Current Medical Imaging - Volume 19, Issue 7, 2023

Medical imaging plays a vital role in medical diagnosis and clinical treatment. The biggest challenge in the medical field is the correct identification of disease and better treatment. Multi-modal Medical Image Fusion (MMIF) is the process of merging multiple medical images from different modalities into a single fused image. The main objective of the medical image fusion is to obtain a large amount of appropriate information (i.e., features) to improve the quality and make it more informative for increasing clinical therapy for better diagnosis and clear assessment of medical-related problems. The MMIF is generally considered with MRI (Magnetic Resonance Imaging), CT (Computed Tomography), PET (Positron Emission Tomography), SPECT (Single Photon Emission Computed Tomography), MRA (Magnetic Resonance Angiography), T1-weighted MR, T2-weighted MR, X-ray, and ultrasound imaging (Vibro-Acoustography). This review article presents a comprehensive survey of existing medical image fusion methods and has been characterized into six parts: (1) Multi-modality medical images, (2) Literature review process, (3) Image fusion rules, (4) Quality evaluation metrics for assessment of fused image, (5) Experimental results on registered datasets and (6) Conclusion. In addition, this review article provides scientific challenges faced in MMIF and future directions for better diagnosis. It is expected that this review will be useful in establishing a concrete foundation for developing more valuable fusion methods for medical diagnosis.

Computer vision has proven that it can solve many problems in the field of health in recent years. Processing the data obtained from the patients provided benefits in both disease detection and follow-up and control mechanisms. Studies on the use of computer vision for COVID-19, which is one of the biggest global health problems of the past years, are increasing daily. This study includes a preliminary review of COVID-19 computer vision research conducted in recent years. This review aims to help researchers who want to work in this field.

Purpose: The aim of the study was to investigate the differential performances in lesions and ¹⁸F-FDG radiotracer distribution detected by PET/CT between multiple myeloma and unknown osteolytic metastasis. Methods: A retrospective study was performed on ¹⁸F-FDG PET/CT imaging of 63 patients with multiple bone destructions without extraosseous primary malignant tumors. By pathological diagnosis, 20 patients were confirmed to have multiple myeloma and 43 patients to have unknown osteolytic metastasis. The whole body was categorized into 8 sites: skull, spine, ribs, pelvis, sternum, clavicle, scapula and limb bone. The length of lesion cross-sections, cortical bone damage, SUVmax and radiotracer distribution were comprehensively compared to differentiate these two diseases. Results: The cross-section lengths and SUVmax of the lesions in 5 sites (e.g., skull, spine, ribs, pelvis, and limb bone) were significantly shorter and lower in the multiple myeloma group than those of the unknown osteolytic metastasis group (P < 0.05). The ¹⁸F-FDG was more uniformly distributed in the lesion sites of the skull, spine, ribs, pelvis, scapula, and limb bone in the multiple myeloma group (P < 0.05). In the spine and rib lesion sites, the multiple myeloma group was more likely to show noncortical bone damage than the unknown osteolytic metastasis group (P < 0.05). Conclusion: Differential observations in lesions and ¹⁸F-FDG distribution between multiple myeloma and unknown osteolytic metastasis were detected by comprehensively comparing the length of lesion cross-sections, cortical bone damage, SUVmax, and the distribution of radiotracer on¹⁸F-FDG PET/CT imaging.

Objective: The study aims to clarify the comparative benefits of X-ray sinography and computed tomography (CT) sinography in assessing the abdominal wall sinus tract. Methods: In this cross-sectional study, patients in our hospital with an abdominal wall sinus tract who had received both X-ray sinography and CT sinography from January 2018 to January 2021 were enrolled. The intraoperative findings were used as the gold standard to calculate the accuracy of the two methods. Kappa statistic was employed to evaluate the concordance between the two methods and the intraoperative findings. Differences in diameters measured on X-ray sinography and CT sinography images were analyzed using the Wilcoxon signed rank test. Results: The study sample consisted of 74 patients. The accuracy of the CT sinography in diagnosing the extent of the sinus invasion was 85.1%, while the accuracy of the X-ray sinography was 59.5%. For the sinus confined to the abdominal wall (Kappa: 0.783 VS 0.248), the sinus extending into the abdominal cavity (Kappa: 0.734 VS 0.339), and the sinus with fistula formation (Kappa: 0788 VS 0.496), the consistency of the CT sinography and surgery were significantly better than that of the X-ray sinography. Diameters of the sinus tract measured on CT images were statistically larger than the diameters measured on X-ray sinography (P<0.001). Conclusion: CT sinography has significant advantages to X-ray sinography in depicting the extent of the abdominal wall sinus tract and the presence of a fistula.

Aims: This study aims to assess the prognostic value of graft patency with coronary computed tomography angiography (CCTA) using a comprehensive single-branch targeted atherosclerotic risk score (CSBS) in patients before coronary artery bypass grafting (CABG). Methods: This retrospective study contains a total of 88 patients who underwent clinical CCTA before off-pump CABG surgery between 2015 and 2018. Graft failure was defined as patients with missing multi-slice CCTA or coronary angiography. The predictive value of CSBS (ranging from 0-70 and divided into 2 groups: < 20 and ≥20) was analyzed using Kaplan–Meier analysis and Cox regression models. Results: Patients' mean age was 61.2 ± 10.5 years, with a mean follow-up of 20.4 ± 15.2 months. A total of 203 grafts (21.5% arterial grafts) were analyzed and 30 of the vessels were occluded (14.8%). There was no significant difference in graft occlusion among the three targeted vessel groups. The Cox proportional hazard analysis showed that CSBS < 20 was a significant predictor of graft failure. Conclusion: Lower comprehensive single-branch targeted atherosclerotic risk score evaluated by CCTA is an independent prognostic factor for graft failure in patients before CABG surgery.

Background: The techniques differed in many of the literature on the detection of Acute Lymphocytic Leukemia from the blood smear pictures, as the cases of infection in the world and the Kingdom of Saudi Arabia were increasing and the causes of this disease were not known, especially for children, which is a serious and fatal disease. Objective: Through this work we seek to contribute to discover the blood cells affected by Acute Lymphocytic Leukem and to find an effective and fast method and to have the correct diagnosis as the time factor is important in the diagnosis and the initiation of treatment. which is based on one of the deep learning techniques that specialize in very deep networks, the use of one of the CNNs is VGG16. Methods: Detection scheme is implemented by pre-processing, feature extraction, model building, fine tuning method, classification are executed. By using VGG16 pre-trained, and using SVM and MLP classification algorithms in Machine Learning. Results: Our results are evaluated based on criteria, such as Accuracy, Precision, Recall, and F1-Score. The accuracy results for SVM classifier MLP of 77% accuracy at 0.001 learning rate and the accuracy for SVM classifier 75% at 0.005 learning rate. Whereas, the best accuracy result for VGG16 model was 92.27% at 0.003 learning rate. The best validation accuracy result was 85.62% at 0.001 learning rate.

Introduction: Since the most prominent effect of iron is increasing R2* and R2 relaxation rates, the iron-overload liver shows little signal with conventional T1ρ sequences like RARE. Whereas UTE MR imaging sequences can detect the signal from short T2/T2* relaxation components in tissues. This study aims to evaluate the difference in R1ρ profiles and compare the correlations between RARE-based and UTE-based sequences with LIC in assessing rat liver iron overload. Methods: Iron dextran (Sigma, 100 mg Fe/ml) was injected into thirty-five rats (25-100 mg/kg body weight), while the rats in the control group were injected with saline (n=5). The liver specimen was taken after one week. A portion of the largest hepatic lobe was extracted to quantify the LIC by inductively coupled plasma, and the remaining liver tissue was stored in 4% buffered paraformaldehyde for 24 h before MRI. Spin-lock preparation with RARE readout and 2D UTE readout pulses were developed to quantify R1ρ on a Bruker 11.7T MR system. Results: The mean R1ρ value of the rat liver with UTE-based R1ρ sequence was significantly higher compared to the RARE-based R1ρ sequence (p<0.001). Spearman’s correlation analysis (two-tailed) indicated that the R1ρ values were significantly correlated with LIC for both UTE-R1ρ and RARER1ρ sequences (r = 0.727, P < 0.001, and r = 0.712, P < 0.001, respectively). Conclusion: The current study adds to evidence that there is a correlation between iron concentration and R1ρ. Moreover, the UTE-based R1ρ sequence is more sensitive to the liver iron than the RAREbased R1ρ sequence. R1ρ might serve as a complementary imaging biomarker for liver iron overload quantification.

Objectives: To demonstrate cerebral arterial flow volume changes during the hypothyroid, euthyroid, and hyperthyroid phases and comparing between laboratory findings and cerebral arterial flow changes with carotid-vertebral duplex Doppler ultrasound (CVA-DUSG) in subclinical Hashimoto thyroiditis (HT) patients. Methods: According to the TSH level, 3 groups were constructed between patient cases. Group 1 (n=29) was the subclinical hyperthyroid group. In this group, the TSH level was between 0.0005 and 0.3 IU/ml. Group 2 (n=175) was the euthyroid group. TSH level in this group was between 0.3 and 4.2 IU/ml. Group 3 (n=76) was the subclinical hypothyroid group. In this group, the TSH level was above 4.2 IU/ml. The control-group (group 4) (n=71) included healthy people. In this group, the TSH level was between 0.3 and 4.2 IU/ml. After obtaining at least three consecutive waves from the bilateral internal cerebral artery and bilateral vertebral artery, volume flows were calculated using CVA-DUSG. Volume flows were calculated as peak systolic velocity + end diastolic velocity/2 × mean arterial diameter. The mean ICA(Internal Carotid Artery) and VA(Vertebral Artery) diameter was measured per ICA and VA. Total cerebral artery flow volume was defined as right ICA + right VA flow volume and left ICA + left VA flow volume. We also demonstrated topographic cerebral artery blood flow changes. Total ICA flow volume was used to assess the anterior part of the brain, total VA flow volume was used to evaluate the posterior part of the brain, right ICA + right VA flow volume was used to assess the right part of the brain, and left ICA + left VA flow volume was used to verify the left part of the brain. Results: There were significant differences between RVA(Right Vertebral Artery) flow volume, LICA (Left Internal Carotid Artery) flow volume, total flow volume, TSH, and T3 and T4 levels in all groups according to the Dunn's multiple comparison test.(p<0.001) Mean TSH level was 0.03 (0.005-0.06) IU/ml in group 1, 2.8 (1.8-3.97) IU/ml in group 2, 7.32 (6.14-9.93) IU/ml in group 3, and 1.76 (1.17-2.49) IU/ml in the control group. The mean T3 level was 4.18 (3.55-5.38) in group 1, 2.88 (2.63-3.16) in group 2, 2.82 (2.49-3.15) in group 3, 3.14 (2.92-3.15) in the control group. The mean T4 level was 1.92 (1.29-2.5) in group 1, 1.16(1.03-1.31) in group 2, 1.01 (0.91-1.16) in group 3, 1.12 (0.97-1.30) in the control group (group 4). Mean total flow volume was 793 (745-898) ml/min in group 1, 742 (684.25-822.5) ml/min in group 2, 747 (692-824) ml/min in group 3, and 700 (673-675) ml/min in the control group. We also demonstrated topographic cerebral arterial volume flow changes with CVA-DUSG. There was a significant difference among all groups in the right and anterior parts of the brain (p < 0.001), and there was a significant difference between groups 1 and 4 in the left part of the brain (p = 0.009). Conclusion: This study demonstrated that total cerebral arterial volume flow increased in the hyperthyroid phase of subclinical HT cases without any internal carotid and vertebral artery diameter changes compared with the euthyroid and hypothyroid phases of subclinical HT and healthy cases. We also verified topographic cerebral arterial blood flow changes in subclinical HT cases with a real-time, easily applicable modality (CVA-DUSG) that does not include X-ray or contrast agents. There was a significant difference between all groups in the right and anterior parts of the brain and there was a significant difference between groups 1 and 4 in the left part of the brain.

Background: The crush injury model of the sciatic nerve in rabbits is a common nerve injury model, but there is little literature on the evaluation of nerve stiffness by ultrasound elastography. Purpose: To explore the value of ultrasound elastography in diagnosing crush injury of the sciatic nerve in rabbits. Materials and Methods: Forty cases of crush injury model of the sciatic nerve in rabbits were examined by conventional ultrasound and elastography. The sonographic manifestations and stiffness of the model were analyzed, and the regularity of nerve injury with time was summarized. Results: Ultrasound could clearly show the location, range, and thickness of the injured nerve in this model. The thickness of the injured area reached a peak in the 2nd week and returned to normal thickness in the 8th week. The nerve stiffness of the injured area increased gradually with time. Conclusion: Conventional ultrasound combined with elastography can comprehensively and quantitatively evaluate the morphological changes and mechanical properties of the injured sciatic nerve in rabbits, which may be of great significance to the repair and rehabilitation of peripheral nerve crush injuries.

Objective: The aim of this study was to evaluate the clinical value of computed tomographyguided localization needle (LN) and methylene blue (MB) for pulmonary nodule localization. Materials and Methods: Between November 2019 and January 2022, 547 patients underwent computed tomography-guided LN (n=171) or MB (n=376) localization and video-assisted thoracoscopic surgery (VATS) resection. Results: In total, 171 and 376 nodules were localized via LN and MB, respectively, with respective technical localization success rates of 92.98 % and 88.56 % (p = 0.111). The pulmonary nodule localization time was significantly shorter for the MB group than for the LN group (p < 0.05). However, the rates of total complication, chest pain, and cough were significantly lower in the LN group (χ ² = 8.251/25.092/5.127, all p < 0.05). Furthermore, the LN group had a shorter VATS time than the MB group (p < 0.05). The VATS achieved a 100% operation success rate in both groups, and there was no significance between groups with respect to the types of surgery (p > 0.05) or the blood loss (p > 0.05). Moreover, logistic regression analysis showed that the localization technique was an independent risk factor for total complications and chest pain. Conclusion: Both techniques can effectively localize pulmonary nodules before VATS. MB had a shorter localization time, but the LN had a shorter VATS time and a lower incidence of complications, especially chest pain.

Introduction: Chordomas are midline tumors that arise from remnants of the primitive notochord, while the heterotopic rests are usually situated extradural within the bones of the axial skeleton. The tumor is locally aggressive with a high recurrence rate but rarely gives rise to metastasis. Case Report: A 55-year-old female presented with complaints of headache and intermittent vomiting for six months and diminution of vision for the last four months. MRI, T1 weighted without contrast of the paranasal sinus, suggested sphenoid sinus malignancy or metastasis. The mass was excised and sent for histopathological examination. Based on the radiological findings, light microscopy, special stains, and immunohistochemistry, a final diagnosis of chordoma was rendered. Results: The chordoma is a well-known entity at the skull base. Skull-based chordomas account for only 0.1-0.2% of all chordomas. The incidence rate of chordomas is 0.08 per 100,000, with a higher incidence rate of 0.1 in males than in females. However, chordoma presenting as a sphenoidal mass will create a diagnostic challenge for all otorhinolaryngologists and head and neck surgeons. Conclusion: This case report aims to add this rare tumor to the differential diagnosis of neoplasms of the sphenoid sinus.

Background: Diffuse large B-cell lymphomas are the most common type of non-Hodgkin lymphoma. Because cutaneous lymphomas predominantly originate from the T cells, primary cutaneous diffuse large B-cell lymphomas are considered a rare subtype of extranodal diffuse large B-cell lymphomas that commonly involve the subcutaneous tissues of the trunk and extremities. To date, only a single case of facial primary cutaneous diffuse large B-cell lymphoma has been reported in the literature. Case Report: We present a case of primary cutaneous diffuse large B-cell lymphoma presented with a small painless nodule in the right nasolabial fold that had persisted for 10 days in a 67-year-old man. Ultrasonographic findings of this lesion mimicked the features of a complicated epidermal inclusion cyst. Primary cutaneous diffuse large B-cell lymphoma was confirmed by an excisional biopsy of the mass. Conclusion: The diagnosis of primary cutaneous diffuse large B-cell lymphomas presenting as “oops lesions” in daily clinical practice can be challenging due to their rarity and nonspecific clinical and radiological findings. Therefore, clinical suspicion and awareness are critical for the accurate diagnosis and management of patients with palpable soft tissue masses in the head and neck region.

Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most common type of non- Hodgkin’s lymphoma (NHL). However, the primary skeletal muscle involvement of DLBCL is extremely rare, comprising less than 1% of all the extranodal lymphoma. To date, only 8 cases of extranodal NHL involving the masticator muscles have been reported in the literature. Case Presentation: A 70-year-old male presented with a rapid progression of painless facial swelling in the left cheek. CT, MRI and US findings demonstrated a well-defined, soft tissue mass in the left masseter muscle. The histopathological diagnosis was DLBCL by US-guided core needle biopsy. The patient received three cycles of chemotherapy. Conclusion: Because of its rarity, primary muscular DLBCL must be considered in differential diagnosis with all possible causes of intramuscular masses. Even the integration of multiple imaging methods does not lead to a definitive diagnosis, the biopsy is the only possibility for an early diagnosis. Therefore, clinical awareness and high suspicion of this disease are important for early diagnosis and proper treatment.

Background: Persistent sciatic artery (PSA) is a congenital malformation due to incomplete involution during the embryonic period. Its etiology is unknown, with an estimated incidence of 0.02 - 0.04% in the whole population and a mean age of 60-65 years. Its presentation can be bilateral. It is asymptomatic in most cases and is usually detected accidentally; however, some symptoms may appear, such as claudication, sciatic neuralgia, and pain in the affected limb. It can also manifest as an aneurysmal dilatation or thrombosis that can generate distal embolism with ischemia. Case Report: In this case study, a patient in her 90s with a suspected peripheral arterial disease, which required an angiotomography of the lower limb, showing a superficial femoral artery running to the middle and distal third of the thigh and a vascular structure running in the sciatic neurovascular bundle corresponding to a persistent sciatic artery presenting atherosclerotic changes and extensive occlusion, was presented. The patient's treatment was clinical with dual antiplatelet therapy and prophylactic anticoagulation. This was due to comorbidities and age. Moreover, the PSA occlusion was not critical and did not significantly impact the patient's quality of life. Conclusion: Most patients with this anatomical variant are asymptomatic all their lives, but some of them may present symptoms with serious consequences. It is important to suspect it by clinical presentation and perform diagnostic confirmation by angiotomography. Treatment has yielded excellent results with endovascular techniques. Certain patients only require conservative treatment with anticoagulants and antiplatelet agents.