Intraoperative augmented reality with heads-up displays in maxillofacial surgery: a systematic review of the literature and a classification of relevant technologies.

Although the term augmented reality appears increasingly in published studies, the real-time, image-guided (so-called 'hands-free' and 'heads-up') surgery techniques are often confused with other virtual imaging procedures. A systematic review of the literature was conducted to classify augmented reality applications in the fields of maxillofacial surgery. Publications containing the terms 'augmented reality', 'hybrid reality', and 'surgery' were sought through a search of three medical databases, covering the years 1995-2018. Thirteen publications containing enough usable data to perform a comparative analysis of methods used and results obtained were identified. Five out of 13 described a method based on a hands-free and heads-up augmented reality approach using smart glasses or a headset combined with tracking. Most of the publications reported a minimum error of less than 1mm between the virtual model and the patient. Augmented reality during surgery may be classified into four categories: heads-up guided surgery (type I) with tracking (Ia) or without tracking (Ib); guided surgery using a semi-transparent screen (type II); guided surgery based on the digital projection of images onto the patient (type III); and guided surgery based on the transfer of digital data to a monitor display (type IV).

Ipsilateral breast cancer recurrence after Deep Inferior Epigastric Perforator (DIEP) flap reconstruction: Incidence and radiological presentation.

PURPOSE: To assess the incidence and presentation of ipsilateral cancer recurrences (ICR) after deep inferior epigastric perforator (DIEP) flap reconstruction for breast cancer. PATIENTS AND METHODS: Data of 247 consecutive women with DIEP flap reconstruction after breast cancer in our institution between 1997 and 2009 were retrospectively reviewed. RESULTS: Mean follow-up time was 4.1years±3.2 (SD) (median: 3years; range: 1month - 14years). Thirty-one patients (12.5%, 95%CI: =8.7-17.3) presented 34 relapses, in average 4.1years±2.6 after mastectomy: 14 (41%) were ipsilateral, 6 (18%) contralateral and 14 (41%) metastatic. ICRs occurred earlier (3.9 vs. 5.8years; P<0.05) than non-ICRs. Most ICRs (10/14, 71%) involved the periphery of the flap and presented as palpable nodules. The remaining (4/14, 29%) involved the axilla and 3/4 (75%) were palpable. Imaging procedures detected infra-clinical ICRs in 3 of 10 imaged patients (30%). CONCLUSION: ICRs after DIEP flap reconstruction are more frequent than contralateral recurrences suggesting the need for imaging follow-up of the reconstructed breast.

Breast tomosynthesis: Dosimetry and image quality assessment on phantom.

PURPOSE: To evaluate using phantom study the average glandular dose (AGD) and image quality in breast tomosynthesis. MATERIALS AND METHODS: The study was performed with a full-field digital mammography system (Mammomat Inspiration(®), Siemens, Erlangen, Germany) combined with tomosynthesis equipment (3D). For AGD evaluation, polymethyl methacrylate (PMMA) plates and a dosimeter were used to directly measure the absorbed doses in 2D and in 3D. The doses were then compared to the doses displayed on the equipment using the Mann-Whitney test. Three phantoms, accredited for 2D digital mammography (MTM 100, ACR RMI 156, BR3D), were imaged three times in 2D then in 3D. For each acquisition, the AGD was recorded. For image quality assessment, scores, defined by the rate of visible inserts, obtained for each acquisition both in 2D and in 3D, and for each phantom, were compared (Kruskall-Wallis and post-hoc Dunn tests). RESULTS: There was no significant difference between the measured and displayed AGD, both in 2D and in 3D imaging (P>0.05). With identical acquisition parameters, AGD were significantly greater in 3D than in 2D P<0.01). For phantoms MTM 100 and ACR RMI 156, there was no significant difference between the rate of visible inserts in 2D and in 3D (P=0.06 and P=0.36, respectively). However for phantom BR3D, the rate was significantly higher in 3D than in 2D (P<0.0001). CONCLUSION: Doses are significantly greater in 3D than in 2D. With tomosynthesis, out of the three phantoms tested, only phantom BR3D showed a higher rate of visible inserts.

The standard tangential fields used for breast irradiation do not allow optimal coverage and dose distribution in axillary levels I-II and the sentinel node area.

BACKGROUND: Recent data from ACOSOG Z0011 and NSABP B32 trials suggested no need for axillary lymph node dissection (ALND) in patients with micrometastatic involvement of the sentinel lymph node (SLN). The low rate of axillary recurrence was attributed to the axilla coverage by the tangential fields (TgFs) irradiation and systemic therapy. This study aimed to evaluate dose distribution and coverage of the axilla levels I-II and the SLN area. PATIENTS AND METHODS: One hundred and nine patients were analyzed according to three groups: group 1 (50 Gy; n = 18), group 2 (60 Gy; n = 34) and group 3 (66 Gy; n = 57). Patients were treated using the standard (STgF; n = 22) or high (HTgF; n = 87) TgF. RESULTS: The median doses delivered to level I using HTgF versus STgF were 33 and 20 Gy (P = 0.0001). The mean dose delivered to the SLN area was only 28 Gy. Additionally, the SLN area was totally included in the HTgF in 1 out of 12 patients who had intraoperative clip placement in the SNL area. CONCLUSIONS: TgFs provide a limited coverage of the axilla and the SNLB area. This information should be considered when only TgFs are planned to target the axilla in patients with a positive SLN without ALND. Standardization of locoregional radiotherapy in this situation is urgently needed.

Assessment of a 27-kDa antigen in enzyme-linked immunosorbent assay for the diagnosis of fasciolosis in Vietnamese patients.

Fasciolosis has emerged as an important zoonotic disease in many parts of the world. In recent years, an increasing number of human cases were reported in Vietnam. In this study, the 27-kDa component protein from the excretory/secretory production of adult Fasciola gigantica, purified by high performance liquid chromatography, was assessed in an enzyme-linked immunosorbent assay (ELISA) to detect antibodies against Fasciola spp. for diagnosis of human fasciolosis. The ELISA showed a high sensitivity (100%) and specificity (97.67%) when tested on patients with fasciolosis, other parasitic infections, cholangiocarcinoma and on healthy controls. The assay was applied for diagnosis on 143 patients in the Viet Duc-Hanoi hospital who presented with clinical signs of liver disease and lesions in their livers as shown by imaging techniques. Antibodies were found in 37 (25.9%) of these patients, of whom only 3 shed Fasciola eggs in their stools (2.1%). The excellent response to triclabendazole treatment of 37 sero-positive patients confirmed the diagnosis of fasciolosis. This study demonstrated the diagnostic potential for human fasciolosis of the 27-kDa antigen ELISA. Fasciolosis should be considered in the differential diagnosis of hepatic disease in Vietnam.

Manure phosphorus extractability as affected by aluminum- and iron by-products and aerobic composting.

Shifts in manure phosphorus (P) chemical forms and pool sizes induced by water treatment residuals and industrial mineral by-products are largely undefined. We conducted a manure P fractionation study to determine mechanisms of reduction of dissolved reactive phosphorus (DRP) in poultry manure upon mineral by-product additions. The effects of composting on the P immobilization efficacy of the by-products were determined using laboratory self-heating composting simulators. The mineral by-products included an aluminum-water treatment residual (Al-WTR) and an iron-rich titanium-processing by-product. The noncomposted manure averaged 0.11 g g(-1) of total P as DRP forms. The by-products significantly reduced manure DRP, by an average of 39 and 48% in the Al- and the Fe-treated manure, respectively. The by-products also reduced the 0.5 M NH4F-extractable phosphorus (FEP) fraction. Shifts in P forms between FEP and 0.1 M NaOH-extractable phosphorus (SHEP) depended upon the Al and Fe contents of the by-products while the combined FEP + SHEP pool remained constant. Phosphate sorption measurements supported the observations that the Fe-rich by-product was more effective at reducing manure DRP and enhancing the formation of SHEP forms at the expense of FEP than the Al-WTR. Composting had no effect on the efficacy of either by-product to reduce DRP. Potential mechanisms of enhanced P stabilization in treated manure upon composting included chemical shifts from the DRP and FEP fractions to the citrate-bicarbonate-dithionite extractable P fraction. Thus, the choice of P immobilization agents affected the stability of immobilized P forms and should be taken into consideration in developing manure processing and nutrient stabilization methods.

MR imaging of the breast in the follow-up evaluation of conservative nonoperatively treated breast cancer.

Because of postradiation changes in the breast, evaluation of the efficacy of conservative local radiation treatment is difficult, and early detection of recurrent disease is often a diagnostic challenge. MR imaging of the breast aids in the follow-up of conservatively treated breast cancers. When recurrent disease is suspected, MR imaging allows for the differentiation between late postradiation changes in the breast and recurrent carcinoma.

Tumor recurrence versus fibrosis in the irradiated breast: differentiation with dynamic gadolinium-enhanced MR imaging.

To assess the value of magnetic resonance (MR) imaging of the breast in the differentiation of late postirradiation fibrosis from recurrent carcinoma, 35 women with a history of breast carcinoma treated conservatively with radiation therapy underwent MR imaging. Nine patients had recurrent tumors confirmed at biopsy and surgery. Twenty-six patients had a localized fibrotic mass confirmed at biopsy and/or during long-term clinical and radiologic follow-up. In all cases, a localized hypointense area was present on plain spin-echo T1-weighted images. In all recurrent tumors, dynamic gadolinium-enhanced T1-weighted images demonstrated early increased signal intensity of the lesion within 3 minutes after bolus injection. The signal intensity over time in localized fibrosis differed from that in tumor recurrence, with no substantial enhancement on post-contrast T1-weighted images. Short inversion time inversion recovery and spin-echo T2-weighted images were not useful in the differential diagnosis of recurrent tumor versus radiation fibrosis.

Detection of multiple myeloma involving the spine: efficacy of fat-suppression and contrast-enhanced MR imaging.

OBJECTIVE: To determine the efficacy of fat-suppressed sequences and contrast-enhanced MR imaging for the detection of focal spinal lesions caused by multiple myeloma, we obtained MR images in 32 patients with newly diagnosed myeloma who had back pain. SUBJECTS AND METHODS: All patients had biopsy-proved myeloma and had MR imaging at the painful level of the spine. Spin-echo T1-weighted, T2-weighted, and short TI inversion-recovery (STIR) images; dynamic ultrafast low-angle shot (turbo-FLASH) images after IV injection of a bolus of paramagnetic contrast material; and contrast-enhanced T1-weighted images were obtained. We qualitatively compared the signal intensities and contrast enhancement of focal lesions with those of the surrounding vertebral bodies. RESULTS: Multiple lesions were detected in all but two of the 32 patients. On T2-weighted and STIR images, all lesions had homogeneously high signal intensity. On T1-weighted images, the lesions were visible as hypointense areas compared with surrounding bone in all except four patients, in whom the lesions were isointense or hyperintense. All tumor nodules enhanced on turbo-FLASH images obtained in the arterial phase. No additional lesions were seen on STIR or contrast-enhanced images. MR findings resulted in a change in the staging of the disease in one patient and led to prompt treatment in five patients with epidural involvement. CONCLUSION: MR imaging appears to be helpful in detecting spinal involvement in patients with multiple myeloma. The diagnosis of spinal lesions is best achieved by using either fat-suppressed or T2-weighted images. Although myeloma lesions enhanced in all patients, contrast material appears to be of no value for the detection of additional lesions.

Value of MR imaging in evaluating focal fatty infiltration of the liver: preliminary study.

Focal fatty infiltration of the liver is a well-known entity that occasionally mimics metastatic disease on ultrasonographic (US) and computed tomographic (CT) scans and requires biopsy for diagnosis. To determine if high-field-strength magnetic resonance (MR) imaging might be useful in the differential diagnosis of the lesions, the authors compared US, CT, and MR findings in three patients with biopsy-proved fatty hepatic lesions. Areas of focal fatty infiltration were hyperechoic on US scans and had low attenuation on CT scans. No mass effect of the lesions on vascular structures or liver contours was observed, particularly on contrast material-enhanced CT scans. For all three patients, MR findings suggested the correct diagnosis by demonstrating focal high signal intensity on spin-echo T1- and T2-weighted images. On the basis of these preliminary findings, it appears that focal fatty infiltration of the liver may be differentiated from metastatic disease by means of high-field-strength MR imaging.

[Basocellular epitheliomas of the eyelids]. / Les épithéliomas baso-cellulaires palpébraux.

On the basis of a retrospective study of 354 basal-cell epitheliomas of the eyelids, we present a study of the most frequently used treatments: surgery, conventional radiation therapy and curietherapy. The results of treatment, both functional and oncological, are generally satisfactory, whatever the method chosen, but with a set of arguments in favor of surgery. The major therapeutic indications are discussed, without formally ruling out any treatment.

Percutaneous Fine Needle Aspiration Cytology and Biopsy in the Diagnosis and Classification of Lymphoma: Clinical Evaluation.

In some patients with suspected de novo or recurrent lymphoma, the absence of a palpable mass or peripheral lymph node enlargement can be a diagnostic challenge. We report our experience of fine needle aspiration (FNA) and biopsy in the management of 47 consecutive patients investigated in our institution over a period of 4 years. Lymphoma was suspected in 32 cases, and recurrent disease in 15 cases. Cytology was performed in all patients and biopsy in 16 patients, when a safe approach was possible. The specimens were obtained with computed tomography guidance and were diagnostic by cytology in 85% of cases: 28 patients had a newly diagnosed lymphoma and 3 had recurrent disease; residual fibrosis was diagnosed in 2 cases. Five patients with a previously diagnosed lymphoma had a new neoplasm: lung carcinoma: 3, renal adenocarcinoma: 1, metastatic lymph nodes: 1. One patient had non-neoplastic intercurrent disease (pulmonary nocardiosis). In 7 patients, no conclusive tissue was obtained (acellular: 1, blood: 3, necrosis: 3). In one case of suspected recurrent disease, a false-positive result was obtained. Cytology always allowed distinction between non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD), with attempts to subclassify NHL according to the International Working Formulation. In 12 patients, immunochemical studies could be performed for immunologic subclassification of lymphoma on the basis of cytology (n = 6) and biopsy (n = 6). Our results show that percutaneous fine needle aspiration cytology is a reliable method for the diagnosis and classification of lymphoma, and immunologic studies can be performed on cytology alone if biopsy is unsafe.

[Comparison of MRI and CT X-ray in the evaluation of bladder cancer. Apropos of 26 cases]. / Comparaison IRM-TDM dans le bilan des cancers de vessie. A propos de 26 cas.

26 urothelial carcinomas studied with MRI and CT have been reviewed. The results are connected with surgical and histological data. The assessment of the size and number of tumoral sites is more accurate with MRI, which allows a correct assessment of bladder wall infiltration in 20 of the 22 tumors studied with T2-weighted sequences. The sensitivity of both techniques is the same for the invasion of fat (92%) and the involvement of neighboring organs (67%), although MRI seems to be more specific (85% and 95% for 77% and 89%). The results are similar for the study of lymph node invasion (71% sensitivity). The performances of MRI for the assessment of bladder cancer extension are therefore comparable to those of CT. The advantages of the former technique include the clearer visualization of the tumor itself, especially for cancers of the neck and dome of the bladder owing to exploration in several planes. In addition, it allows a reliable assessment of the degree bladder wall infiltration and differentiates tumors that are not or not very infiltrating from highly infiltrating tumors.

Pancreatic cystic neoplasms.

Cystic neoplasms are an uncommon group among pancreatic tumors. Because of advances in noninvasive diagnostic procedures, these lesions are more frequently detected and surgically treated. New pathological entities have been recently described with their own prognosis. 1. In a large number of cases, the imaging procedures can differentiate microcystic adenoma from mucinous cystadenoma, the more frequently encountered lesions. A well-defined mass with innumerable small cysts producing a honeycomb appearance with central stellate septae is suggestive of microcystic adenoma. A well-defined multilocular mass containing thin, straight or curvilinear septae with papillary projections and local thickening is suggestive of mucinous cystadenoma. 2. No sonographic or CT finding allows the differentiation between mucinous cystadenoma and cystadenocarcinoma, however; the imaging features depend on the grade of malignancy. 3. Thus, in the majority of cases of cystic lesions, fine needle aspiration with appropriate stains is recommended.