ABSTRACT
Background and objective Susceptibility-weighted imaging (SWI) sequence is crucial for brain MRI examinations, as it is equipped with a high sensitivity to detect calcification, microbleed, and gross hemorrhage. Intracranial venous structures such as the superior sagittal sinus (SSS) and cortical veins are used as reference structures in phase image SWI to differentiate diamagnetic and paramagnetic substances. Our study focuses on the internal cerebral vein (ICV) as another reliable reference structure. We aimed to analyze the diagnostic accuracy and detectability of calcification and hemorrhagic components in brain tumors using ICV, cortical veins, and SSS as references on phase image SWI, with CT scans for comparison. Material and methods A retrospective review of calcification and hemorrhagic components in brain tumors was conducted using MRI and CT from January 2017 to June 2023. Results The study included a total of 192 patients with brain tumors. For calcification components (63 cases), ICV and cortical veins as reference structures showed excellent sensitivity (96.8%), specificity (100%), and accuracy (98.9%). SSS demonstrated slightly lower detectability but maintained high sensitivity (96.5%), specificity (100%), and accuracy (98.8%) levels. No statistical differences were noted among these reference structures (p>0.05) and excellent interobserver agreement (Cohen's Kappa of 1) was observed. Conclusions The ICV is located in the central image, is large, without any nearby arteries, and is easy to identify using SWI phase images. Using the ICV as a reference to characterize intratumoral calcification, microbleed, and hemorrhage demonstrates high accuracy and detectability. With its findings of excellent interobserver agreement, our study will be of immense benefit to radiologists.
ABSTRACT
Acute transverse myelitis is an inflammatory disorder of the spinal cord, characterized by acute or subacute onset of paraparesis, bilateral sensory deficit, and impaired urinary bladder and sphincter tone function. Mycobacterium tuberculosis, a very rare cause of transverse myelitis, especially tuberculous myelitis without meningitis, is extremely rare. The main etiologic mechanism consists of an abnormal activation of the immune system against the spinal cord as well as the direct invasion by the bacillus. We present a 30-year-old Thai woman with AIDS, presenting with paraplegia for two days. Her MRI of the whole spine showed nodular enhancing intramedullary lesions involving the spinal cord at the T11-T12 level, and intramedullary enhancing lesion along the T12 spinal cord to the conus medullaris. Cerebrospinal fluid (CSF) examination revealed only a few white blood cells without hypoglycorrhachia or elevated CSF protein. CSF polymerase chain reaction (PCR) and culture for M. tuberculosis produced negative results. Other investigations did not demonstrate other organ involvement. Spinal cord biopsy at T12 was performed and exhibited diffuse epithelioid histiocytic proliferation admixed with small lymphocytes and plasma cells with numerous acid-fast bacilli (AFB)-positive bacilli organisms. PCR for M. tuberculosis was also detected in spinal cord tissue. Thus, acute transverse myelitis caused by isolated tuberculous myelitis without meningeal involvement was diagnosed. She had marked clinical improvement and neurologic recovery after treatment with anti-tuberculosis and intravenous steroid pulses. Isolated M. tuberculosis spinal tuberculous myelitis without meningitis is exceptionally uncommon and should be carefully considered, particularly in severely immunocompromised individuals residing in regions with a high tuberculosis burden.
ABSTRACT
Spinal epidural abscess (SEA) is a rare but sometimes life-threatening condition. The principal organisms in SEA and spondylodiscitis are gram-positive bacteria, e.g., Staphylococcus aureus and Streptococci. Spontaneous gram-negative SEA and spondylodiscitis especially Klebsiella pneumoniae are very rare. We report a 71-year-old Thai male with diabetes, presenting fever, enlarged neck mass, and progressive painful swallowing a week before admission. MRI of the whole spine demonstrated epidural abscess along the anterior thecal sac from C2 to C7 levels with spinal meningitis; multiple rim-enhancing lesions at the left sternocleidomastoid/levator scapulae, splenius capitis, semispinalis capitis, and bilateral scalene muscles; and rhombencephalitis with brain abscess. Klebsiella pneumoniae was isolated from blood culture. CT of the whole abdomen showed unremarkable intra-abdominal lesion. Intravenous ceftriaxone was administered, but the patient was unable to undergo surgical drainage due to unstable condition and died after two weeks of admission. Spontaneous SEA and spondylodiscitis caused by K. pneumoniae are very rare but sometimes fatal. In the case of SEA and spondylodiscitis, even when K. pneumoniae is uncommon, it should be also considered as a pathogen, especially when the patient had important risk factors.