Multimodality imaging review of ulnar nerve pathologies.

The ulnar nerve is the second most commonly entrapped nerve after the median nerve. Although clinical evaluation and electrodiagnostic studies remain widely used for the evaluation of ulnar neuropathy, advancements in imaging have led to increased utilization of these newer / better imaging techniques in the overall management of ulnar neuropathy. Specifically, high-resolution ultrasonography of peripheral nerves as well as MRI has become quite useful in evaluating the ulnar nerve in order to better guide treatment. The caliber and fascicular pattern identified in the normal ulnar nerves are important distinguishing features from ulnar nerve pathology. The cubital tunnel within the elbow and Guyon's canal within the wrist are important sites to evaluate with respect to ulnar nerve compression. Both acute and chronic conditions resulting in deformity, trauma as well as inflammatory conditions may predispose certain patients to ulnar neuropathy. Granulomatous diseases as well as both neurogenic and non-neurogenic tumors can also potentially result in ulnar neuropathy. Tumors around the ulnar nerve can also lead to mass effect on the nerve, particularly in tight spaces like the aforementioned canals. Although high-resolution ultrasonography is a useful modality initially, particularly as it can be helpful for dynamic evaluation, MRI remains most reliable due to its higher resolution. Newer imaging techniques like sonoelastography and microneurography, as well as nerve-specific contrast agents, are currently being investigated for their usefulness and are not routinely being used currently.

ICA agenesis with transcavernous anastomosis: a systematic review.

PURPOSE: To present two cases of Internal Carotid Artery (ICA) agenesis and conduct a systematic review to assess for associations with other anomalies and intracranial aneurysms. METHODOLOGY: We performed a retrospective review of published cases of patients with ICA agenesis with intercavernous anastomosis in MEDLINE database on August 2022 using search terms "internal carotid artery", "agenesis" and "transcavernous anastomosis". We also included two cases of ICA agenesis with type D collateral that we encountered. RESULTS: Total of 46 studies that included 48 patients and two of our cases resulted in 50 patients. Only 70% of studies reported the location of a collateral vessel of which more than two-thirds were on the floor of sella. More than half of the vessels connected cavernous segments of ICA. A1 segment ipsilateral to the side of ICA agenesis was absent in most of the cases but was not true for all cases. Aneurysm was seen in more than one-quarter of the patients. It can also mimic microadenoma as in prior reported cases as well as in one of our cases. CONCLUSION: ICA agenesis with type D collateral is a rare anomaly but clinically relevant due to the increased risk of an aneurysm or mimic microadenoma or false alarm for occlusion of ICA but knowledge of this rare variant can help in better management of these patients.

Current update on status of saline infusion sonohysterosalpingography.

The purpose of this article is to elucidate the current role of saline infusion sonohysterosalpingography (SIS) in evaluation of various uterine pathologies. SIS improves visualization of the endometrium and pathologies related to endometrial cavity, as well as it can simultaneously assess tubal patency. SIS provides high-resolution images, and three-dimensional (3D) reformatted images provide excellent orientation for radiologists as well as the clinicians about the underlying pathologies. This article will discuss imaging technique, indications, pearls, and pitfalls in imaging, diverse disease pathologies, and ultimately compare performance of SIS among other different imaging modalities. SIS as an adjunct imaging modality results in a greater diagnostic yield for diverse uterine pathologies.

Bilateral supraclavicular abscesses following trigger point injections.

A 54-year-old-woman presented to the emergency department with worsening bilateral shoulder pain six days after trigger point injections in the bilateral supraclavicular areas for chronic pain. A computed tomography scan of the neck revealed bilateral irregular rim enhancing fluid collections. Image-guided percutaneous drainage resulted in marked improvement and near complete resolution by 17 days post-drainage. This case demonstrates the need for early detection of soft-tissue infection and abscess formation related to interventional pain procedures to avoid potentially life-threatening complications, such as Staphylococcus aureus bacteremia.

Primary squamous cell carcinoma of the urinary bladder presenting as an inguinal mass.

This report involves a rare case of a 74-year-old man who presented with a progressively increasing swelling in the right groin, which represented a squamous cell bladder carcinoma herniating into the right inguinal canal. The manuscript discusses the role of multimodality imaging in bladder carcinoma presenting as an inguinoscrotal hernia. The patient subsequently underwent treatment with a chemotherapy regimen consisting of 5-fluorouracil and mitomycin, which was extrapolated from squamous cell carcinoma of the anal canal, and responded well.

COVID-19 induced mesenteric venous infarction.

We present a rare case of mesenteric venous infarction in a 36-year-old man due to coronavirus disease-19 (COVID-19). Although COVID-19 usually presents with respiratory disease, multi-system manifestations are increasingly reported. Coagulopathy manifestations are also reported on imaging, including in vascular thrombosis, embolus, and organ infarction. Because the clinical variables poorly predict or suspect coagulopathy and its complications, it is important to be aware of imaging manifestations of coagulopathy complications of COVID-19.

Rare presentation of chronic recurrent multifocal osteomyelitis of the Iliac wing mimicking Ewing's sarcoma.

This report describes a case of chronic recurrent multifocal osteomyelitis (CRMO) in an 11-year-old girl, involving the iliac bone as an initial, solitary site. Atypical imaging features were suspicious of a bone tumour, such as Ewing's sarcoma. Chronic recurrent multifocal osteomyelitis is a great masquerader and can present atypically. Radiologists should be familiar with both typical and atypical presentations, to determine an accurate diagnosis and guide appropriate management. Timely diagnosis may avoid invasive bone biopsy and inappropriate long-term antibiotic prescription for children.

Laryngeal involvement in a patient with active postprimary tuberculosis: Case report of a rare extrapulmonary manifestation.

A 43-year-old woman was found to have active post-primary tuberculosis and a lateral neck radiograph showing a thickened epiglottis. Bronchoscopy-guided biopsies of the epiglottis and lung were acid fast bacilli stain positive. Histopathology from both showed multiple caseating granulomas. The patient's condition improved with RIPE therapy. This case illustrates the importance for physicians to be aware of possible laryngeal involvement in tuberculosis and that it can present even without evidence of active or latent tuberculosis.

Imaging Findings of Subcutaneous Human Dirofilariasis.

Dirofilariasis is an emerging helminthic zoonosis seldom reported. Humans are accidental hosts and rarely affected. We report a case of dirofilariasis presenting as a subcutaneous nodule in the uncommon location in the thigh with concealed history of dog meat handler. Of the cases published in literature, imaging findings of this disease have been few and far between. In this article, we describe multimodality imaging findings of dirofilariasis in the thigh.

Abdominal aortic aneurysm and its association with duodenal obstruction: aortoduodenal syndrome.

Proximal small bowel obstruction in the region of the duodenum is an uncommon clinical entity. Our case, which involves obstruction of the third portion of the duodenum due to an abdominal aortic aneurysm (AAA), is even more unusual. A review of the relevant literature regarding duodenal obstruction due to extrinsic compression includes features that differentiate aortoduodenal syndrome from superior mesenteric artery syndrome. Management of these conditions range from conservative to surgical, of which now includes a more recent role of metallic stents in some instances.

An unresponsive COVID-19 patient.

Neurological manifestations and complications are increasingly reported in coronavirus disease-19 (COVID-19) patients. Although pulmonary manifestations are more common, patients with severe disease may present with neurological symptoms such as in our case. We describe a case report of a 50-year-old male without previous known comorbidity who was found unresponsive due to COVID-19-related neurological complications. During this pandemic, an emergency radiologist should be well acquainted with various neurological manifestations of COVID-19. In this article, we will discuss the pathogenesis, imaging findings, and differentials of this disease.

Spontaneous rupture of the renal calyx secondary to a vesicoureteral junction calculus.

BACKGROUND: Spontaneous urinary collecting system rupture is caused by increased ureteral intraluminal pressure secondary to an obstruction. Rarely, a small stone exerts high intraureteral pressure especially if it is located distally. Many management modalities with good outcomes have been implicated. PURPOSE: Herein, we present a case of nontraumatic rupture of the renal calyx due to a 4 mm obstructing stone at the vesicoureteral junction. BASIC PROCEDURES: CT scan of abdomen and pelvis without contrast, CT scan of the abdomen and pelvis with intravenous contrast, Cystoscopy, Double-J ureter stent, Urinary Foley catheter. MAIN FINDINGS: The diagnosis was confirmed by CT imaging. Non-contrast enhanced CT scan of abdomen and pelvis showed obstructive calculi measuring 4 mm in the right vesicoureteral junction. Contrast-enhanced CT scan revealed leakage of contrast in the perinephric space at the right major calyx with intact bilateral ureters, suggestive of calyceal rupture. The treatment involved antibiotics and double-J stenting. PRINCIPAL CONCLUSIONS: This case demonstrates that spontaneous calyceal rupture should be suspected in urolothiasis patients presenting for a severe pain even if the calculus is small (less than 5 mm) and the laboratory markers are normal. An immediate management is required to relief symptoms and prevent further complications.

Axumin Positron Emission Tomography: Novel Agent for Prostate Cancer Biochemical Recurrence.

Prostate cancer remains one of the top common cancers in terms of incidence and cancer-related deaths. Approximately 1/3rd cases develop biochemical recurrence during surveillance post-definite therapy. Multiple imaging modalities, including computed tomography (CT), magnetic resonance imaging (MRI) (including multiparametric prostate MRI), bone scan, and positron emission tomography (PET) using different tracers are being used for the characterization of the prostate cancer recurrence. CT and MRI do not provide physiological information, thus have lower sensitivity in detecting the metastasis. A bone scan has low sensitivity (depending on the prostate-specific antigen level) with low specificity as well. Among different PET tracers, Axumin PET appears to be the most promising tool. Axumin PET is Food and Drug Administration approved for the evaluation of prostate cancer biochemical recurrence. Several studies have shown that Axumin PET findings played a key role in treatment modification by finding otherwise undetected lesions. We briefly discuss the salient characteristics, imaging protocol and image interpretation criteria for Axumin PET in the workup of prostate cancer biochemical recurrence.

Bone Causing Abdominal Groans.

Gastrointestinal complications secondary to fish bone ingestion are rare, however important to recognize in timely manner to prevent morbidity and mortality. Diagnosis is often challenging in setting of non-specific and variable symptoms and lack of history of fish bone ingestion. Diagnostic imaging particularly computed tomography is crucial for diagnosis. However, emphasis should be given on identifying underlying cause of abdominal complications because fish bone is often missed unless specifically looked for. Identification of fish bone is essential for extraction of the inciting nidus. Emergency physician should be aware of this entity to identify it and triage the patients in timely manner. We describe here cases of sub-capsular liver abscess and acute cholecystitis caused by fish bone ingestion. The fish bone as a cause of these complication was initially missed in emergency.

Imaging of non-traumatic urinary bladder emergencies.

Non-traumatic urinary bladder emergencies are rare but critical diagnoses to make in an emergency setting. Acute urinary bladder pathologies require an accurate and timely diagnosis to ensure a favorable clinical outcome. Multidetector computed tomography (CT) is the imaging modality of choice for acute and emergent conditions affecting the urinary bladder. MRI is helpful as a problem-solving modality due to better soft tissue characterization and higher in-plane resolution. The purpose of this article is to illustrate the spectrum of urinary bladder emergencies, review the imaging findings, and briefly describe the role of imaging in the evaluation of such patients. Although there are a few cases of bladder emergencies been reported separately, the literature summarizing the spectrum is lacking. The objective of this article is to review the imaging of acute emergencies involving urinary bladder that will help us to think beyond non-specific conclusion in an emergency setting. For the sake of focused discussion, traumatic bladder emergencies will be excluded in this review. In the era of highly image reliant clinical practice, radiologists must be familiar with the diagnostic strategy to approach these entities.

Neuroimaging of Pediatric Arteriopathies.

Pediatric arteriopathies are increasingly recognized in school-aged children with a variety of presenting symptoms ranging from headache, seizures, encephalopathy, and neuropsychiatric symptoms as well as focal neurologic deficits due to acute ischemic strokes. However, unlike the adult stroke population, there are differences in the clinical manifestations, the stroke mechanism, and risk factors in pediatric ischemic stroke. There has been increasing awareness and recognition of pediatric cerebral arteriopathies as a predominant stroke etiology. Prompt diagnosis of arteriopathies is essential to limit injury and prevent recurrent stroke. Based on predominant vessels involved and clinical symptoms, these arteriopathies can be broadly divided into two categories: large-medium size arteriopathies and small vessel arteriopathies. Each category can be further divided into inflammatory and noninflammatory according to their etiologies. The ability to distinguish between inflammatory and noninflammatory etiologies carries major prognostic implications for acute management and secondary stroke prevention as well as screening for systemic complications and counseling.

Pediatric Congenital Cerebrovascular Anomalies.

Congenital cerebrovascular anomalies in the pediatric age group are myriad with diverse etiologies. The purpose of this paper is to provide an imaging overview of congenital vascular malformations and vascular tumors, as these conditions are varied and the characteristic vascular abnormality may even suggest the underlying systemic condition in helping to guide further management. For example, the identification of an arterial anomaly such as agenesis/hypoplasia/duplication may warrant further evaluation for an associated syndrome. Recognition of other pertinent findings, such as persistent carotid-vertebrobasilar anastomoses for instance, would be particularly important for the planning of potential embolization/coiling of associated vascular malformation and/or aneurysm. Awareness of congenital dural sinus anomalies, including hypoplasia, aplasia, and or duplication, prevents the incorrect or overdiagnosis of sinus thrombosis. Moreover, multiple developmental venous anomalies in a patient may require further investigation for its familial association. In a similar context, there may be familial association with multiple cavernous malformations and children with central nervous system vascular malformations may have an association with other vascular conditions, eg, hereditary hemorrhagic telangiectasia, etc. An accurate description of vascular lesions is critical for understanding the natural history of the disease process and ultimately for guiding treatment. An important example of this includes Sturge-Weber syndrome, which is often incorrectly viewed as an arteriovenous malformation, but actually a type of venous malformation. Another example which is important to recognize includes the differentiation between an infantile hemangioma and a vascular malformation, particularly as the course of the pathology and the treatment is so different between the two.

Role of diffusion-weighted imaging in head and neck lesions: Pictorial review.

Head and neck cancers are very common worldwide, causing significant morbidity and mortality. Squamous cell carcinoma originating from the epithelial lining of the upper aerodigestive tract is the most common histology. Many patients with head and neck cancers present with advanced stage disease requiring aggressive treatment consisting of extensive surgery and chemo-radiation. Appropriate treatment planning as well as prognosis of tumors depends to a large extent on accurate histological diagnosis and differentiation of malignant from benign lesions. Routine imaging modalities such as computed tomography and magnetic resonance imaging give volumetric and morphologic information. However, these modalities cannot be reliably used as a substitute for biopsy in treatment planning. However, diffusion-weighted imaging has shown promise in tissue characterization for primary tumors and nodal metastases, differentiation of recurrent tumor from post therapeutic changes, prediction and monitoring of treatment response, and many other clinical scenarios as described later in this article. In this review article, we describe the imaging findings in applications of diffusion-weighted imaging in the head and neck lesions and discuss their added value over anatomic imaging.

Neonatal cranial sonography: ultrasound findings in neonatal meningitis-a pictorial review.

Neonatal bacterial meningitis is a common manifestation of late onset neonatal sepsis. Cranial sonography (CRS) has a crucial role in assessment of infants with clinical suspicion of bacterial meningitis as well as follows up of its complications. CRS is performed with high frequency transducer through anterior fontanelle in both coronal and sagittal planes. Various sonographic findings range from echogenic and widened sulci, ventriculomegaly, ventriculitis, hydrocephalus, extra-axial fluid collections, cerebritis and brain abscess. Sonography is extremely beneficial in evaluating intraventricular contents, especially debris and intraventricular septations. Linear high frequency probe along with color Doppler interrogation are of utmost importance in evaluating extra-axial fluid collection and helps differentiating it from benign subarachnoid space enlargement. Due to low cost, easy portability, speed of imaging, no need for sedation and above all lack of ionizing radiation make it superior to other cross sectional imaging, like CT and MRI, in evaluation of these sick neonates. Apart from textbooks, there is paucity of recently available literature on cranial sonographic findings in neonatal meningitis. This article is written with an educational intent to review the spectrum of findings in neonatal meningitis, with stress on findings that will be beneficial in the clinical practice.