Acute Acquired Metabolic Encephalopathy Based on Diffusion MRI

Metabolic encephalopathy is a critical condition that can be challenging to diagnose. Imaging provides early clues to confirm clinical suspicions and plays an important role in the diagnosis, assessment of the response to therapy, and prognosis prediction. Diffusion-weighted imaging is a sensitive technique used to evaluate metabolic encephalopathy at an early stage.Metabolic encephalopathies often involve the deep regions of the gray matter because they have high energy requirements and are susceptible to metabolic disturbances. Understanding the imaging patterns of various metabolic encephalopathies can help narrow the differential diagnosis and improve the prognosis of patients by initiating proper treatment regimen early.

Monitoring Radiation Doses during Diagnostic and Therapeutic Neurointerventional Procedures: Multicenter Study for Establishment of Reference Levels / 신경중재치료의학

Purpose@#To assess patient radiation doses during diagnostic and therapeutic neurointerventional procedures from multiple centers and propose dose reference level (RL). @*Materials and Methods@#Consecutive neurointerventional procedures, performed in 22 hospitals from December 2020 to June 2021, were retrospectively studied. We collected data from a sample of 429 diagnostic and 731 therapeutic procedures. Parameters including dose-area product (DAP), cumulative air kerma (CAK), fluoroscopic time (FT), and total number of image frames (NI) were obtained. RL were calculated as the 3rd quartiles of the distribution. @*Results@#Analysis of 1160 procedures from 22 hospitals confirmed the large variability in patient dose for similar procedures. RLs in terms of DAP, CAK, FT, and NI were 101.6 Gy·cm2, 711.3 mGy, 13.3 minutes, and 637 frames for cerebral angiography, 199.9 Gy·cm2, 3,458.7 mGy, 57.3 minutes, and 1,000 frames for aneurysm coiling, 225.1 Gy·cm2, 1,590 mGy, 44.7 minutes, and 800 frames for stroke thrombolysis, 412.3 Gy·cm2, 4,447.8 mGy, 99.3 minutes, and 1,621.3 frames for arteriovenous malformation (AVM) embolization, respectively. For all procedures, the results were comparable to most of those already published. Statistical analysis showed male and presence of procedural complications were significant factors in aneurysmal coiling. Male, number of passages, and procedural combined technique were significant factors in stroke thrombolysis. In AVM embolization, a significantly higher radiation dose was found in the definitive endovascular cure group. @*Conclusion@#Various RLs introduced in this study promote the optimization of patient doses in diagnostic and therapeutic interventional neuroradiology procedures. Proposed 3rd quartile DAP (Gy·cm2) values were 101.6 for diagnostic cerebral angiography, 199.9 for aneurysm coiling, 225.1 for stroke thrombolysis, and 412.3 for AVM embolization. Continual evolution of practices and technologies requires regular updates of RLs.

Cerebral Air Embolism: a Case Report with an Emphasis of its Pathophysiology and MRI Findings

Cerebral air embolism (CAE) is a rare complication of various medical procedures. It manifests with symptoms similar to those of typical acute cerebral infarction, however the treatment is quite different. We present a case of arterial CAE that was associated with a disconnected central venous catheter and appeared as punctate dark signal intensities with aliasing artifacts on the susceptibility-weighted filtered phase magnetic resonance image. The susceptibility-weighted filtered phase image can be helpful for diagnosing CAE and the magnetic resonance imaging reflects the pathophysiology of CAE.

Carotid Intraplaque Hemorrhage is Associated with Acute Cerebral Ischemic Events and Progression of Stenosis on Magnetic Resonance Imaging

PURPOSE: To investigate the association of carotid intraplaque hemorrhage (IPH) with acute cerebral ischemic events and progression of stenosis using magnetic resonance (MR) imaging. MATERIALS AND METHODS: From April 2014 to December 2016, 53 patients underwent carotid plaque MR imaging, including magnetization-prepared rapid acquisition with gradient-echo (MPRAGE) sequence. A total of 66 carotid arteries in 53 patients had carotid stenosis, and they were included in this study. Carotid arteries were classified according to the presence of IPH, the age of hemorrhage, and degree of stenosis. We assessed ipsilateral cerebrovascular event rates and progression of stenosis between the IPH and no-IPH groups. RESULTS: Of the 61 carotid arteries assessed, 34 (56%) had IPH, and 27 (44%) had no IPH. Acute cerebral ischemic events were more frequent in the IPH group (47% vs. 22%, P = 0.045), especially in the < 30%-stenosis group (100% vs. 0%, P = 0.028). However, there was no significant difference in the incidence of ischemic events according to the age of hemorrhage (50% vs. 44%, P = 0.492). Among the 61 carotid arteries, 20 carotid arteries had previously undergone carotid artery imaging and were evaluated for plaque progression. The trend for progression of stenosis favored the IPH group versus the no-IPH group, with a marginal P-value (20% ± 12.7 vs. 9.6% ± 5.7, P = 0.063). CONCLUSION: IPH was associated with an increased incidence of acute ischemic events, especially in the mild-stenosis group and it was also associated with progression of stenosis. Evaluation of the carotid IPH by carotid plaque MR could improve discrimination of carotid plaques that cause ischemic events and progression of stenosis.

A Rare Case of Viagra Induced Toxic Encephalopathy

Viagra has been prescribed worldwide to treat men with erectile dysfunction. Clinical trials have shown that Viagra may cause various kinds of adverse effects include some central nervous system (CNS) adverse effects. Although extremely rare, toxic encephalopathy also can be one of those effects. This report presents a case of encephalopathy caused by Viagra in correlation with its radiologic findings. Its pharmacologic mechanism and potential effects on the biochemistry of the CNS are reviewed.

Patient Radiation Exposure During Diagnostic and Therapeutic Procedures for Intracranial Aneurysms: A Multicenter Study / 신경중재치료의학

PURPOSE: To assess patient radiation doses during cerebral angiography and embolization of intracranial aneurysms across multi-centers and propose a diagnostic reference level (DRL). MATERIALS AND METHODS: We studied a sample of 490 diagnostic and 371 therapeutic procedures for intracranial aneurysms, which were performed at 23 hospitals in Korea in 2015. Parameters including dose-area product (DAP), cumulative air kerma (CAK), fluoroscopic time and total angiographic image frames were obtained and analyzed. RESULTS: Total mean DAP, CAK, fluoroscopy time, and total angiographic image frames were 106.2 ± 66.4 Gy-cm2, 697.1 ± 473.7 mGy, 9.7 ± 6.5 minutes, 241.5 ± 116.6 frames for diagnostic procedures, 218.8 ± 164.3 Gy-cm², 3365.7 ± 2205.8 mGy, 51.5 ± 31.1 minutes, 443.5 ± 270.7 frames for therapeutic procedures, respectively. For diagnostic procedure, the third quartiles for DRLs were 144.2 Gy-cm² for DAP, 921.1 mGy for CAK, 12.2 minutes for fluoroscopy times and 286.5 for number of image frames, respectively. For therapeutic procedures, the third quartiles for DRLs were 271.0 Gy-cm² for DAP, 4471.3 mGy for CAK, 64.7 minutes for fluoroscopy times and 567.3 for number of image frames, respectively. On average, rotational angiography was used 1.5 ± 0.7 times/session (range, 0-4; n=490) for diagnostic procedures and 1.6 ± 1.2 times/session (range, 0-4; n=368) for therapeutic procedures, respectively. CONCLUSION: Radiation dose as measured by DAP, fluoroscopy time and image frames were lower in our patients compared to another study regarding cerebral angiography, and DAP was lower with fewer angiographic image frames for therapeutic procedures. Proposed DRLs can be used for quality assurance and patient safety in diagnostic and therapeutic procedures.

Uremic Encephalopathy with Atypical Magnetic Resonance Features on Diffusion-Weighted Images

Uremic encephalopathy is a well-known disease with typical MR findings including bilateral vasogenic or cytotoxic edema at the cerebral cortex or basal ganglia. Involvement of the basal ganglia has been very rarely reported, typically occurring in uremic-diabetic patients. We recently treated a patient who had non-diabetic uremic encephalopathy with an atypical lesion distribution involving the supratentorial white matter, without cortical or basal ganglia involvement. To the best of our knowledge, this is only the second reported case of non-diabetic uremic encephalopathy with atypical MR findings.

Small Cell Carcinoma of the Gallbladder: A Case Report

Small cell carcinoma of the gallbladder is a type of neuroendocrine tumor and very rare. We report ultrasound, CT and MR findings of a small cell carcinoma of the gallbladder that was confirmed by pathology. Small cell carcinoma of the gallbladder was seen as a well-defined mass with peripheral rim enhancement in the gallbladder. In spite of the large size of the mass, direct and extensive invasion of the liver was not detected. However, there were many metastatic lymph nodes.

Comprehension of Two Modalities: Endovascular Coiling and Microsurgical Clipping in Treatment of Intracranial Aneurysms / 신경중재치료의학

A subarachnoid hemorrhage (SAH) is caused by rupture of an intracranial aneurysm. SAHs have significant morbidity and mortality worldwide. Since the 1970s, clipping of intracranial aneurysms has been the standard treatment for SAHs. In the 1990s, a detachable platinum coil device was introduced. This device led to the development of endovascular techniques and reduced the risk of further rupture without a craniotomy. Thus, endovascular coiling has become widely used in patients with ruptured and unruptured intracranial aneurysms (UIAs). Regardless of the treatment technique (clipping or endovascular coiling), the goal of occluding aneurysms is the prevention of rebleeding in ruptured aneurysms and rupture in UIAs. These two treatment techniques have advantages and disadvantages. The question of which technique is more effective in patients with intracranial aneurysms remains controversial. The objective of this article is to provide a comprehensive review of the effect of coiling versus clipping of intracranial aneurysms.

Non-Functioning, Malignant Pancreatic Neuroendocrine Tumor in a 16-Year-old Boy: A Case Report

We report the case of a 16-year-old boy with a solid pancreatic mass which proved to be a nonfunctioning, malignant pancreatic neuroendocrine tumor (PNET). In pediatric patients, malignant pancreatic tumors are rare, especially malignant PNET. When dynamic contrast enhanced MRI showed a well enhancing solid pancreatic tumor on arterial and delayed phases and combined with malignant features, such as vascular invasion, invasion of adjascent organs, and lymphadenopathy, we should include malignant pancreatic neuroendocrine tumor in the differential diagnosis of childhood pancreatic tumors.

MR Imaging of Intradural Extramedullary Tuberculoma of the Spinal Cord: Report of Two Cases

Intradural extramedullary tuberculoma of the spinal cord is a rare manifestation of the spinal tuberculosis, with a few cases described so far. Recently, we have experienced two cases of extensive intradural extramedullary tuberculoma at the thoracic spine. So, we report these cases with review of the literatures.

Primary Hepatic Choriocarcinoma: A Case Report

Choriocarcinoma is one of the most common malignancies associated with pregnancy. The characteristics of this malignancy include abnormal growth of the trophoblastic tissue, direct invasion of adjacent organs, and distant metastasis; however, it rarely presents extragonadally. Recently, we have experienced a case of primary hepatic choriocarcinoma in a middle-aged-man, which was characterized by a solitary large hepatic mass with central necrosis and hemorrhaging, as well as metastases to the lung and lymph nodes along the hepatoduodenal ligament. We report this case with a review of the literature.

Diffusion-Weighted Imaging of Brain Injury Due to Neonatal Hypoglycemia: A Case Report

Profound hypoglycemia results in significant brain injury because glucose is essential for normal brain functioning. We present here a case of transient neonatal hypoglycemia with diffuse brain injury. Magnetic resonance imaging was performed 2 days after onset, and this revealed bilateral regions of restricted diffusion in the parietal, occipital, frontal and temporal lobes. On the T1-weighted images, the regions showed indistinct gray matter-white matter differentiation. There were subtle high signal intensity lesions along the corresponding regions of the FLAIR and T2-weighted images.

A Case of Persistent Trigeminal Artery with Basilar Artery Hypoplasia: MRI, MRA and TCD findings

No abstract available.

The Correlation of Clinical Findings of Neuronal Migration Disorders with Brain Magnetic Resonance Imaging Characteristics / 대한소아신경학회지

PURPOSE: Beginning in the eighth week of fetal life the neuroblasts migrate from the midline to the periphery to form the gray matter of the cerebral cortex. Abnormalities of cell migration are characterized by ectopic location of neurons in the cerebral cortex. This broad group of anomalies include lissencephaly, schizencephaly, cortical dysplasia, gray matter heterotopia, and unilateral hemimegalencephaly. The purpose of this study was to correlate clinical data with anatomic data, which was evaluated by brain magnetic resonance imaging characteristics that are most useful in predicting clinical METHODS: The clinical records, EEG, and MRI findings of 20 patients with neuronal migration disorders were retrospectively reviewed. RESULTS: The 20 patients with neuronal migration disorders consisted of 11 with lissencephaly, 7 with cortical dysplasia, 2 with heterotopia, and 2 with schizencephaly. Clinically, seizure was the most common symptom in 85%, next developmental delay in 50%, and then delayed speech in 25%, motor deficit 15% in order. The main associated brain anomalies included absence of septum pellucidum in 20%, periventricular leukomalacia in 15%, and corpus callosal agenesis in 15% of Patients. Bilateral involvement of lesion in MRI was 60%, comparing to unilateral lesion in 40% of the patients. The most common involved lobes was frontoparietal region. An abnormality of EEG examination was showed in 11 cases of patients(68.7%). Patients with diffuse, bilateral lesion in MRI findings of neuronal migration disorders had significantly developmental delay than those with unilateral lesion(p=0.0007). Patients with unilateral lesion had significantly motor deficit than those with bilateral lesion(p=0.04). CONCLUSION: Seizures were the most common symptoms among neurological manifestations of neuronal migration disorders. Statistically significant correlations of delayed developement with bilateral lesion and motor deficit with unilateral lesion were found.

Closure of Carotid Cavernous Fistula by Manual Carotid Jugular Compression / 대한뇌혈관학회지

A patient with symptomatic dural fistula involving the cavernous sinus did intermittant external manual compression of the cervical carotid artery and jugular vein. We observed complete closure of fistula with improvement of symptoms either clinically or at angiography done 6 weeks later, and recommend this technique with clinical follow up and angiography in selected cases before more definitive therapy is employed.

MR Findings of Kallmann Syndrome

Kallman syndrome is characterised by hypogonadotrophic hypogonadism and anosmia. T1 weighted MR coronal images show the bilateral absence or hypoplasia of olfactory bulbs, tracts, and sulci. We report the MR findings of Kallmann syndrome and revew the literature.

MR Findings of Sturge-Weber Syndrome Without Facial Nevus: Two Cases Report

PURPOSE: We reported the CT and MR findings of 2 cases with Sturge-Weber syndrome which were not accompanied by facial nevi. MATERIALS AND METHODS: They were examined with both CT and MR in one case and with MR only in the other case. RESULTS: CT was better than MR in the demonstration of the characteristic cortical calcification. MR was superior to CT in the depiction of the abnormalities of the surrounding parenchyma and the intense enhancement of pial angiomatosis with Gd-DTPA enhancement. CONCLUSION: Gd-DTPA enhanced MR imaging could be useful in the demonstration of the presence and extent of pial angiomatosis in patients with suspected Sturge-Weber syndrome.

Isolated Spontaneous Dissection of the Superior Mesenteric Artery: Percutaneous Stent Placement in Two Patients

Isolated spontaneous dissection of the superior mesenteric artery (SMA) is a rare cause of acute mesenteric ischemia. Two patients were successfully treated by percutaneous stent placement within the main trunk of the SMA. Emphasis is placed on the feasibility of nonsurgical management with percutaneous stent placement of isolated spontaneous dissection of the SMA.

MR Imaging of Cord Transection without Skeletal Injury: A case Report

Spinal cord transection in children may occur following severe trauma such as a motor vehicle accident, and often without evidence of underlying skeletal injury. We report one case which showed cervical cord transection, where no evidence of underlying skeletal injury was seen on MR imaging, four weeks after trauma. When a neurologic deficit is present despite normal routine plain radiographs, further MR imaging is warranted to exclude a cord transection, as demonstrated in our patient.