[18F]FAPI PET/CT in the evaluation of focal liver lesions with [18F]FDG non-avidity.

PURPOSE: This prospective study was aimed to investigate the potential utility of [18F]fibroblast activation protein inhibitor (FAPI) PET/CT for evaluating focal liver lesions (FLLs) with [18F]FDG non-avidity. METHODS: From January 2021 to March 2022, this prospective study included 80 FLLs that were not avid on [18F]FDG PET/CT from 37 patients, then underwent [18F]FAPI PET/CT. All patients with FLL(s) with biopsy-proof or follow-up confirmation were categorized into four subgroups (20 hepatocellular carcinomas [HCCs]/5 non-HCC malignancies/4 inflammatory FLLs/8 benign noninflammatory FLLs). The diagnostic value of [18F]FAPI for detecting liver malignancy was determined by visual evaluation. Differences in the maximum standardized uptake value (SUVmax) and lesion-to-background ratio (LBR) obtained from [18F]FAPI PET/CT among the four subgroups were analyzed by semiquantitative analysis. RESULTS: Among the thirty-seven enrolled participants (34 males; median age 57 years, range 48-67 years), on visual evaluation, the sensitivity, specificity, and accuracy of [18F]FAPI PET for detecting liver malignancy in the patient-based analysis were 96.0% (24/25), 58.3% (7/12), and 83.8% (31/37), respectively. On semiquantitative analysis, the SUVmax and LBR of [18F]FAPI PET in liver malignancy (33 HCC lesions; 19 non-HCC malignant lesions) were significantly higher than those in 11 benign noninflammatory FLLs [HCC: SUVmax: 6.4 vs. 4.5, P = 0.017; LBR: 5.1 vs. 1.5, P = 0.003; non-HCC: SUVmax: 5.5 vs. 4.5, P = 0.008; LBR: 4.4 vs. 1.5, P = 0.042]. Notably, there was no significant difference in the SUVmax of [18F]FAPI PET between 33 HCC lesions and 17 inflammatory FLLs (6.4 vs. 8.2, P = 0.37), but the LBR of [18F]FAPI PET in HCC were significantly lower than that in inflammatory FLLs (5.1 vs. 9.1, P = 0.003). CONCLUSIONS: [18F]FAPI PET/CT shows high sensitivity in detecting HCC and non-HCC malignancy with [18F]FDG non-avidity. [18F]FAPI might be a promising radiopharmaceutical for the differential diagnosis of benign noninflammatory FLLs and liver malignancy with [18F]FDG non-avidity.

An anatomical study of the origins courses and distributions of the transverse branches of lumbar arteries at the L1-L4 levels.

Pseudoaneurysms of the lumbar arteries following transforaminal lumbar interbody fusion (TLIF) are rare postoperative complications that usually occur around the transverse process. However, there are few detailed descriptions of the transverse branch and other branches of the dorsal branches at the L1-L4 disks. STUDY DESIGN: Ten adult embalmed cadavers were anatomically studied. OBJECTIVES: The purposes of the study were to describe the vascular distribution of the dorsal branches, especially the transverse branches, at the L1-L4 levels and provide information useful for TLIF. METHODS: Ten embalmed cadavers studied after their arterial systems were injected with red latex. The quantity, origin, pathway, distribution range and diameter of the branches were recorded and photographed. RESULTS: The transverse branch appeared in all 80 intervertebral foramina. The transverse branch was divided into 2 types: In type 1, the arteries divided into superior branches and inferior branches; the arteries in type 2 divided into 3 branches (superior, intermedius and inferior branches). CONCLUSIONS: The transverse branches of the dorsal arteries are common structures from L1 to L4, and 2 types of transverse branches were found. A thorough understanding of the dorsal branches, especially the transverse branches of the lumbar artery, may be very important for reducing both intraoperative bleeding during the surgery and the occurrence of pseudoaneurysms after transforaminal lumbar interbody fusion.

The clinical significance of remnant thyroid tissue in thyroidectomized differentiated thyroid cancer patients on 131I-SPECT/CT.

BACKGROUND: To explore the 131I-SPECT/CT characteristics of remnant thyroid tissue (RTT) in differentiated thyroid cancer (DTC), further assess the risk factors and clinical significance. METHODS: 52 DTC patients after total thyroidectomy had undergone neck 131I-SPECT/CT before 131I ablation. The diagnosis of RTT was based on SPECT/CT and follow-up at least 3 months. The anatomic locations and features of SPECT/CT of RTT were assessed by reviewers. The risk factors of RTT with CT positive were analyzed by the chi-square test. RESULTS: A total of 80 lesions of RTT were diagnosed in this study, most of them were mainly located in the regions adjacent to trachea cartilage (37/80) or lamina of thyroid cartilage (17/80). On SPECT/CT of RTT, low, moderate and high uptake were respectively noted in 10, 24 and 46 lesions, definite positive, suspected positive and negative CT findings were respectively noted in 10, 21 and 49. The RTT lesions with definite positive CT findings were mainly located adjacent to lamina of thyroid cartilage (5/10). Primary thyroid tumor (P = 0.029) and T stage (P = 0.000) were the effective risk factors of CT positive RTT. CONCLUSIONS: RTT has certain characteristic distribution and appearances on SPECT/CT. Most of RTT with definite CT abnormalities located adjacent to lamina of thyroid cartilage, which suggest surgeons should strengthen the careful removal in this region, especially primary thyroid tumor involving bilateral and T4 stage. This study can provide a certain value for the improvement of thyroidectomy quality in DTC patients.

Accurate characterization of 99mTc-MDP uptake in extraosseous neoplasm mimicking bone metastasis on whole-body bone scan: contribution of SPECT/CT.

BACKGROUND: 99mTc-labelled methylene diphosphonate (99mTc-MDP) uptake can occasionally be identified in extraosseous neoplasms on whole-body scans (WBSs) and may be misinterpreted as bone metastasis. The purpose of our study was to investigate the frequency of 99mTc-MDP uptake in extraosseous neoplasms and to assess the additional value of SPECT/CT for the localization and characterization of this unusual uptake. METHODS: Data from 7308 patients (SPECT/CT was performed in 2147 patients) with known cancer who underwent WBSs for metastatic work-up between May 2015 and July 2018 were retrospectively reviewed. The locations, numbers, and intensities of extraosseous 99mTc-MDP uptake were evaluated by WBS, and the intratumoural calcification was evaluated by SPECT/CT. The diagnostic accuracy of SPECT/CT in locating 99mTc-MDP uptake in extraosseous neoplasms was compared to that of WBS. RESULTS: A total of 41 patients showed 99mTc-MDP uptake in extraosseous neoplasms. Of these patients, 23 patients had uncertain lesions by WBS, and further SPECT/CT was performed. The incidence of 99mTc-MDP uptake in extraosseous neoplasms was observed to be 0.6% by WBS and 1.1% (by) SPECT/CT. During imaging analysis, WBS had an accuracy of only 35% (14/40), whereas SPECT/CT correctly located and diagnosed all 40 lesion sites in the 23 patients. Twenty-three lesion sites (57.5%, 23/40) showed moderate or high intensity of extraosseous 99mTc-MDP uptake. Of the 23 patients, 17 patients (73.9%, 18/23) with 31 lesion sites (77.5%, 31/40) presented with intratumoural calcification. CONCLUSIONS: 99mTc-MDP uptake in extraosseous neoplasms can be observed as 0.6% on WBS and is usually localized to the breast, liver, and lung. Nuclear physicians should be familiar with such extraosseous uptake when interpreting WBSs. SPECT/CT offers better accuracy than WBS alone for locating the majority of lesions present with intratumoural calcification.

Diagnosis of Insufficiency Fracture After Radiotherapy in Patients With Cervical Cancer: Contribution of Technetium Tc 99m-Labeled Methylene Diphosphonate Single-Photon Emission Computed Tomography/Computed Tomography.

Insufficiency fractures (IFs) are a type of stress fracture caused by the effects of normal or physiological stresses on abnormally weakened bone. Frequently, these fractures are occult, and a portion of these fractures is misdiagnosed as bone metastases on a whole-body bone scan (WBS). The aim of this study was to evaluate a potential benefit of single-photon emission computed tomography/computed tomography (SPECT/CT) with metabolic and morphological imaging to diagnose IF in patients with cervical cancer after radiotherapy. METHODS: This article presents a retrospective review of 35 patients with cervical cancer after radiotherapy in patients (females; mean age, 55.94 ± 8.75 years; range, 36-73 years) who were referred to have WBS to determine whether there was any bone metastasis. The criterion standard was based on radiological investigations, clinical information, and follow-up at a minimum of 12 months. RESULTS: Insufficiency fractures were most frequently observed in the sacrum, accounting for 52.5% (21/40) of lesions. Fracture lines or sclerotic lines were noted in the IF lesion in 19 of 40 lesions on CT, and osteosclerosis was seen in 31 of 40 lesions. On WBS analysis, the sensitivity for detected lesions was 87.5% (42/48) for WBS. Nineteen lesions were interpreted as benign, 6 lesions were malignant, and 21 (43.8%) lesions were equivocal. Based on the criterion standard, WBS had an accuracy of only 47.9% (23/48). On SPECT/CT analysis, all of the lesions were observed on SPECT/CT; only 3 (6.25%) of 48 lesions were equivocal, and the accuracy was 89.6% (43/48). CONCLUSIONS: Single-photon emission computed tomography/computed tomography should be included in the differential diagnoses when lesions show elevated technetium Tc 99m-labeled methylene diphosphonate uptake on WBS. Compared with a WBS alone, a more accurate diagnosis of IF can be obtained using SPECT/CT, which resulted not only in fewer equivocal lesions but also in a higher diagnostic accuracy.

The value of 99mTc-methylene diphosphonate single photon emission computed tomography/computed tomography in diagnosis of fibrous dysplasia.

BACKGROUND: Fibrous dysplasia (FD) is a rare benign bone disorder in which the normal bone is replaced by immature fibro-osseous tissue. However, some case reports have reported that FD showed significantly increased 99mTc-methylene diphosphonate (99mTc-MDP) uptake on whole-body bone scintigraphy (WBS), which may mimic bone metastasis or skeletal involvement of the patients with known cancer. Thus, the purpose of present study is to observe the reliable characteristics and usefulness of single photon emission computed tomography/computed tomography (SPECT/CT) for the diagnosis of FD. METHODS: This was a retrospective review of 21 patients with FD (14 males and 7 females, mean age 51.2 ± 12.5 years) who were referred to have WBS to determine whether there was any osseous metastasis. WBS and SPECT/CT images were independently interpreted by two experienced nuclear medicine physician together with a diagnostic radiologist. In cases of discrepancy, consensus was obtained by a joint reading. The final diagnosis was based on biopsy proof and radiologic follow-up over at least 1 year. RESULTS: The lesions of FD were most frequently found in craniofacial region (15/21). Eighteen of the 21 (85.7%) cases showed moderate and high metabolism on WBS (compared to sternum). On CT imaging, GGO and expansion were the most common finding, were noted in 90.5% and 85.7% of the patients. Lytic lesions were present in 61.9% of the patients, and sclerosis was present in 38.1% of the patients. Cortical disruption was not seen in any patient. CONCLUSIONS: FD has certain characteristic appearance on SPECT/CT. It should be enrolled in the differential diagnoses when lesions show elevated 99mTc-MDP uptake on WBS. For SPECT/CT, the CT features of GGO and expansion in the areas of abnormal radiotracer uptake are helpful for the diagnosis of FD.

18 F-FDG PET/CT Versus 18 F-FAPI PET/CT in a Case of Recurrent Malignant Phyllodes Breast Tumor.

ABSTRACT: A 52-year-old woman with medical history of surgery for left malignant phyllodes breast tumor found a mass on the left chest 3 months ago. A suspicion of recurrent malignant phyllodes breast tumor was made. The patient was enrolled in the clinical trial of 18 F-FAPI PET/CT in recurrent sarcoma (no. NCT05485792). 18 F-FAPI PET/CT and 18 F-FDG PET/CT were performed, and the images demonstrated intense uptake in a huge mass in the left anterior chest wall. Then the patient underwent extended resection of left chest wall tumor. The tumor proved to be recurrent malignant phyllodes breast tumor pathologically.

Intense 18 F-FAPI Uptake in Small Recurrent Lesions of Combined Hepatocellular-Cholangiocarcinoma Negative on 18 F-FDG PET/CT.

ABSTRACT: A 70-year-old man presented with combined hepatocellular-cholangiocarcinoma underwent partial hepatectomy and chemoradiotherapy approximately 3 months ago. Follow-up abdominal ultrasound detected a new small lesion with decreased echogenicity in the hepatic segment I, potentially indicating recurrence. The patient was enrolled in a clinical trial of comparison of 18 F-FDG and 18 F-FAPI PET/CT in hepatic lesions. Compared with non- 18 F-FDG avidity, 18 F-FAPI PET/CT showed intense tracer uptake of the hepatic lesion. Resection of the lesion was subsequently performed, and pathologic analysis confirmed the diagnosis of recurrent combined hepatocellular-cholangiocarcinoma.

Unusual Case of Primary Hepatic Squamous Carcinoma on 18F-FDG PET/CT.

ABSTRACT: Primary hepatic squamous carcinoma is an extremely rare liver tumor type with high malignancy and poor prognosis. We present 18F-FDG PET/CT findings of primary squamous carcinoma of the liver in a 65-year-old man, who was admitted to the hospital with subxiphoid pain in the epigastric region radiating to the left lower back for 2 months. 18F-FDG PET/CT demonstrated a large heterogeneous mild enhancing mass in the left lobe of the liver, with intense circumferential 18F-FDG activity.

Increased 18F-FAPI Uptake in Radiation-Induced Liver Injury.

ABSTRACT: A 51-year-old woman with breast cancer underwent a complete surgical resection and chemoradiotherapy approximately 3 months ago. Follow-up abdominal ultrasound detected a new lesion with decreased echogenicity in the hepatic segment IV/VIII. 18F-FDG PET/CT showed the hepatic lesion without abnormal uptake. The patient was subsequently enrolled in a clinical trial of 18F-FAPI PET/CT to assess the hepatic lesion. An intense 18F-FAPI activity was identified in the hepatic lesion. Finally, pathological analysis combined with imaging follow-up confirmed the diagnosis of radiation-induced liver injury.

Head-to-head comparison of 18F-FAPI and 18F-FDG PET/CT in staging and therapeutic management of hepatocellular carcinoma.

BACKGROUND: Fluorine 18 (18F) fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) has limitations in staging hepatocellular carcinoma (HCC). The recently introduced 18F-labeled fibroblast-activation protein inhibitor (FAPI) has shown promising prospects in detection of HCC lesions. This study aimed to investigate the initial staging and restaging performance of 18F-FAPI PET/CT compared to 18F-FDG PET/CT in HCC. METHODS: This prospective study enrolled histologically confirmed HCC patients from March 2021 to September 2022. All patients were examined with 18F-FDG PET/CT and 18F-FAPI PET/CT within 1 week. The maximum standard uptake value (SUVmax), tumor-to-background ratio (TBR), and diagnostic accuracy were compared between the two modalities. RESULTS: A total of 67 patients (57 men; median age, 57 [range, 32-83] years old) were included. 18F-FAPI PET showed higher SUVmax and TBR values than 18F-FDG PET in the intrahepatic lesions (SUVmax: 6.7 vs. 4.3, P < 0.0001; TBR: 3.9 vs. 1.7, P < 0.0001). In diagnostic performance, 18F-FAPI PET/CT had higher detection rate than 18F-FDG PET/CT in intrahepatic lesions [92.2% (238/258) vs 41.1% (106/258), P < 0.0001] and lymph node metastases [97.9% (126/129) vs 89.1% (115/129), P = 0.01], comparable in distant metastases [63.6% (42/66) vs 69.7% (46/66), P > 0.05]. 18F-FAPI PET/CT detected primary tumors in 16 patients with negative 18F-FDG, upgraded T-stages in 12 patients and identified 4 true positive findings for local recurrence than 18F-FDG PET, leading to planning therapy changes in 47.8% (32/67) of patients. CONCLUSIONS: 18F-FAPI PET/CT identified more primary lesions, lymph node metastases than 18F-FDG PET/CT in HCC, which is helpful to improve the clinical management of HCC patients. TRIAL REGISTRATION: Clinical Trials, NCT05485792 . Registered 1 August 2022, Retrospectively registered.

68 Ga-FAPI Versus 18 F-FDG PET/CT in Recurrent Undifferentiated Pleomorphic Sarcoma of Colon Mesentery.

ABSTRACT: A 56-year-old woman presented with primary undifferentiated pleomorphic sarcoma of colon mesentery underwent complete surgical resection approximately 7 months ago. Abdominal contrast-enhanced CT showed a new mass in the descending colon, suggesting a high probability of tumor recurrence. Under a clinical trial, the patient underwent 68 Ga-FAPI and 18 F-FDG PET/CT to detect whether there are additional recurrent lesions. Compared with 18 F-FDG PET/CT, the recurrent undifferentiated pleomorphic sarcoma of colon mesentery, peritoneum, pelvic lymph node, and lung metastases showed higher uptake in 68 Ga-FAPI PET/CT. This case showed that 68 Ga-FAPI might be a promising radiopharmaceutical in the evaluation of undifferentiated pleomorphic sarcoma.

Statistical Analysis and Machine Learning Prediction of Disease Outcomes for COVID-19 and Pneumonia Patients.

The Coronavirus Disease 2019 (COVID-19) has spread all over the world and impacted many people's lives. The characteristics of COVID-19 and other types of pneumonia have both similarities and differences, which confused doctors initially to separate and understand them. Here we presented a retrospective analysis for both COVID-19 and other types of pneumonia by combining the COVID-19 clinical data, eICU and MIMIC-III databases. Machine learning models, including logistic regression, random forest, XGBoost and deep learning neural networks, were developed to predict the severity of COVID-19 infections as well as the mortality of pneumonia patients in intensive care units (ICU). Statistical analysis and feature interpretation, including the analysis of two-level attention mechanisms on both temporal and non-temporal features, were utilized to understand the associations between different clinical variables and disease outcomes. For the COVID-19 data, the XGBoost model obtained the best performance on the test set (AUROC = 1.000 and AUPRC = 0.833). On the MIMIC-III and eICU pneumonia datasets, our deep learning model (Bi-LSTM_Attn) was able to identify clinical variables associated with death of pneumonia patients (AUROC = 0.924 and AUPRC = 0.802 for 24-hour observation window and 12-hour prediction window). The results highlighted clinical indicators, such as the lymphocyte counts, that may help the doctors to predict the disease progression and outcomes for both COVID-19 and other types of pneumonia.

Combined SUVmax and localized colonic wall thickening parameters to identify high-risk lesions from incidental focal colorectal 18F-FDG uptake foci.

Objective: To evaluate the detection ability of 18F-FDG PET/CT for identifying high-risk lesions (high-risk adenomas and adenocarcinoma) from incidental focal colorectal 18F-FDG uptake foci combining maximum standard uptake value (SUVmax) and localized colonic wall thickening (CWT). The secondary objective was to investigate the factors of missed detection of high-risk adenomas by 18F-FDG PET/CT. Patients and methods: A total of 6394 patients who underwent 18F-FDG PET/CT in our hospital from August 2019 to December 2021 were retrospectively analysed, and 145 patients with incidental focal colorectal 18F-FDG uptake foci were identified. The optimal cut-off value of SUVmax for 18F-FDG PET/CT diagnosis of high-risk lesions was determined by receiver operating characteristic (ROC) curves. SUVmax and localized CWT were combined to identify high-risk lesions from incidental focal colorectal 18F-FDG uptake foci. The characteristics of incidental adenomas detected and high-risk adenomas missed by 18F-FDG PET/CT were compared. Results: Of the 6394 patients, 145 patients were found to have incidental focal colorectal FDG uptake foci (2.3%), and 44 patients underwent colonoscopy and pathological examination at the same time. In fact, 45 lesions, including 12 low-risk lesions and 33 high-risk lesions (22 high-risk adenomas, 11 adenocarcinoma), were found by colonoscopy. The area under the ROC curve of SUVmax for low-risk lesions and high-risk lesions was 0.737, and the optimal cut-off value was 6.45 (with a sensitivity of 87.9% and specificity of 58.3%). When SUVmax ≥6.45, the combination of localized CWT parameters has little influence on the sensitivity and specificity of detection; when SUVmax <6.45, the combination of localized CWT parameters can improve the specificity of detection of high-risk lesions, but the sensitivity has little change. In addition, the size of high-risk adenomas discovered incidentally by 18F-FDG PET/CT was larger than that of high-risk adenomas missed, but there was no significant difference in lesion location, pathological type or intraepithelial neoplasia between the two groups. Conclusions: The combination of SUVmax and localized CWT parameters of 18F-FDG PET/CT helped identify high-risk lesions from incidental focal colorectal 18F-FDG uptake foci, especially for lesions with SUVmax <6.45. Lesion size may be the only factor in 18F-FDG PET/CT missing high-risk adenomas.

Anatomical study and clinical significance of rami communicantes of the lumbar spine.

BACKGROUND AND OBJECTIVES: Rami communicantes (RC) infiltration and radiofrequency lesions are new techniques for the treatment of discogenic low back pain (DLBP). Their efficacy is controversial, and the classification of RC remains unclear. We aimed to explore the differences between RC and reclassify RC according to their anatomical characteristics. METHODS: Sixteen sides of the lumbar spine from eight adult male embalmed cadavers were dissected. The presence of RC was noted. The morphology, origin, distribution, course, quantity and spatial orientation of RC on the lumbar spine were examined. The length and width of the RC were measured by a caliper. RESULTS: A total of 213 RC were found in the 8 cadavers in the lumbar region. RC were divided into three types: superficial rami (70, 32.86%), which penetrated the psoas major (PM) and ran above the aponeurosis of the PM; deep rami (125, 58.69%), which ran along the waist of the vertebral body beneath the aponeurosis of the PM; and discal rami, which ran over and adhered to the surface of the intervertebral disc. Superficial rami were divided into two subtypes: oblique rami (45, 21.13%) and parabolic rami (25, 11.74%), which crossed the vertebra and the disc in an oblique and a parabolic course, respectively. CONCLUSIONS: RC should play an important role in the innervation of the lumbar spine. Detailed knowledge of RC in the lumbar region may help surgeons improve the efficacy of infiltration and percutaneous radiofrequency as a supplementary treatment for DLBP.

Sinuvertebral nerve block treats discogenic low back pain: a retrospective cohort study.

Background: Discogenic low back pain (DLBP) is considered the most common type of chronic low back pain (CLBP). Sinuvertebral nerve block (SVNB) is a rapid and precise intervention performed under local anesthesia to treat DLBP induced CLBP. Thus, in this study, we aimed to explore the clinical efficacy of SVNB for DLBP. Methods: We retrospectively included 32 DLBP patients from July 2020 and April 2021. Inclusion criteria: The patients had chronic pain, diagnosed as single-segment disc degeneration induced DLBP, and suffered from one-year ineffective conservative treatment. SVNB was performed and the patients were followed up at 3 and 7 days, and at 1 and 3 months after SVNB. The basic clinical characteristics, including age and gender, were collected. The measurements of Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) were assessed. Results: The average age was 49.31±14.37 years, and females vs. males was 20 (62.50%) vs. 12 (37.50%). The preoperative VAS and ODI score were 5.75±1.41 and 32.59±21.56, respectively. The VAS score was reduced to 2.50±1.46, 2.63±1.60, 3.53±2.17, and 3.78±2.18 at 3 and 7 days, and 1 and 3 months after SVNB, respectively (P<0.05). The improvement rates in the VAS score were 56.52%, 54.34%, 38.61%, and 34.26% at 3 and 7 days, and 1 and 3 months after SVNB, respectively. 18 patients (56.25%) experienced varying degrees of pain recurrence within 3 months. The ODI score was reduced by 17.28±13.06, 16.84±13.51, 19.63±17.12, and 21.44±19.03 points at 3, 7 days and 1, 3 months after SVNB, respectively (P<0.05). At 3 day and 3 month after SVNB, the ODI scores of 22 patients (68.75%) and 20 patients (62.50%) decreased to ≤20, respectively. The ODI improvement rates were 46.98%, 48.33%, 39.80%, and 34.24% at 3, 7 days and 1, 3 months after SVNB, respectively. Conclusions: We conducted a retrospective study of the clinical efficacy of SVNB for DLBP. As a rapid and cost-effective minimally invasive treatment, SVNB provided some assistance for the short-term pain relief and physical functional improvement of DLBP. SVNB could be a good choice for the treatment of DLBP.

Anatomical study of the innervation of different parts of the posterior ligamentous region of the sacroiliac joint.

BACKGROUND AND OBJECTIVES: The periarticular sacroiliac joint (SIJ) technique has become an important area of focus, and the quartering of the SIJ posterior ligamentous region has been proposed as a way to refine this technique. However, detailed nerve distribution combined with the division of the SIJ posterior ligamentous region is lacking. We aimed to explore the innervation of the SIJ posteriorly based on the quartering of the SIJ posterior ligamentous region. METHODS: Sixteen SIJs from eight embalmed cadavers were studied. Each SIJ posterior ligamentous region was equally divided into areas 0-3 from top to bottom. The origin, distribution, quantity, transverse diameter, spatial orientation, relation with bony structures, and the number of identifiable terminal nerve branches in each area were examined. RESULTS: Areas 0-1 were innervated by the lateral branches of the dorsal rami of L4-L5 directly in all specimens. Areas 2-3 were innervated by that of both lumbar and sacral nerves via the posterior sacral network (PSN), with L5 contributing to the PSN in all specimens and L4 in 68.75%. The number of identifiable terminal nerve branches were significantly higher in areas 2-3 than in areas 0-1. CONCLUSIONS: The inferior part of the SIJ posterior ligamentous region seems to be the main source of SIJ-related pain and is innervated by lumbar and sacral nerves via the PSN. However, the superior part directly innervated by lumbar nerves should not be neglected, and further clinical verification is needed.

The Value of 99mTc-Methylene Diphosphonate Single-Photon Emission Computed Tomography/Computed Tomography in Detecting Atraumatic Costal Cartilage Fracture in Malignant Tumor Patients.

Objectives: To assess the clinical significance and single-photon emission computed tomography/computed tomography (SPECT/CT) features of atraumatic costal cartilage fracture (CCF) in patients with malignant tumors. Methods: This was a retrospective review of 38 tumor patients with atraumatic CCF referred to SPECT/CT, who were served as the study group (SG). The features of SPECT/CT of atraumatic CCF were assessed. Another 100 tumor patients who underwent chest SPECT/CT and did not have CCF were randomly selected as the control group (CG). In all patients (SG + CG), the diagnostic powers in the detection of atraumatic CCF were computed among CT, SPECT, and SPECT/CT. The final diagnosis was based on pathological findings and radiologic follow-up of at least 1 year. Results: On SPECT/CT images of atraumatic CCF in the SG, fracture lines, irregular calcification, deformation, and swelling were, respectively, noted in 26.3, 47.4, 34.2, and 18.4% of lesions; low, moderate, and high uptake were, respectively, noted in 13.2, 52.6, and 34.2% of lesions. In all patients (SG + CG), the diagnostic powers in the detection of atraumatic CCF of CT, SPECT, and SPECT/CT were as follows: sensitivity 63.2, 100.0, and 92.1%; specificity 86.0, 81.0, and 94.0%; negative predictive value 86.0, 100.0, and 96.9%; positive predictive value 63.1, 66.7, and 85.4%; and area under the curve value 0.746, 0.905, and 0.931. Conclusions: Atraumatic CCF has certain characteristic appearances on SPECT/CT. It should be enrolled in the differential diagnoses when costal cartilages of patients with malignant tumors show abnormal elevated 99mTc-MDP uptake on scintigraphy. Single-photon emission computed tomography/CT has excellent diagnostic power in detecting atraumatic CCF.

Biomechanical study of the C5-C8 cervical extraforaminal ligaments.

BACKGROUND: The anatomical distribution of the extraforaminal ligaments in the cervical intervertebral foramina has been well studied. However, detailed descriptions of the biomechanical characteristics of these ligaments are lacking. METHODS: The paravertebral muscles were dissected, and the extraforaminal ligaments and nerve roots were identified. The C5 and C7 or C6 and C8 cervical nerve roots on both sides were randomly selected, and a window was opened on the vertebral lamina to expose the posterior spinal nerve root segments. Five needles were placed on the nerve root and the bone structure around the intervertebral foramen; the distal end of the nerve root was then tied with silk thread, and the weights were connected across the pulley. A weight load was gradually applied to the nerve root (50 g/time, 60 times in total). At the end of the experiment, segments of the extraforaminal ligaments were selectively cut off to compare the changes in nerve root displacement. RESULTS: The displacement of the C5, C6, C7, and C8 nerve roots increases with an increasing traction load, and the rate of change of nerve root displacement in the intervertebral foramen is smaller than that in the nerve root on the outside area (p < 0.05). Extraforaminal ligaments can absorb part of the pulling load of the nerve root; the C5 nerve root has the largest load range. CONCLUSIONS: Cervical extraforaminal ligaments can disperse the tension load on the nerve root and play a role in protecting the nerve root. The protective effect of the C5 nerve root was the strongest, and this may anatomically explain why the C5 nerve roots are less prone to simple avulsion.

The anatomical mechanism of C5 palsy after expansive open-door laminoplasty.

BACKGROUND: Postoperative C5 palsy is not an uncommon complication in patients who undergo expansive open-door laminoplasty. However, the etiology is unclear and likely multifactorial. Nerve root lesions and spinal cord lesions have been previously proposed theories. PURPOSE: To investigate the anatomical mechanism of postoperative C5 palsy after cervical expansive open-door laminoplasty. STUDY DESIGN: A dissection-based study of eight embalmed human cadavers. METHODS: The anatomy was studied in eight whole cervical cadavers (three females, five males), prepared with formaldehyde, whose ages at the time of death ranged from 54 to 78 years. Dissection was performed on the intervertebral foramen and spinal canal. In the C3-C7 of the cervical vertebra, the extraforaminal ligaments and the meningovertebral ligaments were observed. The length, width, and thickness of the ligaments were measured with a Vernier caliper. After an expansive open-door laminoplasty was performed, the shape of the dural sac was changed, and displacement of the nerve root was observed. In addition, the lengths of the anterior rootlets were measured. This study has been supported by grants from Science and Technology Planning Project of Guangdong Province (CN) (Grant No. 2017B020210010) without potential conflict of interest-associated biases in the text of the paper. RESULTS: One hundred seventy-seven extraforaminal ligaments were found to connect the spinal nerve to the surrounding structures. After an expansive open-door laminoplasty was performed, posterior distension of the dural sac and movement of the spinal cord and nerve root were found. The spinal cord was closely attached to the ligamentum flavum by meningovertebral ligaments. In addition, the length of the C5 intradural rootlets (5.81-10.59 mm) was the shortest among the vulnerable segments. CONCLUSION: Traction on and posterior movement of the extradural roots may be the main pathologic mechanism of postoperative C5 palsy when expansive open-door laminoplasty is performed. The meningovertebral ligaments and extraforaminal ligaments might play an important role in the occurrence of postoperative C5 palsy. CLINICAL SIGNIFICANCE: This study provides clinicians with a more detailed understanding of the anatomic structure and potential mechanism of C5 palsy. Consideration of the meningovertebral ligaments and the intervertebral foramen may provide new directions for reducing the incidence of this complication.