Three-Dimensional Evaluation of the Anatomic Variations of the Femoral Vein and Popliteal Vein in Relation to the Accompanying Artery by Using CT Venography

Objective

We wanted to describe the three-dimensional (3D) anatomic variations of the femoral vein (FV) and popliteal vein (PV) in relation to the accompanying artery using CT venography.

Materials and Methods

We performed a retrospective review of 445 bilateral (890 limbs) lower limb CT venograms. After the 3D relationship between the FV and PV and accompanying artery was analyzed, the presence or absence of variation was determined and the observed variations were classified. In each patient, the extent and location of the variations and the location of the adductor hiatus were recorded to investigate the regional frequency of the variations.

Results

There were four distinct categories of variations: agenesis (3 limbs, 0.3%), multiplication (isolated in the FV: 190 limbs, 21%; isolated in the PV: 14 limbs, 2%; and in both the FV and PV: 51 limbs, 6%), anatomical course variation (75 limbs, 8%) and high union of the tibial veins (737 limbs, 83%). The course variations included medial malposition (60 limbs, 7%), anterior rotation (11 limbs, 1%) and posterior rotation (4 limbs, 0.4%). Mapping the individual variations revealed regional differences in the pattern and frequency of the variations.

Conclusion

CT venography helps to confirm a high incidence of variations in the lower limb venous anatomy and it also revealed various positional venous anomalies in relation to the respective artery.     

Correlation between the disc status in MRI and the different types of traumatic temporomandibular joint ankylosis

Objectives:

We aimed to investigate the correlation between the disc status in MRI and the different types of traumatic temporomandibular joint (TMJ) ankylosis.

Methods:

51 consecutive patients (69 joints), diagnosed with traumatic TMJ ankylosis with a residual condyle (Types A2 and A3), were included in this study. All patients had pre-operative MRI, which was reviewed to determine the disc shape, length and position. The results were compared using the Mann–Whitney test.

Results:

There were 37 joints of Type A2 ankylosis and 32 joints of Type A3. All joints of Type A2 and 27 joints of Type A3 (84.4%) definitely had a discernible disc, while 5 joints of Type A3 had no discernible discs. Among the discernible discs, the lateral disc of Type A2 and the whole disc of Type A3 had severe deformity, while the medial disc of Type A2 had mild deformity. The mean (standard deviation) disc length was 10.88 (1.19) mm in Type A2, but 7.50 (0.82) mm in Type A3. There was a significant difference between Types A2 and A3 (p < 0.05). As for the disc position, the intermediate position was found in all joints.

Conclusions:

There is a correlation between the disc status and the different types of traumatic TMJ ankylosis. Therefore, MRI examination is needed to help treatment planning and predict post-operative TMJ function.     

Semi-quantitative contrast-enhanced MR analysis of indeterminate ovarian tumours: when to say malignancy?

Objective:

To evaluate the ability of dynamic post-contrast sequence to specify indeterminate ovarian masses with inconclusive MR features of malignancy. Since management is dramatically different, special focus on the ability to differentiate borderline from invasive malignancy was considered.

Methods:

150 ovarian masses were detected by pelvic ultrasound in 124 patients. Masses had been considered for dynamic post-contrast MRI. We expressed the kinetic parameters (i.e. enhancement amplitude, time peak of maximal uptake and maximal slope) in the form of maximum relative enhancement percentage (MRE%), time of maximal peak of contrast uptake (T_max) and slope enhancement ratio (SER) curves. Histological findings were the gold standard of reference.

Results:

Malignant ovarian masses showed higher MRE% than benign and borderline masses (p < 0.001). T_max was shorter for malignant than benign (p < 0.01) and borderline (p < 0.001) ovarian masses. SER curves were the most suggestive of malignancy with a specificity and accuracy of 85.7% and 84.7%, respectively.

Conclusion:

Dynamic contrast-enhanced MRI could be a specific sequence to differentiate ovarian masses with indeterminate MR morphology with a special discrimination for low potential from invasive ovarian malignancy.

Advances in knowledge:

The study evaluated the diagnostic performance of the individual parameters of dynamic post-contrast MR sequence in evaluating ovarian masses. Management divert between benign, borderline and invasive malignant masses; our work presented a cut-off value for the peak of contrast uptake of 120%, which helped in the differentiation between benign and malignant tumours; the SER curves with Type III (early washout) pattern that was indicative of invasive malignancy was more specific than borderline malignancy.     

Fluoroscopy-Guided Endovenous Sclerotherapy Using a Microcatheter Prior to Endovenous Laser Ablation: Comparison between Liquid and Foam Sclerotherapy for Varicose Tributaries

Objective

To compare the efficacy and adverse effects of endovenous foam sclerotherapy (EFS) and liquid sclerotherapy (ELS) using a microcatheter for the treatment of varicose tributaries.

Materials and Methods

From December 2007 to January 2009, patients with venous reflux in the saphenous vein were enrolled. The foam or liquid sclerosant was injected through a microcatheter just before endovenous laser ablation (EVLA). Patients were evaluated for the technical success, clinical success, and procedure-related complications during the procedure and follow-up visits.

Results

A total of 94 limbs were included: 48 limbs (great saphenous vein [GSV], 35; small saphenous vein [SSV], 13) were managed using EFS and EVLA (foam group; FG), and 46 limbs (GSV, 37; SSV, 9) were treated by ELS and EVLA (liquid group; LG). Varicose tributaries demonstrated complete sclerosis in 92.7% with FG and in 71.8% with LG (p = 0.014). Bruising (78.7% in FG vs. 73.2% in LG, p > 0.05), pain or tenderness (75.6% in FG vs. 51.2% in LG, p = 0.0237) were noted. Hyperpigmentation (51.2% in FG vs. 46.2% in LG, p > 0.05) was found.

Conclusion

Endovenous foam sclerotherapy using a microcatheter is more effective than ELS for eliminating remnant varicose tributaries prior to EVLA. However, EFS is more commonly associated with local complications such as pain or tenderness than ELS. Furthermore, both techniques seem to prolong the duration of hyperpigmentation along with higher costs.     

Bifid mandibular canals: cone beam computed tomography evaluation

Objectives

For surgical procedures involving the posterior mandible, it is important to be familiar with the details of the bifid mandibular canal. To our knowledge, there have been no systematic studies evaluating the bifid mandibular canal using sectional imaging. The purpose of this study is to evaluate the incidence and configuration of the bifid mandibular canal using cone beam CT.

Methods

252 patients (301 mandible sides) underwent cone beam CT between October 2004 and September 2005 and were included in this study. The cone beam CT images were evaluated for the presence and configuration of the bifid mandibular canal. The patterns of bifurcation were classified into four types according to the classification of Nortjé et al (Variations in the normal anatomy of the inferior dental (mandibular) canal: a retrospective study of panoramic radiographs from 3612 routine dental patients. Br J Oral Surg 1977; 15: 55–63). The diameter of the accessory canal was classified into two categories: 50% or more and less than 50% of the diameter of the main mandibular canal.

Results

Of the 301 subjects, 47 (15.6%) demonstrated a bifid mandibular canal. They were Type I in 2, Type II in 40, Type III in 0, and Type IV in 5 cases. The diameter of the accessory canal was greater than or equal to 50% of the main canal in 23, and less than 50% in 24 cases.

Conclusions

On the basis of the cone beam CT, a bifid mandibular canal was found in 15.6% of cases, a markedly higher proportion than found in previous reports using panoramic images. Cone beam CT is considered a suitable modality for detailed evaluation of bifid mandibular canals.     

Biomonitoring of DNA damage and cytotoxicity in individuals exposed to cone beam computed tomography

Objectives

The aim of the present study was to evaluate DNA damage (micronucleus) and cellular death (pyknosis, karyolysis and karyorrhexis) in exfoliated buccal mucosa cells from adults following cone beam CT exposure.

Methods

A total of 19 healthy adults (10 men and 9 women) submitted to cone beam CT were included.

Results

No significant statistically differences (P > 0.05) in micronucleus frequency were seen before and after cone beam CT exposure. In contrast, the tomography was able to increase other nuclear alterations closely related to cytotoxicity such as karyorrhexis, pyknosis and karyolysis (P < 0.05).

Conclusion

In summary, these data indicate that cone beam CT may not be a factor that induces chromosomal damage, but it is able to promote cytotoxicity.     

Central nervous system abnormalities in Fanconi anaemia: patterns and frequency on magnetic resonance imaging

Objective:

Fanconi anaemia (FA) is an inherited disease associated with congenital and developmental abnormalities resulting from the disruption of a multigenic DNA damage response pathway. This study aimed to define the MRI appearances of the brain in patients with FA in correlation with their genetic and clinical features.

Methods:

A review of the brain MRI in 20 patients with FA was performed. Pituitary size and frequencies of the radiological findings of individuals with FA and age-matched controls were determined.

Results:

Abnormalities were identified in 18 (90%) patients with FA, the commonest being a small pituitary (68%, p < 0.01 females and p < 0.001 males). In five cases (25%, p = 0.02), the pituitary morphology was also abnormal. Posterior fossa abnormalities were seen in six cases (30%, p = 0.01) including Chiari I malformation (n = 3), Dandy–Walker variant (n = 2) and cerebellar atrophy (n = 2). Six patients (30%, p = 0.01) had morphological structural variation of the corpus callosum (CC).

Conclusion:

The incidence of central nervous system (CNS) abnormalities in FA is higher than previously reported, with a midline predominance that points to impact in the early stages of CNS development. MRI brain imaging is important for endocrine assessment and pre-transplant evaluation and can make an important contribution to clinical decision-making.

Advances in knowledge:

The incidence of brain structural abnormalities in FA is higher than previously reported, with abnormalities of the posterior fossa, CC and pituitary being common. There is an association with gender and reduction in pituitary size which does not strongly correlate with biochemically evident endocrine abnormality.     

A quantitative analysis of 1H-MR spectroscopy at 3.0?T of three brain regions from childhood to middle age

Objective:

To study age-related metabolic changes in different brain regions.

Methods:

Point-resolved spectroscopy (repetition time/echo time = 2000 ms/30 ms) was performed in the left and right hippocampus, the left thalamus and the left centrum semiovale of 80 healthy subjects (37 females and 43 males aged 7–64 years). Analysis of covariance and linear regression were used for statistical analysis. Both metabolite concentration ratios with respect to total creatine (tCr) and absolute metabolite concentrations were included for analysis.

Results:

Ins (myo-inositol)/tCr (p < 0.001) and absolute Ins concentration (p = 0.031) were significantly increased with age after adolescence. NAA (N-acetylaspartic acid)/tCr (p < 0.001) and absolute NAA concentration (p = 0.010) significantly declined with age after adolescence.

Conclusion:

Age-related increase of Ins and decline of NAA are found in all three regions, especially at the hippocampus, indicating possible gliosis in the ageing brain.

Advances in knowledge:

We could use NAA/tCr and Ins/tCr as an indicator to estimate the neurons-to-glial cells ratio at the thalamus. This may be an index to distinguish normal tissues from gliosis.     

A prospective study comparing radiographer- and clinician-based localization for patients with metastatic spinal cord compression (MSCC) to assess the feasibility of a radiographer-led service

Objective:

To investigate whether there was parity between treatment fields localized by radiographers and clinicians, by comparing geographical variations and hence determining the feasibility of a radiographer-led service.

Methods:

23 patients with metastatic spinal cord compression (MSCC) were prospectively sampled. Four radiographers not involved in the original planning performed localization on each patient. The 92 localizations that they determined were compared with the clinician-approved fields. Agreement was defined as ≤0.5 cm between field length, width and three isocentre co-ordinates. To be feasible, agreement was required in a minimum of 97% of the cases. The potential time saved with a radiographer-led approach was also recorded.

Results:

Agreement between clinicians and radiographers was 97.8%. For all field parameters, the average differences were <0.3 cm and were significantly different from the 0.5-cm median (p < 0.0001) that would establish no agreement using Wilcoxon signed-rank test. The average (range) delay awaiting clinician approval was 54 min (4–141 min).

Conclusion:

Strong agreement between radiographer and clinician localizations was established. It was also highlighted that time could be saved in the patient''s pathway by removing the need to wait for clinician approval. We believe this supports a radiographer-led service.

Advances in knowledge:

This article is novel, as it is the first known comparison between clinicians and radiographers in the localization of MSCC radiotherapy. These data show the feasibility of introducing radiographer-led practice and a methodology that could be potentially transferred to investigate the localization parity for other treatment sites.     

Relationship between peripheral lung cancer and the surrounding bronchi, pulmonary arteries, pulmonary veins: a multidetector CT observation

Aim

This study aimed to investigate the relationship between peripheral lung cancer and the surrounding pulmonary vessels and bronchi using contrast-enhanced multidetector computed tomography (MDCT) and to analyze associated factors such as pathology types, stage, size, density, and location of peripheral lung cancer.

Materials and Methods

A total of 93 patients with solitary peripheral lung cancers underwent contrast-enhanced MDCT before thoracotomy were enrolled. Multiplanar reconstruction, maximal intensity projection, and volume rendering were used for demonstrating the patterns of the tumor-bronchi (Br), tumor-pulmonary artery (PA) and tumor-pulmonary vein (PV) relationship, respectively. Five subtypes were identified: Type1 (Br1, PA1 and PV1), Br, PA, or PV was erupted at the edge of nodule; Type2 (Br2, PA2, and PV2), erupted at the center of nodule; Type3 (Br3, PA3 and PV3), penetrated through the nodule; Type4, (Br4, PA4 and PV4), contacting the nodule but stretched or encased; Type5 (Br5, PA5, and PV5), contacting the nodule but smoothly compressed.

Results

Both bronchi and PA were interrupted in 70 (Type 1+2); both narrowed in 9 (Type 3+4). The bronchi and PA changes surrounding the lung cancer had positive relations (χ²=12.3918, r=0.7524, P<.01). Br1 and PA1 were more often seen in the group of solid, ≥2.0 cm, and Stage II-IV focal lesions, while Br2 and PA2, more often in the group of part-solid, non-solid, <2.0 cm, and Stage I focal lesions. PV2 was more often seen in the part-solid and non-solid focal lesions group, while PV (4+5), more often in solid focal lesions group.

Conclusion

MDCT can demonstrate and subtype relationships among peripheral lung cancer and the bronchi, pulmonary arteries and pulmonary veins. This can be the basis for further clinical research and differential diagnosis.     

Prevalence of calcified carotid artery atheromas on panoramic images of individuals with primary hyperparathyroidism

Objectives:

Primary hyperparathyroidism (PHPT), affecting 1% of the population, is associated with increased cardiovascular morbidity and mortality. The presence of calcified carotid artery plaque (CCAP) on panoramic images is a validated risk indicator of future adverse cardiovascular events. We hypothesized that military veterans aged 50 years or older diagnosed with PHPT by increased parathyroid hormone and calcium levels would frequently have CCAP on their images.

Methods:

We determined the prevalence rates of CCAP on the images of patients diagnosed with PHPT and evaluated their atherogenic risk profiles, including hypertension, dyslipidaemia, diabetes and obesity. Comparisons of atherogenic risk factors were made between subjects with and without observed CCAP on their panoramic images.

Results:

Of the 60 patients (86.7% males and 13.3% females, mean age 73.2 ± 11.3 years) with PHPT, 40% had atheromas. There were no significant differences between CCAP+ and CCAP− groups in gender or race (p > 0.05). The atherogenic profile (age, body mass index, hypertension, diabetes, hyperlipidaemia) in the CCAP+ and CCAP− groups was not significantly different (p > 0.05).

Conclusions:

Calcified carotid artery atheromas are often seen on the panoramic images of patients with PHPT. Thus, dentists must be uniquely vigilant for these lesions when evaluating these studies.     

A cone beam CT investigation of ponticulus posticus and lateralis in children and adolescents

Objectives:

To determine the prevalence and pathogenesis of ponticulus posticus (PP) and ponticulus lateralis (PL) in children and adolescents.

Methods:

Cone beam CT scans of 576 patients were examined for PP and PL. The patients were divided into three age groups: 10 years and younger, 11–13 years and 14 years and older. Ponticulus formation was categorized as absent, partial or complete. Gender, race and location (right, left or bilateral) were recorded. Data were analysed with the χ² test, with significance at p < 0.050. Institutional review board approval was granted.

Results:

Overall prevalence of PP was 26.2%, with complete lesions in 10.4%. The frequency of PP was greater in patients aged 14 years and older (p ≤ 0.038). The occurrence of complete PP was greater in patients aged 11 years and older (p = 0.028). Lesions were more common in males (p = 0.014) and in blacks compared with other non-white races (p = 0.035). Bilateral PP was more common than right-sided lesions (p = 0.008) and more frequent in the oldest cohort (p = 0.006). Overall prevalence of PL was 6.1% (3.0% complete), with no differences between age groups, genders, races or by location.

Conclusions:

PP is not uncommon even in the first decade and increases in frequency, completeness of calcification and numbers in mid-adolescence. It appears to be more common in males and in blacks. PP may be a congenital osseous anomaly of the atlas that mineralizes at various times. PL is less frequent with no demographic predilections.     

Influence of exposure factors on the variability of CBCT voxel values: a phantom study

Objectives:

To assess the influence of milliamperage and kilovolt peak (kVp) on the variability of cone beam CT (CBCT) voxel values.

Methods:

CBCT scans were obtained from radiographic phantoms in varying concentrations of dipotassium hydrogen phosphate solutions (200–1200 mg ml⁻¹) under different protocols of milliamperage and kVp. In addition, scans were performed with and without a dental implant and exo-mass. The variability of CBCT voxel values was measured on each scan, and factorial analysis of variance and the post hoc Tukey test were performed (α = 0.05). Linear regression was performed to assess the relationship between voxel value variability and dipotassium hydrogen phosphate concentration.

Results:

milliamperage and the presence of a dental implant did not produce significant interference (p = 0.28 and 0.87, respectively) in voxel value variability. Scans at the highest kVp value presented a significant reduction (p ≤ 0.0001) in voxel value variability when only exo-mass was not present. Voxel value variability was not influenced by exo-mass in scans at the highest levels of milliamperage and kVp. The presence of exo-mass produced a significant reduction (p ≤ 0.0001) in voxel value variability in most of the scans. Higher concentrations yielded greater variations in voxel values in all scans, except for those operating at the highest levels of mAs and kVp.

Conclusions:

mAs did not influence the variability of CBCT voxel values; higher kVp reduced such variability when only the object was smaller than the field of view.     

Prevalence of palatine tonsilloliths: a retrospective study on 150 consecutive CT examinations

Objectives:

To evaluate the prevalence of palatine tonsilloliths.

Methods:

150 consecutive CT examinations (75 males and 75 females) were read.

Results:

Tonsilloliths were found in 37 patients (24.6%; confidence interval 17.7–31.6%), of which 18 (48%) had a bilateral location. No influence of sex or age was observed (p = 0.37 and p = 0.57, respectively). 26 patients (70%) had more than 1 concretion. The largest tonsillolith was 7 mm. None of the tonsilloliths found were involved in the reason for prescribing the CT. The radiographic density of the tonsilloliths was between 216 and 2959 HU.

Conclusions:

Palatine tonsilloliths could affect approximately one-quarter of the population. This prevalence is likely to be underestimated in daily clinical practice because small concretions do not result in any functional impairment and are not visible on orthopantomographs.     

Mandibular fracture patterns consistent with posterior maxillary fractures involving the posterior maxillary sinus,pterygoid plate or both: CT characteristics

Objectives:

The aim of this study was to determine the incidence of posterior maxillary fractures involving the posterior maxillary sinus wall, pterygoid plate or both, unrelated to major midface fractures in patients with mandibular fractures, and to characterize associated fractures.

Methods:

A CT study was performed in patients with mandibular fractures to identify posterior maxillary fractures. Patients aged under 16 years, those with mandibular fractures involving only dentoalveolar components and those with concurrent major midfacial fractures were excluded.

Results:

13 (6.7%) of 194 patients with mandibular fractures also had posterior maxillary fractures (case group). The injury pattern correlated with the external force directed to the lateral side of the mandible (p < 0.001), alcohol consumption (p = 0.049), the presence of multifocal fractures (p = 0.002) and the fracture regions in the symphysis/parasymphysis (p = 0.001) and the angle/ramus (p = 0.001). No significant difference between the case and non-case groups was seen for age, sex or cause of trauma. Non-displaced fractures in the ipsilateral posterior mandible occurred with significant frequency (p = 0.001) when the posterior maxillary fractures involved only the sinus.

Conclusions:

Mandibular fractures accompanied by posterior maxillary fractures are not rare. The finding of a unilateral posterior maxillary fracture on CT may aid the efficient radiological examination of the mandible based on possible patterns of associated fractures, as follows: in the ipsilateral posterior region as a direct fracture when the impact is a medially directed force, and in the symphysis/parasymphysis or contralateral condylar neck as an indirect fracture.     

Assessment of Placental Stiffness Using Acoustic Radiation Force Impulse Elastography in Pregnant Women with Fetal Anomalies

Objective

We aimed to evaluate placental stiffness measured by acoustic radiation force impulse (ARFI) elastography in pregnant women in the second trimester with a normal fetus versus those with structural anomalies and non-structural findings.

Materials and Methods

Forty pregnant women carrying a fetus with structural anomalies diagnosed sonographically at 18–28 weeks of gestation comprised the study group. The control group consisted of 34 healthy pregnant women with a sonographically normal fetus at a similar gestational age. Placental shear wave velocity (SWV) was measured by ARFI elastography and compared between the two groups. Structural anomalies and non-structural findings were scored based on sonographic markers. Placental stiffness measurements were compared among fetus anomaly categories. Doppler parameters of umbilical and uterine arteries were compared with placental SWV measurements.

Results

All placental SWV measurements, including minimum SWV, maximum SWV, and mean SWV were significantly higher in the study group than the control group ([0.86 ± 0.2, 0.74 ± 0.1; p < 0.001], [1.89 ± 0.7, 1.59 ± 0.5; p = 0.04], and [1.26 ± 0.4, 1.09 ± 0.2; p = 0.01]), respectively.

Conclusion

Placental stiffness evaluated by ARFI elastography during the second trimester in pregnant women with fetuses with congenital structural anomalies is higher than that of pregnant women with normal fetuses.     

The Primary Patency and Fracture Rates of Self-Expandable Nitinol Stents Placed in the Popliteal Arteries, Especially in the P2 and P3 Segments, in Korean Patients

Objective

We wanted to evaluate the status of self-expandable nitinol stents implanted in the P2 and P3 segments of the popliteal artery in Korean patients.

Materials and Methods

We retrospectively analyzed 189 consecutive patients who underwent endovascular treatment for stenoocclusive lesions in the femoropopliteal artery from July 2003 to March 2009, and 18 patients who underwent stent placement in popliteal arterial P2 and P3 segments were finally enrolled. Lesion patency was evaluated by ultrasound or CT angiography, and stent fracture was assessed by plain X-rays at 1, 3, 6 and 12 months and annually thereafter.

Results

At the 1-month follow-up, stent fracture (Type 2) was seen in one limb (up to P3, 1 of 18, 6%) and it was identified in seven limbs at the 3-month follow-up (Type 2, Type 3, Type 4) (n = 1: up to P2; n = 6: P3). At the 6-month follow-up, one more fracture (Type 1) (up to P3) was noted. At the 1-year follow-up, there were no additional stent fractures. Just four limbs (up to P2) at the 2-year follow-up did not have stent fracture. The primary patency was 94%, 61% and 44% at 1, 3 and 6 months, respectively, and the group with stent implantation up to P3 had a higher fracture rate than that of the group that underwent stenting up to P2 (p < 0.05).

Conclusion

We suggest that stent placement up to the popliteal arterial P3 segment and over P2 in an Asian population can worsen the stent patency owing to stent fracture. It may be necessary to develop a stent design and structure for the Asian population that can resist the bending force in the knee joint.     

Usefulness of the ratio of orbital fat to total orbit area in mild-to-moderate thyroid-associated ophthalmopathy

Objective:

To identify a useful predictor of thyroid-associated ophthalmopathy (TAO) from orbital CT images; to evaluate the orbital fat and extraocular muscle area ratio as a CT-derived measure; and to investigate the correlations between this ratio and the clinical manifestations in mild-to-moderate TAO.

Methods:

Between January 2012 and March 2013, 44 patients with TAO and 23 controls were studied prospectively. All of the patients underwent ophthalmic examinations, including clinical activity score, exophthalmometry, clinical photographs, alternate prism and cover test, duction and version test, Hess screen test, binocular single vision test, thyroid function tests and orbital CT. The cross-sectional areas of the four rectus muscles, superior oblique muscle, optic nerve and total orbit area were calculated in the coronal view 6 mm posterior from the posterior pole of globe.

Results:

The cross-sectional area measured on orbital CT showed increased orbital fat in patients with TAO and an increased orbital fat to total orbit area ratio (fat/orbit) in TAO with retraction and proptosis. There were significant correlations between fat/orbit and margin reflex distance 1 (p = 0.022), margin reflex distance 2 (p = 0.013) and the exophthalmometric value (p = 0.007).

Conclusion:

The orbital fat to total orbit area ratio (fat/orbit) is a useful diagnostic index in mild-to-moderate TAO.

Advances in knowledge:

The orbital CT offers a useful diagnostic index in TAO.     

Quantitative MRI analysis of salivary glands in sickle cell disease

Objectives

The purpose of this prospective study was to characterize the MR relaxometric features of the major salivary glands in patients with sickle cell disease (SCD).

Methods

15 patients with SCD (aged 19.8–43.6 years) and 12 controls were imaged with the mixed turbo-spin echo pulse sequence. The major salivary glands were manually segmented and T₁, T₂ and secular T₂ relaxometry histograms were modelled with Gaussian functions.

Results

Shortened T₁ relaxation times were seen solely in the submandibular glands of patients with SCD (747.5 ± 54.8 ms vs 807.1 ± 38.3 ms, p < 0.001). Slight T₂ and secular T₂ shortening were seen in the parotid gland; however, this difference was not significant (p = 0.07). The sublingual gland showed no changes under MR relaxometry. There was no difference in glandular volumes, and no correlation was demonstrated between history of blood transfusion and salivary gland relaxometry.

Conclusions

Patients with SCD exhibited changes in quantitative MRI T₁ relaxometry histograms of the submandibular glands.     

Accumulated dose to the rectum,measured using dose–volume histograms and dose-surface maps,is different from planned dose in all patients treated with radiotherapy for prostate cancer

Objective:

We sought to calculate accumulated dose (D_A) to the rectum in patients treated with radiotherapy for prostate cancer. We were particularly interested in whether dose–surface maps (DSMs) provide additional information to dose–volume histograms (DVHs).

Methods:

Manual rectal contours were obtained for kilovoltage and daily megavoltage CT scans for 10 participants from the VoxTox study (380 scans). Daily delivered dose recalculation was performed using a ray-tracing algorithm. Delivered DVHs were summated to create accumulated DVHs. The rectum was considered as a cylinder, cut and unfolded to produce daily delivered DSMs; these were summated to produce accumulated DSMs.

Results:

Accumulated dose-volumes were different from planned in all participants. For one participant, all D_A levels were higher and all volumes were larger than planned. For four participants, all D_A levels were lower and all volumes were smaller than planned. For each of these four participants, ≥1% of pixels on the accumulated DSM received ≥5 Gy more than had been planned.

Conclusion:

Differences between accumulated and planned dose-volumes were seen in all participants. DSMs were able to identify differences between D_A and planned dose that could not be appreciated from the DVHs. Further work is needed to extract the dose data embedded in the DSMs. These will be correlated with toxicity as part of the VoxTox Programme.

Advances in knowledge:

DSMs are able to identify differences between D_A and planned dose that cannot be appreciated from DVHs alone and should be incorporated into future studies investigating links between D_A and toxicity.