What is the pelvic lymph node normal size? Determination from normal MRI examinations

Evaluating Hip Periprosthetic Joint Infection with Metal-artifact-reduction MR Imaging

PURPOSE

To evaluate the significant findings of hip periprosthetic joint infection (PJI) using metal-artifact-reduction (MAR) MRI and to compare the MRI results to other clinical markers.

METHODS

The results of MRI, including two-dimensional fast-spin echo sequences with increased bandwidth and multi-acquisition variable-resonance image combination selective for hips with orthopedic implants at 1.5T (from April 2014 to November 2021), were retrospectively assessed for imaging findings and diagnostic impressions by two radiologists. Clinical data and courses were also investigated. Univariate and multivariate analyses were performed to identify the significant MRI findings in patients with hip PJI and those who underwent surgical intervention. The MRI impressions were compared with other clinical markers in diagnosing hip PJI.

RESULTS

Thirty-seven hip joints in 24 Asian patients (age = 73.9 ± 10.8 years; 18 females) were included. Twelve hip joints (32%) had PJI; seven underwent a surgical intervention. The significant findings for hip PJI included periosteal edema of the acetabulum, intermuscular edema, intramuscular fluid collection, and lymphadenopathy (P < 0.05). In the cases with surgical intervention, the significant findings included capsular distension, capsular thickening, an osteolysis-like pattern of the femur, subcutaneous fluid collection, and lymphadenopathy (P < 0.05). The MRI impressions had high diagnostic significance for both hip PJI cases and those with surgical intervention (P < 0.001). The MRI impression was more significant for hip PJI than the other clinical markers (P < 0.05), while the other clinical markers were more significant in the cases with surgical intervention (P < 0.05).

CONCLUSION

The significant findings in the hip PJI cases included acetabular periosteal edema, intermuscular edema, intramuscular fluid collection, and lymphadenopathy. The significant findings in the cases with surgical intervention included capsular distention, capsular thickening, a femoral osteolysis-like pattern, subcutaneous fluid collection, and lymphadenopathy. The utilization of MAR MRI demonstrated great diagnostic significance for hip PJI.

Quantifying the Long and Short Axes of the External Iliac Lymph Nodes Using Dual-Energy Computed Tomography: A Potential Diagnostic Approach for Periprosthetic Joint Infection - A Prospective Study

Purpose

Periprosthetic joint infection (PJI) is a severe complication following joint replacement surgery, and there is a current lack of rapid, accurate, and non-invasive diagnostic methods. This study aims to assess the effectiveness of using dual-energy computed tomography (DECT) to quantify the maximum long and short axes of the external iliac lymph nodes (LNs) as a diagnostic tool for PJI.

Patients and Methods

In this prospective controlled study, 112 patients undergoing total hip or total knee revision surgery were enrolled. All patients underwent preoperative DECT scanning to measure the maximum long and short axes of the external iliac LNs on the affected side. The diagnostic value of lymph node size for PJI was assessed using receiver operating characteristic curves.

Results

The AUC (Area Under the Curve) quantifies the diagnostic method's ability to distinguish between positive and negative outcomes in this study. A value closer to 1.0 indicates better discriminatory performance. Compared to erythrocyte sedimentation rate (Area Under the Curve (AUC) = 0.834), percentage of polymorphonuclear leukocytes (AUC = 0.621), and C-reactive protein (AUC = 0.765), the maximum long axis (AUC =0.895) and maximum short axis (AUC = 0.858) of the external iliac LNs better differentiated PJI from aseptic failure. For diagnosing PJI, the threshold for the maximum long axis of the LNs was 20.5 mm, with a sensitivity of 84.21% and a specificity of 87.84%. For the maximum short axis, the threshold was 8.5 mm, with a sensitivity of 89.47% and a specificity of 82.43%. Combining the maximum long and short axes of the external iliac LNs enhanced the diagnostic accuracy for PJI.

Conclusion

Measuring the long and short axes of external iliac LNs using DECT is an effective diagnostic approach for PJI, aiding in the differentiation between PJI and aseptic failure following joint replacement surgery.

Tips and tricks for a proper radiological assessment of abdominal and pelvic lymph nodes

The assessment of lymph node dimensions is a commonly used criterion in analyzing lymphatic involvement related to inflammatory or neoplastic diseases. However, it is important to understand that the interpretation of lymph nodes goes beyond simply considering their size. A pathologic lymph node can present with enlarged dimensions, a heterogeneous appearance, increased cortex thickness, irregular contours, or a lobulated shape. In this context, it is essential to consider not only the dimensions but also the morphology, attenuation, and enhancement of lymph nodes on imaging exams. This article aims to demonstrate how characteristics of lymph nodes, beyond their size, can provide crucial insights that assist in diagnostic reasoning, focusing on computed tomography. By emphasizing different enhancement patterns, attenuation, and the potential contents related to these patterns, the study seeks to show how these features can indicate possible differential diagnoses and guide more accurate clinical assessments.

Prognostic Characteristics of Patients With Colorectal Cancer Who Have Benign Mesenteric Lymph Node Enlargement: A Multi-institutional Cohort Study

BACKGROUND

The characteristics of patients with colorectal cancer who have benign mesenteric lymph node enlargement are not well documented.

OBJECTIVE

The aim of this study is to assess the clinical and prognostic significance of benign mesenteric lymph node enlargement in patients with colorectal cancer.

DESIGN

This is a prospective cohort study.

SETTING

This study was conducted at multitertiary institutions.

PATIENTS

We included 601 patients with stage 0, I, and II colorectal cancer in Tianjin, Shandong, and Zhejiang from January 2010 to April 2014. Patients underwent curative surgery and were separated into 2 groups by the presence of benign mesenteric lymph node enlargement: the enlargement group (n = 275) and the control group (n = 326).

MAIN OUTCOME MEASURES

Univariate log rank and multivariate Cox regression analyses were constructed to identify risk factors for recurrence and mortality.

RESULTS

The risk of recurrence in the enlargement group after curative resection was significantly lower than in the control group, with the 1-, 3-, and 5-year disease-free survival rates being 97.1%, 91.6%, and 86.9% in the enlargement group and 95.7%, 86.2%, and 78.2% in the control group (p = 0.004). The postoperative 1-, 3-, and 5-year overall survival rates were 99.6%, 94.9%, and 90.5% in the enlargement group and 99.4%, 91.4%, and 82.1% in the control group (p = 0.001). Patients in the enlargement group had a higher percentage of patients at a younger age, family tumor history, right-sided tumors, and larger tumor size compared with the control group. For patients in the enlargement group, no significant correlation was observed between the number of enlarged lymph nodes and disease-free survival or overall survival (p = 0.113 and 0.386). Adjusted Cox regression model showed that benign mesenteric lymph node enlargement was an independent prognostic risk factor for both disease-free survival (HR, 0.587; 95% CI, 0.399-0.861; p = 0.007) and overall survival (HR, 0.506; 95% CI, 0.328-0.779; p = 0.002).

LIMITATIONS

No immunological results could be compared with clinicopathological findings.

CONCLUSIONS

The study indicates that benign mesenteric lymph node enlargement can be a useful positive factor in predicting recurrence and long-term survival concerning patients with colorectal cancer. See Video Abstract at http://links.lww.com/DCR/B785.

CARACTERSTICAS PRONSTICAS DE LOS PACIENTES PORTADORES DE CNCER COLORRECTAL CON AGRANDAMIENTO BENIGNO DE LOS GANGLIOS LINFTICOS MESENTRICOS UN ESTUDIO DE COHORTE MULTIINSTITUCIONAL

ANTECEDENTES:Las características de los pacientes portadores de cáncer colorrectal con agrandamiento benigno de los ganglios linfáticos mesentéricos no se encuentran bien documentados.OBJETIVO:El objetivo de este estudio es evaluar la importancia clínica y pronóstica del agrandamiento benigno de los ganglios linfáticos mesentéricos en pacientes con cáncer colorrectal.DISEÑO:Este es un estudio de cohorte de tipo prospectivo.AJUSTE:Este estudio se llevó a cabo en instituciones de educación superior.PACIENTES:Incluimos a 601 pacientes con cáncer colorrectal en estadio 0, I, II en Tianjin, Shandong y Zhejiang desde enero de 2010 hasta abril de 2014. Los pacientes fueron sometidos a cirugía curativa y fueron separaron en dos grupos tomando en cuenta la presencia del agrandamiento benigno de los ganglios linfáticos mesentéricos: grupo con agrandamiento (n = 275) y grupo control (n = 326).PRINCIPALES MEDIDAS DE RESULTADO:Se construyeron análisis de rango logarítmico de una variante y de regresión de Cox con variante múltiple para identificar los factores de riesgo de recurrencia y mortalidad.RESULTADOS:El riesgo de recurrencia en el grupo con agrandamiento tras la resección curativa fue significativamente menor que en el grupo de control, con tasas de periodo libre de enfermedad a los 1, 3 y 5 años de 97,1, 91,6, y 86,9% en el grupo de agrandamiento y con tasas de 95,7, 86,2, y 78,2% en el grupo control respectivamente (p = 0,004). Las tasas postoperatorias de supervivencia general a los 1, 3 y 5 años fueron 99,6, 94,9, y 90,5% en el grupo de agrandamiento y de 99,4, 91,4, y 82,1% en el grupo de control, respectivamente (p = 0,001). Los pacientes del grupo con agrandamiento tenían un porcentaje más elevado de menor edad, antecedente familiar tumoral, tumores del lado derecho y de mayor tamaño tumoral con respecto al grupo de control. Para los pacientes con agrandamiento, no se observó una correlación significativa entre el número de ganglios linfáticos agrandados y el periodo libre de enfermedad o la supervivencia general (p = 0,113 y 0,386). El modelo de regresión de Cox ajustado mostró que el agrandamiento benigno de los ganglios linfáticos mesentéricos era un factor de riesgo pronóstico independiente tanto para la supervivencia libre de enfermedad (cociente de riesgo 0,587; IC del 95%: 0,399-0,861; p = 0,007) como para la supervivencia global (cociente de riesgo 0,506; IC del 95%: 0,328- 0,779; p = 0,002).LIMITACIONES:No fue posible comparar los resultados inmunológicos con los hallazgos clínico-patológicos.CONCLUSIONES:El estudio indica que el agrandamiento benigno de los ganglios linfáticos mesentéricos puede ser un factor positivo útil para predecir la recurrencia y la supervivencia a largo plazo en pacientes con cáncer colorrectal. Consulte Video Resumen en http://links.lww.com/DCR/B785. (Traducción-Dr. Osvaldo Gauto).

What's in a node? The clinical and radiologic significance of Virchow's node

In 1848, Rudolf Ludwig Karl Virchow described an association of left supraclavicular lymphadenopathy with abdominal malignancy. The left supraclavicular lymph node later became commonly referred to as Virchow's node. Charles-Emile Troisier went on to describe the physical exam finding of an enlarged left supraclavicular lymph node, later termed Troisier's sign. Subsequent studies confirmed a predilection of abdominal and pelvic malignancies to preferentially metastasize to the left supraclavicular node. Identification of a pathologically enlarged left supraclavicular node raises the suspicion for abdominopelvic malignancy, particularly in the absence of right supraclavicular lymphadenopathy, and provides a safe and easy target for biopsy. Supraclavicular lymph nodes also represent a great target for diagnosis of metastatic thoracic malignancies, although thoracic malignancies can involve either right or left supraclavicular nodes and do not show a predilection for either. This article presents a review of the history, anatomy, pathophysiology, clinical significance, radiological appearance, and biopsy of Virchow's node. Key points are illustrated with relevant cases.

Ratiometric Raman nanotags enable intraoperative detection of metastatic sentinel lymph node

Sentinel lymph node (SLN) imaging and biopsy has been advocated as an important technique to evaluate the metastatic status of regional lymph nodes and determine subsequent surgical procedure for many cancers, yet there is no reliable means to provide accurate and rapid diagnosis of metastatic SLN during surgery. Here we develop a new approach, named "Ratiometric Raman dual-nanotag strategy", that using folic acid functionalized targeted and nontargeted gap-enhanced Raman tags (FA-GERTs and Nt-GERTs) to detect metastatic SLN based on Raman imaging combined with classical least square data processing methods. By using this strategy, with built-in self-calibration for signal correction, rather than absolute intensity-dependent signal readout, we realize the visualization and prompt intraoperative diagnosis of metastatic SLN with a high accuracy of 87.5 % when the cut-off value of ratio (FA-GERTs/Nt-GERTs) set at 1.255. This approach may outperform the existing histopathological assessment in diagnosing SLN metastasis and is promising for guiding surgical procedure in the future.

NRG Oncology Updated International Consensus Atlas on Pelvic Lymph Node Volumes for Intact and Postoperative Prostate Cancer

PURPOSE

In 2009, the Radiation Therapy Oncology Group (RTOG) genitourinary members published a consensus atlas for contouring prostate pelvic nodal clinical target volumes (CTVs). Data have emerged further informing nodal recurrence patterns. The objective of this study is to provide an updated prostate pelvic nodal consensus atlas.

METHODS AND MATERIALS

A literature review was performed abstracting data on nodal recurrence patterns. Data were presented to a panel of international experts, including radiation oncologists, radiologists, and urologists. After data review, participants contoured nodal CTVs on 3 cases: postoperative, intact node positive, and intact node negative. Radiation oncologist contours were analyzed qualitatively using count maps, which provided a visual assessment of controversial regions, and quantitatively analyzed using Sorensen-Dice similarity coefficients and Hausdorff distances compared with the 2009 RTOG atlas. Diagnostic radiologists generated a reference table outlining considerations for determining clinical node positivity.

RESULTS

Eighteen radiation oncologists' contours (54 CTVs) were included. Two urologists' volumes were examined in a separate analysis. The mean CTV for the postoperative case was 302 cm3, intact node positive case was 409 cm3, and intact node negative case was 342 cm3. Compared with the original RTOG consensus, the mean Sorensen-Dice similarity coefficient for the postoperative case was 0.63 (standard deviation [SD] 0.13), the intact node positive case was 0.68 (SD 0.13), and the intact node negative case was 0.66 (SD 0.18). The mean Hausdorff distance (in cm) for the postoperative case was 0.24 (SD 0.13), the intact node positive case was 0.23 (SD 0.09), and intact node negative case was 0.33 (SD 0.24). Four regions of CTV controversy were identified, and consensus for each of these areas was reached.

CONCLUSIONS

Discordance with the 2009 RTOG consensus atlas was seen in a group of experienced NRG Oncology and international genitourinary radiation oncologists. To address areas of variability and account for new data, an updated NRG Oncology consensus contour atlas was developed.

Magnetic resonance imaging at ultra-high magnetic field strength: An in vivo assessment of number, size and distribution of pelvic lymph nodes

Objective

The definition of an in vivo nodal anatomical baseline is crucial for validation of representative lymph node dissections and accompanying pathology reports of pelvic cancers, as well as for assessing a potential therapeutic effect of extended lymph node dissections. Therefore the number, size and distribution of lymph nodes in the pelvis were assessed with high-resolution, large field-of-view, 7 Tesla (T) magnetic resonance imaging (MRI) with frequency-selective excitation.

Materials and methods

We used 7 T MRI for homogeneous pelvic imaging in 11 young healthy volunteers. Frequency-selective imaging of water and lipids was performed to detect nodal structures in the pelvis. Number and size of detected nodes was measured and size distribution per region was assessed. An average volunteer-normalized nodal size distribution was determined.

Results

In total, 564 lymph nodes were detected in six pelvic regions. Mean number was 51.3 with a wide range of 19–91 lymph nodes per volunteer. Mean diameter was 2.3 mm with a range of 1 to 7 mm. 69% Was 2 mm or smaller. The overall size distribution was very similar to the average volunteer-normalized nodal size distribution.

Conclusions

The amount of in vivo visible lymph nodes varies largely between subjects, whereas the normalized size distribution of nodes does not. The presence of many small lymph nodes (≤2mm) renders representative or complete removal of pelvic lymph nodes to be very difficult. 7T MRI may shift the in vivo detection limits of lymph node metastases in the future.

Value of multidetector computed tomography for the differentiation of delayed aseptic and septic complications after total hip arthroplasty

OBJECTIVE

The differentiation between delayed aseptic and septic complications of total hip arthroplasty is crucial to allow appropriate surgical planning and timely antimicrobial treatment. The aim of this study was to investigate the utility of multidetector computed tomography (CT) findings to diagnose aseptic mechanical loosening, granulomatous reaction, and periprosthetic joint infection in patients who underwent total hip arthroplasty before revision surgery.

MATERIALS AND METHODS

Ninety-six consecutive patients with a clinical suspicion of periprosthetic complications underwent revision surgery over an 8-year period. All patients had been evaluated preoperatively using multidetector CT without contrast media. Two blinded musculoskeletal radiologists reviewed multidetector CT images, including periprosthetic soft-tissue accumulation, prosthetic acetabular malposition, periprosthetic osteolysis, enlarged iliac lymph nodes, and heterotopic ossification. Risk factors for aseptic and septic loosening were identified using multivariate analysis.

RESULTS

Multidetector CT-related variables independently associated with periprosthetic joint infection were high periprosthetic soft-tissue accumulation, periprosthetic osteolysis without expansile periosteal reaction and enlarged iliac lymph nodes. On the other hand, the absence of the following radiological signs: low or high periprosthetic soft-tissue accumulation, mild or severe periprosthetic osteolysis, and enlarged iliac lymph nodes, were predictors of aseptic mechanical loosening. Low periprosthetic soft-tissue accumulation, severe periprosthetic osteolysis with expansile periosteal reaction, and mild acetabular malposition were significant variables associated with granulomatosis.

CONCLUSION

Multidetector CT findings are useful to differentiate between aseptic and septic complications before revision surgery. The presence of osteolysis with expansile periosteal reaction appeared to be a time-dependent variable.

Incidence of mesorectal node metastasis in locally advanced cervical cancer: its therapeutic implications

OBJECTIVE

To evaluate the incidence and risk factors for mesorectal node metastasis (MRNM) in locally advanced cervical cancer.

METHODS/MATERIALS

We performed an observational retrospective cohort study of 122 patients with cervical cancer who received definitive chemo-radiation treatment between December 2013 and June 2017 to evaluate the incidence of MRNM. Three diagnostic radiologists assessed all available pre-treatment images. In this study, the pelvic node metastasis was defined as ≥ 1.0 cm and MRNM as ≥ 0.5 cm for CT and MRI scans and as a maximum standardized uptake value of > 2.5 for PET/CT. The relationship of MRNM with FIGO stage, pelvic node metastasis, and mesorectal fascia involvement was evaluated.

RESULTS

The incidence of MRNM in all 122 patients was 8 (6.6%). However, in advanced stage (III- IV) patients, MRNM occurred in 4 of 39 (10.3%) compared with 4 of 83 (4.8%) in early stage (IB1-IIB) patients (p = 0.27). In patients with a positive pelvic node, MRNM occurred in 7 of 55 (12.7%) and 1 of 67 (1.5%) in those with negative pelvic node (p = 0.02). In addition, the incidence of MRNM was 3 of 9 (33.3%) in the presence of mesorectal fascia involvement and 5 of 113 (4.4%) among those without mesorectal fascia involvement (p = 0.013).

CONCLUSION

This study indicates that pelvic node metastasis and mesorectal fascia involvement are high-risk factors for MRNM. Therefore, vigilance of reviewing images in the mesorectum for MRNM is necessary for high-risk patients.