Precise Image-level Localization of Intracranial Hemorrhage on Head CT Scans with Deep Learning Models Trained on Study-level Labels.

"Just Accepted" papers have undergone full peer review and have been accepted for publication in Radiology: Artificial Intelligence. This article will undergo copyediting, layout, and proof review before it is published in its final version. Please note that during production of the final copyedited article, errors may be discovered which could affect the content. Purpose To develop a highly generalizable weakly supervised model to automatically detect and localize image- level intracranial hemorrhage (ICH) using study-level labels. Materials and Methods In this retrospective study, the proposed model was pretrained on the image-level RSNA dataset and fine-tuned on a local dataset using attention-based bidirectional long-short-term memory networks. This local training dataset included 10,699 noncontrast head CT scans from 7469 patients with ICH study-level labels extracted from radiology reports. Model performance was compared with that of two senior neuroradiologists on 100 random test scans using the McNemar test, and its generalizability was evaluated on an external independent dataset. Results The model achieved a positive predictive value (PPV) of 85.7% (95% CI: [84.0%, 87.4%]) and an AUC of 0.96 (95% CI: [0.96, 0.97]) on the held-out local test set (n = 7243, 3721 female) and 89.3% (95% CI: [87.8%, 90.7%]) and 0.96 (95% CI: [0.96, 0.97]), respectively, on the external test set (n = 491, 178 female). For 100 randomly selected samples, the model achieved performance on par with two neuroradiologists, but with a significantly faster (P < .05) diagnostic time of 5.04 seconds per scan (versus 86 seconds and 22.2 seconds for the two neuroradiologists, respectively). The model's attention weights and heatmaps visually aligned with neuroradiologists' interpretations. Conclusion The proposed model demonstrated high generalizability and high PPVs, offering a valuable tool for expedited ICH detection and prioritization while reducing false-positive interruptions in radiologists' workflows. ©RSNA, 2024.

Predictors of salvage therapy for parasagittal meningiomas treated with primary surgery, radiosurgery, or surgery plus adjuvant radiotherapy.

OBJECTIVE: Parasagittal meningiomas (PM) are treated with primary microsurgery, radiosurgery (SRS), or surgery with adjuvant radiation. We investigated predictors of tumor progression requiring salvage surgery or radiation treatment. We sought to determine whether primary treatment modality, or radiologic, histologic, and clinical variables were associated with tumor progression requiring salvage treatment. METHODS: Retrospective study of 109 consecutive patients with PMs treated with primary surgery, radiation (RT), or surgery plus adjuvant RT (2000-2017) and minimum 5 years follow-up. Patient, radiologic, histologic, and treatment data were analyzed using standard statistical methods. RESULTS: Median follow up was 8.5 years. Primary treatment for PM was surgery in 76 patients, radiation in 16 patients, and surgery plus adjuvant radiation in 17 patients. Forty percent of parasagittal meningiomas in our cohort required some form of salvage treatment. On univariate analysis, brain invasion (OR: 6.93, p < 0.01), WHO grade 2/3 (OR: 4.54, p < 0.01), peritumoral edema (OR: 2.81, p = 0.01), sagittal sinus invasion (OR: 6.36, p < 0.01), sagittal sinus occlusion (OR: 4.86, p < 0.01), and non-spherical shape (OR: 3.89, p < 0.01) were significantly associated with receiving salvage treatment. On multivariate analysis, superior sagittal sinus invasion (OR: 8.22, p = 0.01) and WHO grade 2&3 (OR: 7.58, p < 0.01) were independently associated with receiving salvage treatment. There was no difference in time to salvage therapy (p = 0.11) or time to progression (p = 0.43) between patients receiving primary surgery alone, RT alone, or surgery plus adjuvant RT. Patients who had initial surgery were more likely to have peritumoral edema on preoperative imaging (p = 0.01). Median tumor volume was 19.0 cm3 in patients receiving primary surgery, 5.3 cm3 for RT, and 24.4 cm3 for surgery plus adjuvant RT (p < 0.01). CONCLUSION: Superior sagittal sinus invasion and WHO grade 2/3 are independently associated with PM progression requiring salvage therapy regardless of extent of resection or primary treatment modality. Parasagittal meningiomas have a high rate of recurrence with 80.0% of patients with WHO grade 2/3 tumors with sinus invasion requiring salvage treatment whereas only 13.6% of the WHO grade 1 tumors without sinus invasion required salvage treatment. This information is useful when counseling patients about disease management and setting expectations.

Advancements in Positron Emission Tomography/Magnetic Resonance Imaging and Applications to Diagnostic Challenges in Neuroradiology.

Since the clinical adoption of magnetic resonance (MR) in medical imaging, MR has proven to be a workhorse in diagnostic neuroradiology, with the ability to provide superb anatomic detail as well as additional functional and physiologic data, depending on the techniques utilized. Positron emission tomography/computed tomography has also shown irreplaceable diagnostic value in certain disease processes of the central nervous system by providing molecular and metabolic information through the development of numerous disease-specific PET tracers, many of which can be utilized as a diagnostic technique in and of themselves or can provide a valuable adjunct to information derived from MR. Despite these advances, many challenges still remain in neuroradiology, particularly in malignancy, neurodegenerative disease, epilepsy, and cerebrovascular disease. Through improvements in attenuation correction, motion correction, and PET detectors, combining the 2 modalities of PET and MR through simultaneous imaging has proven feasible and allows for improved spatial and temporal resolution without compromising either of the 2 individual modalities. The complementary information offered by both technologies has provided increased diagnostic accuracy in both research and many clinical applications in neuroradiology.

Radiologic appearance of chronic parapharyngeal Teflon granuloma.

Although Teflon has been used for almost 5 decades to provide tissue augmentation in various surgical indications, including head and neck surgery, its use has significantly declined in the last 2 decades, primarily because of its implication in granuloma formation. Teflon granulomas have been shown to cause false positives on positron emission tomography imaging and have been reported to have a characteristic magnetic resonance imaging (MRI) appearance. We report a patient with a large chronic Teflon granuloma of the parapharyngeal space that caused significant bony erosion of the atlas vertebra. The lesion's MRI signal characteristics were indistinguishable from those of surrounding tissues, while it showed characteristic hyperdensity on computed tomography due to the presence of fluorine atoms within Teflon. As MRI may supersede or replace computed tomography for a number of indications, and as Teflon has been used in large numbers of patients whose records may not always be available, knowledge of these findings has clinical relevance.

Idiopathic Copper Deficiency Myeloneuropathy Resulting in Paraparesis: A Case Report.

Atraumatic spinal cord injuries can be due to inflammatory, vascular, and nutritional etiologies. Due to progression from these causes, the identification and initiation of appropriate treatment are of significant importance. This article explores a case of copper deficiency myeloneuropathy in a patient initially thought to have an inflammatory transverse myelitis. The lack of response to antirheumatologic interventions prompted an extensive workup consistent with copper deficiency. This case stresses the importance of evaluating nutritional causes of myeloneuropathy. LEVEL OF EVIDENCE: V.

CT findings in a patient with bilateral metachronous carotidynia.

Carotidynia is a self-limiting, idiopathic clinical syndrome characterized by acute unilateral neck pain and tenderness of the carotid artery. We describe a unique case of bilateral carotidynia that occurred metachronously, with each incident resolving without long-term sequelae. Knowledge of this entity is important to properly interpret the imaging findings and to not mistake this finding as an ill-defined tumor, thus avoiding unnecessary biopsy.

Imaging of head trauma.

This article reviews the fundamental concepts related to the imaging of head trauma, and it is vital for radiologists to have a thorough understanding of the principal imaging findings in this setting and of the underlying mechanisms which are involved. There is a large and continually expanding body of literature on this subject, and imaging technologies and techniques continue to evolve. Radiologists continue to play an integral role in the assessment and care of patients with head trauma, and in order to maintain and strengthen this role, it is incumbent upon them to stay abreast of these developments.

An unusual appearance of discitis due to gas-forming Escherichia coli with associated pneumocephalus.

STUDY DESIGN: Case report. OBJECTIVE: To report on an unusual case of isolated septic discitis, meningitis, pneumocephalus, and solid organ abscesses associated with urosepsis from gas-producing Escherichia coli. SUMMARY OF BACKGROUND DATA: Isolated septic discitis, or disc infection without involvement of adjacent vertebrae, following E. coli urosepsis is an unusual finding in the adult population and to our knowledge has not been reported previously. METHODS: The clinical manifestations and imaging findings of a patient with a history of back pain are described. The significance of the reported case is discussed. RESULTS: Laboratory finding and imaging studies revealed a Gram-negative sepsis associated with meningitis, discitis, pneumocephalus, and solid organ abscesses. Due to widespread involvement of multiple organs, the infection remained refractory to treatment, and the patient died. CONCLUSION: Our report adds to the literature by describing an unusual appearance of spine infection in an adult. Furthermore, it emphasizes the importance of a systematic approach to the diagnosis and treatment of low back pain.

Underestimation of the presence of breast carcinoma in papillary lesions initially diagnosed at core-needle biopsy.

PURPOSE: To retrospectively determine the degree of underestimation of breast carcinoma diagnosis in papillary lesions initially diagnosed at core-needle biopsy. MATERIALS AND METHODS: Institutional review board approval and waiver of informed consent were obtained for this HIPAA-compliant study. Mammographic database review (1994-2003) revealed core biopsy diagnoses of benign papilloma (n=38), atypical papilloma (n=15), sclerotic papilloma (n=6), and micropapilloma (n=4) in 57 women (mean age, 57 years). Excisional or mammographic follow-up (>or=2 years) findings were available. Patients with in situ or invasive cancer in the same breast or patients without follow-up were excluded. Findings were collected from mammography, ultrasonography, core technique, core biopsy, excision, and subsequent mammography. Reference standard was excisional findings or follow-up mammogram with no change at 2 years. Associations were examined with regression methods. RESULTS: In 38 of 63 lesions, surgical excision was performed; in 25 additional lesions (considered benign), follow-up mammography (24-month minimum) was performed, with no interval change. In 15 lesions, 14-gauge core needle was used; in 48, vacuum assistance (mean cores per lesion, 8.7). Carcinoma was found at excision in 14 of 38 lesions. Core pathologic findings associated with malignancy were benign papilloma (n=1), sclerotic papilloma (n=1), micropapilloma (n=2), and atypical papilloma (n=10). Frequency of malignancy was one (3%) of 38 benign papillomas, 10 (67%) of 15 atypical papillomas, two (50%) of four micropapillomas, and one (17%) of six sclerotic papillomas. Excisional findings included lobular carcinoma in situ (n=2), ductal carcinoma in situ (n=7), papillary carcinoma (n=2), and invasive ductal carcinoma (n=3). Low-risk group (micropapillomas and sclerotic and benign papillomas) was compared with high-risk atypical papilloma group. Core findings were associated with malignancy at excision for atypical papilloma (P=.006). Lesion location, mammographic finding, core number, or needle type were not associated (P>.05) with underestimation of malignancy at excision. CONCLUSION: Benign papilloma diagnosed at core biopsy is infrequently (3%) associated with malignancy; mammographic follow-up is reasonable. Because of the high association with malignancy (67%), diagnosis of atypical papilloma at core biopsy should prompt excision for definitive diagnosis.