Revisiting the "Puffed Cheek" Technique: Advantages, Fallacies, and Potential Solutions.

The "puffed cheek" technique is routinely performed during CT neck studies in patients with suspected oral cavity cancers. The insufflation of air within the oral vestibule helps in the detection of small buccal mucosal lesions, with better delineation of lesion origin, depth, and extent of spread. The pitfalls associated with this technique are often underrecognized and poorly understood. They can mimic actual lesions, forfeiting the technique's primary purpose. This review provides an overview of the puffed cheek technique and its associated pitfalls. These pitfalls include pneumoparotid, soft palate elevation that resembles a nasopharyngeal mass, various tongue displacements or distortions that obscure tongue lesions or mimic them, sublingual gland herniation, an apparent exacerbation of the airway edema, vocal cord adduction that hinders glottic evaluation, and false indications of osteochondronecrosis in laryngeal cartilage. Most stem from a common underlying mechanism of unintentional Valsalva maneuver engaged in by the patient while trying to perform a puffed cheek, creating a closed air column under positive pressure with resultant surrounding soft-tissue displacement. These pitfalls can thus be avoided by instructing the patient to maintain continuous nasal breathing while puffing out their cheek during image acquisition, preventing the formation of the closed air column. Keywords: CT, Head/Neck © RSNA, 2024.

Slow-Flow Venous Vascular Malformation in the Carotid Sheath.

Slow-flow venous vascular malformation is a benign lesion characterized by an abnormal but non-cancerous growth of capillaries. In the carotid space, a slow-flow venous vascular malformation is an exceptionally uncommon occurrence. Here, we present the case of a 58-year-old man who had been experiencing a slow-growing lump on the left side of his neck for the past four years. Upon conducting magnetic resonance imaging (MRI) of the neck soft tissues and computed tomography angiography (CTA) of the neck, imaging findings revealed a venous vascular malformation within the carotid sheath. Venous vascular malformation in the carotid space is rarely reported in the medical literature. The unique imaging findings for venous vascular malformation make our case distinct, which deviates from the more common entities usually encountered in this area, such as schwannoma or carotid body tumor. The atypical presentation of this case has brought about greater awareness among the medical community and readers alike.

Human parechovirus meningoencephalitis.

Human parechovirus-3 (HPeV-3) infection is one of the differential diagnoses of neonatal meningoencephalitis. A 13-day-old full-term female neonate presented with a seizure. Brain MRI showed classic imaging findings of the meningoencephalitis which was confirmed on cerebrospinal fluid analysis. Contribution: The HPeV-3 is an emerging pathogen for neonatal meningoencephalitis. The case in this study is unique with classic imaging findings, which are not routinely encountered in day-to-day practice. This case raises reader awareness.

Treatment of Metastatic Spinal Disease; what the Radiologist needs to know.

Advancements in technology and multidisciplinary management have revolutionized the treatment of spinal metastases. Imaging plays a pivotal role in determining the treatment course for spinal metastases. This article aims to review the relevant imaging findings in spinal metastases from the perspective of the treating clinician, describe the various treatment options, and discuss factors influencing choice for each available treatment option. Cases that once required radical surgical resection or low-dose conventional external beam radiation therapy, or both, are now being managed with separation surgery, spine stereotactic radiosurgery/stereotactic body radiation therapy, or both, with decreased morbidity, improved local control, and more durable pain control. The primary focus in determining treatment choice is now on tumor control outcomes, treatment-related morbidity, and quality of life.

A Comparison of CT-Guided Bone Biopsy and Fluoroscopic-Guided Disc Aspiration as Diagnostic Methods in the Management of Spondylodiscitis.

BACKGROUND AND PURPOSE: Percutaneous tissue biopsy is a key step in the diagnosis and management of spondylodiscitis, often utilizing CT-guided bone biopsy or fluoroscopic-guided disc aspirations. Our objective was to compare radiation exposure, procedure time, sedation requirement & yield between the two modalities. MATERIALS AND METHODS: 103 patients in 2 cohorts underwent fluoroscopic-guided disc aspirations (n = 47) or CTguided bone biopsy (n = 46) for diagnosis of spondylodiscitis. Patient and imaging data were gathered to ensure matched cohorts. Interventional and post-procedural data included radiation exposure, procedure time, complications, and microbiological details. Yield was calculated using MRI findings as the gold standard for infection. RESULTS: There were no significant differences between cohorts in demographics, symptom duration, or pre-procedure antibiotics use. CT-guided bone biopsy required more general anesthesia (26% vs 0%, P < 0.001), had longer radiation exposure time (60 ± 24s vs 2 ± 3s, P < 0.001), radiation dose (114.4 ± 71.6 mGy vs 70.4 ± 147.2 mGy), and procedure time (62 ± 14m vs 31 ± 23m, P < 0.001) than fluoroscopic-guided disc aspirations. There was no significant difference in yield (34% vs 32%, P = 0.661), and it was not affected by antibiotic use. CONCLUSIONS: Both modalities have similar utility in isolating causative organisms in suspected cases of spondylodiscitis. Our results suggest that increased radiation exposure, longer procedure time, and increased anesthesia use are relative disadvantages of CT-guided biopsy without an increase in yield. Controlled trials may be beneficial in determining the optimal choice in different scenarios.

MDP-SPECT Versus Hybrid MDP-SPECT/CT in the Evaluation of Suspected Pars Interarticularis Fracture in Young Athletes.

BACKGROUND AND PURPOSE: To assess benefits of hybrid (single photon emission computerized tomography [SPECT]/computed tomography [CT]) imaging over SPECT imaging only in the management of young athletes with low back pain (LBP) due to suspected pars interarticularis fracture. METHODS: Retrospectively reviewed medical records of 163 consecutive patients who had radionuclide SPECT imaging for evaluation of LBP between January 1, 2010 and December 30, 2015. All enrolled patients were divided into two groups (group 1: patients with radionuclide SPECT imaging only and group 2: patients with radionuclide hybrid imaging). Radiation dose, cost benefits, and mean duration of delay in complete diagnosis were assessed and compared using Fisher's exact test. RESULTS: A total of 91 patients were enrolled after applying inclusion and exclusion criteria. The volume CT dose index and dose length product (DLP) estimated for a scan length of 10 cm (DLP 10) were significantly lower for patients in group II (CTDIvol ) (P  =  .001 and P  =  .001). Although, there was no significant difference in actual DLP (P  =  .52). There was a median delay of 7 days (interquartile range 2-10 days) for complete diagnosis in group I patients. Least expensive imaging for early definitive diagnosis required for the treatment decisions was in patients who had a radionuclide Technetium-99m methylene diphosphonate bone scan with limited lumbar spine planar and SPECT imaging followed by a thin slice, limited CT performed only when SPECT imaging was positive for an active pars interarticularis fracture. No significant difference in the management of patients between the groups (P  =  .47). CONCLUSION: Hybrid imaging should be preferred over SPECT only imaging for initial evaluation of suspected pars interarticularis fracture in young athletes with LBP.

I-123 DaTscan SPECT Brain Imaging in Parkinsonian Syndromes: Utility of the Putamen-to-Caudate Ratio.

BACKGROUND AND PURPOSE: Computer-based analysis of Dopamine transporter imaging (DaTscan) can aid in image interpretation. In this study, we examined the distribution of putamen-to-caudate ratios (PCRs) obtained by using a clinically available semiquantification method. METHODS: Medical records of 32 patients (M:16) with a diagnosis of Parkinson's disease (PD) (n = 22) or Parkinson's plus syndromes (PPS) (n = 10) based on clinical follow-up, were retrospectively reviewed. Single photon emission tomography (SPECT) imaging was performed 4 hours after intravenous injection of 3-5 mCi [I-123]-ioflupane. Semiquantitative evaluation using DaTQUANT software was performed. Utility of PCR with a cutoff of .7 and .8 in the diagnosis of nigrostriatal degeneration was assessed. PD and PPS groups based on clinical assessment and caudate-to-background ratio (CBR) were assessed separately. RESULTS: Minimum PCR for both hemispheres was .74 ± .09 (Mean ± SD, range: .58-.89), with 65.63% patients (21/32) having PCR > .7. Mean PCR in mild nigrostriatal degeneration was .77 ± .08 (range: .62-.89) and in advanced nigrostriatal degeneration was .73 ± .09 (range: .58-.89). Mean PCR in PD group was .73 ± .09 (range: .58-.89) and in PPS group was .75 ± .10 (range: .61-.88). CONCLUSIONS: Although PCR can intrinsically be a useful indication of disease, this ratio obtained in our analysis by using one of the clinically available automatic semiquantitative methods has large variability and might not be a reliable numeric marker in interpretation of [I-123]ioflupane studies. This may be due to difficulty in separating caudate from putamen on SPECT images, as well as the nonuniform decreased Ioflupane uptake in both putamen and caudate.

Dynamic Contrast-Enhanced MRI in the Evaluation of Carotid Space Paraganglioma versus Schwannoma.

OBJECTIVE: To describe the potential role of dynamic contrast-enhanced (DCE) MRI in differentiating carotid space (CS) paraganglioma from schwannoma in the head and neck. MATERIAL AND METHODS: We retrospectively reviewed records of 126 patients who had undergone DCE-MRI between June 2008 and July 2014 and found six patients with histologically verified benign CS tumors. The images were evaluated for tumor T1 and T2 signal characteristics, flow voids, and enhancement pattern. The dynamic data were analyzed for quantitative parameters using extended Toft's model (Ktrans , Kep , Ve , and Vp ) and semiquantitative parameters based on time-intensity curve (area under curve, peak enhancement, wash-in, wash-out, signal-enhancement ratio [SER], and time for maximum enhancement [TME]). Due to the small sample size, groups were compared qualitatively. RESULTS: Patients with CS paraganglioma (P group, n = 2) and schwannoma (S group, n = 4) were included. All tumors were hypointense on T1W imaging, hyperintense on T2W imaging, and show avid enhancement. One patient with paraganglioma had subtle flow voids. The conventional MR images were insufficient to confidently diagnose tumor type. Both paragangliomas had high peak enhancement and SER, and a short TME, while the schwannomas had relatively low peak enhancement and SER with a longer TME. Ktrans, Kep , and Ve were relatively low in the paragangliomas than in the schwannomas. CONCLUSION: DCE-MRI could potentially be used to assist differentiating paraganglioma from schwannoma, when diagnosis is difficult on the conventional MR imaging sequences. Simple assessment of semiquantitative parameters suffices to provide supportive information.

Vessel wall imaging for intracranial vascular disease evaluation.

Accurate and timely diagnosis of intracranial vasculopathies is important owing to the significant risk of morbidity with delayed and/or incorrect diagnosis both from the disease process and inappropriate therapies. Conventional luminal imaging techniques for analysis of intracranial vasculopathies are limited to evaluation of changes in the vessel lumen. Vessel wall MRI techniques can allow direct characterization of pathologic changes of the vessel wall. These techniques may improve diagnostic accuracy and improve patient outcomes. Extracranial carotid vessel wall imaging has been extensively investigated in patients with atherosclerotic disease and has been shown to accurately assess plaque composition and identify vulnerable plaque characteristics that may predict stroke risk beyond luminal stenosis alone. This review provides a brief history of vessel wall MRI, an overview of the intracranial vessel wall MRI techniques, its applications, and imaging findings of various intracranial vasculopathies pertinent to the neurointerventionalist, neurologist, and neuroradiologist. We searched MEDLINE, PubMed, and Google for English publications containing any of the following terms: 'intracranial vessel wall imaging', 'intracranial vessel wall', and 'intracranial vessel wall MRI'.

Neurodegeneration with Brain Iron Accumulation: Clinicoradiological Approach to Diagnosis.

Discovery of genetic abnormalities associated with neurodegeneration with brain iron accumulation (NBIA) has led to use of a genetic-based NBIA classification schema. Most NBIA subtypes demonstrate characteristic imaging abnormalities. While clinical diagnosis of NBIA is difficult, analysis of both clinical findings and characteristic imaging abnormalities allows accurate diagnosis of most of the NBIA subtypes. This article reviews recent updates in the genetic, clinical, and imaging findings of NBIA subtypes and provides a practical step-by-step clinicoradiological algorithm toward clinical diagnosis of different NBIA subtypes.

Imaging of the temporomandibular joint: An update.

Imaging of the temporomandibular joint (TMJ) is continuously evolving with advancement of imaging technologies. Many different imaging modalities are currently used to evaluate the TMJ. Magnetic resonance imaging is commonly used for evaluation of the TMJ due to its superior contrast resolution and its ability to acquire dynamic imaging for demonstration of the functionality of the joint. Computed tomography and ultrasound imaging have specific indication in imaging of the TMJ. This article focuses on state of the art imaging of the temporomandibular joint. Relevant normal anatomy and biomechanics of movement of the TMJ are discussed for better understanding of many TMJ pathologies. Imaging of internal derangements is discussed in detail. Different arthropathies and common tumors are also discussed in this article.

Survival analysis in patients with newly diagnosed primary glioblastoma multiforme using pre- and post-treatment peritumoral perfusion imaging parameters.

The objective of this study was to evaluate if peritumoral (PT) perfusion parameters obtained from dynamic susceptibility weighted contrast enhanced perfusion MRI can predict overall survival (OS) and progression free survival (PFS) in patients with newly diagnosed glioblastoma multiforme (GBM). Twenty-eight newly diagnosed GBM patients, who were treated with resection followed by concurrent chemoradiation and adjuvant chemotherapy, were included in this study. Evaluated perfusion parameters were pre- and post-treatment PT relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF). Proportional hazard analysis was used to assess the relationship OS, PFS and perfusion parameters. Kaplan-Meier survival estimates and log-rank test were used to characterize and compare the patient groups with high and low perfusion parameter values in terms of OS and PFS. Pretreatment PT rCBV and rCBF were not associated with OS and PFS whereas there was statistically significant association of both posttreatment PT rCBV and rCBF with OS and posttreatment rCBV with PFS (association of PFS and posttreatment rCBF was not statistically significant). Neither the Kaplan-Meier survival estimates nor the log-rank test demonstrated any differences in OS between high and low pretreatment PT rCBV values and rCBF values; however, high and low post-treatment PT rCBV and rCBF values did demonstrate statistically significant difference in OS and PFS. Our study found posttreatment, not pretreatment, PT perfusion parameters can be used to predict OS and PFS in patients with newly diagnosed GBM.

Comparing the diagnostic accuracy of contrast-enhanced computed tomographic angiography and gadolinium-enhanced magnetic resonance angiography for the assessment of hemodynamically significant transplant renal artery stenosis.

To compare diagnostic accuracy of contrast-enhanced computed tomographic angiography (CTA) and gadolinium-enhanced magnetic resonance angiography (MRA) for the assessment of hemodynamically significant transplant renal artery stenosis (TRAS). After institutional review board approval, records of 27 patients with TRAS confirmed on digital subtraction angiography (DSA) were retrospectively reviewed. A total of 13 patients had MRA and 14 had CTA before DSA. Two board-certified fellowship-trained radiologists, one each from interventional radiology and body imaging blindly reviewed the DSA and CTA or MRA data, respectively. Sensitivity (SN), specificity (SP), positive predictive value, and negative predictive value of MRA and CTA were estimated using 50% stenosis as the detection threshold for significant TRAS. These parameters were compared between modalities using the Fisher exact test. Bias between MRA or CTA imaging and DSA was tested using the Wilcoxon signed-rank test. Two patients were excluded from the MRA group owing to susceptibility artifacts obscuring the TRAS. The correlation between MRA and DSA measurements of stenosis was r = 0.57 (95% CI:-0.02, 0.87; P = 0.052) and between CTA and DSA measurements was r = 0.63 (95% CI: 0.14, 0.87; P = 0.015); the difference between the 2 techniques was not significant (P = 0.7). Both imaging modalities tended to underestimate the degree of stenosis when compared with DSA. MRA group (SN and SP: 56% and 100%, respectively) and CTA group (SN and SP: 81% and 67%, respectively). There were no significant differences in detection performance between modalities (P>0.3 for all measures). We did not find that either modality had any advantage over the other in terms of measuring or detecting significant stenosis. Accordingly, MRA may be preferred over CTA after positive color Doppler ultrasound screening when not contraindicated owing to lack of ionizing radiation or nephrotoxic iodinated contrast. However, susceptibility of artifacts owing to surgical clips at the anastomosis may limit diagnostic utility of MRA as found in 2 of 13 patients. Trend towards no significant difference between the CTA and enhanced MRA in the detection of hemodynamically significant TRAS.

Hepatocellular carcinoma in the noncirrhotic liver.

OBJECTIVE: Hepatocellular carcinomas (HCCs) that arise in noncirrhotic livers have several histologic and biochemical features that distinguish them from HCCs occurring in the setting of cirrhosis. Because the presentation, management, and prognosis of these entities are distinct, the accurate preoperative characterization of these lesions is of great clinical significance. We review the pathogenesis, imaging appearance, and clinical implications of noncirrhotic HCCs as they pertain to the clinical radiologist. CONCLUSION: HCCs that develop in noncirrhotic patients have distinct etiologic, cytogenetic, histopathologic, and clinical features. Despite a larger tumor burden at the time of HCC diagnosis, noncirrhotic patients with HCC have better overall survival and disease-free survival than cirrhotic patients with HCC. Knowledge of the precise clinical and imaging features of this entity and of other diagnostic considerations for the noncirrhotic liver is essential for improved patient care.

Congenital cystic neck masses: embryology and imaging appearances, with clinicopathological correlation.

Congenital cystic masses of the neck are uncommon and can present in any age group. Diagnosis of these lesions can be sometimes challenging. Many of these have characteristic locations and imaging findings. The most common of all congenital cystic neck masses is the thyroglossal duct cyst. The other congenital cystic neck masses are branchial cleft cyst, cystic hygroma (lymphangioma), cervical thymic and bronchogenic cysts, and the floor of the mouth lesions including dermoid and epidermoid cysts. In this review, we illustrate the common congenital cystic neck masses including embryology, clinical findings, imaging features, and histopathological findings.

Percutaneous transcatheter embolization of pulmonary artery pseudoaneurysms causing massive hemoptysis: two different case scenarios.

Systemic bronchial arterial circulation is the most common source for massive hemoptysis. Rarely, the source of bleeding can be the pulmonary artery. We report 2 different case scenarios of massive hemoptysis due to different etiologies, in which the source of bleeding was the pulmonary artery. Both the patients were treated with percutaneous transcatheter embolotherapy using coils. The 2 cases highlight the importance of considering pulmonary arterial etiology as the cause of hemoptysis while reporting diagnostic computed tomography studies and tailoring the interventional technique toward performing pulmonary angiography instead of searching for a systemic arterial source for hemoptysis.

Rathke cleft cyst. MRI criteria for presumptive diagnosis.

OBJECTIVE: To define MRI criteria for the presumptive diagnosis of Rathke cleft cyst (RCC). METHODS: One hundred and three patient MRI scans suggesting RCC performed between January 2005 and January 2011 were retrospectively reviewed for indications, cyst location, T1 and T2 signal intensity, dimensions, encroachment on optic chiasm, enhancement pattern, and stability over a year. RESULTS: Of the 103 patients analyzed, the suggestion of RCC was an incidental finding in 82.5% (n=85) of patients. Headache was the most common symptom in 11.6% (n=12), visual field deficit in 3.8% (n=4), and both headache and visual field deficit in 0.97% (n=1). The cyst was hyperintense on T1 in 55.3% (n=57), hypointense in 27.1% (n=28), and isointense in 17.4% (n=18). The cyst was T2 hyperintense in 57.2% (n=59), and iso-hypointense in 42.7% (n=54). The cyst showed no enhancement in 80.5% (n=83), and a thin marginal enhancement in 19.4% (n=20). The cyst showed a stable appearance in 99% (n=102) of patients after at least one year follow-up MRI study. CONCLUSION: Rathke cleft cysts typically have a cystic appearance with T1 hyperintensity, sometimes with T1 iso- or hypointensity, variable T2 signal, and no or thin marginal enhancement and remain stable in size over time.