Diameters of lingual, facial, and maxillary arteries measured according to an objective protocol on 3D computed tomography angiography images.

PURPOSE: Retrograde superselective intra-arterial chemoradiotherapy is a radical treatment for advanced oral cancer. The catheter tip is placed into tumor-feeding arteries-the lingual, facial, or maxillary arteries. The diameter of the tumor-feeding arteries newly bifurcated from the external carotid artery is crucial for determining the requirement of a catheter navigation system. This study aimed to measure the diameter and distribution of the tumor-feeding artery according to an objective protocol using 3D computed tomography angiography images reproducibly. METHODS: Angiographic data of 20 noncatheterized carotid arteriesof 10 randomly selected patients were analyzed. We followed the external carotid artery to the entrance of each feeding artery to determine the center point where the artery diameter was measured. The diameter of the optimum circle measured at the adopted center point was taken as the diameter of each tumor-feeding artery. RESULTS: The diameters (mean ± standard deviation) were 3.5 ± 0.45, 2.9 ± 0.56, and 3.5 ± 0.56 mm for the maxillary, lingual, and facial arteries, respectively. The diameters of the maxillary and facial arteries were similar (p = 0.877), whereas the diameter of the lingual artery was smaller than that of the maxillary and facial arteries (p < 0.001). CONCLUSION: The findings of this study will be beneficial in determining the need of a new catheter navigation system and diameter of catheters to be used in the clinical practice. From the viewpoint of measurement automation and reproducibility, 3DCTA vessel measurement taken according to the proposed protocol was considered to be effective.

Radiological analysis of maxillary artery relationships to key bony landmarks in maxillofacial surgery.

The maxillary artery (MA) is a key structure at risk of injury in numerous oral and maxillofacial surgical (OMS) procedures. Knowledge of safe distances from this vessel to surgically familiar bony landmarks could improve patient safety and prevent catastrophic haemorrhage. Distances between the MA and bony landmarks on the maxilla and mandible were measured using CT angiograms on 100 patients (200 facial halves). The vertical height of the pterygomaxillary junction (PMJ) was mean (SD) measurement of 16 (3) mm. The MA enters the pterygomaxillary fissure (PMF) a mean (SD) distance of 29 (3) mm from the most inferior point of the PMJ. The mean (SD) shortest distance between the MA and medial surface of the mandible was 2 (2) mm (with the vessel directly contacting the mandible in 17% of cases). The branchpoint (bifurcation of the superficial temporal artery (STA) and MA) was directly in contact with the mandible in 5% of cases. The mean (SD) distances between this bifurcation point and the medial pole of the condyle were 20 (5) mm and 22 (5) mm, respectively. A horizontal plane through the sigmoid notch perpendicular to the posterior border of the mandible is a good approximation of the trajectory of the MA. The branchpoint is usually within 5 mm of this line and inferior in 70% of cases. Surgeons should take note that both the branchpoint and the MA contact the surface of the mandible in a significant number of cases.

A radioanatomical study of 3rd segment terminal branches of the maxillary artery in the pterygopalatine fossa.

This study describes the clinical anatomical topography and relationship of the terminal branches of the maxillary artery to the bony wall of the maxillary sinus in the pterygopalatine fossa (PPF) to estimate the bleeding risk during surgical interventions. Using contrasted computer tomography records, (i) the route of the maxillary artery in the infratemporal fossa, (ii) the number of the arteries in the critical PPF surgery plane, (iii) the diameter of the largest artery in the area and (iv) its relation to the posterior wall of the maxillary sinus were examined. Furthermore, measurements were extended with (v) the minerality of the bony posterior wall of the maxillary sinus on bone-window images. For statistical analyses Student's t- and Fisher-test were applied. 50 patients (n = 50, 100 cases including both sides) were examined in this study. The maxillary artery reached the pterygomaxillary fissure on the lateral side of the lateral pterygoid muscle in 56% of the cases (n = 32), in 37% (n = 23) on its medial side and in 7% (n = 4) on both sides. The number of arteries at the level of the Vidian canal in the PPF varied between 1 and 4 with a median of 2. The diameter of the biggest branch was 1.2-4.7 mm, the median diameter was 1.90 mm. In 41% (n = 30) of the cases the biggest artery directly contacted the posterior wall of the maxillary sinus, and the mineral density of the posterior wall was decreased in 14.3% (n = 12) of all investigated cases. The present description and statistical analysis of the vasculature of the PPF optimizes operative planning-like clip size or the type and direction of the surgical approach-in this hidden and deep head/neck region.

How I do it: internal maxillary artery to middle cerebral artery bypass to manage giant thrombosed internal carotid artery aneurysm.

BACKGROUND: Internal maxillary artery (IMA) bypass has become popularized due to its medium-to-high blood flow, short graft length, and well-matched arterial caliber between donor and recipient vessels. METHOD: We described an open surgery of a NEW "workhorse," the IMA bypass, to treat a giant, thrombosed cerebral aneurysm. The extracranial middle infratemporal fossa (EMITF) approach was used to unveil the pterygoid segment of the IMA for cerebral revascularization. CONCLUSION: Although this technique is technically challenging, the variations in IMA can be effectively identified and sufficiently exposed in this technique to achieve favorable clinical outcomes with a high bypass patency rate.

[Extra-intracranial bypass surgery using the orifice of maxillary artery in a patient with middle cerebral artery aneurysm. Case report and literature review]. / Pervyi opyt vypolneniya ekstra-intrakranial'nogo shuntirovaniya s ispol'zovaniem ust'ya verkhnechelyustnoi arterii u patsienta s anevrizmoi srednei mozgovoi arterii. Opisanie klinicheskogo sluchaya i obzor literatury.

OBJECTIVE: To present the technique of extra-intracranial bypass surgery using the orifice of maxillary artery bypass, to evaluate the advantages and disadvantages of this and alternative revascularization options. MATERIAL AND METHODS: Radial artery graft harvesting was performed at the 1st stage. Simultaneously, the second team of surgeons performed a combined (submandibular and anterior) access to the donor artery (mandibular segment of maxillary artery behind the ramus of the mandible). Craniotomy and mobilization of potential recipient arteries (M2-M3 segments of the middle cerebral artery) were performed at the 2nd stage. Distal anastomosis in end-to-side fashion was formed with M3 segment of the middle cerebral artery. At the 3rd stage, radial artery was passed through a subcutaneous tunnel in zygomatic region. The orifice of maxillary artery was resected together with distal external carotid artery (ECA) and orifice of superficial temporal artery. After transposition of ECA and orifice of maxillary artery, proximal end-to-end anastomosis was performed with radial artery. After that, the main surgical stage was performed, i.e. exclusion of M3 segment of the middle cerebral artery together with aneurysm. RESULTS: Harvesting of mandibular segment of the maxillary artery as a donor vessel reduces the length of bypass graft to 12-14 cm since this branch is localized close to the skull base. You can also form optimal proximal end-to-end anastomosis for intracranial redirecting blood flow maxillary artery. CONCLUSION: The described method makes it possible to form anastomosis with a short bypass graft and reduce the risk of thrombosis. This procedure is effective for cerebral bypass in patients with skull base tumors, complex aneurysms, and occlusive-stenotic lesions of carotid arteries.

Fenestrated Maxillary Artery.

The external carotid artery divides terminally into the superficial temporal and maxillary arteries (MA), deep to the base of the neck of the mandible. Arterial fenestrations are commonly found in the vertebrobasilar and internal carotid systems but are rarely encountered, or reported, in the external carotid artery system. The archived computed tomography angiograms of a 70-year-old male patient were observed anatomically. Inferior to the posterior end of the lateral pterygoid muscle was found a fenestrated segment of the MA, oriented mediolaterally. The middle meningeal artery left the superior arm of that fenestration. The inferior arm of the fenestration gave off a temporoalveolar trunk, further divided into posterior deep temporal and inferior alveolar arteries. The MA fenestration and the temporoalveolar trunk are rare variations of the MA at the entrance in the infratemporal fossa. These make the MA prone to iatrogenic lesions during different surgical procedures addressed to this region.

Computed Tomography Perfusion Imaging Study of Intracranial Complex Aneurysms Treated by Internal Maxillary Artery Bypass Grafting.

BACKGROUND: Cerebral revascularization strategies through extracranial to intracranial bypass have been adopted in the management of complex intracranial aneurysms. The internal maxillary artery used as a donor in a bypass is an effective method. At present, there are few quantitative analyses of cerebral blood flow perfusion. The main focus of this study was to evaluate the effectiveness of blood perfusion after bypass grafting. METHODS: From April 2015 to December 2017, 19 patients who underwent internal maxillary artery radial artery middle cerebral artery bypass surgery with unobstructed bypass vessels were selected. Cerebral blood flow perfusion before and after bypass surgery was quantitatively evaluated by computed tomography perfusion imaging. The cerebral blood perfusion in the region of interest was measured by computed tomography perfusion. RESULTS: The aneurysms were excised after trapping in 2 cases with mass effects and neural compression. Proximal occlusion of the parent artery was performed in 9 cases of fusiform or giant dissecting aneurysms. Trapping was performed after bypass surgery in 8 cases. Within 3 months after surgery, 17 patients had good outcomes. After the hypothesis test, there was a significant difference between the preoperative △cerebral blood volume and postoperative △cerebral blood volume in the anterior area of the semioval center cross section (P = 0.001 < 0.05). CONCLUSIONS: The internal maxillary artery as a bypass donor is an effective method that can provide sufficient intracranial blood perfusion, and there is usually no cerebral ischemia in the surrounding area.

Botulinum toxin injections in jaw-opening dystonia. The lateral pterygoid - maxillary artery problem.

It has been suggested that the variations in the trajectory of the maxillary artery (MA) near the lateral pterygoid muscle (LPM) play a critical role in Botulinum neurotoxin (BoNT) injections in patients with jaw-opening/deviation dystonia (JOD). In the case of a lateral course to the LPM, an extraoral injection entails risks of MA injury, pain, and hematoma. Previous reports suggest geographical differences in variations of the MA-LPM relationship. We aimed to determine these variations in Turkish individuals and highlight the need to establish a consensus on approach to LPM injections. In 284 individuals, contrast-enhanced magnetic resonance angiography (MRA) images were evaluated by two radiologists on both sides for the variations in the course of the MA in the infratemporal fossa. Images of 44 were excluded due to trauma, arteriovenous malformation, mass, surgery, and imaging artifacts. Of the included, 62.1% were female. In 480 evaluations of 240 individuals, the MA passed lateral to the LPM in 65.6% (n = 315). No sex difference was noted. In 51 individuals (21.3%), the MA course differed on the right and left sides (medial-lateral asymmetry). These results confirm that the lateral course of the MA is more frequent. In patients with JOD, the trajectory of the MA should be determined with imaging prior to extraoral BoNT injections. In the case of a lateral course, an intraoral approach seems to be safer to avoid a potential MA injury.

Radiological evaluation of maxillary artery and descending palatine artery in the pterygopalatine fossa by 3D rotational angiography.

PURPOSE: The aim of this study is to evaluate the branching patterns and topographical features of the third part of the maxillary artery (t-MA) and descending palatine artery (DPA) by 3-Dimensional Rotational Angiography (3DRA) images and to define the radiological classification of their variations, based upon the previous cadaveric studies and a review of the literature. METHOD: This study was conducted from May 2020 through June 2021. All consecutive adult patients who were examined with 3D-RA were enrolled in the study. The morphological evaluations and measurements of t-MA, DPA and their branches were made on maximum intensity projection images with 10-20 mm slice thickness. RESULTS: Eighty-five hemifaces, including 58 females and 45 right sides, were evaluated. The diameter of the t-MA was measured as 1.73 ± 0.30 mm. The most common pattern of the t-MA according to its course was loop type (63/85, 74.1%) and according to branching pattern was Type Ib (29/85, 34.1%). The mean diameter of DPA was 1.19 ± 0.20 mm. The DPA presented as a single trunk in 11/85 cases. Type II, which was defined as one lesser palatine artery originating from distal-DPA, was the most common morphological variation (51.8%). CONCLUSIONS: 3DRA imaging provides valuable information for vascular anatomical studies. The most common morphological variation related to t-MA, DPA is the distal branching pattern.

Proximity of the middle meningeal artery and maxillary artery to the mandibular head and mandibular neck as revealed by three-dimensional time-of-flight magnetic resonance angiography.

PURPOSE: The close topographic relationship between vascular and osseous structures in the condylar and subcondylar region and marked variability in the arterial course has been revealed by both imaging and cadaveric studies. This study aimed to verify the previously published information in a large sample and to determine a safe surgical region. METHODS: We analyzed the three-dimensional time-of-flight magnetic resonance angiography images of 300 individuals. RESULTS: The mean distance between the middle meningeal artery and the apex of the condyle or the most medial point of the condyle was 18.8 mm (range: 11.2-25.9 mm) or 14.5 mm (range: 8.8-22.9 mm) respectively. The course of the maxillary artery relative to the lateral pterygoid muscle was medial in 45.7% of cases and lateral in 54.3%. An asymmetric course was evident in 66 patients (22%). The mean distance between the maxillary artery and condylar process at the deepest point of the mandibular notch was 6.2 mm in sides exhibiting a medial course (range: 3.7-9.8 mm) and 6.6 mm in sides exhibiting a lateral course (range: 3.9-10.4 mm). The distances were significantly influenced by age, gender, and the course of the maxillary artery. CONCLUSION: Our study emphasizes the marked inter- and intra-individual variability of the maxillary and middle meningeal arterial courses. We confirmed the proximity of the arteries to the condylar process. Extensive surgical experience and thorough preparation for each individual case are essential to prevent iatrogenic vascular injury.

Detection of posterior superior alveolar artery using multi-detector row CT: a retrospective study focused on age-related changes.

PURPOSE: The posterior superior alveolar artery (PSAA) is a branch of the maxillary artery that supplies the lateral sinus wall and overlying membrane. This artery is one among several arteries in which arterial damage during surgery can cause massive and fatal bleeding. The purpose of this study was to detect the PSAA using multi-detector row computed tomography (MDCT) by age. MATERIALS AND METHODS: The present study was approved by our university ethics committee (EC19-010). The study included 230 patients (110 males, 120 females; ages 5-91 years, average age 42.5 years) who underwent MDCT of the jaw. The subjects were divided into two groups, one group in which the PSAA was observable and another in which the PSAA was not observable, to perform the Mann-Whitney U test. To perform the Tukey-Kramer multiple comparison test, the subjects were divided into the following ten groups depending on their age: 5-9 years, 10-19 years, 20-29 years, 30-39 years, 40-49 years, 50-59 years, 60-69 years, 70-79 years, 80-89 years, and 90-91 years. RESULTS: The PSAA was identified in 74.5% (5-91 years) of the maxillary sinuses. The average age of subjects in whom the PSAA was observable was 33.4 years, and the average age of subjects in whom the PSAA was not observable was 11.3 years, indicating a significant difference between these two groups (p < 0.01). A comparison by age group showed a significant difference (p < 0.05). CONCLUSIONS: The detection ratio for the PSAA using MDCT increased with increasing age of the subject, reaching a high detection ratio of 94% in adults. This study has shown that MDCT is a very useful tool to observe the PSAA.

Maxillary artery involvement in giant cell arteritis demonstrated by ultrasonography.

We describe two cases of giant cell arteritis where involvement of the superficial temporal artery and maxillary artery were demonstrated using colour doppler ultrasonography. Maxillary artery involvement is responsible for the symptoms of jaw claudication and toothache, and even headaches might be due to the involvement of the middle meningeal artery which is a branch of the maxillary artery. The maxillary artery has been difficult to visualise until now. There are international consensus definitions of ultrasonographic abnormalities seen in the superficial temporal artery affected by giant cell arteritis. We have used those definitions to demonstrate hypoechoic changes in the maxillary artery affected by giant cell arteritis. The maxillary artery can be visualised in the infratemporal fossa from an echo window between the condylar and coronoid processes of the mandible. This is the first proof of concept evidence that maxillary arteries can be visualised using bedside ultrasonography in giant cell arteritis.

Bilateral Maxillary Pseudoaneurysms as a Complication of Craniofacial Fracture: A Case Report.

BACKGROUND Pseudoaneurysms of the head and neck region are relatively rare and consequently there are few reports in the literature. The main causes of pseudoaneurysms in the head and neck area are associated with blunt or penetrating injuries in this area or are iatrogenic, originating during surgical procedures. CASE REPORT The authors illustrate a case of a 16-year-old boy who had an accident on a scooter. A maxillary artery hemorrhage occurred after multiple craniofacial trauma including bilateral fracture of the condylar processes and treatment with intravascular embolization. Due to the anatomical location of the injury and deep location of the maxillary artery, it was impossible to control the bleeding by direct pressure; the only option was vessel embolization using interventional radiology or surgical intervention. The authors describe symptoms of pseudoaneurysm: pain in the area of the temporomandibular joint on the left side, persistent bilateral swelling of the cheeks and parotideomasseteric region with a greater asymmetry on the left side, as well as peripheral paresis of the facial nerve on the left side. The diagnosis was based on magnetic resonance imaging, ultrasound, and angio-CT. A reduction in the clotted pseudoaneurysm size on the left side was confirmed after 6 and 10 months through monitoring ultrasound examination of the neck vessels. CONCLUSIONS No similar case of a patient has been reported in the available literature. The development of bilateral pseudoaneurysms after injury is very rare. However, doctors should be alert to this possibility in the case of massive post-traumatic or postoperative bleeding.

Imaging features of internal maxillary artery and extracranial middle meningeal artery and their relationships on head CTA.

BACKGROUND: The internal maxillary artery and extracranial middle meningeal artery are vitally important. Anatomical studies of the relationship of between them using computed tomography angiography are rare. MATERIAL AND METHODS: This study assessed 75 cases involving 150 sides. And the vascular diameters and lengths of the internal maxillary artery and middle meningeal artery were measured using a GE workstation. The distance between the zygomatic arch midpoint and the internal maxillary artery, the angle between the internal maxillary artery and middle meningeal artery were measured, and the middle meningeal artery branch and internal maxillary artery aneurysm were recorded. The internal maxillary artery course classifications were recorded. All of these parameters were statistically analysed. RESULTS: Ages ranged from 18 to 72 (average 40.2) years, and there were 30 women (40%, 30/75) and 45 men (60%, 45/75). Internal maxillary artery length from its origin to middle meningeal artery origin was 1.37 ± 0.59 cm. The extracranial middle meningeal artery length was 1.79 ± 0.48 cm. The vessel diameters of internal maxillary artery origin, middle meningeal artery origin, and middle meningeal artery at the skull base were 2.93 ± 0.52 mm, 1.58 ± 0.43 mm, and 1.33 ± 0.43 mm, respectively. Among the 150 sides of internal maxillary artery course type, there were 138 superficial (92%, 138/150) and 12 (8%, 12/150) deep course cases. The angle between the internal maxillary artery and middle meningeal artery was 116.2 ± 35.76°. CONCLUSIONS: The findings of this study elucidate the imaging features of the internal maxillary artery and extracranial middle meningeal artery and their relationships, which are helpful for the extracranial-intracranial bypass and endovascular treatment via the internal maxillary artery and middle meningeal artery.

Standing Waves on Computed Tomography Angiography in Multiple Vessels in a Young Trauma Patient.

ABSTRACT: Standing waves are a phenomenon of uncertain etiology seen on imaging. We present the first case demonstrating standing waves on computed tomography angiography in multiple vessels in a single patient with imaging evidence of resolution in some of the vessels. Our case further supports the literature that standing waves are a physiologic phenomenon, likely because of flow mechanics, rather than modality.

Angioembolisation for the Treatment of Pseudo-aneurysm of Internal Maxillary Artery.

Pseudo-aneurysm of internal maxillary artery, following a road traffic accident, is a rare clinical scenario. The consequence of pseudo-aneurysm may be spontaneous rupture of the arterial wall, which may eventually lead to life-threatening hemorrhage. We report a case of a 20-year male who presented with recurrent epistaxis. CT scan was performed, which revealed a pseudo-aneurysm of the internal maxillary artery; this was successfully treated by angioembolisation. Similar cases of traumatic pseudo-aneurysms have been reported, however, none presented with recurrent epistaxis after management of pan-facial fractures. Key Words: Epistaxis, Pseudo-aneurysm, Angioembolisation, Pan-facial fracture.

Angio-anatomical study of the pterygovaginal artery based on cone-beam computed tomography.

PURPOSE: To investigate the anatomical characteristics and clinical implications of the pterygovaginal artery (PtVA), a recurrent branch from the distal internal maxillary artery (IMA), which courses through the pterygovaginal canal that connects the pterygopalatine fossa and nasopharynx. METHODS: Eighty-two patients with 90 sides of cone-beam computed tomography (CBCT) reconstructed from rotational angiography of the external or common carotid artery with a field of view covering the pterygopalatine fossa were retrospectively reviewed. The origin from the IMA, branching type, distribution, and anastomoses was evaluated. The underlying lesions were 36 hypervascular lesions with possible supply from PtVA (17 cavernous sinus arteriovenous fistulas (AVFs), 6 anterior condylar AVFs, and 13 nasopharyngeal, parasellar, or paraclival tumors) and 46 other diseases. RESULTS: PtVA was identified in 75 sides (83%). It originated from the pterygopalatine segment of the IMA in 45 sides (60%) and from the pterygoid segment in 30 sides (40%). It arose independently (77%), sharing the common trunk with the Vidian artery (15%) or with other branches. It ran posteromedially through the pterygovaginal canal to supply the mucosa over the nasopharyngeal roof, the choanae, and the pharyngeal ostium of the eustachian tube. It anastomosed with the ascending pharyngeal artery (n=37), the accessory meningeal artery (n=7), and the mandibular artery from the petrous internal carotid artery (n=2). It served as a feeder of osseous AVFs and skull base tumors. CONCLUSION: PtVA was often identified by CBCT even in normal anatomy. Its detailed angio-anatomy could be evaluated in the presence of parasellar or paraclival hypervascular lesions.

Variant facial artery anatomy revisited: Conventional angiography performed in 284 cases.

A number of studies have evaluated the variable courses of facial artery. However, the results of these differed substantially from each other so not consistent relationships have yet been established. There has also yet to be a relevant study using conventional angiography.We assessed the variant branching pattern of the facial artery and its branches using conventional angiography.Two radiologists retrospectively reviewed 284 cases of angiographies of the external carotid artery in 198 patients. The courses of the facial artery and infraorbital branch of the maxillary artery were classified into 4 types and 2 types, according to the end branch.Among 284 cases of facial artery, type 1 (angular branch) made up 104 cases (36.6%), type 2 (lateral nasal branch) made up 138 cases (48.6%), type 3 (superior labial branch) made up 24 cases (8.5%), and type 4 (inferior labial branch) made up 18 cases (6.3%).Regarding the 284 total cases of maxillary artery, 163 cases (57.4%) had anastomosis with the angular artery or extended to the territory of the angular artery. In addition, 121 cases (42.6%) had nothing done in regard to the angular artery.The results may be helpful for avoiding complications related to facial and maxillary arteries during facial surgeries and cosmetic procedures.

Visual and semiquantitative assessment of cranial artery inflammation with FDG-PET/CT in giant cell arteritis.

BACKGROUND AND AIM: Assessing cranial artery inflammation plays an important role in the diagnosis of cranial giant cell arteritis (C-GCA). However, current diagnostic tests are limited. The use of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT imaging is an established tool for assessing large vessel inflammation but is currently not used for assessment of the cranial arteries. This study aimed to evaluate the accuracy of FDG-PET/CT in the diagnosis of biopsy proven C-GCA and its relation to clinical presentation. METHODS: This retrospective case control study included temporal artery biopsy (TAB) positive C-GCA patients and age- and sex-matched controls. FDG-PET/CT scans were performed according to EANM/EARL guidelines, visually assessed by an experienced nuclear medicine physician, and semiquantitatively assessed using the maximum standardised uptake value (SUVmax). The visual and semiquantitative assessments were performed on the temporal arteries, maxillary arteries, vertebral arteries, and occipital arteries. Clinical signs and symptoms were scored for comparison. RESULTS: A total of 24 C-GCA patients and 24 controls were included in the study. Visual analysis revealed an 83% sensitivity and a 75% specificity. Receiver operating characteristic (ROC) analysis of the semiquantitative assessment revealed a 79% sensitivity and a 92% specificity when measuring SUVmax in the cranial arteries. Visual and semiquantitative assessments showed moderate agreement (Fleiss kappa 0.55). There was a positive correlation between the number of cranial symptoms and the SUVmax in the vertebral artery. CONCLUSION: FDG-PET/CT can reliably diagnose C-GCA by assessing cranial artery inflammation using SUVmax. Extending the use of FDG-PET/CT to include assessment of the cranial arteries may improve its diagnostic value in GCA and provide a suitable alternative to TAB. Moderate agreement between visual and semiquantitative assessment methods suggest diagnostic accuracy may be improved by further standardisation.