Imaging of juvenile spinal disorders.

The growing spine is under excessive stresses during pubertal growth. There are specific pathologies, such as posterior ring apophyseal fractures, spondylolysis, and Hirayama's disease, which are primarily encountered in this subset of patients. Pain and deformity remain the common clinical presentations of these disorders. Imaging plays a vital role in elucidating the radiological manifestations of these unusual pathologies and in their subsequent management.

The value of performing cerebrovascular CT angiography in major trauma patients: a 5-year retrospective review.

AIM: To assess whether routine cerebrovascular imaging is required in all major trauma (MT) patients. MATERIALS AND METHODS: All MT patients with cerebrovascular imaging between January 2015 and December 2020 were included in the study. Data were collated regarding the type of indication for computed tomography (CT) angiography imaging, time interval from the initial trauma, relevant trauma diagnoses on initial trauma imaging, and CT angiography. Findings, such as aneurysms, vascular malformations, luminal thrombus, venous sinus thrombosis, or vascular injury, were collated. Subsequent treatment with anti-coagulants/anti-platelets or surgical/radiological intervention was noted. Follow-up imaging was assessed for residual injury or complications. RESULTS: Two hundred and fifty of the 6,251 MT patients underwent dedicated cerebrovascular imaging and were included in the study. Of these 41 (16.4%) had cervical artery or venous sinus injury. Further positive vascular findings were identified in 25/250 patients who presented with an incidental stroke or a vascular abnormality and were mislabelled as MT patients at presentation. One patient with a carotid injury subsequently died following a large infarction. Another patient with vertebral artery injury suffered a non-lethal stroke. No patients underwent surgery or intervention. CONCLUSION: The present study showed that the overall incidence of detected blunt cerebrovascular injuries was very low (0.6%) and even lower for symptomatic vascular injury (0.03%). Routine cerebrovascular imaging is not recommended in all MT trauma patients, but instead, a continued case-by-case basis should be considered.

The clue is in the kidneys: greater renal contrast medium accumulation on ipsilateral side down CT myelogram after lateral decubitus digital subtraction myelogram as a predictor of laterality of cerebrospinal fluid leak.

AIM: To assess the potential correlation of the laterality of a cerebrospinal fluid (CSF)-venous fistula with the laterality of decubitus computed tomography (CT) myelogram (post decubitus digital subtraction myelogram) based on which side demonstrated more renal contrast medium excretion. MATERIALS AND METHODS: Patients with CSF-venous fistulas diagnosed at lateral decubitus digital subtraction myelograms were reviewed retrospectively. Patients who did not have CT myelogram following one or both left and right lateral decubitus digital subtraction myelograms were excluded. Two neuroradiologists independently interpreted the CT myelogram for the presence or absence of renal contrast, and whether subjectively more renal contrast medium was visualised on the left or right lateral decubitus CT myelogram. RESULTS: Renal contrast medium was seen in lateral decubitus CT myelograms in 28 of 30 (93.3%) patients with CSF-venous fistulas. Having more renal contrast medium in right lateral decubitus CT myelogram was 73.9% sensitive and 71.4% specific for the diagnosis of a right-sided CSF-venous fistula, whereas having more renal contrast medium in the left lateral decubitus CT myelogram was 71.4% sensitive and 82.6% specific for a left-sided CSF-venous fistula (p=0.02). CONCLUSION: When the CSF-venous fistula lies on the dependent side of a decubitus CT myelogram performed after decubitus digital subtraction myelogram, relatively more renal contrast medium is visualised compared to when the fistula lies on the non-dependent side.

Impact of Lymphadenectomy on Survival After Unimodality Transthoracic Esophagectomy for Adenocarcinoma of Esophagus.

BACKGROUND: Debate remains regarding the extent of lymphadenectomy required with esophagectomy. In patients who receive neoadjuvant treatment, this may address lymph node metastases. However, patients with early disease and those with comorbidities may not receive neoadjuvant treatment. The aim of this study is to determine the impact of lymph node yield and location on prognosis in patients undergoing esophagectomy without neoadjuvant treatment. PATIENTS AND METHODS: Data from consecutive patients with potentially curable adenocarcinoma of the esophagus or gastroesophageal junction were reviewed. Patients were treated with transthoracic esophagectomy and two-field lymphadenectomy. Outcomes according to lymph node yield were determined. The prognosis of carrying out less radical lymphadenectomy was calculated according to three groups: exclusion of proximal thoracic nodes (group 1), minimal abdominal lymphadenectomy (group 2), and minimal abdominal and thoracic lymphadenectomy (group 3). RESULTS: 357 patients were included. Median survival was 78 months [confidence interval (CI) 53-103 months]. Absolute lymph node retrieval was not related to survival (p = 0.920). An estimated additional 4 (2-6) cancer-related deaths was projected if group 1 nodes were omitted, 15 (11-19) additional deaths if group 2 nodes were omitted, and 4 (2-6) deaths if group 3 nodes were omitted. Minimal lymphadenectomy (groups 1, 2, and 3) was projected to lead to 19 (15-23) additional cancer-related deaths. CONCLUSIONS: Extensive lymphadenectomy allows accurate staging. In patients who do not receive neoadjuvant treatment, it may confer a survival benefit. The number of lymph nodes retrieved may not be a good surrogate for extent of lymphadenectomy, and correlation with location is required.

Idiopathic spinal cord herniation.

Idiopathic spinal cord herniation is a rare but important and increasingly recognised cause of myelopathy seen in the thoracic spine. The factors that contribute to the aetiology of the condition and of the dural defect through which the cord herniates remain under debate. We discuss the clinical features and proposed pathophysiology of the condition, and illustrate key imaging findings on MRI, fluoroscopy and computed tomography (CT) myelography to establish the diagnosis, and discuss relevant differential diagnoses. Awareness and recognition of the condition is key as surgical intervention can improve outcomes for patients.

The Monro-Kellie Doctrine: A Review and Call for Revision.

The Monro-Kellie doctrine is a well-accepted principle of intracranial hemodynamics. It has undergone few consequential revisions since it was established. Its principle is straightforward: The combined volume of neuronal tissue, blood, and CSF is constant. To maintain homeostatic intracranial pressure, any increase or decrease in one of these elements leads to a reciprocal and opposite change in the others. The Monro-Kellie doctrine assumes a rigid, unadaptable calvaria. Recent studies have disproven this assumption. The skull expands and grows in response to pathologic changes in intracranial pressure. In this review, we outline what is known about calvarial changes in the setting of pressure dysregulation and suggest a revision to the Monro-Kellie doctrine that includes an adaptable skull as a fourth component.

The impact of age on long-term survival following gastrectomy for gastric cancer.

INTRODUCTION: Gastrectomy remains the primary curative treatment modality for patients with gastric cancer. Concerns exist about offering surgery with a high associated morbidity and mortality to elderly patients. The study aimed to evaluate the long-term survival of patients with gastric cancer who underwent gastrectomy comparing patients aged <70 years with patients aged ≥70 years. METHODS: Consecutive patients who underwent gastrectomy for adenocarcinoma with curative intent between January 2000 and December 2017 at a single centre were included. Patients were stratified by age with a cut-off of 70 years used to create two cohorts. Log rank test was used to compare overall survival and Cox multivariable regression used to identify predictors of long-term survival. RESULTS: During the study period, 959 patients underwent gastrectomy, 520 of whom (54%) were aged ≥70 years. Those aged <70 years had significantly lower American Society of Anesthesiologists grades (p<0.001) and were more likely to receive neoadjuvant chemotherapy (39% vs 21%; p<0.001). Overall complication rate (p=0.001) and 30-day postoperative mortality (p=0.007) were lower in those aged <70 years. Long-term survival (median 54 vs 73 months; p<0.001) was also favourable in the younger cohort. Following adjustment for confounding variables, age ≥70 years remained a predictor of poorer long-term survival following gastrectomy (hazard ratio 1.35, 95% confidence interval 1.09, 1.67; p=0.006). CONCLUSIONS: Low postoperative mortality and good long-term survival were demonstrated for both age groups following gastrectomy. Age ≥70 years was, however, associated with poorer outcomes. This should be regarded as important factor when counselling patients regarding treatment options.

Conebeam CT as an Adjunct to Digital Subtraction Myelography for Detection of CSF-Venous Fistulas.

Lateral decubitus digital subtraction myelography is an effective technique for precisely localizing CSF-venous fistulas, a common cause of spontaneous intracranial hypotension. However, despite an optimal imaging technique, digital subtraction myelography fails to identify some CSF-venous fistulas for a variety of reasons. Here, we describe a technique involving conebeam CT performed during intrathecal contrast injection as an adjunct to digital subtraction myelography, allowing identification of some otherwise-missed CSF-venous fistulas.

Utility of Photon-Counting Detector CT Myelography for the Detection of CSF-Venous Fistulas.

CSF-venous fistulas are an increasingly recognized type of CSF leak that can be particularly challenging to detect, even with recently improved imaging techniques. Currently, most institutions use decubitus digital subtraction myelography or dynamic CT myelography to localize CSF-venous fistulas. Photon-counting detector CT is a relatively recent advancement that has many theoretical benefits, including excellent spatial resolution, high temporal resolution, and spectral imaging capabilities. We describe 6 cases of CSF-venous fistulas detected on decubitus photon-counting detector CT myelography. In 5 of these cases, the CSF-venous fistula was previously occult on decubitus digital subtraction myelography or decubitus dynamic CT myelography using an energy-integrating detector system. All 6 cases exemplify the potential benefits of photon-counting detector CT myelography in identifying CSF-venous fistulas. We suggest that further implementation of this imaging technique will likely be valuable to improve the detection of fistulas that might otherwise be missed with currently used techniques.

Gastric outlet obstruction secondary to a wandering spleen: systematic review and surgical management of a case.

INTRODUCTION: A wandering spleen occurs when laxity or absence of the suspensory ligaments allows migration throughout the abdomen. Gastric outlet obstruction resulting from this abnormality is rare. We present a systematic literature search and a case that was managed successfully with surgical intervention at our centre. METHODS: A systematic search of the PubMed, Embase™, Medline® and Google Scholar™ databases was carried out employing the combined search terms "gastric outlet obstruction" AND "wandering spleen". Six results were included for final analysis. RESULTS: All six search results described a single case each. Patients underwent surgical management (open or laparoscopic) after initial investigation utilising a range of modalities. There were no mortalities reported at 90 days. The single case we present was complicated by gastric perforation; the patient made a successful recovery following open splenopexy and stapled wedge resection of the stomach. CONCLUSIONS: A wandering spleen is a rare diagnosis and there are only six reported cases of gastric outlet obstruction secondary to a wandering spleen in the literature. None report associated gastric perforation. There are a variety of presenting symptoms, intraoperative findings and operative techniques used to address the gastrosplenic abnormality. The case reported by our centre adds to this limited evidence base and demonstrates a successful outcome from definitive surgical management. We highlight the need to seek early gastro-oesophageal expertise if any gastric pathology is found together with anatomical abnormality of the spleen.

Temporal Characteristics of CSF-Venous Fistulas on Digital Subtraction Myelography.

BACKGROUND AND PURPOSE: CSF-venous fistula can be diagnosed with multiple myelographic techniques; however, no prior work has characterized the time to contrast opacification and the duration of visualization. The purpose of our study was to evaluate the temporal characteristics of CSF-venous fistula on digital subtraction myelography. MATERIALS AND METHODS: We reviewed the digital subtraction myelography images of 26 patients with CSF-venous fistulas. We evaluated how long the CSF-venous fistula took to opacify after contrast reached the spinal level of interest and how long it remained opacified. Patient demographics, CSF-venous fistula treatment, brain MR imaging findings, CSF-venous fistula spinal level, and CSF-venous fistula laterality were recorded. RESULTS: Eight of the 26 CSF-venous fistulas were seen on both the upper- and lower-FOV digital subtraction myelography, for a total of 34 CSF-venous fistula views evaluated on digital subtraction myelography. The mean time to appearance was 9.1 seconds (range, 0-30 seconds). Twenty-two (84.6%) of the CSF-venous fistulas were on the right. The highest fistula level was C7, while the lowest was T13 (13 rib-bearing vertebral bodies). The most common CSF-venous fistula levels were T6 (4 patients) followed by T8, T10, and T11 (3 patients each). The mean age was 58.3 years (range, 31.7-87.6 years). Sixteen patients were women (61.5%). CONCLUSIONS: This is the first study to report the temporal characteristics of CSF-venous fistulas using digital subtraction myelography. We found that on average, the CSF-venous fistula appeared 9.1 seconds (range, 0-30 seconds) after intrathecal contrast reached the spinal level.

Fluoroscopy- and CT-Guided Gold Fiducial Marker Placement for Intraoperative Localization during Spinal Surgery: Review of 179 Cases at a Single Institution-Technique and Safety Profile.

BACKGROUND AND PURPOSE: Wrong-level spinal surgery, especially in the thoracic spine, remains a challenge for a variety of reasons related to visualization, such as osteopenia, large body habitus, severe kyphosis, radiographic misinterpretation, or anatomic variation. Preoperative fiducial marker placement performed in a dedicated imaging suite has been proposed to facilitate identification of thoracic spine vertebral levels. In this current study, we report our experience using image-guided percutaneous gold fiducial marker placement to enhance the accuracy and safety of thoracic spinal surgical procedures. MATERIALS AND METHODS: A retrospective review was performed of all fluoroscopy- or CT-guided gold fiducial markers placed at our institution between January 3, 2019, and March 16, 2022. A chart review of 179 patients was performed detailing the procedural approach and clinical information. In addition, the method of gold fiducial marker placement (fluoroscopy/CT), procedure duration, spinal level of the gold fiducial marker, radiation dose, fluoroscopy time, surgery date, and complications (including whether wrong-level surgery occurred) were recorded. RESULTS: A total of 179 patients (104 female) underwent gold fiducial marker placement. The mean age was 57 years (range, 12-96 years). Fiducial marker placement was performed by 13 different neuroradiologists. All placements were technically successful without complications. All 179 (100%) operations were performed at the correct level. Most fiducial markers (143) were placed with fluoroscopy with the most common location at T6-T8. The most common location for placement in CT was at T3 and T4. CONCLUSIONS: All operations guided with gold fiducial markers were performed at the correct level. There were no complications of fiducial marker placement.

Reassessing the Carotid Artery Plaque "Rim Sign" on CTA: A New Analysis with Histopathologic Confirmation.

BACKGROUND AND PURPOSE: The CTA "rim sign" has been proposed as an imaging marker of intraplaque hemorrhage in carotid plaques. This study sought to investigate such findings using histopathologic confirmation. MATERIALS AND METHODS: Included patients had CTA neck imaging <1 year before carotid endarterectomy. On imaging, luminal stenosis and the presence of adventitial (<2-mm peripheral) and "bulky" (≥2-mm) calcifications, total plaque thickness, soft-tissue plaque thickness, calcification thickness, and the presence of ulcerations were assessed. The rim sign was defined as the presence of adventitial calcifications with internal soft-tissue plaque of ≥2 mm in maximum thickness. Carotid endarterectomy specimens were assessed for both the presence and the proportional makeup of lipid material, intraplaque hemorrhage, and calcification. RESULTS: Sixty-seven patients were included. Twenty-three (34.3%) were women; the average age was 70.4 years. Thirty-eight (57.7%) plaques had a rim sign on imaging, with strong interobserver agreement (κ = 0.85). A lipid core was present in 64 (95.5%) plaques (average, 22.2% proportion of plaque composition); intraplaque hemorrhage was present in 52 (77.6%), making up, on average, 13.7% of the plaque composition. The rim sign was not associated with the presence of intraplaque hemorrhage (P = .11); however, it was associated with a greater proportion of intraplaque hemorrhage in a plaque (P = .049). The sensitivity and specificity of the rim sign for intraplaque hemorrhage were 61.5% and 60.0%, respectively. CONCLUSIONS: The rim sign is not associated with the presence of intraplaque hemorrhage on histology. However, it is associated with a higher proportion of hemorrhage within a plaque and therefore may be a biomarker of more severe intraplaque hemorrhage, if present.

Sacral CSF-Venous Fistulas and Potential Imaging Techniques.

This is the first study to describe CSF-venous fistulas involving the sacrum, a location that may be underrecognized on the basis of current imaging techniques. We describe a delayed decubitus flat CT myelogram technique that may be useful to identify sacral CSF-venous fistulas.

Percutaneous CT-Guided Core Needle Biopsies of Head and Neck Masses: Review of 184 Cases at a Single Academic Institution, Common and Special Techniques, Diagnostic Yield, and Safety.

BACKGROUND AND PURPOSE: Percutaneous CT-guided core needle biopsies of head and neck lesions can be safely performed with vigilant planning. This largest-to-date single-center retrospective study evaluates multiple approaches with consideration of special techniques and examines the histopathologic yield. MATERIALS AND METHODS: Retrospective review of CT-guided core biopsies of head and neck lesions from January 1, 2010, to October 30, 2020, was performed. We recorded the following: patient demographics, sedation details, biopsy needle type and size, lesion location and size, approach, patient positioning, preprocedural intravenous contrast, proceduralists' years of experience, complications, and pathology results. RESULTS: One hundred eighty-four CT-guided core biopsies were evaluated. The initial diagnostic yield was 93% (171/184). However, of 43/184 (23%) originally "negative for malignancy" biopsies, 4 were eventually positive for malignancy via rebiopsy/excision, resulting in a 2% false-negative rate and an adjusted total diagnostic yield of 167/184 (91%). Biopsies were performed by 16 neuroradiologists with variable experience. The diagnostic yield was essentially the same: 91% (64/70) for proceduralists with ≤3 years' experience, and 90% (103/114) with >3 years' experience. The diagnostic yield was 93% (155/166) for lesions of >10 mm. The diagnostic yield per biopsy needle gauge was the following: 20 ga, 81% (13/16); 18 ga, 93% (70/75); 16 ga, 90% (64/71); and 14 ga, 91% (20/22). There were 4 asymptomatic hematomas, with none requiring intervention. CONCLUSIONS: Percutaneous CT-guided core needle biopsies are safe procedures for superficial and deep head and neck lesions with a high diagnostic yield. Careful planning and special techniques may increase the number of lesions accessible percutaneously while minimizing the risk of complications.

Impact ionization-induced bistability in CMOS transistors at cryogenic temperatures for capacitorless memory applications.

Cryogenic operation of complementary metal oxide semiconductor (CMOS) silicon transistors is crucial for quantum information science, but it brings deviations from standard transistor operation. Here, we report on sharp current jumps and stable hysteretic loops in the drain current as a function of gate voltage V G for both n- and p-type commercial-foundry 180-nm-process CMOS transistors when operated at voltages exceeding 1.3 V at cryogenic temperatures. The physical mechanism responsible for the device bistability is impact ionization charging of the transistor body, which leads to effective back-gating of the inversion channel. This mechanism is verified by independent measurements of the body potential. The hysteretic loops, which have a >107 ratio of high to low drain current states at the same V G, can be used for a compact capacitorless single-transistor memory at cryogenic temperatures with long retention times.

Recent onset neck pain with associated neurological deficit--Pott's disease remains an important differential diagnosis.

The incidence of spinal tuberculosis is increasing in developed nations. In Ireland, half of all cases seen in the most recent decade for which figures are available were diagnosed in 2005-2007, the three most recent years for which there is complete data. We discuss a patient who presented with neurological complications due to destructive spinal tuberculous disease affecting the sixth cervical vertebra.

Trainee performance in radical gastrectomy and its effect on outcomes.

BACKGROUND: This study aimed to determine whether trainee involvement in D2 gastrectomies was associated with adverse outcomes. METHODS: Data from a prospectively created database of consecutive patients undergoing open D2 total (TG) or subtotal (STG) gastrectomy with curative intent between January 2009 and January 2014 were reviewed. Short- and long-term clinical outcomes were compared in patients operated on by consultants and those treated by trainees under consultant supervision. RESULTS: A total of 272 D2 open gastrectomies were performed, 123 (45·2 per cent) by trainees. There was no significant difference between consultants and trainees in median duration of surgery (TG: 240 (range 102-505) versus 240 (170-375) min respectively, P = 0·452; STG: 225 (150-580) versus 212 (125-380) min, P = 0·192), number of resected nodes (TG: 30 (13-101) versus 30 (11-102), P = 0·681; STG: 26 (5-103) versus 25 (1-63), P = 0·171), length of hospital stay (TG: 15 (7-78) versus 15 (8-65) days, P = 0·981; STG: 10 (6-197) versus 14 (7-85) days, P = 0·242), overall morbidity (TG: 44 versus 49 per cent, P = 0·314; STG: 34 versus 25 per cent, P = 0·113) or mortality (TG: 4 versus 2 per cent; P = 0·293). No difference in predicted 5-year overall survival was noted between the two cohorts (TG: 68 per cent for consultants versus 77 per cent for trainees, P = 0·254; STG: 70 versus 75 per cent respectively, P = 0·512). The trainee cohort had lower median blood loss for both TG (360 (range 90-1200) ml versus 600 (70-2350) ml for consultants; P = 0·042) and STG (235 (50-1000) versus 360 (50-3000) ml respectively; P = 0·053). CONCLUSION: Clinical outcomes were not compromised by supervised trainee involvement in D2 open gastrectomy.

ANTECEDENTES: El hecho de que en operaciones complejas la experiencia quirúrgica sea limitada puede influir en los resultados. Esto puede ser especialmente relevante cuando estas operaciones son realizadas por cirujanos en formación bajo supervisión. El objetivo de este estudio fue determinar si la participación del cirujano en formación en las gastrectomías D2 se asociaba con resultados adversos. MÉTODOS: Se revisó la información recogida en una base de datos prospectiva de pacientes consecutivos sometidos a gastrectomía D2 abierta total (total gastrectomy, TG) o subtotal (subtotal gastrectomy, STG) con intención curativa desde enero de 2009 a enero de 2014. Los pacientes se dividieron en dos grupos, uno de pacientes operados por un cirujano consultor y otro, de pacientes operados por un cirujano en periodo formación bajo la supervisión de un cirujano consultor. Se compararon los resultados clínicos a corto y largo plazo incluyendo la supervivencia global esperada a los cinco años. RESULTADOS: Se realizaron un total de 272 gastrectomías D2 abiertas (45% por cirujanos en periodo de formación). Las características demográficas de los pacientes fueron similares en los grupos de los cirujanos en formación y cirujanos consultores. En la TG y STG, no se apreciaron diferencias significativas entre ambas cohortes en el tiempo operatorio (P = 0,45)y (P = 0,19), número de ganglios linfáticos extirpados (P = 0,68) y (P = 0,17), duración de la estancia hospitalaria (P = 0,98) y (P = 0,24), morbilidad global (P = 0,31) y (P = 0,11), mortalidad (P = 0,29) y supervivencia global esperada a los 5 años (P = 0,25) y (P = 0,51). La pérdida sanguínea en ambas TG y STG fue menor en la cohorte de cirujanos en formación (P < 0,05). CONCLUSIÓN: La práctica de una gastrectomía D2 abierta por cirujanos en periodo de formación supervisados por consultores no comprometían los resultados clínicos.

A multicentre, prospective, observational cohort study of variation in practice in perioperative analgesia strategies in elective laparoscopic colorectal surgery (the LapCoGesic study).

INTRODUCTION: Enhanced recovery programmes are established as an essential part of laparoscopic colorectal surgery. Optimal pain management is central to the success of an enhanced recovery programme and is acknowledged to be an important patient reported outcome measure. A variety of analgesia strategies are employed in elective laparoscopic colorectal surgery ranging from patient-controlled analgesia to local anaesthetic wound infiltration catheters. However, there is little evidence regarding the optimal analgesia strategy in this cohort of patients. The LapCoGesic study aimed to explore differences in analgesia strategies employed for patients undergoing elective laparoscopic colorectal surgery and to assess whether this variation in practice has an impact on patient-reported and clinical outcomes. MATERIALS AND METHODS: A prospective, multicentre, observational cohort study of consecutive patients undergoing elective laparoscopic colorectal resection was undertaken over a two-month period. The primary outcome measure was postoperative pain scores at 24 hours. Data analysis was conducted using SPSS version 22. RESULTS: A total of 103 patients undergoing elective laparoscopic colorectal surgery were included in the study. Thoracic epidural was used in 4 (3.9%) patients, spinal diamorphine in 56 (54.4%) patients and patient-controlled analgesia in 77 (74.8%) patients. The use of thoracic epidural and spinal diamorphine were associated with lower pain scores on day 1 postoperatively (P < 0.05). The use of patient-controlled analgesia was associated with significantly higher postoperative pain scores and pain severity. DISCUSSION: Postoperative pain is managed in a variable manner in patients undergoing elective colorectal surgery, which has an impact on patient reported outcomes of pain scores and pain severity.

Imaging Review of Paraneoplastic Neurologic Syndromes.

Paraneoplastic syndromes are systemic reactions to neoplasms mediated by immunologic or hormonal mechanisms. The most well-recognized paraneoplastic neurologic syndrome, both clinically and on imaging, is limbic encephalitis. However, numerous additional clinically described syndromes affect the brain, spinal cord, and peripheral nerves. Many of these syndromes can have imaging findings that, though less well described, are important in making the correct diagnosis. Moreover, imaging in these syndromes frequently mimics more common pathology, which can be a diagnostic challenge for radiologists. Our goal is to review the imaging findings of paraneoplastic neurologic syndromes, including less well-known entities and atypical presentations of common entities. Specifically, we discuss limbic encephalitis, paraneoplastic cerebellar degeneration, paraneoplastic brain stem encephalitis, cranial neuropathy, myelitis, and polyneuropathy. We also demonstrate common diagnostic pitfalls that can be encountered when imaging these patients.