Imaging features and surgical management of giant parathyroid adenoma with autoinfarction.

Autoinfarction of a parathyroid adenoma can have an atypical clinicoradiologic features that can mimic an inflammatory process or malignancy. In addition, the associated fibrosis makes surgical resection more challenging than for regular parathyroid adenomas. The implications of these findings are that while autoinfarction of parathyroid adenomas is a rare phenomenon, this entity should be considered when there are heterogeneous and cystic components on imaging in patients without hypercalcemia. Ultimately, histopathology is necessary for definitive diagnosis.

A preliminary diagnostic accuracy study of quantitative MRI biomarkers for differentiating parotid tumor types.

Background: Differentiating among the different types of parotid tumors on imaging is useful for guiding clinical disposition, which ultimately may lead to surgical management. The goal of this study was to determine whether quantitative T2 signal characteristics and morphologic features on magnetic resonance imaging (MRI) can serve as predictive biomarkers for distinguishing between tumor types. Methods: A retrospective review of T2-weighted MRIs in patients with pathology-proven parotid tumors was performed. Quantitative T2 maps and surface regularity measurements of the tumors were obtained via semi-automated regions of interest (ROI). Linear Discriminant Analysis was used to populate the receiver operating characteristics (ROCs) curves for these variables. A P value of <0.05 was considered to be significant. Results: A total of 35 tumors (21 benign and 14 malignant neoplasms) were included in this analysis. For differentiating the benign versus malignant classes of parotid tumors, T2 signal and surface regularity combined yielded an area under the curve of 0.62 (P value: 0.2) through the ROC analysis. However, for the pleomorphic adenomas versus other types of parotid tumors, using both T2 signal and surface regularity yielded an area under the curve of 0.81 (P value: 0.007) through the ROC analysis. Conclusions: T2 signal and surface regularity combined can significantly differentiate pleomorphic adenomas from other types of parotid tumors and can potentially be used as a predictive imaging biomarker.

Imaging Features of Intratumoral Injection of NBTXR3 for Head and Neck Squamous Cell Carcinoma Lymph Node Metastases.

NBTXR3 nanoparticle injection is a relatively novel radioenhancer for treatment of various cancers. CT scans following NBTXR3 injection of metastatic lymph nodes from head and neck squamous cell carcinoma were reviewed in a small series of patients. The radioenhancing appears as hyperattenuating, with a mean attenuation of the injected material of 1516 HU. The material was found to leak beyond the margins of the tumor in some cases.

MR imaging of Nasal and Paranasal Sinus Malignant Neoplasms.

MRI is useful for evaluating sinonasal malignancies. In particular, MRI can provide important information pertinent to treatment planning, such as delineating the presence of intracranial and orbital extension. This article reviews the MRI protocols, staging, imaging features, and differential diagnosis related to malignant nasal and paranasal sinus neoplasms.

Preliminary Computed Tomography Radiomics Model for Predicting Pretreatment CD8+ T-Cell Infiltration Status for Primary Head and Neck Squamous Cell Carcinoma.

PURPOSE: Immunotherapy has emerged as a treatment option for head and neck squamous cell carcinoma (HNSCC), with tumor response being linked to the CD8+ T-cell inflammation. The purpose of this study is to assess whether computed tomography (CT) radiomic analysis can predict CD8+ T-cell enrichment in HNSCC primary tumors. METHODS: This retrospective study included 71 patients from a head and neck cancer genomics cohort with CD8+ T-cell enrichment status. Pretreatment contrast-enhanced neck CT scans were retrospectively reviewed using 3D Slicer for primary lesion segmentation.The SlicerRadiomics extension was used to extract 107 radiomic features. Ridge regression and lasso regression were applied for feature selection and model construction. RESULTS: Lasso regression defined Coarseness as the most important variable, followed by SmallDependenceEmphasis, SmallAreaLowGrayLevelEmphasis, Contrast.1, and Correlation.Ridge regression defined Coarseness as the most important variable, followed by SmallDependenceLowGrayLevelEmphasis, Contrast.1, DependenceNonUniformityNormalized, and Idmn. These variables identified by lasso and ridge regressions were used to create a combined logistic regression model. The area under the curve (AUC) for the lasso-generated model was 0.786 (95% confidence interval [CI], 0.532-1.000), and the AUC for the ridge-generated model was 0.786 (95% CI, 0.544-1.000). Combining the radiomic variables identified by lasso and ridge regressions with clinical characteristics including alcohol use, tobacco use, anatomic site, and initial T stage produced a model with an AUC of 0.898 (95% CI, 0.731-1.000). CONCLUSIONS: T-cell inflammation status of HNSCC primary tumors can be predicted using radiomic analysis of CT imaging and thereby help identify patients who would respond well to immunotherapy.

Magnetic Resonance Imaging Findings of Crystalloid-Containing Parotid Cysts.

Crystalloids are occasionally encountered on fine needle aspiration of cystic parotid lesions. This goal of this study was to retrospectively characterize the MRI features of a series benign crystalloid-containing parotid cysts. A total of 4 patients with fine needle aspiration findings of crystalloids and available parotid MRI scans were identified. Review of the imaging revealed that the cystic lesions contain layering material that corresponds to crystals.

Magnetic resonance imaging (MRI) features of cataracts in pediatric and young adult patients.

BACKGROUND: The goal of this study is to systematically evaluate the magnetic resonance imaging (MRI) signal characteristics and size of cataracts that may be encountered in pediatric and young adult patients. METHODS: A retrospective analysis of the MRI features with cataracts in a series of cases, including characterization of signal intensity on T2-weighted and T1-weighted sequences, as well as measuring the thickness of the lens. RESULTS: Among nine cataracts in seven patients, three lenses were thickened and hyperintense on T2-weighted sequences, presumably related to osmotic effects. The rest of the lenses were either normal in size and signal characteristics, such as in the cases of neurofibromatosis type 2 or small in cases of microphthalmos, with signal characteristics related to calcifications. CONCLUSIONS: There are several different types of cataracts that can occur in pediatric and young adult patients, which may or may not be conspicuous on MRI. The findings in this study can serve as a guide for what abnormalities of the lens may be encountered on MRI.

Differential Change in Size of Human Papillomavirus-Positive Cystic Versus Solid Squamous Cell Carcinoma Lymph Node Metastases in Response to Induction Chemotherapy.

PURPOSE: According to certain cancer treatment protocols, the response to induction chemotherapy of lymph node metastases based on radiographic measurements guides further management. The aim of this study is to verify the observation that cystic metastatic lymph nodes tend not to shrink as rapidly as solid metastatic lymph nodes in response to induction chemotherapy in patients with human papillomavirus-related oropharyngeal squamous cell carcinoma. METHODS: The lymphadenopathy in a cohort of patients from a clinical trial with human papillomavirus-related oropharyngeal squamous cell carcinoma with both baseline and postinduction chemotherapy (carboplatin/paclitaxel/cetuximab) contrast-enhanced neck computed tomography was retrospectively reviewed. The appearance of the metastatic lymph nodes on computed tomography was characterized as cystic or solid. A cystic lymph node was defined as having a hypoattenuating component greater than 20% of the total volume. The rates of short-axis and volume changes of cystic and solid lymph nodes were compared using 1-tailed t test. RESULTS: A total of 46 patients were included in this study, comprising 39 solid and 45 cystic lymph nodes. The rate of short-axis decrease was significantly greater for solid (1.33% per day) than cystic (1.08% per day) lymph nodes (P = 0.036). Likewise, the rate of volume decrease was significantly greater for solid (2.13% per day) than cystic (1.87% per day) lymph nodes (P = 0.014). CONCLUSIONS: This study suggests that in patients with human papillomavirus-related oropharyngeal squamous cell carcinoma solid lymph node metastases generally decrease in size at a greater rate than cystic lymph nodes after induction chemotherapy.

High-Resolution MRI Microscopy Coil Assessment of Parotid Masses.

The goal of this study was to determine whether high-resolution magnetic resonance imaging (MRI) microscopy coil imaging can improve the depiction parotid masses. A total of 14 parotid masses, including 7 salivary neoplasms, 2 abnormal lymph nodes, and 5 benign cystic lesions were imaged with T2-weighted and fat-suppressed postcontrast T1-weighted sequences using a 47-mm diameter microscopy coil in addition to conventional MRI sequences acquired with a conventional head and neck neurovascular coil. Compared to conventional parotid MRI sequences, microscopy coil images provided better definition of the margins of neoplasms, provide more detailed definition of lymph node morphology, and better depict certain cyst contents in the superficial portions of the parotid gland. The microscopy coil images provided significantly better definition of lesions and surrounding tissues within the superficial parotid gland with resptect to the deep parotid gland structures due to loss of signal. Furthermore, the fat-suppressed postcontrast T1-weighted microscopy coil images were significantly better than the corresponding T2-weighted images for delineating the superficial parotid gland. Ultimately, the microscopy coil sequences added over 10 minutes to the examination time.

Correlation of post-contrast T1-weighted MRI surface regularity, tumor bulk, and necrotic volume with Ki67 and p53 in glioblastomas.

PURPOSE: p53 and Ki67 status can be relevant to the management of glioblastoma. The goal of this study is to determine whether tumor morphology and bulk depicted on MRI correlate with p53 and Ki67 in glioblastoma. METHODS: A retrospective review of 223 patients with glioblastoma and corresponding p53 or Ki67 status, along with T1-weighted post-contrast MR images was performed. Enhancing tumors were outlined for determining surface regularity, tumor bulk, and necrotic volume. The median value of 0.1 was chosen for p53 and 0.2 for Ki67 to separate each data set into two classes. T tests and receiver operating characteristic analysis were performed to determine the separation of the classes and the predicting power of each feature. RESULTS: There were significant differences between tumor surface regularity (p = 0.01) and necrotic volume (p = 0.0429) according to Ki67 levels, although neither had statistically significant predictive power (AUC = 0.697, p = 0.0506 and AUC = 0.577, p = 0.164, respectively). There were also significant differences between tumor bulk (p = 0.0239) and necrotic volume (p = 0.0200) according to p53 levels, but again no significant predictive power was found using ROC analysis (AUC = 0.5882, p = 0.0894 and AUC = 0.567, p = 0.155, respectively). CONCLUSION: Quantitative morphological tumor characteristics on post-contrast T1-weighted MRI can to a certain degree provide insights regarding Ki67 and p53 status in patients with glioblastoma.

Imaging Findings in Syndromes with Temporal Bone Abnormalities.

There is a wide variety of congenital syndromes that can involve the temporal bone. Many of these have overlapping features due to common embryologic abnormalities, such as first and second branchial anomalies. Diagnostic imaging is often important in the workup of hearing deficits related to congenital syndromes. This article reviews the imaging features of selected congenital syndromes with temporal bone abnormalities, including Treacher Collins syndrome, oculo-auriculo-vertebral dysplasia spectrum, Klippel-Feil syndrome, branchio-oto-renal syndrome, Pierre Robin sequence, CHARGE syndrome, Pendred syndrome, Down syndrome, Trisomy 18, Turner syndrome, and neurofibromatosis type 2.

CT Imaging Findings after Craniosynostosis Reconstructive Surgery.

Several surgical options are available for treating the different types of craniosynostosis, including fronto-orbital advancement and remodeling, total or subtotal cranial vault remodeling, barrel stave osteotomy with cranial remodeling, endoscopic suturectomy, monobloc advancement and cranioplasty, and revision cranioplasty. High-resolution, low-dose CT with 3D reconstructed images and volumetric analysis can be useful for evaluating the craniofacial skeleton following surgery. The various types of craniosynostosis surgery and corresponding imaging findings are reviewed in this article.

Imaging of Benign Neoplastic and Nonneoplastic Salivary Gland Tumors.

This article reviews the multimodality diagnostic imaging features of benign neoplastic and nonneoplastic tumors associated with the major salivary glands. Examples of neoplastic conditions that are depicted and discussed include pleomorphic adenoma, Warthin tumor, oncocytoma, peripheral nerve sheath tumors, lipoma, and hemangiomas or hemangioendotheliomas. Examples of nonneoplastic conditions that are depicted and discussed include ranulas, benign lymphoepithelial lesions, Kimura disease, and vascular malformations. Specific imaging and clinical features of these conditions are emphasized in this article.

Comparison between whole-body and head and neck neurovascular coils for 3-T magnetic resonance proton resonance frequency shift thermography guidance in the head and neck region.

The purpose of this study is to compare the image quality of magnetic resonance (MR) treatment planning images and proton resonance frequency (PRF) shift thermography images and inform coil selection for MR-guided laser ablation of tumors in the head and neck region. Laser ablation was performed on an agar phantom and monitored via MR PRF shift thermography on a 3-T scanner, following acquisition of T1-weighted (T1W) planning images. PRF shift thermography images and T2-weighted (T2W) planning images were also performed in the neck region of five normal human volunteers. Signal-to-noise ratios (SNR) and temperature uncertainty were calculated and compared between scans acquired with the quadrature mode body integrated coil and a head and neck neurovascular coil. T1W planning images of the agar phantom produced SNRs of 4.0 and 12.2 for the quadrature mode body integrated coil and head and neck neurovascular coil, respectively. The SNR of the phantom MR thermography magnitude images obtained using the quadrature mode body integrated coil was 14.4 versus 59.6 using the head and neck coil. The average temperature uncertainty for MR thermography performed on the phantom with the quadrature mode body integrated coil was 1.1 versus 0.3 °C with the head and neck coil. T2W planning images of the neck in five human volunteers produced SNRs of 28.3 and 91.0 for the quadrature mode body integrated coil and head and neck coil, respectively. MR thermography magnitude images of the neck in the volunteers obtained using the quadrature mode body integrated coil had a signal-to-noise ratio of 8.3, while the SNR using the head and neck coil was 16.1. The average temperature uncertainty for MR thermography performed on the volunteers with the body coil was 2.5 versus 1.6 °C with the head and neck neurovascular coil. The quadrature mode body integrated coil provides inferior image quality for both basic treatment planning sequences and MR PRF shift thermography compared with a neurovascular coil, but may nevertheless be adequate for clinical purposes.

Chapter 4 Thyroid Malignancy: Staging and Restaging.

Determining the extent of disease is necessary for guiding the management of thyroid carcinomas. Diagnostic imaging, including ultrasound, computed tomography, magnetic resonance imaging, and nuclear medicine scans, plays an essential role in staging and restaging of thyroid carcinomas. This article reviews the approaches and imaging findings for evaluating the primary tumor, regional lymph node metastases, and distant metastases. In addition, potential pitfalls are discussed and depicted.

Salivary Gland Secretory Carcinoma With High-Grade Transformation, CDKN2A/B Loss, Distant Metastasis, and Lack of Sustained Response to Crizotinib.

BACKGROUND: Salivary gland secretory carcinoma is usually a low-grade neoplasm. However, high-grade transformation can occur and has important implications for clinical outcome. METHODS: A patient presented with an enlarging buccal mass. Magnetic resonance imaging (MRI) showed a tumor with a biphasic appearance along the right parotid duct. Local excision and histopathologic examination confirmed the diagnosis of secretory carcinoma with high-grade transformation. ETV6-NTRK3 translocation and loss of CDKN2A/B were identified. RESULTS: The patient subsequently presented with cough and dyspnea and was found to have pleural metastases. Carboplatin and paclitaxel exacerbated the symptoms. Crizotinib resulted in initial symptomatic and radiographic improvement; however, the patient soon succumbed to progressive intrathoracic disease. CONCLUSIONS: High-grade salivary gland secretory carcinoma can have a biphasic appearance on MRI. Diagnosis is confirmed by the histologic appearance and associated ETV6-NTRK3 fusion. Additional molecular genetic events leading to transformation are unknown; however, loss of CDKN2A/B may have contributed. Treatment with multimodal chemotherapy was of limited benefit.

Disseminated Malignant Rhabdoid Tumor of the Head and Neck.

Disseminated extrarenal malignant rhabdoid tumors of the head and neck are very rare, but aggressive tumors. Although the features on radiological imaging may be nonspecific, the imaging is useful for assessing the extent of tumor involvement. Key pathologic features are those of a cellular "blue cell tumor" with variable rhabdoid appearance. These cells express a combination of markers usually viewed as characteristic of diverse lines of differentiation, including EMA, cytokeratins, smooth muscle markers, and GFAP, and occasionally synaptophysin. At a molecular level, the entity is defined by mutations or alterations in the SMARB1/INI1 gene resulting in loss of INI1 expression. Diagnostic features include rhabdoid cells, expression of keratin with absence of desmin, S100 protein and CD34, and loss of INI1 expression. These features are exemplified in this sine qua non radiology-pathology correlation article.