Effectiveness of PET/CT and VATS for detecting and treating internal mammary lymph node metastasis: a case series.

OBJECTIVE: We occasionally observed internal mammary lymph node metastases of breast cancer in a clinical setting. However, unlike a standard treatment in axillary metastasis, surgical resection for internal mammary lymph node metastasis is not prevalent because of unclear safety and benefits. Thus, we aimed to evaluate the diagnostic ability and clinical outcomes of positron emission tomography/computed tomography and video-assisted thoracoscopic surgery. METHODS: We retrospectively investigated 34 patients with breast cancer with abnormal 18F-fluorodeoxyglucose uptake in internal mammary lymph nodes, at a single centre, between January 2015 and June 2022 and identified 11 female patients (mean age ± SD, 51.5 ± 12.9 years) who underwent video-assisted thoracoscopic surgery resection. Positron emission tomography/computed tomography was used to determine the clinical stage. We reviewed the surgical pathology of eleven and two patients who underwent direct-view internal mammary lymph node resection to calculate the positive predictive value of positron emission tomography/computed tomography. RESULTS: Ipsilateral fluorodeoxyglucose accumulation was observed, with an average maximum standardized uptake value of 8.9 (range, 3.1-24.0). No perioperative complications occurred, and all patients who underwent video-assisted thoracoscopic surgery alone were discharged from the hospital on post-operative day 2 or 3. The estimated positive predictive value was 80%. All patients were alive, and seven of nine patients with metastasis were relapse-free, at a mean follow-up period of 17.9 months (range, 1-51). However, two patients had recurrence at 16 and 14 months after surgery for internal mammary lymph node relapse. CONCLUSIONS: Radiotherapy is the standard treatment for suspected internal mammary lymph node metastasis detected using positron emission tomography/computed tomography; however, we could safely perform minimally invasive video-assisted thoracoscopic surgery resection, leading to a definite pathological diagnosis.

Detection of intracranial aneurysms using deep learning-based CAD system: usefulness of the scores of CNN's final layer for distinguishing between aneurysm and infundibular dilatation.

PURPOSE: We evaluated the diagnostic performance of a clinically available deep learning-based computer-assisted diagnosis software for detecting unruptured aneurysms (UANs) using magnetic resonance angiography and assessed the functionality of the convolutional neural network (CNN) final layer score for distinguishing between UAN and infundibular dilatation (ID). MATERIALS AND METHODS: EIRL brain aneurysm (EIRL_BA) was used in this study. The subjects were 117 UAN and/or ID cases including 100 UAN lesions (average sizes of 2.56 ± 1.45 mm) and 40 ID lesions (average sizes of 1.75 ± 0.41 mm) in any of internal carotid artery, middle cerebral artery, and anterior communicating artery, and 123 normal controls. The sensitivity, specificity, and accuracy of EIRL_BA were determined for UAN and ID or UAN only. Furthermore, the relationship between the lesion category and score was examined using a linear regression analysis model, and the receiver operating characteristic (ROC) analysis was used to assess whether the scores represent UAN-like characteristics. RESULTS: EIRL_BA showed a total of 203 candidates (an average of 1.73/case) in UAN and/or ID cases and 98 candidates (an average of 0.80/case) in normal controls. For diagnosing either UAN/ID, EIRL_BA showed an overall sensitivity of 80%, specificity of 84.2%, and accuracy of 83.7%, resulting in the positive likelihood ratio of 5.0. For diagnosing UAN only, the overall sensitivity of 89.0, specificity of 82.6%, and accuracy of 83.2% resulting in the positive likelihood ratio of 5.1. In a linear regression analysis, the scores significantly increased in the candidates' first and second ranks in UAN (p < 0.05) but not in ID. An ROC analysis using the score for diagnosing UAN showed an area under the curve of 0.836. CONCLUSION: EIRL_BA is applicable for detecting small UAN, and the CNN's final layer scores may be an effective index for discriminating UAN and ID and representing the likelihood of UAN.

Phosphoglyceride crystal deposition disease requiring differential diagnosis from malignant tumors and confirmed by Raman spectroscopy: A case report.

BACKGROUND: Phosphoglyceride crystal deposition disease (PCDD) is a rare acquired disease in which phospholipid crystals deposit in bone and soft tissue long after surgery, trauma, or repeated injections. CASE SUMMARY: A 60-year-old-woman was referred to our department because of multiple abdominal masses after open splenectomy for idiopathic thrombocytopenic purpura 29 years earlier. All the masses showed marked fluorodeoxyglucose (FDG) uptake on 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) and were strongly suspected to be malignant tumors. Surgical biopsies were performed, and the abdominal masses were found to be aligned vertically, three in a row, along the tissue layers cut in the patient's previous surgery. Pathological finding of the specimens showed foreign body granuloma consisting of histiocytes and multinucleated giant cells accumulating around needle-like crystals. The crystals were confirmed as phosphoglyceride by Raman spectroscopy, and PCDD was diagnosed. To our knowledge, this is the first report of PCDD diagnosed by Raman spectroscopy. CONCLUSION: We made a definitive diagnosis of PCDD in a patient with multiple tumors showing marked FDG uptake on 18F-FDG-PET by incisional biopsy and compo- sition analysis using Raman spectroscopy, a method that has not previously been reported for the diagnosis of PCDD.

Clinical prediction model based on 18F-FDG PET/CT plus contrast-enhanced MRI for axillary lymph node macrometastasis.

Purpose: Positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) are useful for detecting axillary lymph node (ALN) metastasis in invasive ductal breast cancer (IDC); however, there is limited clinical evidence to demonstrate the effectiveness of the combination of PET/CT plus MRI. Further axillary surgery is not recommended against ALN micrometastasis (lesion ≤2 mm) seen in sentinel lymph nodes, especially for patients who received proper adjuvant therapy. We aimed to evaluate the efficacy of a prediction model based on PET/CT plus MRI for ALN macrometastasis (lesion >2 mm) and explore the possibility of risk stratification of patients using the preoperative PET/CT plus MRI and biopsy findings. Materials and methods: We retrospectively investigated 361 female patients (370 axillae; mean age, 56 years ± 12 [standard deviation]) who underwent surgery for primary IDC at a single center between April 2017 and March 2020. We constructed a prediction model with logistic regression. Patients were divided into low-risk and high-risk groups using a simple integer risk score, and the false negative rate for ALN macrometastasis was calculated to assess the validity. Internal validation was also achieved using a 5-fold cross-validation. Results: The PET/CT plus MRI model included five predictor variables: maximum standardized uptake value of primary tumor and ALN, primary tumor size, ALN cortical thickness, and histological grade. In the derivation (296 axillae) and validation (74 axillae) cohorts, 54% and 61% of patients, respectively, were classified as low-risk, with a false-negative rate of 11%. Five-fold cross-validation yielded an accuracy of 0.875. Conclusions: Our findings demonstrate the validity of the PET/CT plus MRI prediction model for ALN macrometastases. This model may aid the preoperative identification of low-risk patients for ALN macrometastasis and provide helpful information for PET/MRI interpretation.

Early detection of intravascular large B-cell lymphoma by (18)FDG-PET/CT with diffuse FDG uptake in the lung without respiratory symptoms or chest CT abnormalities.

Intravascular large B-cell lymphoma (IVLBCL) is a rare and aggressive subtype of systemic extranodal non-Hodgkin diffuse large B-cell lymphoma (DLBCL). We report a rare case of IVLBCL who showed diffuse 18F-fluorodeoxyglucose (FDG) uptake in the lung in FDG-positron emission tomography/computed tomography (PET/CT) without respiratory symptoms or chest CT abnormalities. Serum biochemical studies showed a raised level of lactate dehydrogenase (LDH) and serum soluble interleukin-2 receptor (sIL-2R), which suggested the presence of malignant lymphoma strongly. A non-contrast CT showed no abnormalities in the lung fields, no lymphadenopathy was found. FDG-PET/CT revealed diffuse FDG uptake in the both lungs and in spleen as well as multiple hot spots in the liver. Under the suspicion of IVLBCL especially by the diffuse FDG uptake in the lung, a random skin biopsy was performed from three regions, the left forearm, right abdomen and left thigh in which there had been no evidence of FDG uptake. The definite diagnosis of IVLBCL was made based on the pathological analysis of the specimen from the left thigh. She achieved complete remission (CR) after combined chemoimmunotherapy. FDG-PET/CT was useful for the early detection of IVLBCL even without respiratory symptoms or any abnormal findings by chest CT.

Voxel-based analysis of (201)Tl SPECT for grading and diagnostic accuracy of gliomas: comparison with ROI analysis.

PURPOSE: The aim of this retrospective study was to assess the utility of a voxel-based analysis (VBA) method for (201)Tl SPECT in glioma, compared to conventional ROI analysis. METHODS: We recruited 24 patients with glioma (high-grade 15; low-grade 9), for whom pre-operative (201)Tl SPECT and MRI were performed. SPECT images were coregistered with MRI. The uptake ratio (UR) images of tumor to contralateral normal tissue were measured on early and delayed images, and the (201)Tl retention index (RI) map was calculated from the early and delayed uptake ratio maps. In the ROI analysis, tumors were traced on a UR map, and the mean and maximal uptake ratio values on the early images were, respectively, defined as the mean and maximal UR. The mean and maximal RI values (mean and maximal RI) were calculated by division of the mean and maximal UR, respectively, on the delayed image by the mean and maximal UR on the early image. For the RI map calculated voxel by voxel, the maximal RI value was defined as VBA-RI. We evaluated sensitivity and accuracy of differential analysis with the mean and maximal UR, RI, and VBA-RI. RESULTS: The high- and low-grade groups showed no significant difference in mean and maximal RI (0.98 ± 0.12 vs. 1.05 ± 0.09 and 0.98 ± 0.18 vs. 1.05 ± 0.14, respectively). The AUC and accuracy of the mean and maximal RI were 0.681 and 66.7 %, and 0.622 and 62.5 %, respectively. In contrast, VBA-RI was higher in high-grade than in low-grade glioma (1.69 ± 0.27 vs. 0.68 ± 0.66, p < 0.001). The AUC and accuracy of VBA-RI were 0.963 and 95.8 %, which are higher than those obtained for mean (p < 0.05) and maximal RI (p < 0.01). There was no significant difference in ROC between the VBA-RI and the mean UR (0.911, p = 0.456) and maximal UR (0.933, p = 0.639); however, the AUC, sensitivity, and diagnostic accuracy of VBA-RI were all higher than those of the mean and maximal UR. CONCLUSION: The voxel-based analysis method of (201)Tl SPECT may improve diagnostic performance for gliomas, compared with ROI analysis.

Evaluation of primary prostate cancer using 11C-methionine-PET/CT and 18F-FDG-PET/CT.

OBJECTIVE: The objective of this study was to evaluate the capability of (11)C-methionine (MET)-PET/CT and (18)F-2-deoxy-2-fluoro-D: -glucose (FDG)-PET/CT to diagnose primary prostate cancer using recently developed Gemini TF PET/CT (Philips Healthcare, Cleveland, OH). METHODS: Twenty men who had been referred for a diagnostic work-up for prostate cancer were enrolled in this study. MET- and FDG-PET/CT by high-resolution mode were carried out on the same day prior to prostate biopsy and each maximum standardized uptake value (SUVmax) was compared with the pathological findings. The regions of interest (about 100 mm(2) small round) were placed at standard 6 points of the peripheral zone and 4 points in the apex of the transitional zone in cases that had undergone biopsy of the internal gland. We summed two scores if a specimen had inhomogeneous Gleason scores (e.g. GS 7; 4 + 3) and doubled the score when the Gleason score was the same (e.g. GS 8; 4 × 2). We divided the tumors into three groups. If the summed Gleason score of the specimens was 5 or less, they were grouped as NG (no grade with the Gleason score). If the summed Gleason score was 6 or 7, the tumors were defined as LG (low Gleason score group), and if the summed Gleason score was 8, 9 or 10, the tumors were classified as HG (high Gleason score group). The mean SUVmax was calculated and one-way analysis of variance or Kruskal-Wallis test and the Tukey post hoc test were performed for statistical comparisons. The capabilities of MET and FDG for diagnosing prostate cancer were evaluated through analysis of the area under the curve of the receiver operating characteristic (ROC) curve. The cut-off levels of SUVmax for the highest accuracy were determined by the results of the ROC analysis, and the sensitivity, specificity and accuracy were calculated. RESULTS: The PET images, obtained with Gemini TF PET/CT, allowed visual identification of anatomical locations within the prostate gland. Among the mean SUVmax of MET, FDG early phase and FDG delayed phase, the differences between NG and HG were all statistically significant (P < 0.01). With MET the difference between NG and LG was also significant (P < 0.05). And for the elevation rate from FDG early to delayed phase, the difference between NG and HG was significant (P < 0.05). The cut-off SUVmax, sensitivity, specificity, accuracy for distinguishing between NG and LG + HG by MET, FDG early and delayed phase were 3.15/78.7/75.6/78.3, 2.81/61.7/80.0/70.7 and 3.00/62.8/78.9/70.7, respectively. And the same factors between NG + LG and HG were 3.76/70.1/89.7/82.6, 2.88/70.1/82.9/78.3 and 3.47/62.7/86.3/77.7, respectively. CONCLUSIONS: In terms of the capability to diagnose prostate cancer of high Gleason score (≥8), there was no significant difference between MET and FDG. MET appears to be useful for detecting prostate cancer of both low and high Gleason score.

Diagnostic Imaging of Pulmonary Thromboembolism by Multidetector-row CT.

For diagnosis of pulmonary thromboembolism, multidetector-row computed tomography (CT) is a minimally invasive imaging technique that can be performed rapidly with high sensitivity and specificity, and has been increasingly employed as the imaging modality of first choice for this disease. Since deep vein thrombosis in the legs, which is important as a thrombus source, can be evaluated immediately after the diagnosis of pulmonary thromboembolism, this diagnostic method is considered to provide important information when deciding on a comprehensive therapeutic strategy for this disease.

Validation of fast-RAMLA in clinical PET.

OBJECTIVE: Images using the fast row action maximum likelihood algorithm (fast-RAMLA), which employs half-interpolated sinograms of conventional 3DRAMLA, are immediately generated following positron emission tomography (PET) scanning and are invariably produced in the process of line-of-response RAMLA (LOR-RAMLA) reconstruction. We quantitatively and visually compared the clinical validity of dual time point [(18)F]-FDG imaging with fast-RAMLA and LOR-RAMLA. METHODS: An International Electrotechnical Commission (IEC) phantom was established in which the ratio of the activities in the hot sphere was set up and a background of 3.8:1 was scanned and reconstructed using both algorithms. The contrast recovery coefficient was then calculated. The clinical study retrospectively analyzed 35 patients (25 men and 10 women; age range 30-84 years; mean age 63.9 years) with confirmed specific pathological lesions or clinical follow-up; 21 of the patients had 51 malignant lesions and 15 had 23 benign lesions. The maximum standard uptake value (SUV(max)) was measured in all lesions using LOR-RAMLA. The maximal counts of all lesions determined manually were divided by the average count of bilateral ventricles and the aortic arch for standardization on fast-RAMLA, and the values were compared with the SUV(max) of LORRAMLA. Inter-observer variation in detection was determined among three radiologists who blindly reviewed and scored 70 maximum intensity projection images from 35 patients reconstructed using LORRAMLA and fast-RAMLA. RESULTS: We identified a quantitative correlation and determined the visual quality of lesion detection between fast-RAMLA and LOR-RAMLA and indicated usefulness and improvement point on fast-RAMLA. CONCLUSIONS: Fast-RAMLA can improve the strategy for using dual time point [(18)F] fluorodeoxyglucose positron emission tomography ([(18)F]-FDG-PET) and increase the efficiency of the [(18)F]-FDG-PET scanner.

Relationships among regional diastolic impairment, elongation of global time to peak filling rate, and global diastolic function using ECG-gated myocardial perfusion SPECT in heart failure.

OBJECTIVE: The relationships among regional diastolic impairment, the elongation of global time to peak filling rate (g-TPF), and global diastolic function were examined by a novel program using electrocardiography-gated myocardial perfusion single-photon emission computed tomography (SPECT) (GMPS) in heart failure (HF). METHODS: Fifteen control subjects and 70 HF patients, New York Heart Association functional classification I (N-1) 41 cases, classification II (N-II) 15 cases, and classification III (N-III) 14 cases, were examined by GMPS. Using the reference mean +2 SD (standard deviation) of g-TPF derived from control group (CG), HF patients were divided into a normal g-TPF group (NG) and elongated g-TPF group (EG). The distributions of g-TPF and regional (r-) TPF were estimated by histograms. The extension of regional diastolic impairment was estimated by the number of r-TPF elongated segments (NES). RESULTS: g-TPF and r-TPF mainly distributed from 100 ms to 220 ms and demonstrated a peak around 150 ms in CG and NG. g-TPF distributed from 240 ms to 560 ms, but r-TPF distributed from 90 ms to 690 ms and demonstrated two peaks around 150 ms and 350 ms in EG. NES significantly correlated with g-TPF (r=0.79, P=6x10(-10) in N-I; r=0.69 and P<0.005 in N-II; r=0.89, P=2x10(-5) in N-III). NES negatively correlated with first third filling fraction (1/3FF) (r=-0.83, P=3x10(-11) in N-I; r=-0.72, P<0.0005 in N-II) and first third filling rate (1/3FR) (r=-0.49, P=0.002 in N-I; r=-0.52, P=0.002 in N-II; r=-0.81, P<0.0005 in N-III). g-TPF significantly correlated with 1/3FF (r=-0.67, P=1.5x10(-6) in N-I; r=-0.69, P<0.005 in N-II) and 1/3FR (r=-0.41, P<0.01 in N-I; r=-0.69, P<0.01 in N-III). CONCLUSIONS: The development of regional early diastolic impairment makes g-TPF elongation and induces global dysfunction in early diastole.

Global and regional evaluation of systolic and diastolic left ventricular temporal parameters using a novel program for ECG-gated myocardial perfusion SPECT--validation by comparison with gated equilibrium radionuclide angiography and speckle-tracking radial strain from echocardiography.

BACKGROUND: A newly developed program, named cardioGRAF, enabled the evaluation of left ventricular (LV) systolic and diastolic temporal parameters for the estimation of heart failure using ECG-gated myocardial perfusion SPECT (GMPS). OBJECTIVE: The feasibility of those global (g-) and regional (r-) parameters was validated to compare with gated equilibrium radionuclide angiography (ERNA) and speckle-tracking radial strain (STS) from echocardiography. METHODS: Thirty-three patients were studied using GMPS and ERNA (n=11) or GMPS and STS (n=22). The following g- or r-parameters obtained by cardioGRAF and ERNA or STS were compared: time to end systole (TES), time from end systole to peak filling rate (TPF1), time from 0 to peak filling rate (TPF2), time to peak radial strain (TPS), time from peak strain to peak negative strain rate (TP-SR1), and time from 0 to peak negative strain rate (TP-SR2). RESULTS: All g-parameters were successfully obtained by cardioGRAF and ERNA. The results demonstrated good correlations (g-TES: r = 0.79, p < 0.005; g-TPF1: r = 0.75, p < 0.02; TPF2: r = 0.83, p < 0.005). The differences were 11.9 +/- 31.8 ms in g-TES, 19.9 +/- 65.4 ms in g-TPF1, and 37.7 +/- 67.4 ms in g-TPF2. All r-parameters were successfully obtained by cardioGRAF. Eight patients and 12 segments were excluded because of the inadequate quality of routine echocardiography for STS analysis. However, r-parameters obtained by cardioGRAF were significantly correlated with those of STS (r-TES and r-TPS: r = 0.61, p = 1 x 10(-8); r-TPF1 and r-TP-SR1: r = 0.69, p = 3 x 10(-11); r-TPF2 and r-TP-SR2: r = 0.76, p = 2 x 10(-15)). The differences were 22.1 +/- 38.2 ms between r-TES and r-TPS, 7.0 +/- 123.4 ms between r-TPF1 and r-TP-SR1, and 38.1 +/- 111.5 ms between r-TPF2 and r-TP-SR2. CONCLUSION: The feasibility of evaluating systolic and diastolic temporal parameters by a new program was validated. This program has the potential to evaluate both diastolic and systolic heterogeneous wall motions which express dyssynchrony in heart failure.