Accurate Preoperative Localization Research Articles

Accurate Preoperative Localization of Thoracolumbar Disc Extrusion in Dogs: A Prospective Controlled Study.

Intervertebral disc disease (IVDD) is a very common cause of spinal cord compression in dogs. The errors of human surgeons operating on the wrong level or wrong side is a recognized problem and has been largely analyzed. To date, little information is available regarding these errors in dogs. The objective of this study was to assess the accuracy of disc localization prior to possible surgery for IVDD to ensure the surgeon begins their incision directly over the extruded disc. Eighty-five chondrodystrophic or brachycephalic dogs that presented with IVDD confirmed by CT or MRI scan were included in the study. Two small Backhaus clamps were placed cranial and caudal to the lesion site and a control clamp placed at the wing of the ilium. The main interest was whether the surgeon was able to preoperatively pinpoint the correct site for the surgery. Dorsoventral radiographs were taken to verify by another person if the clamps had been placed in the correct position. If the result was incorrect, the surgeon was asked to try again without knowing that the clamps were incorrect, and another radiograph was taken. This was repeated until the position was correct. The results were recorded as correct or incorrect and the number of attempts were registered. The results suggested no significant trend over time for any of the outcomes examined. There were some slight improvements over time, but none of the results was close to statistical significance. The findings of the study showed that in the thoracolumbar region the surgeon has a higher chance of incorrectly marking the exact site for surgery.

Parathyroid Adenoma Orientation for Gland Embryologic Origin on Ultrasonography

Accurate preoperative localization is critical to success in targeted parathyroidectomy for primary hyperparathyroidism. To determine if the association between the long axis of a parathyroid adenoma (PTA) candidate and strap musculature on sagittal ultrasonography (US) can be used to predict the embryologic origin of the gland. This diagnostic study was performed using the Stanford Research Repository. Patients 18 years or older with primary hyperparathyroidism who underwent parathyroidectomy between January 2009 and October 2021 were considered. Additional inclusion criteria were having clear sagittal view of the adenoma candidate on US, confirmation of the gland of origin intraoperatively, and confirmation of hypercellular parathyroid on final pathology. Data were analyzed from October 2021 to June 2022. B-mode US and surgical parathyroidectomy. The index test was using US to measure the angle between the long axis of an adenoma candidate and the strap musculature in the sagittal plane. This angle was used to test whether inferior and superior PTAs could be accurately assigned. The hypothesis was formulated prior to data collection. A total of 426 patients (mean [range] age, 61.1 [20-96] years; 316 [74.2%] female) with 442 adenomas met inclusion criteria. Of the 442 adenomas, 314 (71.0%) had measurable angles, of which 204 (46.2%) were assigned a superior origin, 238 (53.8%) were assigned an inferior origin, and 128 (29%) were indeterminate. Of the surgically identified superior PTAs, 144 (70.6%) had a definable angle, and of the surgically identified inferior PTAs, 170 (71.4%) had a definable angle. The receiver operating characteristic analysis found 94° as the optimized angle for differentiating true negatives from true positives, with an overall sensitivity of 74% and specificity of 72%. This supported using 90° as a break point for US review. True positives were considered superior adenomas with an angle greater than 90°; true negatives were inferior adenomas with an angle less than 90°. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of angulation analysis for determining PTA origin were 72.2% (95% CI, 64.9%-79.5%), 73.5% (95% CI, 66.9%-80.1%), 69.8% (95% CI, 62.5%-77.1%), 75.8% (95% CI, 69.3%-82.3%), and 72.9%, respectively. A subgroup analysis of 426 adenomas using the posterior carotid artery border on transverse US as a surrogate for predicting gland origin showed the following for sensitivity, specificity, positive predictive value, negative predictive value, and accuracy: 49.5% (95% CI, 42.6%-56.4%), 82.3% (95% CI, 77.3%-87.3%), 71.4% (95% CI, 63.9%-78.9%), 64.6% (95% CI, 59.1%-70.1%), and 66.9%, respectively. This diagnostic study showed that PTA angulation on sagittal plane US can be used to predict gland of origin and guide surgery. The relationship between adenoma and posterior carotid artery border on transverse US can also be used to predict gland origin. These easy-to-apply US-based tests can be used in conjunction with other imaging modalities to guide targeted parathyroidectomy.

Feasibility of focused parathyroidectomy in developing countries-a scoping review.

The mainstay of treatment of primary hyperparathyroidism involves a parathyroidectomy, which depending on the number of affected parathyroid glands and the availability of resources, may involve a bilateral neck exploration with four gland assessment or a minimally invasive, focused parathyroidectomy (FP) necessitating pre-operative localisation. The feasibility of the latter is yet to be demonstrated in developing countries. A scoping review was performed with published literature evaluated from the past 15 years (2007 & onwards). Articles were screened and only included if they discussed FP, preoperative localisation, economic impact and they originated from a developing country (upper middle or lower middle-income). A total of 18 articles met the inclusion criteria, comprising seven developing countries (two upper middle-income and five lower middle-income countries). Preoperative localisation was performed in all studies, with overall accuracy rates of 75.5% for ultrasound and 85.7% for 99mTc sestamibi. A total 1,202 patients (70%) had FP. Five hundred and fifty-five patients underwent FP without intraoperative adjuncts and 647 underwent FP with intraoperative adjuncts, with adjusted cure rates of 95.3% and 99.2% respectively. Overall cure rate for FP was 96.4%. With access to accurate preoperative localisation and excellent cure rates with and without intraoperative adjuncts, we conclude that FP is feasible in developing countries.

The efficacy and safety of CT-guided localization of pulmonary nodules by medical adhesives containing methylene blue before surgery

BackgroundThe accurate preoperative localization of pulmonary nodules is essential for a successful video-assisted thoracic surgery (VATS). The aim of this research was to clarify the efficacy and safety of CT-guided localization of pulmonary nodules by mixture of methylene blue and medical adhesive. MethodsBetween January 2020 and January 2021, 103 subjects who have received the CT-guidance pulmonary nodules localization operation were included and retrospectively analyzed. The data on efficiency and complications of preoperative localization using medical adhesives mixed with methylene blue mixture were collected and analyzed. Results103 patients with 111 localized pulmonary nodules were included, 95 of whom had one nodule and 8 of whom had two nodules. The nodule localization success rate reaches as high as 100 %. The mean diameter of pulmonary nodules was 9.50 ± 3.67 mm. The mean distance of pulmonary nodule and pleural surface was 19.95 ± 14.92 mm. The mean depth of localized adhesive in the lung parenchyma was 18.99 ± 11.62 mm, and the mean time required for localization was 16.98 ± 5.72 min. The average time from the nodule localization to VATS surgery was 16.97 ± 7.34 h. The common complications of localization were minor pulmonary hemorrhage (9.74 %) and mild pneumothorax (15.53 %). Besides, pulmonary hemorrhage was related with depths of medical adhesives and nodules in lung parenchyma (p = 0.018 and 0.002, respectively). ConclusionMedical adhesive mixed with methylene blue is safe and effective in pulmonary nodules localization for VATS, and surgeons have flexibility in scheduling the procedure.

Intraoperative radio-guided localization of parathyroid adenomas using 3D freehand SPECT technology.

Parathyroidectomy for primary hyperparathyroidism (PHPT) could have poor outcomes, even with accurate preoperative localization of the adenomas, because their intraoperative localization can be challenging. Freehand single photon emission computed tomography (fhSPECT) is a new technique for radio-guided intraoperative navigation. Its use during parathyroidectomy could be useful and such data are limited. We herein present our experience on the feasibility of fhSPECT for intraoperative detection of abnormal parathyroid glands. We retrospectively reviewed the clinical data of 55 patients (30-77years old) with PHPT due to parathyroid adenomas, that were subjected to parathyroidectomy from 12/2017 to 7/2022. In average, 111 ± 74MBq of Tc-99m Sestamibi were injected intravenously, approximately 2h before the operation and fhSPECT was used to generate 3D images during parathyroidectomy. Measurements of PTH and calcium levels were performed preoperatively, postoperatively and 4-6months after the procedure. FhSPECT successfully identified the parathyroid adenoma in all the patients. It took 3min (median time) for fhSPECT to detect at least one radioactive spot in all patients. The mean duration of the operation was 66.6 ± 7.3min. Forty-nine patients out of 55 had solitary and 6/55 had multiple adenomas, whereas 6/55 had ectopic abnormal parathyroid glands. None of the patients had persistent hyperparathyroidism during follow-up. To the best of our knowledge, this is the largest series of patients with PHPT that underwent fhSPECT assisted parathyroidectomy. Our data suggest that this navigation system is helpful in identifying parathyroid adenomas intraoperatively.

Diagnostic Performance of 18F-fluorocholine PET/CT Compared to 99mTc-Sestamibi Scintigraphy in Diagnosis of Parathyroid Adenoma

Background: In most hyperparathyroidism cases, the disease is related to parathyroid adenoma (PTA). Owing to the inconsistencies of currently approved imaging methods, novel methods for detecting PTA are being evaluated. This study aimed to compare 18F-fluorocholine PET/CT with 99mTc-sestamibi SPECT/CT in identifying PTA in Saudi patients.Methods and Results: The study included 40 adult patients with PTA diagnosed by histopathological findings. 99mTc-sestamibi SPECT/CT and 18F-fluorocholine PET/CT examinations were performed for each patient, and parathyroid hormone (PTH) levels and histologic findings were recorded. The diagnostic ability of 18F-fluorocholine PET/CT (AUC=0.720; P=0.029) was superior to 99mTc-sestamibi SPECT/CT (AUC=0.623; P=0.214) in identifying PTA. The sensitivity and accuracy of 18F-fluorocholine PET/CT (81.5% and 75%, respectively) were significantly (P<0.05) higher than that of 99mTc-sestamibi SPECT/CT (63% and 62.5%, respectively). 18F-fluorocholine PET/CT findings were correlated significantly (P=0.023) with PTH results. Conclusion: 18F-fluorocholine PET/CT is a diagnostic imaging method superior to conventional modality 99mTc-sestamibi SPECT/CT in the detection of PTA and, thus, allows for accurate preoperative localization.

Diagnostic Performance of Magnetic Resonance Imaging for Parathyroid Localization of Primary Hyperparathyroidism: A Systematic Review.

Accurate preoperative localization is crucial for successful minimally invasive parathyroidectomy in primary hyperparathyroidism (PHPT). Preoperative localization can be challenging in patients with recurrent and/or multigland disease (MGD). This has led clinicians to investigate multiple imaging techniques, most of which are associated with radiation exposure. Magnetic resonance imaging (MRI) offers ionizing radiation-free and accurate imaging, making it an attractive alternative imaging modality. The objective of this systematic review is to provide an overview of the diagnostic performance of MRI in the localization of PHPT. PubMed and Embase libraries were searched from 1 January 2000 to 31 March 2023. Studies were included that investigated MRI techniques for the localization of PHPT. The exclusion criteria were (1) secondary/tertiary hyperparathyroidism, (2) studies that provided no diagnostic performance values, (3) studies published before 2000, and (4) studies using 0.5 Tesla MRI scanners. Twenty-four articles were included in the systematic review, with a total of 1127 patients with PHPT. In 14 studies investigating conventional MRI for PHPT localization, sensitivities varied between 39.1% and 94.3%. When employing more advanced MRI protocols like 4D MRI for PHPT localization in 11 studies, sensitivities ranged from 55.6% to 100%. The combination of MR imaging with functional techniques such as 18F-FCH-PET/MRI yielded the highest diagnostic accuracy, with sensitivities ranging from 84.2% to 100% in five studies. Despite the limitations of the available evidence, the results of this review indicate that the combination of MR imaging with functional imaging techniques such as 18F-FCH-PET/MRI yielded the highest diagnostic accuracy. Further research on emerging MR imaging modalities, such as 4D MRI and PET/MRI, is warranted, as MRI exposes patients to minimal or no ionizing radiation compared to other imaging modalities.

Robotic parathyroidectomy is a feasible technique for primary hyperparathyroidism

PurposeFocused parathyroidectomy is the gold standard treatment modality for primary hyperparathyroidism, which allows accurate preoperative localization. Robotic parathyroidectomy has emerged as a feasible procedure for focused parathyroidectomy. This study aimed to report the experiences of gasless robotic transaxillary parathyroidectomy for primary hyperparathyroidism in a single center.MethodsWe assessed the data obtained from patients who underwent gasless robotic parathyroidectomy with the transaxillary approach between December 2013 and August 2022 and were diagnosed with primary hyperparathyroidism at our institute. The data included clinical, biochemical, and pathological features and operation time.ResultsOf the 12 patients, 11 were women and one was a man. The median age of the patients was 44.5 years (range: 15–65 years). The median preoperative maximum mass diameters on ultrasonography and neck computed tomography were 1.2 ± 0.5 and 1.1 ± 0.6 cm, respectively. The median size of the postoperative maximum mass diameter in gross pathology was 1.3 ± 0.4 cm. The location of the enlarged parathyroid was left superior in five patients, right inferior in four, left inferior in three, and no right superior in one. In the final pathological examination, all cases were parathyroid adenomas. Only one case experienced a postoperative bleeding complication. At six months from surgery, average of an axillary scar length was 5.85 cm, and an average width was 0.21 cm. The mean operative time was 113 ± 48 min. The mean robot docking and console times were 9 ± 5 and 47 ± 52 min, respectively.ConclusionsRobotic transaxillary parathyroidectomy is a feasible technique in select patients with primary hyperparathyroidism and preoperatively localized disease. The gasless robotic transaxillary approach provides procedural safety as well as superior cosmetic results without a neck scar.

Preoperative identification of small parathyroid adenomas-better done by fluorocholine positron emission tomography/computed tomography.

Preoperative localization imaging studies are crucial for safe and successful parathyroidectomy in patients with primary hyperparathyroidism (pHPT), especially in focused approaches. A common imaging sequence is ultrasound followed by scintigraphy. These techniques, but not 18F-fluorocholine positron emission tomography/computed tomography (PET/CT), show lower detection rates in multiglandular disease (MGD), which is associated with smaller adenomas. In this study, we evaluate the accuracy of these modalities in small parathyroid adenomas (PAs) and discuss the potential sequence of preoperative localization diagnostics. Patients undergoing parathyroidectomy for pHPT were retrospectively categorized into small adenoma (specimen diameter <10 mm) and large adenoma. The groups were compared for accuracy of preoperative imaging studies, short-term and long-term outcomes. Among 147 patients retrospectively analyzed in this study, 38 small PAs were found. Preoperative correct quadrant prediction for small adenomas was significantly lower for ultrasound (P=0.03) and single-photon emission computed tomography/CT (SPECT/CT) (P<0.01) but not for choline PET/CT. While PET/CT was performed significantly more often in small PAs (P<0.01), it showed highly significant superiority over the other imaging modalities in accurate preoperative localization in both small (P<0.0001) and large PAs (P<0.01). There was no difference in calcium and parathyroid hormone (PTH) levels at latest follow-up with slightly more recurrences in small adenomas (P=0.08). Choline PET/CT showed a better diagnostic yield especially for small and multiple adenomas and was better in prediction of the correct localization. It could therefore serve as a second-line imaging modality.

Customised 3D-Printed Surgical Guide for Breast-Conserving Surgery after Neoadjuvant Chemotherapy and Its Clinical Application.

For patients eligible to undergo breast-conserving surgery (BCS) after neoadjuvant chemotherapy, accurate preoperative localisation of tumours is vital to ensure adequate tumour resection that can reduce recurrence probability effectively. For this reason, we have developed a 3D-printed personalised breast surgery guide (BSG) assisted with supine magnetic resonance imaging (MRI) and image 3D reconstruction technology, capable of mapping the tumour area identified on MRI onto the breast directly using dual positioning based on the manubrium and nipple. In addition, the BSG allows the colour dye to be injected into the breast to mark the tumour region to be removed, yielding more accurate intraoperative resection and satisfactory cosmetic outcomes. The device has been applied to 14 patients from January 2018 to July 2023, with two positive margins revealed by the intraoperative biopsy. This study showed that the BSG-based method could facilitate precise tumour resection of BCS by accurately localising tumour extent and margin, promoting the clinical efficacy in patients with breast cancer as well as simplifying the surgical process.

Utility of Virtual Bronchoscopy in Tracheal Tumors.

Tracheal tumors are rare neoplasms, most of which are malignant. Conventional bronchoscopy (CB) and biopsy are used in the primary evaluation of these tumors, while Contrast-Enhanced Computed Tomography (CECT) is usually used for assessing extraluminal extension and nodal spread. Virtual bronchoscopy, created by postprocessing the three-dimensional volume data acquired from CECT, attempts to recreate the endoluminal features as seen in CB. The complexity of tracheal surgery necessitates accurate preoperative localization of the lesion and planning. It can assist in evaluation of patients in whom CB cannot be performed and for airway assessment in a preoperative setting. Although it cannot replace CB, it can be resorted to, in specific clinical scenarios. In this pictorial essay, we aim to highlight the technique, role, and clinical utility of Virtual Bronchoscopy (VB) in tracheal tumors.

Role of four-dimensional computer tomography (4D-CT) in non-localising and discordant first-line imaging in primary hyperparathyroidism.

Accurate preoperative localisation of parathyroid adenoma is imperative for the success of minimally invasive parathyroidectomy (MIP). Our study aimed to evaluate the role of four-dimensional computer tomography (4D-CT) scan as an imaging modality in patients with failed and discordant localisation reported in the first-line imaging modalities (ultrasonography and 99mTc-MIBI-SPECT/CT). This is a prospective cohort study performed at a university teaching centre from March 2013 to July 2021. All patients with primary hyperparathyroidism who had failed localisation by ultrasonography and 99mTc-MIBI-SPECT/CT (SpCT), or discordance between them, had 4D-CT performed in this study. One hundred and two sporadic cases of pHPT with failed/discordant first-line imaging had 4D-CT imaging prior to parathyroidectomy. In 102 patients, 105 parathyroid adenomas were reported on histopathology. 4D-CT was able to localise 78% of them to the correct side and 64% to the correct quadrant in 102 patients, as compared with US (correct side 21%, correct quadrant 16%) and 99mTc-MIBI-SPECT/CT (correct side 36%, correct quadrant 31%). 4D-CT had a sensitivity, precision, accuracy and F1 score for correct quadrant localisation as 79%, 81%, 66% and 80%; and for correct side localisation as 82%, 98%, 80% and 89%, respectively. 4D-CT was able to identify three ectopic adenomas (two in superior mediastinum and one in the oesophageal wall) which were not detected on US or SpCT. 4D-CT was found to be sensitive and accurate in preoperative localising of the diseased parathyroid glands after failed/discordant US and SpCT. This led to more patients being offered MIP as the primary surgery and improved operative outcomes.

Combined indocyanine green and medical glue enables stable and precise position in animal studies: promising for fluorescence-guided pulmonary ground glass nodule resection.

Accurate preoperative localization of pulmonary nodules is crucial for surgical treatment. The use of indocyanine green (ICG) for localization is prone to thoracic contamination and spread, resulting in the eventual failure of localization. By using medical glue combined with ICG, we can accurately and permanently locate various tissues in animal study, which can provide evidences for clinical translations. A series of medical glue and ICG volume ratios of 2:3, 3:3, 4:3, 6:3, and 9:3 were mixed and injected immediately into subcutaneous tissues of BALB/c nude mice; either medical glue or ICG was injected singly in the control group. Fluorescence intensity over time and boundary sharpness were investigated to determine the optimal ratio. Then, fluorescence guided resection of tissue was performed ex vivo on the pig intestine utilizing optimal ratio. Further, localization agents with the optimal ratio were injected into the organs of living mice, and fluorescence imaging for accurate positioning was performed 24 hours later. The localization agents with a volume ratio of 4:3 showed the best boundary sharpness and the strongest photostability. With the guidance of fluorescence navigation, the marked tissues were accurately separated and removed from the surrounding tissue both on mice and on pig intestines. In the organs of living mice, the localization agents (ratio 4:3) realized accurate positioning of marked tissues. Additionally, the medical glue limited the diffusion of ICG, promising to enable more stable and precise positioning of the nodules during surgery. The combination of ICG and medical glue presents a superior approach when compared to the individual use of either ICG or medical glue. This technique offers enhanced precision and durability and sealed the wound, thereby mitigating the risk of pneumothorax following puncture procedures. This innovative technique optimizes the properties of medical adhesive to augment tissue density while harnessing the real-time fluorescent endoscopic marking capabilities of ICG during surgical interventions. By employing this innovative technique, it holds significant promise for augmenting the accuracy of pulmonary nodule localization in thoracoscopic surgery within future clinical applications.

Unmasked insulinoma occasioned by severe hypoglycemic coma immediately postpartum: a case report

BackgroundInsulinoma in women during pregnancy and postpartum is very rare; approximately 65% of cases are diagnosed early in pregnancy and ~ 35% immediately after delivery, few being found in middle or late pregnancy, likely due to increased insulin resistance seen after early-stage pregnancy. We successfully treated a case of insulinoma in which severe hypoglycemic coma immediately after delivery occasioned detailed investigation and diagnosis.Case presentationOur patient experienced hypoglycemic coma in the 3rd month of pregnancy (initially considered due to her hyperemesis gravidarum) that improved spontaneously during the gestational period. No abnormalities of plasma glucose or body weight were found in regular checkups during her pregnancy; however, recurrence of hypoglycemic coma after delivery led us to suspect insulinoma. While contrast enhanced computer tomography and endoscopic ultrasonography (EUS) initially failed to detect a tumor in the pancreas, selective arterial calcium stimulation test revealed an insulin-secreting tumor localized in the pancreatic body. She then underwent spleen-preserving distal pancreatectomy; a 10-mm tumor positive for chromogranin A, synaptophysin and insulin was identified.ConclusionsAlthough pregnancy can mask insulinoma-associated symptoms and make diagnosis challenging, hypoglycemic episodes during early pregnancy, which were observed in this case, are suggestive of insulinoma. Importantly, in this case, accurate preoperative localization of the tumor enabled prompt curative surgery after delivery. Thus, clinical vigilance for the occurrence of insulinoma and its localization is appropriate for pregnant women suffering severe hypoglycemia.

Application of Magnetic Resonance Diffusion Tensor Imaging in Diagnosis of Lumbosacral Nerve Root Compression

The aim of this study was to assess the value of 3.0T magnetic resonance (MR) Diffusion tensor imaging (DTI) in the diagnosis of lumbosacral nerve root compression. The radiology reports, and clinical records of 34 patients with nerve root compression caused by lumbar disc herniation or bulging and 21 healthy volunteers who had undergone magnetic resonance imaging (MRI) and DTI scan were retrospectively reviewed. The differences in fractional anisotropy (FA) and apparent diffusion coefficient (ADC) between compressed and non-compressed nerve roots from patients and the normal nerve roots from healthy volunteers were compared. Meanwhile, the nerve root fiber bundles were observed and analyzed. The average FA and ADC values of the compressed nerve roots were 0.254 ± 0.307 and 1.892 ± 0.346 10^-3mm2/s, respectively. The average FA and ADC values of the non-compressed nerve roots were 0.377 ± 0.659 and 1.353 ± 0.344 10^-3mm2/s, respectively. The FA value of compressed nerve roots was significantly lower than that of non-compressed nerve roots (P < 0.01). The ADC value of compressed nerve roots was significantly higher than that of non-compressed nerve roots. There were no significant differences between the left and right nerve roots of normal volunteers in FA and ADC values (P > 0.05). The nerve roots at different levels of L3-S1 had significantly different FA and ADC values (P < 0.01). Incomplete fiber bundles with extrusion deformation, displacement or partial defect were observed in the compressed nerve root fiber bundles. The real diagnosis of the clinical situation of the nerve can provide neuroscientists with an important computer tool to help them infer and understand the possible working mechanism from the experimental data of behavior and electrophysiology. The compressed lumbosacral nerve roots can be accurately localized through 3.0T magnetic resonance DTI, which is instructive for accurate clinical diagnosis and preoperative localization.

Diffusion MRI of the facial-vestibulocochlear nerve complex: a prospective clinical validation study

ObjectivesSurgical planning of vestibular schwannoma surgery would benefit greatly from a robust method of delineating the facial-vestibulocochlear nerve complex with respect to the tumour. This study aimed to optimise a multi-shell readout-segmented diffusion-weighted imaging (rs-DWI) protocol and develop a novel post-processing pipeline to delineate the facial-vestibulocochlear complex within the skull base region, evaluating its accuracy intraoperatively using neuronavigation and tracked electrophysiological recordings.MethodsIn a prospective study of five healthy volunteers and five patients who underwent vestibular schwannoma surgery, rs-DWI was performed and colour tissue maps (CTM) and probabilistic tractography of the cranial nerves were generated. In patients, the average symmetric surface distance (ASSD) and 95% Hausdorff distance (HD-95) were calculated with reference to the neuroradiologist-approved facial nerve segmentation. The accuracy of patient results was assessed intraoperatively using neuronavigation and tracked electrophysiological recordings.ResultsUsing CTM alone, the facial-vestibulocochlear complex of healthy volunteer subjects was visualised on 9/10 sides. CTM were generated in all 5 patients with vestibular schwannoma enabling the facial nerve to be accurately identified preoperatively. The mean ASSD between the annotators’ two segmentations was 1.11 mm (SD 0.40) and the mean HD-95 was 4.62 mm (SD 1.78). The median distance from the nerve segmentation to a positive stimulation point was 1.21 mm (IQR 0.81–3.27 mm) and 2.03 mm (IQR 0.99–3.84 mm) for the two annotators, respectively.Conclusionsrs-DWI may be used to acquire dMRI data of the cranial nerves within the posterior fossa.Clinical relevance statementReadout-segmented diffusion-weighted imaging and colour tissue mapping provide 1–2 mm spatially accurate imaging of the facial-vestibulocochlear nerve complex, enabling accurate preoperative localisation of the facial nerve. This study evaluated the technique in 5 healthy volunteers and 5 patients with vestibular schwannoma.Key Points• Readout-segmented diffusion-weighted imaging (rs-DWI) with colour tissue mapping (CTM) visualised the facial-vestibulocochlear nerve complex on 9/10 sides in 5 healthy volunteer subjects.• Using rs-DWI and CTM, the facial nerve was visualised in all 5 patients with vestibular schwannoma and within 1.21–2.03 mm of the nerve’s true intraoperative location.• Reproducible results were obtained on different scanners.

Radio-frequency identification (RFID) tag localisation of non-palpable breast lesions a single centre experience.

The purpose of this study is to report the surgical experience and outcomes with pre-operative localisation of non-palpable breast lesions using the RFID tag system. The cohort for this prospective study included patients over the age of 18 with biopsy proven, non-palpable indeterminate lesions, DCIS or breast cancer requiring pre-operative localisation before surgical excision between September 2020 and July 2022. A total of 312 RFID tags were placed in 299 consecutive patients. Indications for localisation included non-palpable invasive cancer in 255 (85.3%) patients, in situ disease in 38 (12.7%) and indeterminate lesions requiring surgical excision in 6 (2.0%). Both in situ and invasive lesions had a median size of 13mm (range 4-100mm) on pre-operative imaging. The RFID tags were in situ for a median time of 21 days before surgery (range 0-233 days). Of the 213 tags, 292 (93.6%) were introduced using ultrasound (USS) guidance and stereotactically in 20 (6.4%). In 3 (1.0%) cases the RFID tag was either not satisfactorily deployed at the intended target or retrieved intra-operatively. Following discussion of post-operative histology by the multi-disciplinary team, further surgery for close or involved margins was for 26 (8.7%) patients. The Hologic RFID tag system can be used for accurate pre-operative localisation of non-palpable masses as well as diffuse abnormalities such as mammographic distortions and calcifications. It has advantages of flexibility for scheduling image-guided insertion independently of scheduled operating lists and can be placed to localise lesions prior to initiating neoadjuvant systemic treatment.

Comparative Effectiveness of MRI, 4D-CT and Ultrasonography in Patients with Secondary Hyperparathyroidism.

Accurate preoperative localization of abnormal parathyroid glands is crucial for successful surgical management of secondary hyperparathyroidism (SHPT). This study was conducted to compare the effectiveness of preoperative MRI, 4D-CT, and ultrasonography (US) in localizing parathyroid lesions in patients with SHPT. We performed a retrospective review of prospectively collected data from a tertiary-care hospital and identified 52 patients who received preoperative MRI and/or 4D-CT and/or US and/or 99mTc-MIBI and subsequently underwent surgery for SHPT between May 2013 and March 2020. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of each imaging modality to accurately detect enlarged parathyroid glands were determined using histopathology as the criterion standard with confirmation using the postoperative biochemical response. A total of 198 lesions were identified intraoperatively among the 52 patients included in this investigation. MRI outperformed 4D-CT and US in terms of sensitivity (P < 0.01), specificity (P = 0.455), PPV (P = 0.753), and NPV (P = 0.185). The sensitivity and specificity for MRI, 4D-CT, and US were 90.91%, 88.95%, and 66.23% and 58.33%, 63.64%, and 50.00%, respectively. The PPV of combined MRI and 4D-CT (96.52%) was the highest among the combined 2 modalities. The smallest diameterof the parathyroid gland precisely localized by MRI was 8×3 mm, 5×5 mm by 4D-CT, and 5×3 mm by US. MRI has superior diagnostic performance compared with other modalities as a first-line imaging study for patients undergoing renal hyperparathyroidism, especially for ectopic or small parathyroid lesions. We suggest performing US first for diagnosis and then MRI to make a precise localization, and MRI proved to be very helpful in achieving a high success rate in the surgical treatment of renal hyperparathyroidism in our own experience.

18F-fluorocholine PET/MRI versus ultrasound and sestamibi for the localization of parathyroid adenomas.

Accurate preoperative localization is imperative to facilitate a minimally invasive parathyroidectomy (MIP) in primary hyperparathyroidism (pHPT). This study aims to compare the diagnostic value of standard-of-care localization techniques (ultrasound [US] and 99mTechnetium (99mTc) -sestamibi scintigraphy) to [F-18]-fluorocholine positron emission tomography/magnetic resonance imaging (FCH-PET/MRI) to determine the additional clinical usefulness of PET/MRI in a Canadian cohort. We conducted a prospective, appropriately powered, study to compare the diagnostic value of -FCH PET/MRI to that of the US and 99mTc-sestamibi scintigraphy for localization of parathyroid adenomas in a patient with pHPT. The primary outcome was the per-lesion sensitivity and positive predictive value (PPV) of FCH-PET/MRI, US, and 99mTc-sestamibi scintigraphy. Intraoperative surgeon localization, parathormone levels, and histopathological findings were used as reference standards. Forty-one patients underwent FCH-PET/MRI of which 36 patients had parathyroidectomy. In these 36 patients, 41 parathyroid lesions were histologically confirmed as adenomas or hyperplastic glands. Per-lesion sensitivity of FCH-PET/MRI was 82.9% and of US and 99mTc-sestamibi scintigraphy combined at 50.0%, respectively. The sensitivity of FCH-PET/MRI was superior to that of US and 99mTc-sestamibi scintigraphy (p = 0.002). In the 19 patients in whom both US and 99mTc-sestamibi scintigraphy were negative, PET/MRI correctly identified the parathyroid adenoma in 13 patients (68%). FCH-PET/MRI is a highly accurate imaging modality for localization of parathyroid adenomas in a tertiary center in North America. It is a superior functional imaging modality to 99mTc-sestamibi scintigraphy alone and more sensitive for localization of parathyroid lesions than US and 99mTc-sestamibi scintigraphy combined. This imaging modality could become the most valuable preoperative localization study given its superior performance in localizing parathyroid adenomas.

Interictal Electrophysiological Source Imaging Based on Realistic Epilepsy Head Model in Presurgical Evaluation: A Prospective Study

Invasive techniques are becoming increasingly important in the presurgical evaluation of epilepsy. Adopting the electrophysiological source imaging (ESI) of interictal scalp electroencephalography (EEG) to localize the epileptogenic zone remains a challenge. The accuracy of the preoperative localization of the epileptogenic zone is key to curing epilepsy. The T1 MRI and the boundary element method were used to build the realistic head model. To solve the inverse problem, the distributed inverse solution and equivalent current dipole (ECD) methods were employed to locate the epileptogenic zone. Furthermore, a combination of inverse solution algorithms and Granger causality connectivity measures was evaluated. The ECD method exhibited excellent focalization in lateralization and localization, achieving a coincidence rate of 99.02% ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$p &lt; 0.05$</tex> ) with the stereo electroencephalogram. The combination of ECD and the directed transfer function led to excellent matching between the information flow obtained from intracranial and scalp EEG recordings. The ECD inverse solution method showed the highest performance and could extract the discharge information at the cortex level from noninvasive low-density EEG data. Thus, the accurate preoperative localization of the epileptogenic zone could reduce the number of intracranial electrode implantations required.