Magnetic resonance imaging of ankle tendons and ligaments: Part I – Anatomy

Magnetic resonance imaging is an excellent technique for imaging the tendons and the ligaments of the ankle. Owing to the advantage of detailed demonstration of soft‐tissue structures and capability for multiplanar demonstration of the ankle ligaments and tendons, MRI has been increasingly used in the evaluation of the ligamentous and the tendon injuries of the ankle. Knowledge of normal anatomy and of MRI appearances are essential to recognize pathological appearances. In this pictorial essay, the first of a three part series, we review the normal MRI appearances of the ankle tendons and ligaments. The anterior, lateral and medial tendon groups, the Achilles tendon and the lateral, the syndesmotic and the medial ligament groups are described and illustrated. Anatomy of the sinus tarsi is also described. Tendon and ligament pathology will be illustrated in the second part of the series, and imaging approach to ankle injuries will be outlined in the final part of this series.     

Magnetic resonance imaging of the ankle: Pathology of the lateral and posterior compartments

Magnetic resonance imaging (MRI) is the gold standard for imaging the tendons and the ligaments of the ankle. MRI combines excellent tissue contrast and accurate anatomic delineation of joint structures. In the first article of this series, we discussed a compartmental approach to the interpretation of ankle pathology focusing on the anterior and medial compartments. This article will complete the MR review of the ankle, with a focus on the lateral and posterior compartments of the ankle.     

人膝关节半月板不同测量方法的准确性和匹配性研究

目的：明确X线测量方法、MRI测量方法、解剖学测量方法三者的相互关系以及准确性和匹配性。方法选取意外死亡男性膝关节6只,年龄20～45岁,排除膝关节创伤和疾患,随机编号,分别行X线标准正侧位摄像、常规膝关节MRI扫描,将所得影像数据资料导入Unisight图象分析系统对相关指标进行测量并记录,然后将膝关节离断,直视下按照我院组织库的半月板测量方法进行测量并记录相关数据。X线测量指标包括：内侧胫骨平台矢状径、外侧胫骨平台矢状径、胫骨平台冠状径、内侧胫骨平台冠状径、外侧胫骨平台冠状径。MRI测量指标包括：胫骨平台冠状径、内侧胫骨平台冠状径、外侧胫骨平台冠状径、内侧胫骨平台矢状径、外侧胫骨平台矢状径、内外侧半月板的厚度（前角、体部、后角）、内外侧半月板的宽度（前角、体部、后角）。解剖学测量的指标包括：胫骨平台冠状径、内侧胫骨平台冠状径、外侧胫骨平台冠状径、内侧胫骨平台矢状径、外侧胫骨平台矢状径、内外侧半月板的厚度（前角、体部、后角）、内外侧半月板的宽度（前角、体部、后角）。结果在半月板测量的直接指标中,除内侧半月板体部宽度、内侧半月板前角厚度、外侧半月板体部厚度的MRI测量变异系数＜10%之外,所有指标变异系数均＞10%。外侧半月板后角宽度及外侧半月板前角宽度的MRI测量,变异系数分别为65.97%、70.26%。半月板测量的间接指标,变异系数均＜10%。半月板厚度的MRI测量总大于解剖学测量结果。3种测量方法的一致性方面存在关联,但仍有差异。结论半月板相关测量指标中,X线测量值均偏大,经MRI测量的指标与解剖学测量结果接近,MRI所测的半月板指标较X线测量指标更具准确性及稳定性,值得推荐其作为临床匹配性测量的方法,其中胫骨平台冠状径、内侧胫骨平台矢状径、外侧胫骨平台矢状径是稳定性最好的3个指标,变异系数均＜7%,且胫骨平台冠状径值得作为匹配性测量的首要指标。     

Radiological classification of meniscocapsular tears of the anterolateral portion of the lateral meniscus of the knee

In an arthroscopic–MRI correlation study of acute injuries to the knee it was found that anterolateral meniscocapsular separations of the lateral aspect of the knee were missed on MRI reporting. Eighty sports‐related injuries of the knee were seen by experienced orthopaedic surgeons at the University of Malaya Medical Centre and at the National Sports Centre, Malaysia from January 1996 to July 1997. Fifty of the patients were suspected to have meniscal tears that were either lateral or medial on clinical examination and they were sent for MRI. Many of these patients were tertiary referrals. Magnetic resonance imaging examinations in 27 of the 50 patients were reported as not showing any intrasubstance or obvious meniscocapsular tears, but arthroscopy performed on them revealed anterolateral meniscocapsular tears of the lateral meniscus of varying degrees in nine of these patients. In retrospect the tears could be seen on MRI, and a pattern to the tears was noted and classified as follows. Type 0, normal; type 1, torn inferior or superior meniscocapsular attachment; type 2, both meniscofemoral and meniscotibial ligaments torn but with minimal separation of meniscus and capsule by fluid or synovitis; and type 3, marked separation of meniscus and capsule by fluid (> 3 mm). Ten patients who did not undergo arthroscopy for various personal and financial reasons underwent MRI which showed type 1 and type 2 tears, and were treated conservatively. These patients were all asymptomatic after 4–6 weeks with regard to clinical signs, suggesting a lateral meniscal tear. Magnetic resonance imaging therefore does reveal minor degrees of meniscocapsular tears anterolaterally when one understands the normal anatomy in this region.     

不稳定性下胫腓联合损伤的诊治研究进展

Syndesmosis is a kind of fibrous articulation in which the opposing joint surfaces are united by ligaments. The distal tibiofibular syndesmosis consists of a complex of ligaments that provide stability to the joints. The anterior, posterior and transverse tibiofibular ligaments together with the interosseous ligament form the distal tibiofibular syndesmosis. Syndesmosis injuries are rare, but very debilitating and frequently misdiagnosed. It is estimated that 10% of all ankle fractures and 20% of operatively treated ankle fractures are accompanied by syndesmotic injury. Distal tibiofibular syndesmotic ligament injury can also occur in isolation mostly due to an extorsion or in association with damage to the lateral ankle ligaments. Syndesmotic injury leads to subsequent mortise instability and should be treated with syndesmotic stabilization to prevent long-term complications of ankle joint. Immediate reconstruction of the unstable syndesmosis is indicated, because a delay could expedite the development of degenerative arthritis. However, the precise diagnosis of distal tibiofibular syndesmotic ligament injury is critically difficult. The distinction should be made between syndesmotic ligament disruption and real syndesmotic instability. Radiographic measures including tibiofibular overlap, tibiofibular space, medial and superior space are of little value in detecting distal tibiofibular syndesmosis, because all these parameters depend on the rotation of the ankle joint. CT and MRI could also be used in detecting syndesmotic disruption in patients with distal tibiofibular syndesmotic ligament injuries. Intra-operative stress testing is essential in the diagnosis for syndesmotic injuries. Although ankle arthroscopy is a more sensitive method than radiography, it is more invasive and not all surgeons have the expertise to perform ankle arthroscopy. Therefore, there has no“gold standard”diagnostic measure in testing the instability of distal tibiofibular syndesmotic ligament injuries. Furthermore, the need for distal tibiofibular syndesmotic fixation is not fully clear despite the abundance of literature concerning the treatment of ankle fractures and isolated syndesmotic injuries. Fixation using screw is widely preferred in the current concepts of surgical treatment. At present, the following items in treating distal tibiofibular syndesmotic ligament injuries are still in the arguments: location of the screw fixation, number of the screws used in the fixation, 3 or 4 cortex penetrated, diameter of the screw and the foot position. Therefore, the purpose of the present review article is to summarize the evidence about the diagnosis and treatment of instable distal syndesmotic injuries.     

Magnetic resonance imaging of the ankle: Pathology of the anterior and medial compartments

Magnetic resonance imaging (MRI) is the gold standard for imaging the tendons and the ligaments of the ankle. MRI combines excellent tissue contrast and accurate anatomic delineation of joint structures. In this pictorial essay, the first of two parts, we delineate the ankle into anatomic compartments and use this as a template for describing pathology in each compartment.     

A Case of Contiguous Primary Hepatic Marginal Zone B-Cell Lymphoma and Hemangioma Ultimately Diagnosed Using Contrast-Enhanced Ultrasonography

Primary hepatic marginal zone B-cell malignant lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is extremely rare. We present a case in which a lesion was diagnosed as 2 contiguous tumors (MALT lymphoma and hemangioma) using contrast-enhanced ultrasonography (US) with sonazoid. There has been no previous case of contiguous hepatic MALT lymphoma and hemangioma. The present case was a female with no medical history. We detected a snowman-like appearance, which was a tumor of 15 mm in diameter with hypo- and hyper-echogenicities in the lateral and medial parts, respectively, in the Couinaud''s segment (S6) of the liver on US. The tumor appeared as a single lesion with a low-density area in the unenhanced phase and prolonged enhancement in the equilibrium phases on dynamic CT. On MRI, the whole lesion showed a low-intensity signal on T1-weighted imaging, but isointensity in the lateral part and high intensity in the medial part were seen on T2-weighted imaging. On contrast-enhanced US, the lateral hypoechoic region was homogenously hyperenhanced in the early vascular phase, and the contrast medium was washed out after about 30 s; in contrast, the medial hyperechoic region was gradually stained from the margin toward the central region. The tumor showed a defect in both hypo- and hyperechoic regions in the postvascular phase. Hemangioma was suspected for the medial part based on the typical image findings, but the lateral part was not given a diagnosis. Thus, surgical resection was performed. The medial part was a hemangioma, and the lateral part was a MALT lymphoma by histopathological findings.Key Words: Primary hepatic malignant lymphoma, Malignant lymphoma of mucosa-associated lymphoid tissue, Hemangioma, Contrast-enhanced ultrasonography     

半月板的MRI测量指标及多元回归结果

目的为明确半月板移植手术前同种异体半月板匹配性测量方法,探索有效的半月板的MRI测量方法。方法选取我院门急诊、住院患者58膝,行MRI检查,采用UniSight系统进行半月板有关指标的测量。以性别、年龄、身高、体重为自变量,以胫骨平台冠状径（CWTP）、内侧胫骨平台冠状径（CWMTP）、内侧胫骨平台矢状径（SWMTP）、外侧胫骨平台冠状径（CWLTP）、外侧胫骨平台矢状径（SWLTP）、内侧半月板前角厚度（TAMM）、外侧半月板前角厚度（TALM）、内侧半月板后角厚度（TPMM）、外侧半月板后角厚度（TPLM）等指标为应变量,采用CHISS2006统计学软件进行统计学分析。结果胫骨平台冠状径、内侧胫骨平台矢状径、外侧胫骨平台矢状径、内外侧半月板后角厚度符合正态分布,测量的重复性好,数据稳定性好,与性别、身高有相关性,与年龄、体重无相关性。内侧胫骨平台冠状径、外侧胫骨平台冠状径、内外侧半月板前角厚度等指标受到的干扰因素较多,测量的重复性较差,数据稳定性欠佳,与自变量无相关性。结论胫骨平台冠状径、内侧胫骨平台矢状径、外侧胫骨平台矢状径、内外侧半月板后角厚度等指标可作为半月板移植前同种异体半月板匹配性测量的指标。     

Delineation of a Cardiac Planning Organ-At-Risk Volume Using Real-Time Magnetic Resonance Imaging for Cardiac Protection in Thoracic and Breast Radiation Therapy

PurposeCardiac radiation is associated with cardiotoxicity in patients with thoracic and breast malignancies. We conducted a prospective study using cine magnetic resonance imaging (MRI) scans to evaluate heart motion. We hypothesized that cine MRI could be used to define population-based cardiac planning organ-at-risk volumes (PRV).Methods and MaterialsA total of 16 real-time acquisitions were obtained per subject on a 1.5 Tesla MRI (Philips Ingenia). Planar cine MRI was performed in 4 sequential sagittal and coronal planes at free-breathing (FB) and deep-inspiratory breath hold (DIBH). In-plane cardiac motion was assessed using a scale-invariant feature transformation–based algorithm. Subject-specific pixel motion ranges were defined in anteroposterior (AP), left-right (LR), and superoinferior (SI) planes. Averages of the 98% and 67% of the maximum ranges of pixel displacement were defined by subject, then averaged across the cohort to calculate PRV expansions at FB and DIBH.ResultsData from 20 subjects with a total of 3120 image frames collected per subject in coronal and sagittal planes at DIBH and FB, and 62,400 total frames were analyzed. Cohort averages of 98% of the maximum cardiac motion ranges comprised margin expansions of 12.5 ± 1.1 mm SI, 5.8 ± 1.2 mm AP, and 6.6 ± 1.0 mm LR at FB and 6.7 ± 1.5 mm SI, 4.7 ± 1.3 mm AP, and 5.3 ± 1.3 mm LR at DIBH. Margins for 67% of the maximum range comprised 7.7 ± 0.7 mm SI, 3.2 ± 0.6 mm AP, and 3.7 ± 0.6 mm LR at FB and 4.1 ± 0.9 mm SI, 2.7 ± 0.8 mm AP, and 3.2 ± 0.8 mm LR at DIBH. Subsequently, these margins were simplified to form PRVs for treatment planning.ConclusionsWe implemented scale-invariant feature transformation-based motion tracking for analysis of the cardiac cine MRI scans to quantify motion and create cohort-based cardiac PRVs to improve cardioprotection in breast and thoracic radiation.     

Preoperative MRI marking technique for the planning of breast-conserving surgery

Background

When performing breast-conserving surgery (BCS), it is essential to achieve a complete resection of the tumor while preserving the cosmetic outcome. The aim of this study was to evaluate the accuracy of a MRI marking technique for planning of BCS.

Methods

A retrospective review was performed of 14 consecutive patients who underwent MRI in the supine position (supine MRI) using a MRI marking technique. The preoperative histopathological diagnosis was ductal carcinoma in situ in 11 and invasive ductal carcinoma in 3. All of the patients with invasive ductal carcinoma were treated with neoadjuvant chemotherapy. The pills of Breath Care^® used as MRI markers were placed in the Penrose drain with 2-cm intervals, and drains were put on the resection lines as determined by ultrasonography (US). The final resection lines were modified using information obtained by supine MRI. The rate of the margin-tumor distance (RMTD: longer margin-tumor distance/shorter margin-tumor distance) was calculated.

Results

Thirteen patients (93%) needed modification of the first resection line, whereas one patient (7%) needed no modification. Twelve patients (86%) had negative margins, but two patients (14%) had positive margins: one patient had a medial margin, while the other had a distal margin. One patient showed a pathologically complete response after chemotherapy; the RMTD was not evaluated. Among the 12 patients with medial and lateral negative margins, the medial and lateral margin-tumor distances ranged from 1.0 to 3.5 cm (average 2.1 cm), and the RMTD ranged from 1 to 3.0 (average 1.5).

Conclusion

Our MRI marking technique may be useful for evaluating the extent of the tumor as determined by the US examination in difficult cases.     

Internal mammary lymph node (IMN) coverage by standard radiation tangent fields in patients showing IMN drainage on lymphoscintigraphy: therapeutic implications

The purpose of this report is to evaluate the variability in coverage of the internal mammary nodal chain (IMN) by standard radiation tangential fields in those patients with medial drainage on lymphoscintigraphy. Twenty-two patients who showed lymphoscintigraphic IMN drainage underwent radiation simulation planned with computed tomography (CT). Standard tangent fields were placed and CT scans were reviewed to assess IMN inclusion and correlation with presternal fat thickness. Of the 22 patients who showed IMN drainage on lymphoscintigraphy, 10 (45%) had lateral primary lesions, 9 (41%) had medial lesions and 3 (14%) had subareolar lesions. Of these 22 women, 4 (19%) had the IMN completely within the standard tangent fields. Twelve women (55%) had only partial coverage of the IMN and the remaining 6 women (27%) had the IMN region completely outside. Presternal fat thickness greater than 10 mm was less likely associated with complete IMN coverage than fat thickness 10 mm or less, P = 0.001. Lymphoscintigram drainage to the IMN in breast cancer patients may suggest an increased risk of IMN involvement. Our data show that a majority (73%) of these patients had complete or partial incidental inclusion of the IMNs with standard tangents, which may in part explain the historically low IMN failure rate.     

腰椎横突形态学研究

目的：研究腰椎横突的形态结构，为后路脊柱手术，尤其是后外侧横突间融合术提供详尽的解剖学资料。方法：CE LightSpeed QX/iCT扫描仪检查20名中国人的L1—5共100个椎骨。数据重建后测量200个腰椎横突参数：横突长度、横突宽度、横突厚度、横突冠状面倾斜角和横突水平面倾斜角。观测腰椎横突内外部形态结构及节段性变化特点。结果:各参数左右间差异无显意义(P＞0．05)；除L5外，相同节段内侧、中间宽度差异无显意义(P＞0．05)，但与外侧相比差异有显意义(P＜0．01)；而相同节段内侧、中间和外侧的厚度均差异有显意义(P＜0．01)。L1长度最短，约10mm；L2、4、5长度相似，约15mm；L3最长，约19mm。L1—4厚度节段性变化不明显，但在L5水平较L4增大1倍左右。各节段横突宽度、厚度从内到外逐渐变窄、变薄。L5宽度和厚度在各节段中均最大。横突水平面角均偏向后侧，从冠状面看各节段横突几乎水平走向。结论：横突是腰椎后方的重要结构，虽有一定的形态学规律，但某些横突参数的个性化特点显，术前利用重建CT详尽地测量横突参数，可以最大程度的保证横突间融合术的安全性，提高融合率。     

Aromatase inhibitors reverse tamoxifen induced endometrial ultrasonographic changes in postmenopausal breast cancer patients

Objective Aromatase inhibitors may decrease endometrial thickness in breast cancer patients previously having short-term tamoxifen treatment. There is a necessity to find out if aromatase inhibitors can also decrease endometrial thickness in patients previously treated with long-term tamoxifen treatment. Methods Prospective comparison of the last ultrasonographic endometrial thickness measurement taken before discontinuation of long-term tamoxifen treatment in 36 postmenopausal breast cancer patients, with further measurements, performed following aromatase inhibitors administration. Results There was a significant decrement of endometrial thickness, following 36.2 ± 16.8 months of tamoxifen treatment, from a mean value of 9.1 ± 5.8 mm, measured at the last ultrasonographic measurement performed before discontinuation of tamoxifen treatment, down to a mean value of 6.0 ± 5.0 mm, measured following 5.8 ± 5.8 months of aromatase inhibitors therapy (P = 0.001). A second ultrasonographic measurement performed in 8 patients following of additional 7.5 ± 4.0 months of aromatase inhibitors treatment revealed further decrement of mean endometrial thickness to 4.8 ± 2.1 mm (P = 0.002 compared to baseline). In 28 patients (77.8%), endometrial thickness was reduced following the administration of aromatase inhibitors, in four patients (11.1%) there was no change in endometrial thickness and four (11.1%) patients demonstrated an increase of endometrial thickness. Conclusions Aromatase inhibitors may reverse endometrial thickening induced by long-term tamoxifen treatment in postmenopausal breast cancer patients.     

MRI simulation: effect of gradient distortions on three-dimensional prostate cancer plans

PURPOSE: To quantify the dosimetric consequences of external patient contour distortions produced on low-field and high-field MRIs for external beam radiation of prostate cancer. METHODS AND MATERIALS: A linearity phantom consisting of a grid filled with contrast material was scanned on a spiral CT, a 0.23 T open MRI, and a 1.5 T closed bore system. Subsequently, 12 patients with prostate cancer were scanned on CT and the open MRI. A gradient distortion correction (GDC) program was used to postprocess the MRI images. Eight of the patients were also scanned on the 1.5 T MRI with integrated GDC correction. All data sets were fused according to their bony landmarks using a chamfer-matching algorithm. The prostate volume was contoured on an MRI image, irrespective of the apparent prostate location in those sets. Thus, the same target volume was planned and used for calculating the anterior-posterior (AP) and lateral separations. The number of monitor units required for treatment using a four-field conformal technique was compared. Because there are also setup variations in patient outer contours, two different CT scans from 20 different patients were fused, and the differences in AP and lateral separations were measured to obtain an estimate of the mean interfractional separation variation. RESULTS: All AP separations measured on MRI were statistically indistinguishable from those on CT within the interfractional separation variations. The mean differences between CT and low-field MRI and CT and high-field MRI lateral separations were 1.6 cm and 0.7 cm, respectively, and were statistically significantly different from zero. However, after the GDC was applied to the low-field images, the difference became 0.4 +/- 0.4 mm (mean +/- standard deviation), which was statistically insignificant from the CT-to-CT variations. The mean variations in the lateral separations from the low-field images with GDC would result in a dosimetric difference of <1%, assuming an equally weighted four-field 18-MV technique for patient separations up to approximately 40 cm. CONCLUSIONS: For patients with lateral separations <40 cm, a homogeneous calculation simulated using a 1.5 T MRI or a 0.23 T MRI with a gradient distortion correction will yield a monitor unit calculation indistinguishable from that generated using CT simulation.     

Dose Variation at Bone/Titanium Interfaces Using Titanium Hollow Screw Osseointegrating Reconstruction Plates

Purpose: To evaluate dose variations at bone/titanium interfaces in an experimental model designed to simulate postoperative radiotherapy in patients with mandibular reconstructions using a titanium hollow-screw osseointegrating reconstruction plate (THORP) system.Materials and Methods: The model consisted of a 25 × 25 × 10 mm³ block of fresh bovine femoral diaphysis, to the surface of which a segment of THORP system reconstruction plate was fixed by means of a solid titanium screw 4 mm in diameter and 10 mm in length. Using specially designed thermoluminescent dosimeters (TLD) 2 mm in diameter and 0.13 mm in thickness, dose measurements were carried out at four distances from the screw axis (0.1, 0.3, 0.6, and 1 mm). ⁶⁰Co and 6-MV photon beams were used at incidences both perpendicular and parallel (“axial”) to the screw axis.Results: For 6-MV X-ray beams incident perpendicular to the screw axis, the maximum dose enhancement (due to backscatter) and the maximum dose reduction (due to attenuation) at the bone/titanium interface were 5% (± 2%) and 6% (± 2%), respectively. The corresponding values for ⁶⁰Co beams were 6% (± 5%) and 10% (± 5%). For the axial incidences, a maximum dose enhancement of 5–7% was noted for both 6-MV X-rays and ⁶⁰Co for beams incident on the surface containing the THORP plate segment, whereas beams incident on the opposite surface induced only a very small dose enhancement (2–3%).Conclusion: Using a new experimental model, TLD measurements showed only marginally significant dose variations at bone/titanium interfaces around THORP screws, all measured values being very close to the uncertainty limits (± 5%) associated with the method. For both ⁶⁰Co and 6-MV beams, dose variations appeared smaller for axial than for perpendicular incidences. Because photon beams used in head and neck cancer treatment are most often directed parallel to the screw axes, these results suggest that failures of prosthetic osseointegration are unlikely to be explained by an overdosage at the bone/titanium interface.     

乳腺鳞状细胞癌影像学及临床特征探讨

 【摘要】　目的　探讨乳腺鳞状细胞癌的影像学特征及临床特点。方法　回顾分析经病理证实的5例乳腺鳞状细胞癌患者的磁共振成像（MRI）和B型超声特点,其中4例行MRI扫描,5例经B型超声（US）检查。对照术后病理表现,探讨其临床表现、病理学特征与影像学的联系。结果　影像学表现,MRI：肿瘤径较大,50 mm左右;均发生在乳头周围;伴有皮肤肥厚2例;肿瘤边缘不整,肿瘤壁的构造鲜明,呈不均一的肥厚,无向内腔突入的乳头状阴影;T1WI等信号,T2WI部分高信号;增强扫描显示肿瘤充实性部分被强化,中心坏死部分强化不明显。US所见：肿瘤平均直径40 mm,5例中4例乳头距肿瘤距离为0 mm,1例为19 mm;肿瘤呈块状或分叶状,边缘不整,后方高回声,2例伴有侧方回声,4例显示肿瘤内部血流丰富,2例显示内部伴有液化和坏死的囊性低回声。乳腺钼靶检查（MMG） ：怀疑为恶性2例,良性1例;肿瘤呈均一的高密度,无明显的毛刺征和微细钙化。均采用乳房全切术进行治疗。术后病理分期：ⅢB期3例、ⅡB期1例、ⅡA期1例。雌激素受体（ER）、孕激素受体（PR）检查均为阴性。术后施行辅助化疗者3例,术后跟踪随访其他脏器转移（肺、脑）2例。结论　乳腺鳞状细胞癌患者术前MMG检查不具典型性影像学特征。MRI检查有较为突出的特征性表现,结合B型超声US及穿刺细胞、组织学检查手段,能够推测组织类型及浸润范围,对手术方式的选择及指导治疗具有重要的作用。     

Comparison of Electronic Portal Imaging and Cone Beam Computed Tomography for Position Verification in Children

AimTo compare the accuracy of radiotherapy set-up using an electronic portal imaging device (EPID) versus megavoltage cone beam computed tomography (MV-CBCT) in paediatric patients.Materials and methodsIn total, 204 pairs of EPID and MV-CBCT were carried out for 72 patients in the first 3 treatment days and weekly thereafter.ResultsFor the whole group, the mean systematic EPID set-up errors were 1.8 (±1.7), 1.6 (±1.3), 1.4 (±1.5) mm and 2.3 (±1.7), 1.6 (±1.3), 2.4 (±1.6) mm for MV-CBCT in the longitudinal, lateral and vertical directions, respectively, whereas the mean EPID random errors were 2.0 (±1.7), 1.4 (±1.5), 1.2 (±1.6) and 1.9 (±1.5), 1.5 (±1.3), 2.1 (±1.7) mm for MV-CBCT in the longitudinal, lateral and vertical directions, respectively. For systematic errors of head and neck patients, there was a statistically significant difference in the lateral and vertical directions (P = 0.027, 0.003), whereas in the non-head and neck patients there was a statistically significant difference in the lateral direction only (P = 0.031). In head and neck patients, the mean random errors were significantly different in the vertical and lateral directions, whereas in non-head and neck patients, they were significantly different in the vertical direction only. The larger values alternate between the two modalities. The systematic and random errors (detected by EPID and MV-CBCT) were significantly correlated in almost all direction in all tumour sites.ConclusionsThe comparison between set-up error in EPID and MV-CBCT was not in favour of any of the two modalities. However, the two modalities were strongly correlated but fairly agreed and the differences between the shifts reported were small and hardly influenced the recommended planning target volume margin.     

Absence of white matter changes on magnetic resonance imaging in children treated with CNS prophylaxis therapy for leukemia

Previous studies have shown that magnetic resonance imaging (MRI) is sensitive to white matter changes in children receiving cranial radiation of 3000 cGy or greater. The current study used MRI to investigate the integrity of white matter in children receiving 1800 to 2400 cGy of cranial radiation. Ten survivors of acute lymphoblastic leukemia (ALL) who received intrathecal methotrexate (MTX) and either 1800 or 2400 cGy of cranial radiation were studied with MRI and neuropsychologic testing. Magnetic resonance (MR) scans were normal in nine of ten patients. One patient had prominent and asymmetrical lateral ventricles and mildly enlarged cortical sulci. White matter tracts were normal in appearance. However, seven of nine children had below average intellectual functioning. Results indicate that children receiving less than 2500 cGy of cranial radiation fail to show white matter changes on MRI, despite evidence of cognitive impairment.     

Ultrasound Examination of the Normal Pyloric Sphincter in Neonates

Real time ultrasound examination is rapidly becoming the initial diagnostic investigation for infantile hypertrophic pyloric stenosis (IHPS). While published studies have documented the size of the abnormal pylorus, no studies of the normal diameter of the canal have been performed, and suggested values have merely been extrapolated from suspected patients considered normal in retrospect. A prospective study of 112 normal neonates, ranging from premature to 6 weeks of age, demonstrated that the normal transverse pylorus is elliptical and measures 8.7 (±/- 1.4) by 9.7 (±/- 1.33)mms, while the muscle thickness measures 2.0 (±/- 0.6) and 2.1 (±/- 0.6)mm. The examination is simple to perform, and requires no prior preparation or sedation. The size of the pylorus does not vary significantly with weight or maturity of the child, nor in relation to feeding.     

18F-FDG PET/CT in primary brain lymphoma

The actual role of 18F-FDG PET/CT in evaluating primary brain lymphoma is still an open issue. Brain lymphoma usually show elevated 18F-FDG uptake, often higher than other brain tumors or inflammatory processes, but the metabolic behavior of this lymphoma is not still understood. Our aim was to investigate the particular metabolic behavior of this lymphoma. Forty six patients (21 female, 25 male) with histologically-confirmed brain lymphoma who underwent 18F-FDG PET/CT from vertex to the mid-thigh for initial staging were retrospectively evaluated. The PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value (SUVmax), lesion-to-liver SUVmax ratio, lesion-to-blood pool SUVmax ratio and the tumor to normal brain uptake ratio (T/N ratio) and compared with epidemiological (age, sex, HIV infection) and morphological (tumor size, MRI appearance) characteristics. Thirty-eight patients (83%) had positive 18F-FDG PET/CT (average SUVmax was 15.6?±?9.2; lesion-to-liver SUVmax ratio 5.8?±?2.8; lesion-to-blood pool SUVmax ratio 7.1?±?3.8, T/N ratio 3.1?±?1.7) at the corresponding brain lesion; the remaining 8 (17%) were not 18F-FDG avid. 18F-FDG avidity was significantly associated with morphological appearance and tumor size and not correlated with other features. 18F-FDG PET/CT detected extracranial disease in two cases (4%) with negative bone marrow biopsies and CT. In conclusion, brain lymphomas are 18F-FDG avid in 83% of cases showing high 18F-FDG uptake and 18F-FDG avidity is correlated with tumor size and morphological appearance of the lesion. PET/CT helped to recognize extracranial disease in two patients.