A cone-beam volume CT using a 3D angiography system with a flat panel detector of direct conversion type: usefulness for superselective intra-arterial chemotherapy for head and neck tumors

CT reconstruction and MRI fusion of 3D rotational angiography in the evaluation of pediatric cerebrovascular lesions

PURPOSE

Complex neurovascular lesions in children require precise anatomic understanding for treatment planning. Although 3DRA is commonly employed for volumetric reformation in neurointerventional procedures, the ability to reconstruct this data into CT-like images (3DRA-CT) is not widely utilized. This study demonstrates the feasibility and usefulness of 3DRA-CT and subsequent MRI fusion for problem solving in pediatric neuroangiography.

METHODS

This retrospective study includes 18 3DRA-CT studies in 16 children (age 9.6 ± 3.8 years, range 2-16 years) over 1 year. After biplane 2D-digital subtraction angiography (DSA), 5-second 3DRA was performed with selective vessel injection either with or without subtraction. Images were reconstructed into CT sections which were post-processed to generate multiplanar reformation (MPR) and maximum intensity projection (MIP) images. Fusion was performed with 3D T1 MRI images to precisely demonstrate neurovascular relationships. Quantitative radiation metrics were extracted and compared against those for the entire examination and for corresponding biplane 2D-DSA acquisitions.

RESULTS

In all 18 cases, the 3DRA procedure and MRI fusion were technically successful and provided clinically useful information relevant to management. The unsubtracted and subtracted 3DRA acquisitions were measured to deliver 5.9 and 132.2%, respectively, of the mean radiation dose of corresponding biplane 2D-DSA acquisitions and contributed 1.2 and 12.5%, respectively, to the total procedure dose.

CONCLUSION

Lower radiation doses, high spatial resolution, and multiplanar reformatting capability make 3DRA-CT a useful adjunct to evaluate neurovascular lesions in children. Fusing 3DRA-CT data with MRI is an additional capability that can further enhance diagnostic information.

Effectiveness of CT assists for intraarterial chemotherapy: therapeutic outcome of chemoradiation for advanced head and neck cancer extending across the anatomical midline

OBJECTIVE

The purpose of this study was to evaluate the effectiveness of CT assist for intraarterial chemotherapy in relation to the therapeutic outcomes of intraarterial chemoradiation for advanced head and neck cancer with extension across the anatomical midline (EAM).

METHODS

This retrospective study evaluated 64 consecutive patients. In total, 26 and 38 patients had cancer with or without EAM, respectively. These patients underwent an intraarterial cisplatin infusion (200 mg/m(2), days 1 and 35) and intravenous 5-FU infusion (800 mg/m(2), days 1-5 and 36-39) concomitantly with radiotherapy. Angiography-assisted CT was performed to confirm complete coverage during the intraarterial chemotherapy. The accuracy of diagnosing tumor vessels by digital subtraction angiography (DSA) was evaluated using receiver-operating characteristic analysis by two radiologists. The overall survival and locoregional control rates were calculated by the Kaplan-Meier method.

RESULTS

DSA was not useful for diagnosing tumor vessels. The 2-year overall survival rates for the patients with cancer with or without EAM were 83 and 90 %, while the 2-year locoregional control rates were 95 and 82 %, respectively. Locoregional control or the overall survival rates showed no significant differences.

CONCLUSIONS

Intraarterial chemotherapy using angiography-assisted CT during chemoradiation therapy can achieve comparable therapeutic outcomes for cancer with and without EAM.

Calculating nasoseptal flap dimensions: a cadaveric study using cone beam computed tomography

We hypothesize that three-dimensional imaging using cone beam computed tomography (CBCT) is suitable for calculating nasoseptal flap (NSF) dimensions. To evaluate our hypothesis, we compared CBCT NSF dimensions with anatomical dissections. The NSF reach and vascularity were studied. In an anatomical study (n = 10), CBCT NSF length and surface were calculated and compared with anatomical dissections. The NSF position was evaluated by placing the NSF from the anterior sphenoid sinus wall and from the sella along the skull base towards the frontal sinus. To visualize the NSF vascularity in CBCT, the external carotic arteries were perfused with colored Iomeron. Correlations between CBCT NSFs and anatomical dissections were strongly positive (r > 0.70). The CBCT NSF surface was 19.8 cm(2) [16.6-22.3] and the left and right CBCT NSF lengths were 78.3 mm [73.2-89.5] and 77.7 mm [72.2-88.4] respectively. Covering of the anterior skull base was possible by positioning the NSF anterior to the sphenoid sinus. If the NSF was positioned from the sella along the skull base towards the frontal sinus, the NSF reached partially into the anterior ethmoidal sinuses. CBCT is a valuable technique for calculating NSF dimensions. CBCT to demonstrate septum vascularity in cadavers proved to be less suitable. The NSF reach for covering the anterior skull base depends on positioning. This study encourages preoperative planning of a customized NSF, in an attempt to spare septal mucosa. In the concept of minimal invasive surgery, accompanied by providing customized care, this can benefit the patients' postoperative complaints.

Impact of intra-arterial chemotherapy including internal carotid artery for advanced paranasal sinus cancers involving the skull base

Background:

The most significant problem of intra-arterial chemotherapy for advanced paranasal sinus carcinomas and residual cancers supplied by internal carotid artery (ICA) and involving the skull base is the lack of salvage therapies.

Objective:

The objective of the study was to evaluate the usefulness of intra-arterial chemotherapy including ICA infusion for treating advanced paranasal sinus carcinomas, which have invaded the skull base.

Methods:

Forty-six patients with advanced paranasal sinus carcinomas supplied by ICA were treated by intra-arterial chemotherapy using CDDP and sodium thiosulphate (STS) as a neutraliser of CDDP toxicity. After evaluating CT angiography, 150 mg m⁻² of CDDP was superselectively administered weekly to each feeding artery including ICA four times.

Results:

The 10-year overall survival rate and progression-free survival rate were 70.7 and 60.2%, respectively. Compared with control group without infusing ICA, recurrences at anterior skullbase or anterior ethomoid sinus were significantly diminished. Of 32 patients in which the orbital apex had been invaded, 29 patients were treated with successful preservation of orbital contents. The CT angiography could efficiently determine all feeding arteries supplying the cancers. Consequently, chemotherapy could be administered on schedule, and side effects were minimal and acceptable.

Conclusions:

This new method has promising applications in the treatment of advanced paranasal sinus carcinomas involving the skull base.

Significant improvement in superselective intra-arterial chemotherapy for advanced paranasal sinus cancer by using indocyanine green fluorescence

Recent advances in indocyanine green (ICG) fluorescence imaging have enabled the visualization of the blood supply to tissues. For advanced head and neck cancer, intra-arterial chemotherapy has been applied for improving the prognosis and organ preservation. To identify the tumor-feeding artery, CT angiography has been shown to be useful. However, the presence of dental metals sometimes disturbs the precise evaluation of paranasal sinus cancer patients by CT angiography. The objectives of the study were to assess the feasibility of the ICG fluorescence technique during intra-arterial chemotherapy for advanced maxillary cancer. Thirty-six patients with paranasal sinus cancer who were treated by intra-arterial chemotherapy were included. Conventional CT angiography followed by 5 mg of ICG injection was performed to confirm the areas in which the drug had dispersed. Intra-arterial chemotherapy was administered at 150 mg/m² of CDDP four times weekly. Additional information about the arteries feeding the tumors provided by ICG was evaluated. Out of 36 cases, in 17 (47%) the blood supply to the cancer was clearly detected by CT angiography. By adding the infrared ICG evaluation, the blood supply to the tumor was confirmed easily in all cases without radiation exposure. The information obtained from fluorescence imaging was helpful for making decisions concerning the administration of chemo-agents for paranasal sinus cancers in cases involving dental metal, or skin invasion. ICG fluorescence imaging combined with intra-arterial chemotherapy compensated for the deficiencies of CT angiography for paranasal sinus cancer. ICG fluorescence provided us clearer and more useful information about the feeders to cancers.

Analysis of the dynamic relationships between the lingual artery and lingual markers in patients with obstructive sleep apnea

PURPOSE

To determine the relationships between the lingual artery and the lingual markers in tongue resting and extended positions in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) for the clinical application of functional tongue surgery.

METHOD

Computed tomography angiography (CTA) of the lingual artery was performed on 30 OSAHS patients using a 16-slice spiral CT scanner. The anatomical relationships between the lingual artery and the lingual markers were analyzed with the tongue in resting and extended positions using the CTA images.

RESULTS

The course of the lingual artery resembled the configuration of the Big Dipper constellation when the tongue was in a resting position. When the tongue was in a full-extended position, the majority of the lingual artery moved forward and upward with the hyoid and formed a "√" fashion. The positions of the tip of the greater horn of the hyoid changed with the tongue positions. While the relationship between the main lingual artery and the tip of the greater horn of the hyoid, as well as the distances between bilateral lingual arteries, remained constant in both tongue positions.

CONCLUSIONS

In conditions of dynamic tongue movement, the tip of the great horn of the hyoid and the lingual midline are constant anatomical markers to indicate the course of the lingual artery.

Selective intraarterial chemoradiation therapy for oropharyngeal carcinoma with high-dose cisplatin

PURPOSE

Cisplatin has shown a high tumor response rate among head and neck carcinomas, and the tumor response is related to the cisplatin dosage. The purpose of this study was to evaluate the efficacy and toxicity of selective intraarterial chemoradiation therapy for oropharyngeal carcinomas with high-dose cisplatin.

MATERIALS AND METHODS

This retrospective study consisted of 21 patients with oropharyngeal carcinoma, stages II-IVB, in whom intraarterial chemoradiation therapy was performed between 2000 and 2008. All patients were given two courses of selective intraarterial infusions of cisplatin (300 mg/m(2)), systemic chemotherapy with 5-fluorouracil, and simultaneous radiation therapy (58-61 Gy/30 fractions), with a 1-week rest period.

RESULTS

The 2-year overall survival rate of the 15 patients who completed the therapeutic regimen was 71.3%. The 2-year locoregional control rate and disease-free survival rate were 95.0% and 67.7%, respectively.

CONCLUSION

Selective intraarterial high-dose cisplatin chemotherapy with concomitant radiation therapy shows results similar to those of original methods in terms of survival and locoregional control with a reduction in the number of procedure times.

Knife inflicted penetrating injuries of the maxillofacial region: a descriptive, record-based study

Penetrating knife injuries of the face are more common in South Africa than the rest of the world. These injuries can be life-threatening, especially where the major blood vessels of the face are involved. The approach to treatment should be multidisciplinary, beginning with the trauma unit to provide airway maintenance and haemodynamic stabilisation. An interventional radiologist may be consulted for angiography. The aim of the present study was to retrospectively analyse all cases of knife-inflicted penetrating injuries to the maxillofacial region with the knife in situ and subsequently develop a management protocol to be used by maxillofacial surgery registrars when presented with such cases.

MATERIALS AND METHODS

It was a retrospective, cross-sectional and record-based study, analysing all penetrating knife injuries reported at various hospitals for a period of 11 years. In this study, 24 cases of knife injuries were analysed.

RESULTS

Twenty-one patients (87.5%) in this series were male and three (12.5%) were female. Of these 24 patients, 13 (54.2%) were coloured and 11 (45.8%) were black. There were no white or Indian patients. Post-surgical recovery of all patients was rapid and uneventful, and there were no fatalities.

CONCLUSION

Patients with knife injuries to the face with no definite signs of vascular injury can thus be safely and accurately managed on the basis of physical examination and plain-film radiography. An angiogram is mandatory if the patient presents with excessive bleeding, an expanding haematoma or if the knife blade is in the region of any large vessels.

Noise power properties of a cone-beam CT system for breast cancer detection

The noise power properties of a cone-beam computed tomography (CT) system dedicated for breast cancer detection were investigated. Uniform polyethylene cylinders of various diameters were scanned under different system acquisition conditions. Noise power spectra were calculated from difference data generated by subtraction between two identical scans. Multidimensional noise power spectra (NPS) were used as the metric to evaluate the noise properties of the breast CT (bCT) under different system acquisition and reconstruction conditions. A comprehensive investigation of the noise properties was performed in regard to system acquisition parameters including kVp, mA, number of cone-beam projection images used, cone angle, and object size. The influence on reconstruction parameters including interpolation method, reconstruction filter, field of view, matrix size, and slice thickness were also studied. Under certain conditions, the zero-dimensional NPS (image variance) was used as a quantitative index to compare the influence from different scan parameters, especially the radiation dose. If the total scan dose is changed by linearly changing the total number of projection images while the dose per frame is kept constant, the noise power has a linear relationship with the reciprocal of the total dose. If the total scan dose is changed by linearly changing the dose per frame while the total number of projection images is kept constant, the noise power has a quadratic relationship with the reciprocal of the total dose. With the same amount of total dose, using fewer projection images results in lower image noise power in the CT image. Quantitative results from this noise power analysis provide guidance for the bCT system operation, optimization, and data reconstruction.

Feasibility and potential value of flat-panel detector–based computed tomography in myelography after spinal surgery

Object

The purpose of this study was to assess the value of myelography using flat-panel detector–based computed tomography (fpCT) in 5 patients in whom the image quality of multislice CT (MSCT) or MR imaging was limited by metal artifacts.

Methods

The application of fpCT to myelographic imaging of the lumbar spine and cervicothoracic junction after surgery was feasible. Multiplanar, preferably sagittal, and 3D reconstructions adequately depicted disc space implants and provided high resolution images of osseous structures.

Results

The images obtained with fpCT allowed evaluation of anatomical details such as single nerve roots and proved especially valuable in a patient with impaired MR imaging results caused by metal artifacts from an intraoperative abrasion. In a case of recurrent disc herniation, imaging results of myelographic fpCT and MSCT scanning were in good agreement.

Conclusions

The novel imaging technique the authors describe yielded adequate results in patients with a history of spinal surgery, may be superior to MSCT scanning in depicting osseous structures and metallic implants, and has the potential to provide multilevel spinal images. Myelographic fpCT scanning may be the preferred modality in patients with expected or known metal artifacts on myelographic MSCT scans and/or MR images.

Intraoperative DynaCT detection and immediate correction of a type Ia endoleak following endovascular repair of abdominal aortic aneurysm

Reintervention following endovascular aneurysm repair (EVAR) is required in up to 10% of patients at 30 days and is associated with a demonstrable risk of increased mortality. Completion angiography cannot detect all graft-related anomalies and computed tomographic angiography is therefore mandatory to ensure clinical success. Intraoperative angiographic computed tomography (DynaCT; Siemens, Germany) utilizes cone beam reconstruction software and flat-panel detectors to generate CT-like images from rotational angiographic acquisitions. We report the intraoperative use of this novel technology in detecting and immediately treating a proximal anterior type Ia endoleak, following an endovascular abdominal aortic repair, which was not seen on completion angiography. Immediate evaluation of cross-sectional imaging following endograft deployment may allow for on-table correction of clinically significant stent-related complications. This should both improve technical success and minimize the need for early secondary intervention following EVAR.