Posterior hypothalamic involvement on pre-operative MRI predicts hypothalamic obesity in craniopharyngiomas.

PURPOSE: Hypothalamic obesity (HO) is a complication associated with craniopharyngioma (CP). Attempts have been made to perioperatively predict the development of this complication, which can be severe and difficult to treat. METHODS: Patients who underwent first transsphenoidal surgical resection in a single center between February 2005 and March 2019 were screened; those who have had prior surgery or radiation, were aged below 18 years, or did not have follow up body mass index (BMI) after surgery were excluded. Primary end point was BMI within 2 years post-surgery. Hypothalamic involvement (HI) was graded based on preoperative and postoperative imaging with regards to anterior, posterior, left and right involvement. Data on baseline demographics, pre-operative and post-operative MRI, and endocrine function were collected. RESULTS: 45 patients met the inclusion and exclusion criteria. Most patients in our cohort underwent gross total resection (n = 35 patients). 13 patients were from no HI or anterior HI only group and 22 patients were classified as both anterior (ant) and posterior (post) HI group. There was no significant difference between the two groups in the gross total, subtotal or near total resection. Pre-operative BMI and post-operative BMI were significantly higher in patients who had ant and post HI on pre-operative MRI (p < 0.05 and p < 0.01, respectively). Similarly, post-operative BMI at 13-24 months was also significantly higher in the ant and post HI group on post-op MRI (p < 0.01). There was no significant difference between the two groups in terms of baseline adrenal insufficiency, thyroid insufficiency, gonadal insufficiency, IGF-1 levels, hyperprolactinemia, and diabetes insipidus. Diabetes insipidus was more common following surgery among those who had anterior and posterior involvement on pre-operative MRI (p < 0.05). CONCLUSIONS: HO appears to be predetermined by tumor involvement in the posterior hypothalamus observed on pre-operative MRI. Posterior HI on pre-operative MRI was also associated with the development of diabetes insipidus after surgery.

Best Practices: Application of NI-RADS for Posttreatment Surveillance Imaging of Head and Neck Cancer.

Imaging surveillance is an important component of posttreatment management of head and neck cancers. There is variability in the surveillance regimen used by various practitioners and institutions, with no official National Comprehensive Cancer Network guidelines for patients showing no symptoms beyond 6 months posttreatment. Moreover, imaging of the neck after treatment is a complex examination with significant interreader heterogeneity, particularly in terms of the manner in which degree of suspicion for disease recurrence is expressed. The Neck Imaging Reporting and Data System (NI-RADS) was introduced by the American College of Radiology (ACR) in 2018 as a practical guide for the interpreting radiologist. NI-RADS is a proposed interpretive framework that can be applied to any standardized or institutional surveillance imaging protocol. NI-RADS simplifies communication between radiologists and referring clinicians and provides management guidance linked to specific levels of suspicion. The ACR NI-RADS Committee also provided general best practice recommendations for imaging surveillance modality and timing in the 2018 white paper. This article will review existing literature regarding choice of modality and timeline for surveillance in treated cancer of the head and neck. NI-RADS will then be presented as an approach to imaging reporting, interpretation, and design of next steps in management.

Imaging of Temporal Bone Trauma: A Clinicoradiologic Perspective.

Imaging plays an important role in the evaluation of temporal bone trauma. Certain imaging findings can significantly change patient management or change surgical approach. Precise knowledge of clinical or surgical management can guide the review of imaging to detect these key findings. This article reviews the clinical and imaging findings as well as management of complications from temporal bone trauma, including hearing loss, vertigo, perilymphatic fistula, cerebrospinal fluid leak, facial nerve injury and vascular injury.

Prostate Cancer: assessing the effects of androgen-deprivation therapy using quantitative diffusion-weighted and dynamic contrast-enhanced MRI.

PURPOSE: To investigate the effects of androgen-deprivation therapy (ADT) on MRI parameters and evaluate their associations with treatment response measures. MATERIALS AND METHODS: The study included 30 men with histopathologically confirmed prostate cancer who underwent MRI before and after initiation of ADT. Thirty-four tumours were volumetrically assessed on DW-MRI (n = 32) and DCE-MRI (n = 18), along with regions of interest in benign prostatic tissue, to calculate apparent diffusion coefficient (ADC) and transfer constant (K(trans)) values. Changes in MRI parameters and correlations with clinical parameters (change in prostate-specific antigen [PSA], treatment duration, PSA nadir) were assessed. RESULTS: Prostate volume and PSA values decreased significantly with therapy (p < 0.001). ADC values increased significantly in tumours and decreased in benign prostatic tissue (p < 0.05). Relative changes in ADC and absolute post-therapeutic ADC values differed significantly between tumour and benign tissue (p < 0.001). K(trans) decreased significantly only in tumours (p < 0.001); relative K(trans) changes and post-therapeutic values were not significantly different between tumour and benign tissue. The relative change in tumour ADC correlated significantly with PSA decrease. No changes were associated with treatment duration or PSA nadir. CONCLUSIONS: Multi-parametric MRI shows significant measurable changes in tumour and benign prostate caused by ADT and may help in monitoring treatment response. KEY POINTS: • Androgen-deprivation therapy caused changes of ADC, K (trans) in tumour and benign prostate. • Prostate volume and PSA values decreased significantly with therapy. • ADC values may be helpful for monitoring treatment response.

Benign mural nodules within fluid collections at MRI after soft-tissue sarcoma resection.

OBJECTIVE: The purpose of this study was to determine the prevalence and clinical significance of nodules within fluid collections on MRI after surgical resection of soft-tissue sarcoma. MATERIALS AND METHODS: This retrospective study included 175 patients who underwent resection of primary soft-tissue sarcoma and whose postoperative MRI reports mentioned fluid. Images were reviewed to determine the presence of fluid collections of 1 cm or greater in diameter in the surgical bed and any nodule (measuring ≥ 0.7 cm) within the collection. Signal intensity and characteristics of each collection and rim and presence of septa or blood products were recorded. Size, signal intensity, and contrast enhancement of nodules were reviewed. Nodules were classified as benign or malignant on the basis of histologic results or clinical or MRI follow-up. RESULTS: Fluid collections were present in 75 patients. Of those, 45 collections (60%) showed homogeneous fluid signal intensity and 30 (40%) were heterogeneous; septa were present in 45 (60%) and blood products in 12 (16%). Most collections showed a thin rim (59%) and rim enhancement (88%). Nodules were present along the inner wall of six (8%) collections. Four (66%) nodules enhanced and two (33%) were T1 hyperintense. At follow-up MRI, two nodules were stable in size, one decreased, and three resolved. Nodules in three patients were biopsied; all were benign. Two other patients had no recurrence at follow-up, and another died at 3 months. CONCLUSION: A nodule within a postoperative fluid collection at MRI after soft-tissue sarcoma resection generally does not represent tumor recurrence; short-interval follow-up MRI is recommended rather than immediate biopsy.

Recurrent skeletal extra-axial chordoma confirmed with brachyury: imaging features and review of the literature.

A small number of tumors bearing histological resemblance to axial chordoma arising from the bone or soft tissue outside the axial skeleton have been reported. These lesions have historically been referred to as parachordoma, chordoma periphericum (CP), or extra-axial chordoma (EAC). With the introduction of the immunohistochemical stain brachyury, a sensitive and specific marker for notochordal origin, chordomas arising in extra-axial locations (i.e., CP, EAC), are now diagnosed with more accuracy and distinguished from parachordoma, which resembles chordoma on histology. The distinction between EAC and parachordoma is clinically important because EAC confirmed by immunoreactivity for brachyury tends to grow and recur with local bone destruction. Prior to the introduction of brachyury, the diagnosis of EAC was challenging and therefore the imaging features of EAC have not been comprehensively described. We report two cases of recurrent EAC confirmed by the expression of brachyury arising from the distal femur and distal tibia and describe the imaging findings from radiography and MRI at initial diagnosis and at recurrence.

Comparison between esophagography and chest computed tomography for evaluation of leaks after esophagectomy and gastric pull-through.

PURPOSE: To assess the diagnostic performance of esophagography and chest computed tomography (CT) for detecting leaks after esophagectomy and gastric pull-through. MATERIALS AND METHODS: Our database revealed 29 patients who had undergone esophagography and chest CT after esophagectomy. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for postoperative leaks were determined for esophagography and CT, separately and combined, on the basis of a retrospective image review. Patients were also stratified for esophagograms with water-soluble contrast alone versus water-soluble contrast and high-density barium and for CT with and without oral contrast. Our findings were retrospectively compared with those reported at initial image interpretation. RESULTS: Clinically relevant leaks were present in 14 (48%) of 29 patients after esophagectomy. Esophagography had a sensitivity of 79%, specificity of 73%, PPV of 73%, and NPV of 79% for detecting leaks, whereas CT had a sensitivity of 86%, specificity of 33%, PPV of 55%, and NPV of 71% and esophagography and CT combined had a sensitivity of 100%, specificity of 27%, PPV of 56%, and NPV of 100%. The sensitivity of esophagography increased with high-density barium, whereas the sensitivity of CT was the same with and without oral contrast agent. Finally, esophagography and CT were seen to have a higher sensitivity and lower specificity on retrospective review compared with the results reported at initial image interpretation. CONCLUSIONS: Esophagography had a slightly lower sensitivity and substantially higher specificity compared with CT for detecting leaks after esophagectomy, whereas esophagography and CT combined had a sensitivity of 100% for detecting leaks. Therefore, postoperative leaks can be excluded with confidence after esophagectomy when both tests are negative.

Giant cell tumor of the tendon sheath mimicking a primary intramedullary metatarsal tumor.

Giant cell tumor of the tendon sheath (GCTTS) is one of the most common benign soft tissue tumors in the extremities, and is frequently associated with bone abnormalities. Although extrinsic bone erosion is the most common bone abnormality associated with GCTTS, intraosseous invasion of GCTTS occurs rarely and may mimic a primary bone tumor, making diagnosis more challenging. We report an unusual imaging presentation of GCTTS mimicking a primary intramedullary metatarsal tumor and review the literature on the frequency of bone involvement of GCTTS.