium spinal hardware on a 1.5T GE 450W scanner. Clinical computed tomography (CT) images were used to measure the volume of the implant using seed-based region growing. Using 30-40 landmarks, the MARS and 3D-MSI images were coregistered to the CT images. Three independent users manually segmented the artifact volume from both MR sequences. For five L-spine subjects, one user independently segmented the nerve root in both MARS and 3D-MSI images. RESULTS: For all 10 subjects, the measured artifact volume for the 3D-MSI images closely matched that of the CT implant volume (absolute error: 4.3 ± 2.0 cm3 ). The MARS artifact volume was ∼8-fold higher than that of the 3D-MSI images (30.7 ± 20.2, P = 0.002). The average nerve root volume for the MARS images was 24 ± 7.3% lower than the 3D-MSI images (P = 0.06). CONCLUSION: Compared to 3D-MSI images, the higher-resolution MARS images may help study features farther away from the implant surface. However, the MARS images retained substantial artifacts in the slice-dimension that result in a larger artifact volume. These artifacts have the potential to obscure physiologically relevant features, and can be mitigated with 3D-MSI sequences. Hence, MR study protocols may benefit with the inclusion both MARS and 3D-MSI sequences to accurately study pathology near the spine. LEVEL OF EVIDENCE: 2 J. Magn. Reson. Imaging 2017;45:51-58.

Delayed hydrocephalus associated with traumatic atlanto-occipital dislocation: Case report and literature review.

BACKGROUND: Traumatic atlanto-occipital dislocation (AOD) is a rare but often fatal injury. Consequently, long-term data regarding surviving patients have been limited. In particular, the occurrence of hydrocephalus is not well-documented. CASE DESCRIPTION: A 33-year-old male sustained AOD as a consequence of a motor vehicle collision. Although he did well initially after an occipitocervical fusion, 1 month after his operation, he exhibited signs of increased intracranial pressure (bilateral abducens nerve palsies, worsening headaches, and fatigue). He was found to have hydrocephalus, which was responsive to shunting. CONCLUSION: Manifestations of hydrocephalus after AOD can be variable, ranging from interval ventricular dilatation to pseudomeningoceles and syringomyelia. In addition, the timing of presentation can be acute, requiring emergent external ventricular drainage, or delayed, requiring ongoing vigilance. Consequently, as more patients survive this once thought to be fatal injury, caution for hydrocephalus is stressed.

Brain metastases from breast cancer during pregnancy.

BACKGROUND: Brain metastasis during pregnancy is a rare occurrence. In particular, there have only been three prior cases regarding breast cancer metastasis. We report a patient with breast cancer metastasis to the brain during pregnancy and review the literature. CASE DESCRIPTION: The patient was a 35-year-old female with a history of breast cancer (estrogen receptor/progesterone receptor negative, human epidermal growth factor receptor 2/neu positive, status post-neoadjuvant docetaxel/carboplatin/trastuzumab/pertuzumab therapy, status post-bilateral mastectomies), and prior right frontal brain metastases (status post-resection, capecitabine/lapatinib/temozolomide therapy, and cyberknife treatment). Patient was found to be pregnant at 9 weeks' gestation while on chemotherapy; the patient elected to continue with the pregnancy and chemotherapy was discontinued. At 14 weeks' gestation, she returned with recurrent right frontal disease. She was taken for a craniotomy at 16 weeks' gestation, which confirmed metastases. Six weeks later, patient returned with worsening headaches and fatigue, with more recurrent right frontal disease. She was started on decadron and chemotherapy (5-fluorouracil, adriamycin, and cyclophosphamide). Serial magnetic resonance imaging (MRI) demonstrated enlarging right frontal lesions. She underwent a craniotomy at 27 weeks' gestation, and chemotherapy was discontinued promptly. Starting at 30 weeks' gestation, she received whole brain radiation for 2 weeks. Subsequently, she delivered a baby girl via cesarean section at 32 weeks' gestation. At 6 weeks follow-up, an MRI brain demonstrated no new intracranial disease, with stable postoperative findings. CONCLUSION: There is a lack of guidelines and clinical consensus on medical and surgical treatment for breast cancer metastases in pregnant patients. Treatment usually varies based upon underlying tumor burden, location, gestational age of the fetus, and patient's preference and symptomatology.

Primary atypical teratoid/rhabdoid tumor of the spine in an adult patient.

BACKGROUND: Atypical teratoid/rhabdoid tumor (AT/RT) is an aggressive neoplasm of the central nervous system that generally arises intracranially in patients under 2 years of age. Primary spinal AT/RT in an adult is rare. CASE DESCRIPTION: A 23-year-old female presented with left lower extremity sciatica attributed to a magnetic resonance imaging (MRI)-documented intradural mass between L2 and L4. The lesion was biopsied (was unresectable) and treated with high-dose chemotherapy (methotrexate, vincristine, cyclophosphamide, etoposide, and cisplatin) with autologous hematopoietic stem cells rescue, followed by 2 months of radiation therapy (36 Gy to craniospinal axis, 20 Gy to lumbar region) with concurrent temozolomide; the latter was discontinued after 3 weeks due to myelosuppression. Tumor relapsed 1 year later at C7-T1 level. She was started on oral metronomic therapy, and bevacizumab was added 2 months later. Three months later, a cervical MRI showed progression of the tumor, along with new lesions in the thoracic/lumbar spine plus intracranial punctate nodular tumors. Following resection of the C7/T1 lesion, she was started on palliative alisertib; a month later, a cranial computed tomography showed progression of her disease with hydrocephalus. Treatment was discontinued, and she expired 12 months after initial diagnosis. CONCLUSION: Primary spinal AT/RT in the adult patient is rare. The pathology is associated with early recurrence and a poor prognosis. Although potential benefits of metronomic chemotherapy and alisertib have been reported, the patient in this study did not favorably respond to these modalities.

Central cord syndrome in a patient with systemic sclerosis and cervical calcinosis: case report and review of literature.

Systemic sclerosis, or scleroderma, rarely involves the cervical spine. The disorder can induce dystrophic calcinosis that can cause spinal canal stenosis and spinal instability. An association between this pathology with acute traumatic central cord syndrome and dural erosion is rare. This case report highlights such an association and postulates the underlying mechanisms. A 57-year-old female, with a history of chronic obstructive pulmonary disease (COPD), schizophrenia and systemic sclerosis, presented with weakness in all extremities after a minor fall. Imaging demonstrated a calcified soft-tissue mass at C4/5 causing severe cord compression, cord edema spanning C3-C6, calcified soft-tissue masses at right C2/C3 facet joint and bilateral C4/5 facet joints, and significant subluxation at C4/5. Patient underwent C4-C7 laminectomies, and C3-T1 fixation and fusion. The calcinosis appeared to erode through the dura, which necessitated dura repair once the calcionsis was carefully debulked. The patient recovered well, and improved clinically with rehabilitation. Dystrophic calcinosis from underlying systemic sclerosis can cause significant chronic cervical stenosis, which may reduce the threshold for acute traumatic cervical cord syndrome under minor trauma. Moreover, dystrophic calcinosis may exhibit a propensity for dural erosion, possibly through chronic adhesions secondary to chronic inflammation. Aggressive removal of the calcinosis may breach the dura. Consequently, subtotal debulking may be reasonable if the spinal canal is adequately decompressed after laminectomies.

Diffusion tensor imaging of the spinal cord: a review / Imagem da medula espinal por tensor de difusão / Imagen de difusión tensora de la médula espinal: una revisión

Diffusion tensor imaging (DTI) is a magnetic resonance technique capable of measuring the magnitude and direction of water molecule diffusion in various tissues. The use of DTI is being expanded to evaluate a variety of spinal cord disorders both for prognostication and to guide therapy. The purpose of this article is to review the literature on spinal cord DTI in both animal models and humans in different neurosurgical conditions. DTI of the spinal cord shows promise in traumatic spinal cord injury, cervical spondylotic myelopathy, and intramedullary tumors. However, scanning protocols and image processing need to be refined and standardized.

O exame por imagem de ressonância magnética utilizando a técnica de tensores de difusão (DTI, Diffusion tensor imaging) consegue medir a magnitude e direção da difusão de moléculas de água em vários tecidos. A DTI está começando a ser usada para avaliar uma série de patologias da medula espinal, tanto para prognósticos como para orientar o tratamento. O presente artigo revisa a literatura sobre DTI da medula espinhal, em modelos animais e humanos, em diferentes condições neurocirúrgicas. A DTI da medula espinal é promissora para lesões traumáticas da medula, mielopatia espondilótica cervical e tumores intramedulares. Contudo, os protocolos de escaneamento e processamento de imagens precisam ser refinados e padronizados.

La técnica de imagen por difusión tensora (DTI, Diffusion tensor imaging) es una técnica de resonancia magnética que mide la magnitud y dirección de la difusión de moléculas de agua en varios tejidos. El uso de DTI se ha expandido para evaluar una variedad de disturbios de la columna vertebral tanto para pronóstico como para orientación de la terapia. La finalidad de este artículo es revisar la literatura sobre DTI de la médula espinal tanto en modelos animales como en humanos en diferentes condiciones neuroquirúrgicas. La DTI de la médula espinal se muestra promisora en las lesiones traumáticas de la médula, en la mielopatía espondilótica cervical y en los tumores intramedulares. Sin embargo, los protocolos de barrido y el procesamiento de imágenes necesitan ser refinados y estandarizados.