Effects of combining multiple dose reduction techniques on coronary computed tomography angiography.

BACKGROUND: Coronary computed tomography angiography (CCTA) is the preferred non-invasive examination method for coronary heart disease. However, the radiation from computed tomography has become a concern since public awareness of radiation hazards continue to increase. AIM: To explore the value of multiple dose reduction techniques for CCTA. METHODS: Consecutive normal and overweight patients were prospectively divided into two groups: Group A1, patients who received multiple dose reduction scans (n = 82); and group A2, patients who received conventional scans (n = 39). The scan parameters for group A1 were as follows: Isocentric scan, tube voltage = 80 kV, and tube current control using 80% smart milliampere. The scan parameters for group A2 were as follows: Normal position, tube voltage = 100 kV, and smart milliampere. RESULTS: The average effective doses (EDs) for groups A1 and A2 were 1.13 ± 0.35 and 3.36 ± 1.30 mSv, respectively. There was a statistically significant difference in ED between the two groups (P < 0.01). Furthermore, noise was significantly lower, and both signal-to-noise ratio and contrast signal-to-noise ratio were higher in group A2 when compared to group A1 (P < 0.01). Moreover, the subjective image quality (IQ) scores were excellent in both groups, in which there was no significant difference in subjective IQ score between the two groups (P = 0.12). CONCLUSION: Multiple dose reduction scan techniques can significantly decrease the ED of patients receiving CCTA examinations for clinical diagnosis.

Magnetic Resonance Imaging Features and Misdiagnosis of Spinal Epidural Cavernous Hemangioma.

OBJECTIVE: Spinal epidural cavernous hemangiomas (SECHs) are rare, and merely a few have previously been described in case reports. The present study aims to explore the magnetic resonance imaging (MRI) features of SECHs and analyze the causes of their preoperative misdiagnosis. METHODS: The present retrospective study included 11 patients (three male and eight female patients, mean age ± standard deviation: 47.55±17.39 years old) with histopathologically confirmed SECH between January 2015 and April 2021. The MRI features of SECH were analyzed by two radiologists. RESULTS: The cervical, thoracic and thoracolumbar segments were involved in 2, 7 and 2 patients, respectively. All lesions grew along the long axis of the spine. The tumors were shuttle-shaped in six patients, oval in two patients, pseudopodia-shaped in one patient, clamp-shaped in one patient, and growing outward along the intervertebral foramen in one patient. Nine SECHs had relatively uniform isointense or hypointense T1-weighted imaging (T1WI) and hyperintense T2-weighted imaging (T2WI) signals. On the T2WI, filamentary low-signal shadows (i.e., the hairline or grid sign) with significant contrast enhancement and asymptotic strengthening were observed. Two SECHs had mixed high and low signals on T1WI and T2WI, with significant heterogeneous enhancement, hemorrhage, and hemosiderin deposition. The SECH was misdiagnosed as meningioma, neurofibromatosis and schwannoma in 1, 1 and 4 patients, respectively, while this was not diagnosed in one patient. The preoperative diagnosis was correct in merely approximately 36% of patients. Among the four patients with a correct preoperative diagnosis, hemosiderin deposition was found in three patients and small tortuous vascular shadows were found in one patient. CONCLUSION: SECH presents as a long spindle-shaped mass, and the "'pen cap sign" is common at the lesion edges. SECH also exhibits a hairline or grid sign on T2WI. Furthermore, some lesions present with hemorrhage and hemosiderin deposition. Therefore, the hairline, grid sign and hemosiderin deposition are valuable diagnostic features of SECH.

[An abnormal deeper lateral femoral notch is an indirect evidence for anterior cruciate ligament tear].

OBJECTIVE: To investigate the relationship between degree of abnormal deeper lateral femoral notch between anterior cruciate ligament tear. METHODS: The radiograph and MRI image material of 16 patients with anterior cruciate ligament injury from January 2013 to November 2013 were reviewed including 14 males and 2 females with an average age of 28.3 years old ranging from 18 to 52 years. Eleven cases was on right side and 5 on left. Survey tool of PASC imaging system was used to measure the depth of lateral femoral notch in patients with abnormal indicated by lateral X-ray view or sagittal view of MRI in knee joint,while clinical data,physical examination,image material in arthroscopy of these patients were retrospective researched. RESULTS: Four patients had an abnormal lateral femoral notch with the depth of 2 mm on lateral X-ray and sagittal MRI, while positive anterior drawer sign and Lachman test as well as anterior cruciate ligament tears on MRI, and completed tears were comfirmed on the operation of arthroscopy. Two patients without abnomal lateral femoral notch on lateral view of X-ray while with the depth of 1 mm on sagittal view of MRI were also coupled with positive anterior drawer sign and Lachman test as well as anterior cruciate ligament tears on MRI, and one of them were comfirmed completed anterior cruciate ligament tears on the arthroscopy operation and completed tear could not comfirmed on another one because of disagreed with arthroscopy operation. CONCLUSION: There appears to be an association between abnormal lateral femoral notch on lateral view of knee with anterior cruciate ligament tears. An abnormal deeper lateral femoral notch is an indirect evidence for anterior cruciate ligament tears.